There are two finishing files on this site. "Finish and Polish" is aimed at bringing metal projects or parts to a smooth or otherwise appropriate surface texture, and discusses some of the finishes that might be applied -- for any combination of durability or protection or appearance. "Finish for Tools" mainly discusses surface preparation and finishes appropriate for our machines or tools. It is suggested that you also look through the "Cleaning Tips" file to obtain advice on cleaning items preparatory to finishing. The "Lubricants General" file will provide ideas on products that will make your tools or projects work more efficiently, minimize wear, and protect them from the elements. If you got to this file directly from my HOME PAGE, return there by using your browser's back button. BUT if you came to this file as the result of a web search engine, see more than 70 additional files on my home page Machining and Metalworking at Home http://www.janellestudio.com/metal/ SAFETY WARNING BEWARE: DO NOT ASSUME that any subject matter or procedure or process is safe or correct or appropriate just because it was mentioned in a news/user group or was included in these files or on this site or on any other web site or was published in a magazine or book or video. Working with metals and machinery and chemicals and electrical equipment is inherently dangerous. Wear safety devices and clothing as appropriate. Remove watches, rings, and jewellery -- and secure or remove loose clothing -- before operating any machine. Read, understand and follow the latest operating procedures and safety instructions provided by the manufacturer of your machine or tool or product. If you do not have those most recent official instructions, acquire a copy through the manufacturer before operating or using their product. Where the company no longer exists, use the appropriate news or user group to locate an official copy. Be careful -- original instructions may not meet current safety standards. Updated safety information and operating instructions may also be available through a local club, a local professional in the trade, a local business, or an appropriate government agency. In every case, use your common sense before beginning or taking the next step; and do not proceed if you have any questions or doubts about any procedure, or the safety of any procedure. Follow all laws and codes, and employ certified or licenced professionals as required by those laws or codes. Hazardous tasks beyond your competence or expertise should also be contracted to professionals. Let's be really careful out there. (c) Copyright 2003 - 2007 Machining and Metalworking at Home The form of the collected work in this text file (including editing, additions, and notes) is copyrighted and this file is not to be reproduced by any means, including electronic, without written permission except for strictly personal use. ============================================================================ Date: Mon, 12 Feb 2001 16:38:16 -0000 From: gavin.Eyrex~xxrsl.com Subject: Polishing Well my collection of small connecting rods is gradually increasing - and they now have accurate 46.72" radius curves :D. My next question relates to cleaning up the parts. I have removed all the machining marks with some very fine swiss cut needle files, but trying to remove the file scratches with various grades of wet and dry prior to buffing with the Dremel is driving me crazy. Any suggestions please? Gavin Eyre Gavin.Eyrex~xxrsl.com -------------------------- Date: Mon, 12 Feb 2001 10:59:33 -0600 From: Ron Roske Subject: Re: Polishing Popsicle sticks! I always keep some on hand. They can be easily cut to the needed shape, charged with whatever grinding/polishing compound needed and are cheeeep! Don't know if I can explain this real well or not, but will give it a try. I came up with this idea while working on jewelry and then on clocks. There never seemed to be a "right" tool on hand to polish certain areas that needed detailing. While a jewelers motorized hand piece or Dremel have their place and will work wonders in some areas, they just won't get into all of the nooks and crannies. I cut, carve, sand or shape the end of the stick to conform to the shape of the area that I need to clean up/polish/or whatever. Then I rub the stick on a bar of the appropriate compound to embed some of the compound into the wood and this is called "charging". This allows me to easily get into areas that were previously a pain to get to and gives me the control to apply the amount of force that is needed for that particular job and material. Craft sticks work well (costs around $3 for a lifetime supply size package) or you can obtain these the hard way. 1. Go to the store 2. Buy popsicles or fudgesicles 3. Take them home 4. Use an appropriate method for removing the excess material that surrounds the stick. 5. Dry the stick Some may find this to be a cumbersome procedure, but I find it enjoyable. Quick, simple, easy and inexpensive.. Another tool along this line are small (1/4"x1/4"x6") spring loaded plastic sticks (can't remember exactly what they are called) that you put 1/4" bands of sandpaper around the ends. These give you a rounded end, a wedge shaped end and a flat area to sand with. When one area of the sand paper gets worn, you just rotate the band a bit and you have a fresh surface to work with. Several grits are available and the sticks come in assorted colors so that you can put a different grit on each and makes for easy identification. These are available at jewelry supply houses. Hope that I have explained rather than confused... -Ron- ------------------------ Date: Mon, 12 Feb 2001 10:35:03 -0800 From: "Marcus" Subject: Re: Polishing Hi Gavin: If you want to remove those scratches efficiently, the best way is to use moldmaker's polishing stones. A popular brand is Gesswein, another is Norton. Call a local toolroom, and find out where they are getting theirs. A box of each of 240, 300, 400, and 600 grit will do you nicely for a long time. The stones are soft, and can be shaped on an ordinary bench grinder. Use them with a light oil, instead of kerosene (too smelly) My preference is a product called A9 aluminum cutting fluid. It is made by Relton and is widely available. It is safe to get on your hands and smells pleasant. The best way to use the stones, is not to file out the milling marks, but to begin stoning right away. The stones leave scratches that are far less deep than file marks. I realize that you have already filed on the parts; not a big deal, but it will take you longer to clean up the deep scratches that files typically leave. Cheers Marcus ---------------------------- Date: Mon, 12 Feb 2001 10:08:07 -0800 From: "Yasmiin Davis" Subject: RE: Polishing You can probably get your desired results with craytex -- or rubber based abrasive points. Dremel only sells a couple one of which is small and round and might do. However, go to a machine tool catalog or better to a large jewelers supply and you will find them in various sizes and grits. Fine grit puts on a nice shine but are aggressive enough to accomplish what I think you are after. Yasmiin ---------------------------- [QUESTION RE DIAL MARKINGS] >What is the material called used to fill milled letters with black stuff? Smart alec answer - paint ;-) Actually there are a number of ways to get the lines to blacken. All involve getting the lines to contrast with the surface. I've restored brass plates such as those on old lathe gearboxes by painting the entire plate, wiping the surface with a lint free cloth stretched tightly on a flat surface, then letting dry. Gently remove the excess dried paint on the high areas with 600 grit wet or dry contact cemented to a flat surface. Milled letters are likely large enough to made this the preferred method. If the letters are fairly deep and narrow in line width, you can use a fine artists brush and let the paint wick into the letters. The tiny bit that will get on the face of the work can be removed later with abrasive or at the time it happens with the corner of a lint free rag with the appropriate solvent for the paint being used. If you want to get a really bombproof marking on steel, make the letters 10 thou deeper than the final depth wanted, and the work 10 thou thicker. Blue the work, and then turn/mill off the extra 10 thou. Lots of work but super durable! Fine lines such as on many handwheel collars, mikes, camera f-stop rings, and such can have the paint pressed into the lines. There are special paint sticks sold for just this purpose. I got my red and black ones (yellow, white, and orange are also available) from Fargo Enterprises, mine are labeled "Lacquer-Stik Fill In Paint", made by LA-CO Industries Inc/Markal Company. Fargo is a good company to deal with for camera repair parts and supplies, and as such can be of interest to HSM's, even it they don't have a camera to fix. Fargo is on the web at: http://www.fargo-ent.com/ You can also use the paint approach for fine lines, just thin the paint so capillary action can do its thing. Using any of these methods requires the work to be well degreased and clean. I use brake or carb cleaner, it is nasty stuff, but the spray gets down into the lines and numbers and gets things super clean. Don't use the eco-approved stuff for this, you want the low flash point stuff with all the warnings on the can. If you don't want to use this sort of stuff, or can't due to being on a 12th story condo without a balcony, health risks, whatever, washing with detergent and hot water with a scrub brush followed by an isopropyl alcohol rinse is almost as good. Don't use 70 percent rubbing alcohol, it often contains glycerin as a lubricant for rub downs. The 90+ % stuff sold for sterilizing hypodermic needles and injection sites is what you want. Most drug stores have it, labeled as isopropyl alcohol rather than rubbing alcohol. Wear gloves while handling the cleaned parts, a fingerprint in the middle of the job will ruin the outcome unless you want to use it as a signature ;-) ----------------------- Date: Mon, 26 Mar 2001 17:59:21 +0100 From: Tony Jeffree Subject: Re: Questions for the gurus At 11:27 26/03/2001 -0500, you wrote: >You can also use the paint approach for fine lines, just thin the paint so >capillary action can do its thing. >Using any of these methods requires the work to be well degreased and clean. >I use brake or carb cleaner, it is nasty stuff, but the spray gets down into >the lines and numbers and gets things super clean. Another point to bear in mind is what environment the resulting filled engraving will have to cope with. My "Engravers wax" response is OK for engraving on surfaces that are not going to be maltreated (e.g., clock faces); however, it would be no good for a surface that will have to deal with solvents, oils etc. I have had problems with using markers labelled as "paint markers" that are oil soluble when dry; its no good having a nicely engraved handwheel (for example) if the black filling material comes off on greasy hands. Some oil-based paints do not dry to an oil resistant surface. Regards, Tony ----------------------- Date: Mon, 15 Jan 2001 07:16:43 -0500 From: Ronald Thibault Subject: Re: Rebuild time > Can any one tell me about the paint they have used and what >I should look for so that it will stand up good I remember something >about paint that would stain easy and would like to stay away from >that. Rex thanks for your help, without it I would have to wait >another year. Randy Randy; That was my post. On my lathe I used Rustolium Light Machine Gray. Every oily finger print shows. On the mill I'm rebuilding now, I used Dark Machine Gray. This is a better choice. Ron Thibault North Augusta, SC USA Builder Miinie #2 Captain R/C Combat Ship USS Arizona http://pages.prodigy.net/thibaultr/ ------------------------ Date: Mon, 16 Apr 2001 16:13:16 EDT From: WRSmith2x~xxaol.com Subject: Heat bluing shop tip All, Some of you may wish to heat blue tools or part that you have made. This afternoon, I needed to blue the frame screws for a clock I am presently building. Here is what I found. With the screw head polished and free of oil or other contaminants, I placed them, one at time, in a bluing holder that is a piece of brass about 0.020" thick and 5/8" x 3/4" with a hole in it to accept the screw and with a handle. I mention the size only to indicate that it is not a great heat sink. An alcohol lamp was used that has a wick of about 3/8" in diameter. Here is the interesting thing that I noted. Once the screw began to change color, I could remove it completely from the flame and it would continue to increase in color for as long as about 10-seconds. To me, this indicates that the screw temperature was high enough for the blue I wanted, and possibly even more, but it took time for the oxide to form. This also indicates the need to quench the screw at the right color because it could possibly pass through that color and have to be re-polished for another try at bluing. TTYL W. R. (Bill) Smith --------------------------- From: "Jim Lewis" Date: Sun Jul 1, 2001 4:17 pm Subject: Polishing brass Hi Guys Is there anyway to get brass to STAY real shiny? I've got the normal cream stuff which claims to add a silicone protection layer but after some handling for a few days the shine is gone and it starts getting blotchy. I once sprayed a plastic coating on a brass piece which worked for a year or so but after that it got black spots. Is this an unsolvable problem or is there a good solution? Thanks. Jim http://www.emachineshop.com -------------------- From: Tony Jeffree Date: Sun Jul 1, 2001 5:56 pm Subject: Re: [taigtools] Polishing brass Problem is that the sweat you deposit in fingermarks etc. is acidic & attacks the surface of the metal. You can buy suitable lacquers from suppliers of clockmaking materials that will protect the surface - if the part is going to be handled often, you may need something heavier though. Clean up the brass so that it is free of all fingermarks etc. before lacquering. Regards, Tony ---------------- From: Alison & Jim Gregg Date: Sun Jul 1, 2001 9:40 pm Subject: Re: [taigtools] Polishing brass The classic finish used by the old instrument makers is to polish or buff ti a high polish,and then apply a hot laquer finish. Do not touch the visible surfaces after polishing, for all the reasons others have given. The special laquer is then applied to the heated part - the finish is dependant on the fact that it is heated. There are several colour variations available in the laquer ranging from a pale straw yellow to one that gives a dark golden almost red/brown colour. I will enquire tomorrow at the W.A. SMEE meeting for any additional information, - there are people who have done most things in that group! To forestall the inevitable question -where to get the laquer, - I don't know, but would suggest serious antique restorers suppliers, or as previously. suggested clock makers suppliers. Jim Gregg W. Australia ------------------ From: joel_mowersx~xxp... Date: Sun Jul 1, 2001 7:46 pm Subject: Re: Polishing brass The best luck I've had with watch and clock parts is polishing and buffing with jeweler's rouge. It doesn't stop the return of oxidation, but the metal is mirror smooth so it looks good (i.e. no surface roughness shows up when the patina forms). Joel ------------------------- From: "David Robertson" Date: Sun Jul 1, 2001 8:00 pm Subject: Re: [taigtools] Re: Polishing brass Polishing with car wax (Carnuba) helps but won't allow much handling... some clock repairmen use this as an alternative to lacquering. Dave --------------------- From: J.C.Beechx~xxs... Date: Mon Jul 2, 2001 8:53 am Subject: Re: Polishing brass Hi jim, may I add, for handling brass, a pair of white cotton gloves, freshly washed are ideal for handling metal that is easily marked from fingers. The gloves need to be washed regularly, or the sweat will leach through. Other than this use a wooden jig for handling the components. Not sure if this IS related to your question, but probably more my interpretation of the thread. Joules -------------------------- From: tadici283x~xxc... Date: Mon Jul 2, 2001 8:56 am Subject: Re: [taigtools] Polishing brass Jim, This is a good one, but you did not say if the brass needs to take wear? In the clock business and watches, parts that are not wear items are gold plated and they have looked good for years. High dollar clocks like the Atoms are gold plated and in some cases last some 40 or so years, I had a brass lamp my Grandmother gave me and I wanted to restore it so after careful polishing I coated it with clear lacquer and it has lasted some 15 years, but the clear coat did cut some of the shine. For auto uses some parts are electrostatic powder coated and it wears like iron, but this is not a choice for the home machinist due to cost of tools, your best bet is polish it very well and clean it very well and coat it very well under clean, dry average temp and it should last better than one year, but the adherence is what keeps it from oxidation. Lacquer is a better choice than plastic type coatings IMHO. Chris of Bradenton FLA --------------------- From: "John Shadle" Date: Mon Jul 2, 2001 9:09 pm Subject: Avoiding fingerprints on polished brass. I've never been able to work on a clock while wearing gloves. I last about 3 minutes, then off they come. What I do is first clean the parts in clock cleaning solution (ammonia + detergent), rinse without handling, dry without handling, then I spray them with Pledge and wipe it off. It's not 100% but it sure helps with fingerprints. A trick I learned from the Clocksmiths list. Washing hands frequently helps too. John --------------------------- Date: Fri, 22 Feb 2002 20:53:50 -0000 From: "jimdlewis" Subject: Re: Deburring [MACHINED EDGE] Hi Doug Another option is to put some fine sand or emery paper grit up on a flat table and draw the edge over the paper. Use a slight rotating motion for rounding. Regards, Jim http://www.emachineshop.com - Frog CNC --------------------------------------------------- Date: Fri, 22 Feb 2002 13:38:55 -0800 From: "Van Lupo" Subject: RE: Re: Deburring From: jimdlewis [mailto:jimlewisx~xxmiclog.com] Sent: Friday, February 22, 2002 12:54 PM To: sherlinex~xxyahoogroups.com Subject: [sherline] Re: Deburring Hi Doug Another option is to put some fine sand or emery paper grit up on a flat table and draw the edge over the paper. Use a slight rotating motion for rounding. Regards, Jim http://www.emachineshop.com - Frog CNC For what it's worth, I bought one of those small vibrator tumblers. It does a really nice job of evenly cleaning off the burrs. It also reduces much of the tool marks left by end mills and such. Van ------------------------------------------ Date: Fri, 22 Feb 2002 16:03:11 -0800 From: "David Goodfellow" Subject: Re: Re: Deburring I did the same, Van. I already had a rotating drum tumbler, but I find the vibrator is much faster. Dave Goodfellow Northridge, CA "No problem too small to baffle this expert" --------------------------------------------- Date: Sat, 23 Feb 2002 01:10:21 -0000 From: "jamesbknighton" Subject: Re: Deburring Dave, I'm assuming your vibrating tumbler is rather like those used by reloaders to clean brass "empties". Perhaps one of those could do double duty? What kind of media do you use for deburring? Thanks, Jim Knighton jimknightonx~xxworldnet.att.net --------------------------------------------- Date: Fri, 22 Feb 2002 21:39:59 -0800 From: "David Goodfellow" Subject: Re: Re: Deburring Aaagh! You had to ask, didn't you? Now I can't find my receipt that identifies the stuff. I bought the vibrator from Caswell, and the media they recommended. They had it in ceramic triangles, rough, medium and fine. I bought the rough and medium, and treated corn for polishing brass. So far I've only used the vibrator on aluminum and brass. The ceramic triangles bring the aluminum to very smooth, but requiring polishing. The corn brings the brass to a high gloss. I tried the corn out on some old 30.06 brass I have, and it did wonders for it. The manual lists that as one of its prime uses. Dave Goodfellow ---------------------------------------------- Date: Sat, 23 Feb 2002 22:25:44 -0000 From: "jamesbknighton" Subject: Re: Deburring Dave, Thanks for the info. I have a vibrating tumbler for reloading, and I use the walnut shell media with good results. The literature I've seen suggests that walnut shell and corn cob media is good for cleaning and polishing, but not deburring even aluminum and/or brass. I've toyed with the idea of using other media, but the stuff I've seen (ceramic triangles) was pretty coarse stuff, 1/2 - 3/4" in size. Some of the stuff offered by MSC and McMaster is apparently used with some sort of lubricating liquid as well, and I had visions of leaks and all manner of other problems with a machine designed for dry media. The sheer size of this media also scared me off and I've not done anything with it. Is the media you are using in this size range or do you have something more fine? Also, this stuff seemed to be terribly expensive and apparently came only in something like 50 lb containers. This is much more costly than I can afford just to experiment with. Was your media packaged in a more manageable quantity? JBK ---------------------------------------------- Date: Sat, 23 Feb 2002 17:09:15 -0800 From: "Scott A. Stephens" Subject: Re: Re: Deburring I tried BB's steel for reloading in my rock tumbler and also for some of the parts I machined. Lubricant was one or two Tsp or delo 400 15w 40w I think. Pick it up at Price club. I've had good results ---------------------------------------------- Date: Sat, 23 Feb 2002 17:59:09 -0800 From: "Van Lupo" Subject: RE: Re: Deburring I bought my vibratory tumbler from Airgas (Rutland Tool now and no online ordering) along with the starter kit, which included 3/8 x 3/16 angle cut ceramic triangles (P-20 stock) and a quart of soap and a quart of anti-rust solution. This kit was only 38.50 +tax and supplied enough media for one fill. Was cheaper to get then a 50lbs bag for $80+. The media has held up well for 8+ hours so far but has given a really good finish too. Van ----------------------------------- Date: Sat, 23 Feb 2002 19:56:18 -0800 From: "David Goodfellow" Subject: Re: Re: Deburring This came in 5 lb containers. I'm sending a photo to you direct, as I think this group does not allow attachments. The longest dimension of the average piece is about 1/5". The 5-lb bag cost in the neighborhood of $28.50. I suspect it's going to last me a long, long time. I use the ceramic media dry, and the corn with a Fitz product, also available from Caswell. Their URL is -- http://www.caswellplating.com/ Usual disclaimers -- just a satisfied customer. Dave Goodfellow Northridge, CA ------------------------------------ Date: Fri, 08 Mar 2002 05:21:44 -0000 From: "rw13555" Subject: RE:Paint recommendations [FOR ALUMINUM] Just in case it may come in handy for anyone, I'll add a posting on what PPG Automotive Refinish has available for aluminum treatments: DX533 Aluminum Cleaner : phosphoric acid based cleaner, brightener, and prepaint conditioner for aluminum. Prepares aluminum prior to painting or welding or a sunsequent chemical coating DX503 Aluminum Conditioner : chromic acid based chemical that produces a chrome conversion coating on aluminum. Produces a gold / tan coating that becomes part of the aluminum surface. DX501 Aluminum Conditioner : clear version of DX503, used when it is desired to maintain the silver-white finish of aluminum. DAU75 : clearcoat finish suitable for aluminum parts Ron ------------------------------------- Date: Sun, 10 Mar 2002 15:14:53 -0500 From: "Daniel J. Statman" Subject: Re: Great Source for Miniature Endmills [NEW SUBJECT IS ABOUT ANODIZING] Yes I do my own anodizing. I built a 0-200 VDC 3Amp power supply and I use that for the anodizing process. Titanium anodizing is a little different than aluminum anodizing. Titanium does not require a pigment to be added, the color develops from a surface grown oxide layer. The thickness of the layer determines the color, and the applied voltage will vary the film thickness. The dark blue color happens at a relatively low voltage of 25 V. The anodizing process takes less than 10 seconds. Obviously the entire piece comes out blue and then you just polish off the high spots. Titanium anodizing is not very durable and the recessed grooves help in preventing the color from being scratched. I also do some kiln-fired enameling processes, but you have to use an argon blanketed kiln since titanium will oxidize and burn. I have just started this technique and you can see a black enameled ring at the following link: http://members.rennlist.com/statmandesigns/Style-CK002-Black.html Daniel J. Statman, Statman Designs www.statmandesigns.com -------------------------- Date: Wed, 19 Jun 2002 23:11:43 -0400 From: RichD Subject: Re: Question about finishing/coloring steel Bill Rutiser wrote: > > I used 12L14 for the base portion of the jack. One of the finishing > > techniques mentioned in the book for steel is to coat them in oil > > and heat at 350 for 10-15 minutes. Does anybody have any ideas > > on the type of oil that should be used? Is 10W30 like you use in your > > car going to work? or is there some other type of oil > > which would be more appropriate? Bill & all, It's an old blacksmith's method to blacken steel with old crankcase oil. The more used the better. My first batch wasn't doing the job, but the next lot works very well. This gives a very black oxide coating. The trick is to heat the steel evenly only to a dull red in dim light and then dunk in the oil till cool. I keep it in a gallon tin can (restaurant size). If you overdo it, the coating is easy to chip off. It's still not as good as professional hot chemical tool blackening, but can fill the bill in most cases. RichD ------------------------------------------------- Date: Thu, 20 Jun 2002 08:53:15 -0400 From: "Marshall Pharoah" Subject: RE: Question about finishing/coloring steel Heat the item, then immerse in oil. You may want to try different temperatures. I have taken some small parts to red hot then quenched in used motor oil. This hardens them as well as giving them a black finish. Just heating them will often give them a permanent blue color. Much depends on the grade of steel. You may have to experiment (don't forget to write down successful processes). Gun shops will usually have chemical bluing, and sometimes blacking kits. Marshall --------------------------------------------------- Date: Tue, 26 Nov 2002 07:45:42 -0500 From: Chabannes Rene N Contr ASC/YCD Subject: RE: Lathe Cleaning - black oxyde tank We used to black oxide a lot of parts on our machinery. We used "Black Diamond". Several gun smiths in the area bought it from us. Needless to say, what comes out is only as good as what goes in. We grit blasted small parts which gave a satin like finish. Ground parts still showed the grind pattern - we never polished anything. We blued a few guns for people. After metal prep, it was basically four steps: degrease, what I'll call a hot soap bath/preheat, "Blue", rinse. We always coated the parts with a preservative afterwards. The bluing/oxide solution was pretty thick, especially when cold and very caustic - be careful. It will boil over if too hot. Don't do this on the wife's stove. I can assure you, it's not worth the wife's wrath after a boil over. Don't ask how I know. Of course, the fumes aren't good for you. Read up on the subject for specifics, but it isn't hard. One potential problem: in the latter seventies with prices going up for everything, recy!cling and the availability of stainless became more prevalent. We started getting C1018, in particular, from a number of sources that had streaks and spots that wouldn't blue. Different alloys may require modifying the process to get a uniform color. In those days, we never found a cold blue as good as the hot version. That may have changed. Rene N. Chabannes (Titan) ASC/YC - Productions Operations C-17 SPO, WPAFB, OH 937-255-1042 (DSN 785-1042) rene.chabannesx~xxwpafb.af.mil ----------------------------------------------------------- Date: Thu, 01 May 2003 00:16:32 -0000 From: "Ed Chesnut" Subject: How do I . . . "spot finishing(?)" on aluminum I am restoring an Observed Trials Motorcycle originally mfgd in the early '70's. There are some aluminum panels which should clean up fine if they were "spot finished(?)". I hope I am using the correct term. I am referring to the same sort of finish which is seen on the engine cowl of "The Spirit of St. Louis" (Lindberg's Atlantic crossing aircraft). How is that done? I am envisioning setting up on a large drill press with a 3/8" or 1/2" copper or aluminum rod chucked up (faced end). Charge the end of the rod with valve grinding compound or some other abrasive and touch down on the aluminum panel. Then use the x-y table to traverse 1/2 diameter and touch down again. Is this even remotely on the right track? Is something more compliant needed for the abrasive rod? Steel brush? Some sort of pad? There is also a steel flywheel weight which was added to the normal magneto flywheel. It needs clean up too. I'm trying to decide whether to install the riser block for the headstock on my Taig Lathe to clean it up by turning off a few thou - it is 4.4" in diameter - or to attempt spot finishing it. Any tips for spot finishing on steel? It does seem like I might be picking a tough battle to spot finish the curved OD surface. Thanks in advance for any guidance you might offer, Ed ----------------------- Date: Wed, 30 Apr 2003 14:42:31 -1000 (HST) From: Tom Benedict Subject: Re: How do I . . . "spot finishing(?)" on aluminum Sounds like you're right on track. I've done that with a couple of different abrasives (including a hardwood dowel run at high speed with polishing compound on it... definitely low tech). Works like a charm. Tom ------------------------- Date: Thu, 01 May 2003 01:29:06 -0000 From: "ulav8r2000" Subject: Re: How do I . . . "spot finishing(?)" on aluminum Another name for the process is "engine turning". Hard tool (wood, steel, aluminum) can be used with lapping compound or sandpaper disks. For round parts you need a compliant tool, such as wire brushes sold by Brownell's, used with lapping compound. ------------------------- Date: Wed, 30 Apr 2003 15:51:55 -1000 (HST) From: Tom Benedict Subject: Re: Re: How do I . . . "spot finishing(?)" on aluminum I ran into something while reading up on rosette engines that made a distinction between engine turning and spotting. Spotting is done using an abrasive as has been described. Engine turning produces similar patterns, but uses a rosette engine and a single point cutting tool instead. The patterns you can get with a rosette engine are a lot more varied than those with spotting, but the equipment is a lot more involved. I've now seen two rosette engines come up on ebay. One was a traditional lathe with eccentric chuck and rosette cams. I forget what it went for. I think it was over ten thousand. The other was a linear rosette engine that looked like a cross between a shaper (turned vertically) and a traditional rosette engine that was unrolled (it had linear cams). That one went for even more. I've never seen mention of such a beast since. Tom ------------------------ Date: Thu, 01 May 2003 06:27:31 -0000 From: "sikn1gh7" Subject: Re: How do I . . . "spot finishing(?)" on aluminum I've seen the terms jeweling and engine turning used for refering to the "spirit of st louis" finish, I believe the term "Jeweling" is prefered". Engine turning, depending on the background of the machinist you ask, can refer to cutting decorative patterns on a "rose engine", or "Decorative lathe", which uses a single point cutting tool to cut patterns like a spirograph. This is often found on antique (1800s) pocket watch covers. Of course, with the advent of CNC, BOTH can now be done easily on a CNC mill. My robotics team had *some* luck doing a quick and dirty jeweling of aluminum, using a felt bob (used on dremels for polishing), and some 800 grit lapping compound. The bob was just chucked up in an 1/8" collet, and the machine was programmed to lower the head about 0.020" below the surface of the piece, dwell for 5 seconds, up and repeat. Someone with a bit of time, a good eye for design, and some programming skills can probably write something to generate coordinate points that simulate a spirograph's movement. (Hrm, interesting problem, actually). I've heard that mustard jar lids and wine corks also works great for holding the lapping compound. Relevant Links: Jewelry techniques: http://users.lmi.net/~drewid/ Rose engine work: http://ourworld.compuserve.com/homepages/jeharr/rosengin.htm http://ourworld.compuserve.com/homepages/jeharr/ecc_patt.htm http://www.rgmwatches.com/engine99.html Jeweling work: http://www.angelfire.com/sports/customjewelshop/rifles.html http://www.cs.ucr.edu/~eamonn/et/et.htm Hope this helps! -=- Terence -------------------------- Date: Thu, 1 May 2003 13:50:09 -0700 From: "Nicholas Carter and Felice Luftschein" Subject: Re: Re: How do I . . . "spot finishing(?) THANK YOU for the wealth of I will add my experience, I have used a dowel with lapping compound (messy, and a pain), a cratex rod (needs lube but works well) and beartex discs on a mandrel (works best, but loads up with Al and still needs lube). The beartex works best as it is spongy and has some spring as well as self renewing. I have seen plans for a spring loaded mandrel so you always have pressure. felicex~xxcasco.net is Felice Luftschein and Nicholas Carter. See our web pages http://www.cartertools.com/nfhome.html --------------------------- Date: Thu, 01 May 2003 20:44:29 -0000 From: "Ed Chesnut" Subject: Re: How do I . . . "spot finishing(?) THANK YOU for the wealth of . . . information. The rose turning machines weren't exactly on target - but it was quite enjoyable to review that information too. Gentlemen, you gave me direct answers to many of my unspoken questions and strong hints about others. I'm ready to go play, er, um, work on the project! I've already established that valve grinding compound is better for drilling through the aluminum [test piece :-)] than it is for polishing. Rubbing compound and wood dowel seem like good components/tools. I wonder about gluing a disc of rubber on the end of the dowel or rod? Ah, well, here I go. Thanks again for all the good responses (and links)! Ed ---------------------------- Date: Thu, 01 May 2003 23:31:20 +0100 From: Steve Blackmore Subject: Re: Spam Alert: Re: How do I . . . "spot finishing(?) THANK YOU for the wealth of On Thu, 01 May 2003 21:42:01 -0000, you wrote: >How timely this thread is! I am just about to get into doing the >same kind of finish to dress up the knurling tool that I am >making :) I am planning to use a 1/4 cylindrical abrasive india stone. > btw, I have also seen this technique called demascening... Wrongly :( Damascening the art of decorating iron, steel, or bronze with inlaid threads of gold or silver, or producing a watered effect in forging, as in sword blades, gun barrels, and various metal objects. The method, long practised in the Middle East as well as in China and Japan, was highly developed in Italy. The inlay forms a delicate and intricate pattern upon the contrasting background. The whole fabric is penetrated by the ornamental treatment, so that grinding does not remove it. I've seen guns with effects ranging from "wood grain" to barley twist patterns and there are some superb ornamental examples in the Royal Armories. It was originally done to incorporate very expensive pure iron and alloys, with cheap stuff, but still produce a viable weapon that wouldn't break. The ornamental examples followed as a lucrative sideline. Steve Blackmore ------------------------------ Date: Thu, 7 Aug 2003 04:52:59 -0700 (PDT) From: Scott Meyer Subject: Re: Polishing Aluminium for a Beginner Bruce Buchner wrote: >>> I have some aluminum cubes that I have made with my fly cutter that I would like to polish up. What is the easiest way to do this? They came out pretty smooth but there are some radial tool marks from the fly cutter. At the hardware store they have buffing wheels and several sticks of different polishing compounds. How are those used? Do you rub the stick on the metal and then buff it off like car wax? What type of material is best on aluminum? I've never tried putting a finish on anything I have made till now. Bruce Buchner <<< Flat pieces are always pretty easy to polish. Do you need to hold a dimensional tolerance? How about a flatness tolerance? Squareness? Aluminum is not really polishable, you will never get it to a mirror finish like you can with a decent tool steel. Having said that, if you have a cube, put a piece of 220 or so sandpaper on a surface plate (or a piece of glass, really anything that is flat, the flatter the better) and run yout part in a figure 8 around the sandpaper. As soon as the tool marks are gone, change the sandpaper to a finer grit, like 320 or so. Repeat the process until you have the finish you desire. Aluminum is very soft, so polishing goes fast, but if you don't clean up the dust from the previous sandpaper before you polish with the new one, you may be getting scratches from much coarser grit than you want. Scott ------------------------------ Date: Thu, 7 Aug 2003 07:43:26 -0500 From: "Ron Thompson" Subject: Re: Polishing Aluminium for a Beginner >Aluminum is not really polishable, you will never get it to a mirror >finish like you can with a decent tool steel. This is not true. Look on any highway at all the long haul semi trucks with shiny fuel tanks and "chrome" wheels, etc. Most of these items are aluminum. There are people in the parking lots of truck stops that make their living polishing wheels and tanks. Most truck stops sell polishing supplies. Some are hand polished, but more and more are done using a hand held high speed buffer. The most common machine buffers use muslin wheels and wax based compounds. The compounds are color coded and come with directions. Ron Thompson On the Beautiful Mississippi Gulf Coast USA http://www.plansandprojects.com ------------------------------------- Date: Thu, 7 Aug 2003 08:03:28 -0500 From: "Nance, Tom" Subject: RE: Polishing Aluminium for a Beginner Hi Ron, The problem with aluminum is it oxidizes almost immediately. In fact, it oxidizes so fast that you rarely see the raw element. What you are actually seeing when looking at a bar of "aluminum" is actually aluminum oxide. Granted, there is raw aluminum under the surface, but you can't see it. It is this property that requires aluminum to be welded with special equipment that surrounds the weld in a halo of gas which keeps oxygen away from the surface. It is also this property that makes polishing a futile excercise. You may be able to acheive a nice finish for a few hours, but then it will revert to its normal dull surface. What I like to do with aluminum is sort of split the difference. I buff it with steel wool. That produces a very even, albeit dull, finish that I think is more pleasing than the standard mill finish. It also remove small scratches that unfortunately occur from handling. Tom Nance Corpus Christi, TX ------------------------------------- Date: Thu, 07 Aug 2003 13:31:41 -0000 From: "Charles Hixon" Subject: Re: Polishing Aluminium for a Beginner If the aluminum is a grade with silicon in it, it will not polish to as high a luster as those grades without silicon. A few grades are formulated to come out shiny with just an acid dip. I sand by hand with progressive grades of sandpaper (change direction to remove scratches each grit) on a flat surface under running water down to 1000 grit (2000 grit introduces deeper scratches from the residue) and then 9 micron and 1 micron polishing compound. This leaves an undeformed surface. Some folks mention buffing, which will also work with some success depending on the grade of aluminum, but it deforms the surface with loss of dimensional control. Charles Hixon ------------------------------------- Date: Thu, 07 Aug 2003 13:34:57 -0000 From: "lan_brooks" Subject: Re: Polishing Aluminium for a Beginner Having seen the other replys I can't resist responding. I used to have a business making Laser Pointers and one of the finishes I had available was created by having the parts polished on a Buffer wheels with polishing compound which resulted in a mirrorlike finish. This was then hard anodized and dyed black. The result looked like black glass. The anodized finish is actually clear and will preserve the surface finish that was present on the aluminum prior to anodizing. Without the dye, the parts look like polished chrome. So aluminum can be polished although I agree that without a protective finish they will grey out. The parts I made were from 6061 and the polished surface lasted the week or so it took to transport them to the anodizer. For home use, it might be possible to use a thinned lacquer to protect the finish in much the manner it is done to protect polished brass. The reply on using a glass plate and progressivelly finer sanding, which I would to wet, is on the mark and will preserve the flatness and corner detail. To actually polish, two cloth wheels are used. The polishing compound is applied to one, the part is then polished against that wheel and then the secondwheel is used to buff the part and remove the polish. With cuges, BE CAREFUL, the cloth heels will grab and throw the part unbelievably fast. Work on the lower part of the wheel and work from the middle of the cube to the edge. Kinda like this )_ not this )-. Have fun! Lan Brooks ------------------------------------------- Date: Thu, 7 Aug 2003 07:54:24 -0700 From: "Brown, Mark A (SPO)" Subject: RE: Polishing Aluminium for a Beginner I agree with Ron. I have routinely polished aluminum to the point that it shines like chrome. Generally I start with 400 grit after the machine work. You could start with a lower grit but usually the final tooling passes leave a finish that needs very little sanding and aluminums sands quite fast. With that said I feel very strongly that besides the lathe and mill you absolutely need two more tools. A powered saw of some kind to rough cut your material prior to machining. Trust me. The hacksaw gets old real fast. The second is a grinder motor. I rebuilt a car some time ago and got three buffing wheels and compound for each of them for polishing stainless steel from a company called Eastwood. I don't know of they are ideal for aluminum but after a quick spin on the grinder motor with each successive polishing wheel your aluminum parts look like chrome. I couldn't imagine polishing by hand. Mark ------------------------------------------ Date: Thu, 07 Aug 2003 11:09:21 -0400 From: Jim Ash Subject: Re: Polishing Aluminium for a Beginner Not on my surface plate. A nice flat surface, yes. A tool grade surface plate, no, but then I'm one of those fanatics that won't let grinding grit anywhere near close tolerance tooling. Some aluminum comes coated, especially sheet. But if you cut all six sides of your cube, that ship has sailed. To answer your question, those buffing compounds are usually meant to dress your buffing wheel, color coded for the finish grade you'd like. I'd be careful with your cubes around buffers and sanders; they can round off your edges. Depending on the size of the cube and the size of the wheel, I might not try it at all; I've had a few things ripped out of my hands on buffing and wire wheels, and the results are somewhere from not pretty to outright hazardous to life and limb. Stick with the flat surface idea. Jim Ash -------------------------------------- Date: Thu, 7 Aug 2003 08:03:34 -0700 From: "Brown, Mark A (SPO)" Subject: RE: Polishing Aluminium for a Beginner Good point Tom. Here's something everyone can try. Anodizing. It is very simple, inexpensive, and can be done in your shop. Use caution, follow direction...blah, blah, blah...standard disclaimer. Anodizing not only produces a beautiful finish it hardens the surface of the aluminum considerable and stop the oxidation process. Check into it you will be surprised how simple the process is and the colors available. Here is the website of the guy I got all my information from. http://www.focuser.com/atm/anodize/anodize99.html Here is my home page. http://www.geocities.com/mbstingray/ There are a few items on it that have been anodized. So far I have done just black but the color options are virtually limitless. Note the black and gold flywheel. On my web page it says I hope to some day make that flywheel part of an engine/motor of my own design. Well it's almost done after 9 months. Hopefully I'll have pictures soon. It is all black (anodized aluminum) and gold (brass). Mark --------------------------------------- Date: Thu, 7 Aug 2003 10:25:56 -0500 From: "Ron Thompson" Subject: Re: Polishing Aluminium for a Beginner >Anodizing not only produces a beautiful finish it hardens the surface >of the >aluminum considerable and stop the oxidation process. It is my understanding that anodizing is a good protectant, but it starts FTER the polishing. It will preserve whatever finish is already on the piece. Ron Thompson On the Beautiful Mississippi Gulf Coast USA http://www.plansandprojects.com --------------------------------------- Date: Thu, 07 Aug 2003 11:33:36 -0400 From: Jim Ash Subject: Polishing Aluminium for a Beginner On the polishing debate, I used to teach a lab in semiconductor fabrication. My students each made their own IC from a silicon wafer blank. One of the last steps in the normal manufacturing processes of the dies is to coat the wafer with metal, mask it off and etch it. Our first lab was to take a cleaned microscope slide and metallize it, using a process called filament evaporation (I used sputtering and electron-beam systems, too, but the students from that class weren't allowed to near them). Gory physics aside, the end result was to vaporize a piece of pure aluminum wire and let the vapor condense on the slide, leaving a thin coating. If the slide was cleaned properly beforehand (part of the exercise), it produced a beautiful front-surface mirror(and rear, too). As luck would have it, that was the year of my tenth anniversary, which is the year you give your spouse tin/aluminum. I metallized one slide, and wrote a 'Happy Anniversary note' to my wife on another. I used the second as a mask for the first. I mounted both in a frame and gave it to her. She thought it was really cool.I'll bet nobody else's wife has anything like that. I believe some kind of metallization is used to put an aluminum coating on telescope mirrors, but I don't know the specifics of the process. In defense of the other side, aluminum does oxidize very rapidly, so don't expect any finish to last without some kind of coating. If you don't coat it, it will coat itself. Jim Ash ---------------------------------------- Date: Thu, 07 Aug 2003 12:17:17 -0400 From: Jim Ash Subject: Re: Polishing Aluminium for a Beginner Anodizing is an oxidation-based process. The surface aluminum reacts with the oxygen it contacts. This can happen in any oxygen-rich environment, be it uncontrolled in open air, or in a liquid-based process like anodizing. As the surface aluminum gets sacrificed to oxide and the coating gets thicker, it becomes harder and harder for the oxygen to get through the coating to the non-oxidized aluminum underneath. This is a temperature-dependent process; the hotter it is, the more energy the oxygen molecules have, and the deeper they can penetrate the metal. Eventually, the process slows to the point of effectively stopping. Technically, in a temperature-controlled environment, it never truly stops, but you won't live long enough to be able to measure a difference. On the side, oxidizing silicon causes the final oxide to be thicker than the original metal. This is also true for aluminum (and all kinds of other metals), but I don't know the numbers for them. With the silicon in the lab, we were talking final oxide thicknesses in units of Angstroms (1/10000000000 of a meter), usually around 5000, but I don't know if an anodized coating is thick enough to change the dimensions of a critical part or not. ... more than you ever wanted to know. This is hobby machining. Play with it and find out what works for you. Jim Ash --------------------------------------- Date: Thu, 7 Aug 2003 12:38:21 -0400 From: "Statman Designs, LLC" Subject: Re: Polishing Aluminium for a Beginner For aluminum the anodizing process requires a dye to be introduced to get any color on the surface. The reactive metals of titanium, tantalum, and niobium form their anodized colors without a dye present. In these metals the oxide coating that is grown is also clear, but there is a portion of incident light that reflects from the surface of the oxide and their is a portion that penetrates to the bottom of the oxide and is then reflected from the metal surface. These two types of light then interact and develop very striking colors, much like oil droplets on a puddle of water can produce a rainbow. For aluminum anodizing you change the dye used to get different colors. For reactive metal anodizing, you change the applied voltage to grow thicker or thinner oxide surfaces to change the colors. More than you ever wanted to know. Daniel J. Statman, Statman Designs www.statmandesigns.com dan.statmanx~xxrennlist.com ps The colors on titanium also cycle as the voltage is increased. However the second time through the spectrum the colors have a more pastel hue to them. In order to get to the third cycle the voltage must exceed 120 VDC and the surface of the titanium needs to be etched with hydrofluoric acid or the colors get very mottled and muddy looking. Also at those higher voltages any chlorine present in your anodizing bath, even trace amounts, will cause all kinds of surface problems. ------------------------------------ Date: Fri, 08 Aug 2003 03:31:11 -0000 From: "John" Subject: Re: deburring small holes [ABOUT 0.030"] --- In atlas_craftsmanx~xxyahoogroups.com, Wayde C. Gutman wrote: > Regarding abrasive threads, not urban legend, try MicroMark (I think). Wayde, you're a godsend! I found www.micromark.com & they have it! I then did a google search on "abrasive cord", and found even smaller cord all the way down to .012" dia. at www.abrasivesales.com. Thanks again, John ----------------------------------- Date: Fri, 8 Aug 2003 08:55:39 -0700 From: Frank Evan Perdicaro Subject: Abrasive cord One standard abrasive cord is dental floss saturated in toothpaste. Good for polishing carburator jets. But this idea has a long history. Wax saturated cotton/linen/reed cord rolled in abrasive must be thousands of years old. Sisal, glue and sand must be old, too. More recently there are nylon cords with glass powder attached. At Home Depot you can buy RemGrit flexible cutting rods for hack saws. Diamond impregnated bandsaw blades are used for cutting glass, so there must be diamond wire for similar uses. ----------------------------------------- Date: Sat, 9 Aug 2003 02:03:31 EDT From: catboat15x~xxaol.com Subject: Re: Digest Number 1584 Abrasive string is available from MicroMark and should be great for smoothing out holes in metal. Also it would seem that you could saturate cotton string with some oil and abrasive and do the job, but either way may destroy the accuracy of the hole. ---------------------------------------- Date: Sat, 9 Aug 2003 15:39:10 EDT From: LouD31M066x~xxaol.com Subject: Re: Deburring small holes Machinery's Handbook give explicit directions on how to work up diamond dust laps(at least my 1946 edition does.) This may be overkill for your purposes or maybe not. Louis -------------------------------------- Date: Fri, 28 Nov 2003 09:05:50 -0800 From: "Dave Hylands" Subject: RE: Parts Tumbler > Anyone know of a place I can get a relatively inexpensive > parts tumbler that can handle parts up to 6" across? I would > also be interested in building a tumbler if anyone knows > where I can get a set of plans. Here's one that could be scaled down: http://www.acc.umu.se/~widmark/lwtrumld.html Dave Hylands Vancouver, BC, Canada http://www.DaveHylands.com/ -------------------------------------------- Date: Thu, 11 Dec 2003 18:32:54 -0000 From: "eferg2001" Subject: Re: Titanium anodising? > Anyone know anything about anodising techniques for Titanium I anodize titanium all the time. The colors depend on the DC voltage applied to the Ti piece in a conductive bath (I have the color range pictured on my web site). The total process takes about 10 seconds. There are many plans to be found on the Internet for building an anodizer - be aware that most of them are unsafe (lethal voltages and currents are involved). I have a degree in electronics and built my anodizer with safety in mind. I suggest you begin your research here: http://www.reactivemetals.com/ Ed Ferguson www.cascadiadesignstudio.com ---------------------------------------- Date: Fri, 12 Dec 2003 06:02:16 +1000 From: "Des Bromilow" Subject: RE: Digest Number 1275 www.mrtitanium.com has some useful info but appears contradicted by the info from Dan... Ask me after this weekend. Also, here is part of an email from Dan Statman There are a few problems that you will have. The anodizing is VERY fragile and scratches off immediately unless in a recessed portion of the ring. To get the bronze color you need to anodize at 15VDC, not sure where you got your 40-120V information. 20V gives dark purple, 25V dark blue. To remove the anodizing you simply use emery cloth of whatever grit you want, 320 works well. You will not be able to get a clean division between the anodized portion and the brushed portion because the act of brushing the surface will strip the anodized coating off the entire ring. And if you brush it first then you will need to remove the anodized coating from the brushed portion, yet retain the brushed look. The anodizing bath is best if it is trisodium phosphate, but really anything will work. Avoid chloride ions, but at 15V it won't really matter at all. Use Stainless for the negative electrode and titanium for the positive. You will not get a very vibrant color with grade-2 titanium unless you chemically etch the surface first, but this is probably too involved for a one-time ring. Grade-5 titanium anodizes MUCH better than grade-2, and you don't need to etch unless you are doing some other colors in the 50V to 100V range. --------------------------- Date: Fri, 12 Dec 2003 05:50:09 -0000 From: "eferg2001" Subject: Re: Titanium anodising? > My plan is to use the technique as a decorative finish for clock > parts - assuming that I can fix the problem of machining the metal > appropriately! Tony Jeffree A clock with anodized titanium components would be stunning. Also, unfinished titanium can be polished to a very high luster (think platinum). If you combined recessed milled areas (such as numerals in the dial) with the anodized technique you will have a very unique project. Also, you can experiment with a technique where you anodize in layers. For example, if you anodize with a higher voltage color, then scribe away a portion, you can anodize again with any lower voltage color. The lower voltage color will not disturb the higher voltage oxide layer. You can also mask off areas you don't wish to color with nail polish or tape. And if you make a mistake, just polish the thin oxide layer away and re-anodize. Please share a photo when you get around to this project. And please, be safe when anodizing - it's the current level, not the voltage that presents a shock danger. I've seen some very unsafe plans for constructing titanium anodizers on the web. Regards, Ed Ferguson www.cascadiadesignstudio.com -------------------------------------------------- Date: Fri, 16 Jan 2004 16:36:34 -0800 From: Alan Marconett KM6VV Subject: acid pickle I'm in a pickle! Or rather, my fabricated brass crank is in a pickle (acid bath) to remove the flux or scum or whatever, and when I remove the part, it's nicely copper plated. BUT I don't want it copper plated! I have to use fine emery paper to remove it. Not a problem on flat external surfaces, but in the tight corners, it's hard to remove. Am I doing things wrong? Or is there a simpler way to remove the copper? Alan KM6VV --------------------- Date: Sat, 17 Jan 2004 07:02:10 -0800 From: "Orrin Iseminger" Subject: Re: acid pickle You haven't copper plated it, you've removed the zinc with the acid. In effect, what you have is a porous copper surface, now. Orrin ------------------- Date: Sat, 17 Jan 2004 10:55:39 -0800 From: Dave Martindale Subject: Re: acid pickle >the part, it's nicely copper plated. BUT I don't want it copper plated! Brass is made of copper and zinc. The acid that you are using isn't plating the part with copper, it is stripping the surface layer of zinc leaving (porous) copper. What acid are you using? Could you use something milder that won't attack the brass to remove the flux? Perhaps hot water, or alcohol, or some other solvent combined with mechanical brushing? Dave ------------------- Date: Sat, 25 Apr 1970 15:37:41 -0800 From: "Wm. Dubin" Subject: Re: acid pickle Alan, It sounds like you have used a part or a tool in the pickle which has caused this reaction. A pickle must be kept pure. For brass parts, I use ONLY a copper tongs for immersion and removal. As I don't pickle steel parts, I'm not certain what should be used, The pickle should also be well covered, as any metal dust in the workshop can contaminate it. Re-mix it, and start from scratch. On the parts you have now, use a strong soap (like LAVA), hot water, and a "fine" brass wire scratching brush, it may help. I use this in any case after I pickle any brass part. There are very good pickles you can get from Rio Grande, and if at all possible, use LOW heat (I use an old hot plate). Good luck, Wm. ------------------ Date: Sat, 17 Jan 2004 11:42:31 -0800 From: Alan Marconett KM6VV Subject: Re: acid pickle Hi Wm., Yeah, I had steel parts silver brazed into the brass rod ends. I've mixed up a new batch, and put in hydrogen peroxide per the article mentioned. Seems to be improving. I've also used a brass wire brush on the parts. Almost got it! Didn't have LAVA, tried a hand cleaner, but it wasn't the abrasive type. Alan KM6VV ------------------- Date: Sat, 17 Jan 2004 15:00:10 -0800 From: "Orrin Iseminger" Subject: Re: acid pickle You'll get this result on brass, whether iron is involved, or not. Perhaps some other cleaning agent will work I don't see any way to use an acid pickle on brass without dissolving the zinc. Maybe someone else can step in here with more definitive information. Orrin ------------------ Date: Sat, 17 Jan 2004 20:15:37 -0500 From: Jeff Demand Subject: Re: acid pickle Alan, With a sparex (or even a sulphuric acid) pickle ANY iron or steel in electrical contact with the part will cause the copper plating. Another sneakey culprit is nickle plating on the piece. If you are soldering steel use just hot water to remove the flux, otherwise just keep the iron/steel out of the pickle. To remove the copper flash you could try ferric chloride printed circut board etch, just watch out for other stuff getting eaten too. Some times its possible to heat up the part to soldering temperatures to oxidize the copper then pickle away the oxides. A nitric acid bright dip would also work if you are set up & qualified to handle such nasties. Jeff Demand Designs Analog/Digital Modeling & Goldsmithing http://www.aztec-net.com/~jdemand --------------- Date: Sat, 17 Jan 2004 17:36:55 -0800 From: Alan Marconett KM6VV Subject: Re: Re: acid pickle Hi Dave, I was using a recommended mixture of sulfuric acid and water, normally used for copper boilers. I had unknowingly pickled a connecting rod with a steel shaft before this. This apparently messes up the solution. I made up a new batch, per Instructions I just received, this time with hydrogen peroxide. The majority of the copper is gone, and I was able to finish up the parts nicely with emery cloth. I put the hot part directly into the pickle, to remove the oxidation and fluxes (read it somewhere). Secret seems to be not to put steel in the pickle! Next crankshaft, I'll try JUST hot water and H2O2, and avoid the acid. Alan KM6VV ------------------------------------------- Date: Wed, 11 Feb 2004 18:44:26 -0000 From: "Ray Feldman" Subject: Re: metal blackening > Anyone know of an easy way to blacken, (not gun blue), metal? I'm > mainly interested in steel & potmetal. Thanks John I just came across this query and want to add my 2 cents to the discussion. Brownells make a product called GUN-KOTE. It comes in a spray can and requires that the item to be coated, is pre-heated in an oven to 100deg F. After the item is coated it is then baked in the oven at 300 deg F. It comes in Gloss and matte black, plus other colors. Here is a direct quote from Brownells Literature: "Brownells GUN-KOTE is a durable, second-generation epoxy, thermoset resin finish that will not break down, peel or dissolve. In fact, once it is applied, the only way to remove Brownells GUN-KOTE is to abrasive blast the part. It is resistant to all known gun solvents and thinners. Each coat is approximately .0004" thick so Brownells GUN-KOTE can be used on both internal and external parts where a close-tolerance fit is required without having to worry about interference." Ray --------------- Subject: Re: polishing lucite? From: "Arthur Bailey" Date: Fri, 19 Mar 2004 09:47:41 -0500 [OldTools Group] > > So I have these "Shark-O-Lite handles that have rattled around in > > toolboxes too many years an need a good polishing up> I use Novus polishing products for plastic and bakelite radio cabinets. Works very well, and you can probably find it at your local plexiglass supply house. It comes in 3 grits, the heaviest two in a light paste form and the last is liquid. Art Bailey Queens, NY --------------- Date: Sun, 18 Apr 2004 00:59:25 EDT From: transdoctor3x~xxaol.com Subject: Re: brushed finish Use scotch bright on end of wooden dowel w/lapping compound, gives very good pattern, lots of definition transdoctor3 ------- Date: Mon, 10 May 2004 08:42:24 -1000 (HST) From: benedictx~xxhawaii.rr.com Subject: Re: Anodizing question.... [taigtools group] On Tue, 11 May 2004, Chet R Biggerstaff wrote: > Another question not totally related to the Taig. Is there an easy > way to anodize at home? Are there any good sources for learning on > the web and such? Is there anyone here with experience? Thanks You betcha! If you search on "anodizing" and "atm", you should reach a site where the guy goes into a great deal of detail about how he anodizes focusing units for telescopes. This guy (whose name I can't remember) sells a booklet off his web site. I got it, and it's well worth the cash. He uses supplies from Caswell Plating. I haven't picked up a Caswell anodizing kit, but they look pretty complete. You supply sulfuric acid and a power supply (12V battery charger worked for the few times I've done this on my own), and the Caswell kit supplies the rest. When I was doing anodizing I was using Rit fabric dyes. They work, but exposure to UV light fades them. I was never able to get a true black, but apparently this is the beast of all colors to do using Rit dyes. All in all it's very very doable in the home shop. Electropolishing is another one that's very very doable in the home shop. An electropolishing setup runs about $150 US. The big advantage to electropolishing over mechanical polishing for me is that mechanically polished parts that are used in a vacuum tend to outgas like crazy. Electropolished parts don't. A business thought for the small shop: We make a bunch of parts at work that are to be used in vacuum or in harsh environments. I'd love to have an anodizing and electropolishing setup at work, but for reasons of EPA regs it's not worth the trouble. I'd love to set one up at home, but for reasons of conflict of interest I wouldn't be able to charge for the service if I did this to parts made at work. If you have labs in your area that do vacuum stuff, or medical facilities that need tools polished, having an electropolishing setup at home can be an easy way to bring in a little shop cash. Likewise, if you've got labs with in-house shops that work in aluminum, or if you have an active paintball community in your area, having an anodizing setup in your home shop would be another way to bring in a little shop cash. At some point I'd like to set up both of these in my shop, just for my own work. Tom ------- Date: Tue, 11 May 2004 09:45:01 -0700 From: "John Swope" Subject: Re: Anodizing question.... I found the following to be very helpful on anodizing. He also touches on tumbling and offers a complete guide for $20. http://www.focuser.com/atm/anodize/anodize99.html John [NOTE TO FILE: Tom Benedict then replied: > That's the dude. That's the one I bought the booklet from. < ] ------- Date: Tue, 11 May 2004 19:26:57 -0000 From: "JohnW" Subject: Re: Anodizing question.... The Yahoo group I mentioned is http://groups.yahoo.com/group/anodizing101/ The fellow who has the focuser web page is an active member of that group. Process can be done with "ordinary" kitchen/shop supplies. battery acid, lye, baking soda, dyes and boiling water. Commercial dye and degreasing products probably give better results. The only thing that is keeping me from trying it is the tub of battery acid you need. There's nothing better than acid fumes when it comes to corroding metal. John ------- Date: Fri, 14 May 2004 05:24:02 -0000 From: "asrpas" Subject: Re: Anodizing question.... Please check this link, lot of information thru forums and other stuff not only anodizing but dedicated to all sort of finishing techniques. Hope that helps http://www.finishing.com/Letters/index.html#2a Cheers, Rick ------- Date: Tue, 8 Jun 2004 16:06:12 -0700 (PDT) From: ken cox Subject: RE: How easy is it to chrome at home? [SHERLINE GROUP] Most of the quality of a chrome job is in the prep. If you only want the part really shiny, you could sand your way up to 1200grit, or better, 2000 grit, and then use Semichrome paste. Make sure all the lines (from the paper) are going the same direction on the part. I've used it extensively, and with some effort, it is very much like chrome. I fooled some guys at work once doing this, they wouldn't believe the part wasn't plated. For aluminum, I've not encountered anything near it in quality. You'll have to judge for yourself though. Other than this, I would agree with the others' responses that for 5 parts or so, you are much better off "jobbing" the chrome plating on them out rather than trying to do this at home. Aside from the legal issues pertaining to zoning for industrial processes (most of the chemicals for a good job are very caustic and doing industrial processes involving some of this stuff at home, is likely not legal for where you are zoned) You would also have to have the buffing wheels, compounds, etc. When chrome comes out of the plating solution, it isn't shiny, from what I remember. You must buff it. You do have the option of a caswell kit, but I don't think it'll be as chip resistant as you get from a shop using the very nasty chemicals. I've used their gold plating kit, and while it did turn out pretty, I don't really think it is the quality of a professional jewelers gold plating. It is much thinner too. Perhaps more importantly: You are much more likely to have a part stay good looking after a piece of gravel hits it at 65mph if you get it done by a dedicated shop. That isn't to say it can't be done at home, but you have to weigh money vs quality and plating longevity. You can build an extraordinary amount of cool stuff with home (sherline/taig) equipment, but just be aware that some processes (plating, enamelling, etc.) have their downsides not just with health issues, but some legal ones as well. If you are looking to have fun and learn from your projects, there are of course other considerations. Plating might be something you want to do a lot more of. Only you can tell. If you aren't in a hurry, ask someone at a plating place near you if you can get a price break by leaving the parts with them for a few days, and have them plate them next time there is a large group of parts being done. I'd try that. Best of luck, have fun, Ken ------- Date: Wed, 9 Jun 2004 08:20:55 EDT From: Holyelvisx~xxaol.com Subject: Re: How easy is it to chrome at home? I think I will contact a local plating shop and try to develop a relationship there. I have no interest in chemical processes. (c: Thanks for the info guys. Devin ------- Date: Sun, 12 Dec 2004 17:15:14 -0800 (PST) From: John Maki Subject: Interesting Finish on Small Brass Parts I have been experimenting with methods for finishing small scale brass parts in order to replicate a cast surface. This one seems to work nicely! I begin by polishing the part with a 600 grid pad to remove scratches. Then I lightly sandblast the part using a Badger Air Brush designed for sandblasting (and sold by MicoMark), using their silicon carbide grit. After cleaning off the grit, I lightly polish the part using Flitz polish and finish with a coat of wax. The resulting surface is a good approximation to a finely cast part. I have some photos of my miniature tools which demonstrate this finish at http://www.flickr.com/photos/13976390x~xxN00/sets/53870/ I have also posted photos of some of my miniature tools which show more detail of the machining work at http://www.flickr.com/photos/13976390x~xxN00/sets/52075/ In all cases, you can get additional details on the tool by clicking on the photos. John Maki ------- Date: Fri, 04 Mar 2005 17:28:22 -0000 From: "n2562001" Subject: Re: Hi everyone: I have a question about polishing parts while chucked on the lathe> [sherline group] > I haven't had very much success in polishing items on my lathe, I am > wondering if anyone else has a method that works. I would like to be > able to high polish some areas and contrast with crisp edges and > brushed finishes. I have tried using 320 and finer sandpaper and then > charging wooden dowels with tripoli and other forms of polishing > compound but I end up losing my edges(they become rounded). The > material I am frequently milling is gold, stainless steel and > platinum. Any help would be appreciated, thanks in advance for your > replies. Cary James Cary This one took awhile to find the right combinations for a good quality finish. What has worked best for me is as follows. I first turn the tool post so that the cutting tool is parallel with the lathe bed. I then cut a strip of 3M Silicon Carbide wet dry paper to be used under a fine cut Pillar file. Next the Pillar file is layed over the top of the cutting tool so it will remain parallel with the surface to be polished. This also makes the sharp edge you are looking for possible as well as much easier to achieve. The paper is placed under the file for polishing the surface. For most sufaces I use 600 grit but will go up to 4000 grit if needed. I am not sure what it is with 3M silicon Carbide wet dry paper but it gives a far superior finish than other brands I have tried. Jerry Kieffer ------- Date: Sat, 05 Mar 2005 00:30:59 -0000 From: "n2562001" Subject: Re: Hi everyone: I have a question about polishing parts while chucked on the lathe> Alan Marconett wrote: > Hi Jerry, > Polishing parts is one (of many) area I could improve in. But I'm not > sure what you are talking about doing. A tool bit, a file, AND abrasive > paper? I get it that the tool bit is parallel to the bed. After that, > I'm not sure whether you're using the crossslide and carriage to move the > paper or what. Is the file for backing up the paper? And what kind of > file is it? Alan. A pillar file is a rectangle file with parallel sides that generally comes in a very fine cut. If you look them up in a tool catalog I am sure they will have pictures. I use the file as a flat surface to apply pressure to the paper so I can get a even finish on the part I am polishing. In other words you have the surface to be polished, then the paper and the file over the top of it. When you apply downward pressure on the file, it will apply pressure on the paper and polish the part. I like the pillar files because they come in many different sizes that work well for this operation. The fine cut is enough to hold the paper in place but not too coarse to come through and score the part. The only purpose of the lathe tool is a square surface to lay the rear part of the file on so it will stay parallel to the surface you are polishing. My explanations generally have a lot to be desired. Feel free to contact me off list and I will send you a drawing if this is not clear. Jerry Kieffer ------- Date: Fri, 04 Mar 2005 17:08:59 -0800 From: Alan Marconett Subject: Re: Re: Hi everyone: I have a question about polishing parts while chucked on the lathe> HI Jerry, so you're "bridging" the file with it's paper wrap across the part and the toolbit "support" at right angles? OK, I think I get it. Much like having the T-Rest Sherline offers for hand held tools? http://www.sherline.com/2110inst.htm I get it now. I'm sure it wasn't your description, just my slow uptake! Thanks again for the description, I'll give it a try. Alan KM6VV ------- Date: Sat, 05 Mar 2005 03:29:11 -0000 From: "hotchicken12000" Subject: Re: Hi everyone: I have a question about polishing parts while chucked on the lathe> Hi Jerry and Alan, Thanks for your responses! Jerry do you use any kind of polishing compound like Tripoli or Rouge or do you just finish your polish with super fine sandpaper? I have used a similar technique- a lot of goldsmiths use sandpaper wrapped around a rectangular piece of wood in order to gain leverage on their parts to be sanded. Usually I use 320 grit sandpaper mounted on a piece of wood and then I finish with felt or cotton wheels mounted on a polishing machine. Then I proceed to a wheel charged with Tripoli first and then finally to a soft cotton buffing wheel dedicated to the finer grit Rouge. Thanks again, I look forward to your responses. Cary James ------- Date: Sat, 05 Mar 2005 05:20:39 -0000 From: "n2562001" Subject: Re: Hi everyone: I have a question about polishing parts while chucked on the lathe> Cary, I seldom use anything other than paper to polish except for gold. For gold I generally only use appropriate compounds for polishing a previously polished surface. Jerry Kieffer ------- Date: Sun, 24 Jul 2005 15:57:14 -0000 From: "Lynn Livingston" Subject: Re: Epoxy Color Fill [taigtools] "juniorcdn" wrote: > Does anyone know of a product to color-fill machined aluminum key > chains? I think it is a colored epoxy. What other methods are you > guys using to fill the machined lines in your art and give it a little > bit of color. Thanks in advance, Michael. These guys supply engraving fills; look under laser supplies. Though I haven't tried them personally yet, I have had several pen engravings filled with it and it works great. http://www.laserbits.com/ Lynn ------- Date: Sun, 24 Jul 2005 08:50:38 -1000 (HST) From: benedict-listx~xxhawaii.rr.com Subject: Re: Epoxy Color Fill I've used model paint when I don't want to completely fill the engraved line. That works well. As a cheesy I've used a Sharpie or crayon, but they're not durable. Pigmented epoxy works well, as has been mentioned. I know Rio Grande sells pigments and very clear epoxies for doing jewelry work. Other jewelry suppliers should have similar products. Tom ------- Date: Sun, 24 Jul 2005 20:30:37 -0000 From: "Tom Murray" Subject: Re: Epoxy Color Fill I think you might achieve this with Ceramit. It is a two part epoxy that cures to a fairly durable material. It comes in a lot of different premixed colors and is reasonably priced. Maximum hardness is achieved when it is cured at 200-250 degrees fahrenheit for a short period of time, but it will also cure at room temperature after a day or so. Here are a couple of suppliers: http://shorinternational.com/Ceramit.htm http://www.lacytools.ca/catalog/default.php/cPath/336 The Shor International site has detailed instructions for using Ceramit. Tom Murray ------- Date: Mon, 01 Aug 2005 13:58:59 -0000 From: "Jerry Robinson" Subject: Re: Epoxy Color Fill For Sail and Power Boats, Epoxy is used a lot. So there are a lot of very good reference manuals out there. A favorite of mine is West Systems (www.westsystem.com ). There is a lot of information on site. They also publish manuals and videos. Another place is Mr. Fiberglass (www.mrfiberglass.com). They have just the basic materials - including tints and fillers for Epoxy. Usual comment: not affiliated - just a cutomer. jerry ------- Date: Tue, 02 Aug 2005 00:57:31 -0000 From: "campgems" Subject: Re: Epoxy Color Fill There is an epoxy type material that hardens with a "Ceramic like surface, which resembles kiln fired enamels in both appearance and physical properties". The quote is from a Jewelry supply catalog, and the product is Ceramit. It is a two part, color and catalyst, and is cooked at 200F for 1 hour. I used to sell it when I had my store, but never had the need to use it. It has been around for years, and has a good rep. My Catalog is about 5 years old, and in it, a 2oz color is $4.30 and an 8oz of catalyst is $8.45. They claim that it can be "stoned and polished" after hardening and can be applied to metals, wood plastics, ceramics, etc. I would guess that an hour at 200F for plastic may be asking a lot though. They also state that it can be brushed, sprayed, or applied with a spatula or squeeze bottle. My guess is that for most applications where you want some color on a piece, this would give a better finished product than epoxy, especially around oil and water. Oh yes, it ships as a hazardious material with special shipping charges. If you could find it in stock at a local lapidary or jewelers store, it may save you some bucks. The sur-charge was $10 to $20 per package. No connection, just passing along some info. Don ------- NOTE TO FILE: The following thread starts initially as machining tips to reduce tooling marks on the product. It quickly gets into finishing techniques that can be used after any mechanical metal work. ------- Date: Fri, 05 Aug 2005 23:54:59 -0000 From: "juniorcdn" Subject: Tooling Marks [taigtools] I still can't get rid of the tooling marks on my projects. I have tried everything now with no luck. I have buffed and tumbled my projects and the lines are still there. Tumbling also makes all my work dull looking. Here is an example of a project. http://members.shaw.ca/huntmw/Decals/Cross.JPG These marks are in all of the pockets I mill out or engrave. I thought that it was endmill flex because I use 1/16 inch and 1mm endmill mostly. I then tried a design with a 1/8th endmill with similar findings. Do any of you have this problem with the stuff you make on your cnc? If I make a contour design it looks good, but the 2 1/2 dimension stuff looks way better. ------- Date: Fri, 5 Aug 2005 17:13:39 -0700 From: "Felice Luftschein and Nicholas Carter" Subject: Re: Tooling Marks Unless you want to polish those out with a flex shaft and abrasives there's really nothing you can do. You might try taking a finishing pass on the bottom with a ball endmill and a stepover of .005" or so and see if that cleans them up, but chances are you will always have them in some way or another. The ball endmill will cut more in the center than the periphery and might mitigate the marks. If you filled it with black paint or epoxy it would look pretty radical. Anyway, great work nonetheless. Check out our homepage www.cartertools.com/nfhome.html ------- Date: Sat, 6 Aug 2005 12:17:35 +1200 From: "Alan" Subject: RE: Tooling Marks Are u using ballnose or flatbottom cutter? With flatbottom cutter only move over 2/3 cutter dia. ------- Date: Fri, 5 Aug 2005 17:25:08 -0700 (PDT) From: juan gelt Subject: Re: Tooling Marks I get those too, even if I flood with oil. They are really much less than .001 and make rainbows when viewed sidelong, so the scratches must be very fine to act as a diffraction grating. I'm new enuff that I don't know how acceptable this is as a standard of performance. But I took a tip from microsoft and wrote an applet to make spirally pockets so at least it looks like a deliberate feature! I used to do jewellery, and one uses 'jeweller's rouge' which is iron oxide superfine abrasive in a wax stick, on a buffer wheel. This is for a final mirror finish and it's called 'coloring' the metal for some reason. Perhaps you could get a tiny dremel mandrel and felt buffing cone and run your final depth pass one time separately with the rouge. It WILL remove material and it IS possible to overbuff, but if you really want a mirror in the pockets it would be one way to achieve it. Usually the 'coloring' is done after a rough polish using a coarser material in a wax stick called 'tripoli'. Oh - and I usually make a finish pass taking off .002 just fyi so you can gauge performance... lemme see...there is a picture at http://cnc-g-spot.com/testmold/pockets.gif I'd sure like to know if we're missing something and if a better result is possible, too! ------- Date: Sat, 06 Aug 2005 01:26:24 -0000 From: "juniorcdn" Subject: Re: Tooling Marks I am using flat carbide endmills. I use smart tap tapping fluid as a lubricant. My endmills cost between $10-15 each. That is not too cheap I hope. I am afraid to use a heat-treated endmill my friend gave me worth $70. I have broken 3 bits in the last two months, anymore would start to get expensive in my opinion. I tried color filling with a resin and don't like it at all. It is the worst stuff I have ever worked with. It did not stick to the aluminum either. Paint/powdercoat may be my last option. I just love the look of poslished aluminum though. How do the big companies finish thier products to a mirror shine finish? ------- Date: Sat, 06 Aug 2005 02:53:19 -0000 From: "Paul Huffman" Subject: Re: Tooling Marks Any time you use a tool that has to have step over to machine a pocket, you will have these marks, as far as I know. I run full size cnc machines and have them the only way I know is to use what they call wiper inserts on a face mill, which is used to face off sides of blocks and such, where the tool only makes one pass over the complete surface. Paul in OKC ------- Date: Sat, 6 Aug 2005 15:49:01 +1200 From: "Alan" Subject: RE: Tooling Marks The other thing is u must have your cutter head clocked up with a dial indicator over the width of the table. ------- Date: Sat, 06 Aug 2005 05:30:10 -0000 From: "Robin S." Subject: Re: Tooling Marks First, as others have said you're never going to completely remove these marks without doing some kind of operation after machining. The Taig (and any similarly sized machine) is not rigid enough to be able to run a cutter without making those tool marks. It is possible with much larger and more expensive machines, however. I would strongly suggest you not use carbide. Typically, carbide cutters are not as sharp as HSS cutters, nor are they even capable of being sharpened to the same degree (due to the size of the grain structure of tungsten carbide). Using carbide creates more machine deflection and vibration than using HSS which results in deeper tool marks. You best option is to make a very fine finishing pass at a high surface speed (probably something like 300 to 500 feet per minute) and a reasonably fine feedrate (probably less than .001"/flute, although you can experiment with this). The axial depth of cut should be something like .002", and a good radial depth of cut will be something like 1/3 the cutter's diameter. All of these values should be tweaked to find a finish that you're willing to wait for. BTW, I'm assuming you're using aluminum. If steel, the surface speed will need to be decreased to about 100-120 for mild steel (slower for higher carbon/alloy steels) and you may want to start with a smaller radial depth of cut. Make sure to get rid of chips as you're machining. Recutting chips left in the pocket will create major tool marks and wear your cutter prematurely. Lastly, you may want to try and stay .001" or so off the side walls for your finishing pass. You'll have to experiment to see, but touching the side walls during a finishing pass could very well cause fairly major tool deflection (more marks). HTH. Regards, Robin ------- Date: Sat, 06 Aug 2005 15:31:31 -0000 From: "Lynn Livingston" Subject: Re: Tooling Marks Another method you could employ to get rid of the marks is to use a backing plate to provide the background for the letters. Just mill like you normally would, except cut the letters all the way through. Then cut an identical shape without the letters, and glue, solder, whatever to the backside of the front piece. Also, you could use this to method to make interesting effects, such as brass, copper or wood veneer inserts to get "color". Just a thought... Lynn ------ Date: Sat, 06 Aug 2005 23:59:00 -0400 From: hudakjmx~xxmcmaster.ca Subject: Re: Tooling Marks Back in the day when I was still working in a metallurgical lab what we used to do was to mount the job on a flat holder. We then polished the work piece on successively smaller grit sizes of silicon carbide papers using water or kerosene as a flood lubricant. By this I mean we actually submerged the paper in water and did our grinding/polishing under the liquid. Of course we had motorized machines to do this but it can be done by hand. Silicon carbide papers come in very fine grit sizes. I've seen them as small as 8000 grit in auto body shop supply shops. There are even finer ones but they get pretty expensive. By the time you get to this small size of grit you are in effect polishing the work piece. It won't necessarily be a "mirror" finish but it will be shiny. All this grinding/polishing actually goes quite quickly - typically just minutes if you are working with aluminum. You didn't say if this is production job or you're doing just a few pieces. As others have said, you'll probably never get rid of the marks with just machining. Of course it pays to minimize the marks during the machining process. Part of the reason is that the machining process actually causes sub-surface damage to the microstucture of the metal. Just buffing will not get rid of it as the buffing process will just reveal more of the sub-surface damage. You must first grind past the damage layer and then buff/polish. Aluminum can be particularly prone to this damaging effect. I would also agree here that using carbide tool bits is probably part of the problem. Some carbides, like the tungsten carbide in the bits, can actually make the situation worse. Another way to get rid of machining marks as used in industry is by electrochemical means, although this requires some extremely nasty chemicals, so we won't go there. So ... I'd say you're pretty much going to have to use some sort of mild grinding and then polishing to get your "polished" look. Good luck. John ------- Date: Sat, 6 Aug 2005 23:44:54 -0700 From: "Larry Richter" Subject: Re: Re: Tooling Marks John is right. Here's the deal: Buffing works, you can really put a finish on parts with buffing, shops avoid it whenever possible and dread it, and buffing as an industry earns a lot of money. From this you might guess: 1) there is more to buffing than just polishing, 2) it's a whole dern other business than machining, 3) you can't learn it as a lark or a joke or without getting some real equipment, 4) not everybody can have two professions or major hobbies that aren't much alike without shorting one or both; even while hating the expense, shops will either hire it out to experts or hire in some experts, 5) there are such things as experts, and for you to become one or like one is going to cost. To me, the closest that a hobby/one-man-shop industry comes to getting a grip on hard metal buffing, which like the man says, involves 3 or 4 stages of treatment that use buffs, but with grinding compounds on them instead of polish, is gunsmithing. I did it on knifeblades for awhile, was fair, or rather got by, but had the advantage of getting advice (actually, direct orders and commands) from Bob Brownell, of Brownell's Gunsmithing supply in Montezuma, Iowa. He liked everything about firearms, but good buffing practice was like a religion to him, he preached it and taught it, as a treat and a duty, and he got results. He impressed. Brownell's is still there, and still sells the right stuff and the best of everything for small scale metal finishing, but it's hard to imagine they have anybody like the old man now. Changes in polishing because of new applications, I think first begun in electronics, means too that are many systems of buffing now that really work, but with what I've seen, it's whole hog or no hog. You can only get a cheap handle on it by being lax on standards, or by being lucky, by which I mean having a use that can just be shorted for some reason. Specifics: the idea is to start with a coarse grit, maybe 150 or 200, maybe 80 or 60, in a grease or glue base, then buff until all coarser defects than those from your grit have gone, then go to the next finer grit, with new buffs, switch the direction of buffing 90 degrees, and wipe away all the scratches from the grit before, go to the next finer, all new, switch 90 again, until you get to a polish stage at 600 or so, with a hard felt wheel. Nothing mixed or contaminated. The metal (hardened steel in my case, and brass doodads) will simply glow. Odds are it will also have all sorts of lost corners, rolled edges, and other kinds of low viz defects that a good professional buffer can routinely avoid. It's an investment and a new field no matter how you go at it, and like architects couldn't get fully back into architecture until they mastered computer drafting a couple decades ago, you'll have to make an investment to get back to business too. Habits of hand usage and safety and job thinking are different, and exciting experiences with objects shooting across the room at high speed (possibly including toward you if you don't come up with good stop bars, and maybe even if you do) are guaranteed. Knife blades are especially attention-getting in this respect. Still fun in it, even so. People are always mystfied by shiny, go figure, sometimes it's fun when they say "gosh!" or the like. A shame you can't hear Bob Brownell on it. He was great. ------- polishing and deburring [taigtools] Posted by: "Collins, Graham" collingx~xxnavcanada.ca Date: Mon Aug 28, 2006 8:55 am (PDT) Anyone use a rock tumbler for polishing, deburing or smoothing machined parts edges? If so, what type of media for what type of materials? Rotary or vibratory? I ask from the point of view of small aluminum, steel, cast iron, and brass parts used in small model engines.' Comments, suggestions ? Thanks, Graham in Embrun near Ottawa, Canada ------- Re: polishing and deburring Posted by: "Nicholas Carter and Felice Luftschein" felicex~xxcasco.net Date: Mon Aug 28, 2006 9:29 am (PDT) I have a small vibratory I use, as does a friend who uses a large vibratory tumbler for aluminum parts he is sending out to anodize. You generally use ceramic media (available in different sizes/abrasivenesss). A vibratory tumbler is quicker, but a rotary will work fine if speed isn't an issue. See our homepage at www.cartertools.com/nfhome.html ------- Re: polishing and deburring Posted by: "Collins, Graham" collingx~xxnavcanada.ca Date: Mon Aug 28, 2006 9:37 am (PDT) Is there any advantage (or conversely dis-advantage) of one over the other in regards to removing too much? I suppose that is really a question of the type and coarseness of the media, too coarse and you will wear away too much too quickly. Speed isn't an issue and I have been looking at the rotary ones. Some of the smaller vibrating ones are actually cheaper than the rotary ones. There is lots of info and opinions in various groups around the internet which just makes it more confusing. Thanks for your comments. Cheers, Graham ------- Re: polishing and deburring Posted by: "Nicholas Carter and Felice Luftschein" felicex~xxcasco.net Date: Mon Aug 28, 2006 9:41 am (PDT) It is grit/size of media/part size dependent as well as vibratory/rotary dependent. I have found that all tumbling ultimately requires some experiment until you have an idea - stop every half hour, note finish of part, resume if not done. Take notes of grit/size/speed and you will build up some data. See our homepage at www.cartertools.com/nfhome.html ------- Re: polishing and deburring Posted by: "Collins, Graham" collingx~xxnavcanada.ca Date: Mon Aug 28, 2006 9:49 am (PDT) Good advice and I was already thinking down those lines. Always something new to try and in that is the challenge that sends me off down these different paths. Thanks again, Cheers, Graham ------- Re: polishing and deburring Posted by: "Jeff Demand" jdemandx~xxgmavt.net Date: Mon Aug 28, 2006 4:32 pm (PDT) Graham, I use vibratory tumblers for smoothing jewellery castings (after initial manual filing, emery paper etc) with green plastic medium media. I use a water flow thru set-up, the ground up media soap scum etc. really slows the action down after a couple of hours without the flow thru keeping everything clean. For light deburring you Might be able to work without the flow. For other than a very slow polishing process (rouge charged walnut shells dry in a vibratory) you are talking about a wet process...might not agree with cast iron :-) For cheap dry vibratories look at re-loader gun sites, for wet ones jewellery tool suppliers (premium $). Or consider just buying the bowl and making a spring mounted plate with a motor spinning an off balance weight. Study the available pictures, it's not rocket science. But I'd recommend buying the media, and there are a couple of jewellery related books out there. Jeff ------- Re: polishing and deburring Posted by: "Don Rogers" Donx~xxCampbell-Gemstones.com Date: Tue Aug 29, 2006 12:01 pm (PDT) I used to sell tumblers in my store. The Vibrator type will be your best bet. The rotary tumblers eat the corners, followed by the edges and then finally start on the flats. The vibrator attacks more evenly. Make sure the part(S) can easily slide around in the barrel or tub. There should be enough depth to cover the part plus at least 1/4 the part depth. Note, the vibrator types are very aggressive so watch your time closely. Don ------- Re: Flywheel finishing question [Min_Int_Comb_Eng] Posted by: "fishnotchips" chris.hubbardx~xxtiscali.co.uk Date: Fri Oct 6, 2006 9:32 am (PDT) "corey94945" wrote: > I went to the GEARS show two weeks ago and one of the things that > caught my attention was how beautifully finished the flywheels were on > many of the engines. The rims were in a high state of polish with no > rust. Someone that I spoke to said that he treats the wheel with > laquer after polishing to prevent rust. What I'm wondering is how the > flywheels are prepared to get that mirror finish. Are they shined up > with progressively finer grits of sandpaper on the lathe and that's > it. Or, do they get buffed on a wheel, and if so does this happen in > the lathe or freehand? Any tips and pointers appreciated. I assume that you mean the flywheels on hit & miss engines. I polish these in the lathe & use "Wet&Dry" paper that is used when spraying cars. Start with 400 grade & work up to 1200grade. Tear a strip of paper and fit on a piece of thin flat steel-a 6" rule is ideal. Then with caution use this to polish the rim. The lathe needs to be going reasonably fast. As you work through the various grades of paper the quality of finish will improve considerably. To further improve this you could then use diamond pastes. Start with 25 micron & finish with 5 micron. Apply a very small amount of the paste to a piece of flat wood, mahogany is ideal, press lightly onto the rim. With care a mirror-like finish is easily obtained. When finished clean the work and apply a couple of coats of car polish. This will stop air getting to the surface & will prevent rusting. Coating with lacquer is o.k. but it discolours and eventually starts to come off. I hope this helps ------- Re: Flywheel finishing question Posted by: "David Everett" deverett2003x~xxyahoo.co.uk Date: Fri Oct 6, 2006 1:26 pm (PDT) Corey: If you are modelling an antique engine, then in all probability the original flywheel and any unpainted parts would not have been buffed up. They were utility engines after all, and usually built down to a price! But if you want to have a mirror finish on the bare metal, then go for it. Beauty is in the eye of the beholder. Regards Dave Saudi-Arabia-On-Sea ------- Painting, etc. [LittleEngines] Posted by: "Jim Knighton" jim_knightonx~xxmsn.com Date: Sun Nov 12, 2006 12:43 pm ((PST)) Hi! I'm new to steam engines, although not to hobby machining. Interests change over time, and all that, and I'm now building a few steam engines to see if they hold my interest. Current project is a PM Research Model 3 that's nearing completion. Anyway, I see a lot of photos here of elegantly painted models and I'm trying to figure out how to get similar results. In years past I tried painting some model RR metal stuff with only fair results, so I guess I was doing something wrong. How do you guys go about getting a model ready for painting, and how do you go about it (the painting)? Since I don't have a spare oven I can dedicate to shop use, like for curing, I don't think powder coating is an option for me. I have an airbrush and have used it to good effect with Floquil paints on wood and plastic. So, the question isn't so much about that as stuff like polishing, prep, type of paints to use, appropriate primers, curing (if necessary), etc. Can anyone give me some tips and/or point me to a good source of relevant information? Regards, Jim -------- Re: Painting, etc. Posted by: "corey renner" vandal968x~xxgmail.com Date: Sun Nov 12, 2006 1:37 pm ((PST)) Jim, prep and painting of model engines was last month's technical topic in my model engineering club. A description of the techniques used by one of our more accomplished members should be published in the newsletter next week. Most of the newsletters are available on our website: http://www.baemclub.com/ If you are in the Bay Area of California, you should drop by the meeting and check it out. cheers, c ------- Re: Painting, etc. Posted by: "buffaloman97405" bhudson9216x~xxmsn.com Date: Sun Nov 12, 2006 11:25 pm ((PST)) I use an older Pache H airbrush. This works fine for enamel or lacquer. But any kind of air brush or spray gun requires a lot of clean up of the gun after the spray job. It is hardly worth all that mess for a project as small as a model engine. Floquil is not a good paint for engines. It is designed mainly for railroad and military model work. Enamel is probably the best to use on engines as it is not bothered by fuel or oil. Rattle cans off the shelf are limited in types and colors of paints available but in the next town from here is a paint company that will put your paint into a rattle can for you. I have my paint mixed at a commercial automtive paint company and then have it put into the rattle can. But the problem is the rattle can costs about $8 to buy and fill. Another alternative (my preference when the job is too small for a spray gun set up) is to use a PreVal. It is a pressurized unit (charged with a propellant) that screws on the top of a jar. You can buy the charge unit and jars separately. I have my paint mixed, then use the PreVal to spray. Actually works pretty good. Of course when I have a larger job I use a touch up gun. But the clean up is time consuming. I like the PreVal so I can just pour out the paint from the jar and rinse out with thinner or just put a cap on it and save it for another time. To clean the spray unit I just keep a jar with thinner in it and screw the unit on the thinner jar and blow a little thinner through it. At the automotive paint store I also buy an etching primer (rattle can) which is sandable. I build up a nice primer base with a final wet sanding of 400 wet or dry. Let it dry overnight and then apply color coat. The smoother your primer coat the better your top coat will be. The less you have to work the top enamel coat the better. Enamel does not take to sanding or rubbing out well. Bill ------- Re: Painting, etc. Posted by: "Ken Brockway" WB2TDGx~xxaol.com Date: Mon Nov 13, 2006 11:52 am ((PST)) Hi Jim, If you're looking for a high gloss finish you have to "finish" the castings and then apply 2 or 3 coats of a sandable primer while sanding in between the coats. You should finish up using 1000 grit paper using it wet. The finish paint hides little or no defects at all. I use a high quality model airplane paint from Top Flight called Lustrecoat. It goes on very smooth with no orange peel and dries quickly to a high gloss. The best part is that it will not be affected by oils or fuels your engine may come in contact with. It may be bought at hobby shops or mail ordered thru Tower Hobbies. A link to the paint is: www2.towerhobbies.com/cgi-bin/wti0001p?&I=LXCZW4&P=7 I also like using powdercoat. It is not as hard to use as a lot of people say it is. I just use a toaster oven to bake on my finishes. The toaster oven will hold most steam engines and more. I even was able to do my full size sidewheel steam boat paddles in it. The finish I like the best is obtained from using Rustoleum's Texture paint directly on my castings. It is a VERY FINE sand like finish that dries to a semigloss finish. It gives your project that "Old Look" and is easy to apply. I just file the rough casting marks, clean with a degreaser and paint. It will hide some marks. An example maybe seen on my web site. www.mysidewheeler.com When you get there just click on the page for how I built PM Research's New Dynamo. You may also see the powdercoating done on my paddles. Have fun and I'm glad to see you're trying to do a nice job on the finishes. I've seen many a nice engine but a lot of them lack good finishes and a nice display base. You might post a picture when you're done. Ken Brockway ------- Re: Painting, etc. Posted by: "Gordon" glachnietx~xxyahoo.com Date: Mon Nov 13, 2006 11:57 am ((PST)) There are many colors available with a quality spray like Rustoleum and many tractor colors at places like Tractor Supply or Farm and Fleet. There are also many automotive colors available at your auto supply store. The trick is to put on a good sandable primer and sanding with fine sandpaper like 400 or finer before putting on the top coat. If you can see scratches in the primer coat you will see them in the finish coat. Clear coat can be applied over the final coat or over unpainted surfaces. Probably talking to the auto supply store where they sell automotive paint will get you the right materials. ------- Re: Painting, etc. Posted by: "Jim Knighton" jim_knightonx~xxmsn.com Date: Mon Nov 13, 2006 11:25 am ((PST)) Bill: Thanks for the tips - they help a lot. I know what you mean about the cleanup problem, but if the only tool you have is a hammer, every problem looks like a nail. I've spent a LOT of time cleaning the airbrush. Anyway, I guess I'll try some enamel in rattle cans and see how it works. I have some enamel touch up paint that came with my mill/drill. That stuff is pretty insensitive to surface prep and I've brushed it on over all sorts of crap to hide dings and whatnot. It acts like primer isn't needed, at least on cast iron. Some Testor's spray enamel I have on hand says it can be sprayed over bare but clean metal. Is this a good idea, or should I use the primer? Regards, Jim ------- Re: Painting, etc. Posted by: "buffaloman97405" bhudson9216x~xxmsn.com Date: Mon Nov 13, 2006 9:02 pm ((PST)) >Some Testor's spray enamel I have on hand says it can be sprayed over >bare but clean metal. Is this a good idea, or should I use the primer? Jim, I would stay completely away from model paints, even the primers. Most likely they are not compatible. Go the extra distance and get a good automotive primer. You will not be sorry. Also if using rattle can paint check to see time limit for second coat. Many of the newer Rustolium etc. cannot be given a second coat after so many hours. You will end up with a crinkle finish. Special note: Hammers do not work well for cleaning air brushes. ;-). Bill ------- Re: Painting, etc. Posted by: "buffaloman97405" bhudson9216x~xxmsn.com Date: Mon Nov 13, 2006 10:07 pm ((PST)) >>Special note: Hammers do not work well for cleaning air brushes. ;-). > Bill, how do you know that? :o) Carl Loaned out my $90 Pasche to a friend (????) He ran acrylic through it and let it set up before he tried to clean it. Rather than bring it back to me and let me run lighter fluid through it he tried to scrape the needle with an Xacto knife blade. When I told him he had ruined it and it was only good for the scrap bin he asked if I would give it to him. Didn't offer to pay for a new air brush. While he was looking I grabbed my sledge hammer and flattened the air brush out on my anvil and then gave it to him. It really was worth the look on his face. Bill ------- Re: Best finish on 6061 Al? [atlas_craftsman] Posted by: "Jay Greer" redwitch1x~xxearthlink.net Date: Wed Feb 21, 2007 10:03 am ((PST)) on 2/21/07 9:36, Mike Andre at mandrex~xxen.com wrote: > I've made a few items out of 6061 and the surface finish, while pretty > good, certainly isn't in the 'mirror' category. I'm hoping to anodize > these and understand one needs to have an ultra-smooth finish > otherwise the anodizing will exaggerate any imperfections. > Not wanting to re-invent the wheel, what method do you folks use to > get a bright finish on 6061? All the best, Mike Mike, I polish off with several ultra fine grits of wet and dry paper. Emery cloth doesn't hack it. Fair Winds, Jay Greer Boat Builder -------