Soldering skills are useful in the home workshop in many ways. The electrical joining of wires and components by soldering is a common use, but only scratches the surface of soldering's potential. A few other applications include: - joining sheet metal as in making metal trays for the workshop; - soft and hard (silver) soldering according to the need of the metal parts; - joining small parts together when the whole could not have been machined on a small metal lathe or milling machine; - joining machined smaller parts together for a complex shape when no casting was available. 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 - 2008 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: Wed, 21 Mar 2001 08:12:34 -0800 From: "David Goodfellow" Subject: Re: Re: Steam Engine > Quick question: What did you use to solder the intake tubes to the > aluminum backing plate? Hi Dean: I used a low-temperature solder/flux mix that comes in a tube. Forget its name. It's a specific for aluminum to other metals such as brass, etc. It's in the Micro-Mark catalog. As to self-starting a single-acting wobbler, I think you're right. Others have commented similarly, and have told me why, in this morning's messages to the list. Have to study those. Dave Goodfellow ------- Date: Mon, 02 Apr 2001 03:55:56 -0400 From: Pavel Korensky Subject: Re: Re: First project with my new rotary table Hmmm, do you remember when I mentioned you (in the e-mail) that I am doing the inlayed titanium ring for my girlfriend ? Since this time, I made couple of similar rings with radial, axial and angular inlays from various kinds of gold for my friends (and girlfriends of my friends) and I never used anything you mentioned above. All inlays are OK, rock solid and everything what I used was a cutting tool, small endmills, small hammer and pliers. And of course the Sherline mill and lathe ;-) Although I am not professional, IMHO the inlays are not rocket science. Just watch the tolerances, use eyes and hands. If all else fails (especially with radial inlays made from hard gold), use soldering iron - the normal material which is used for soldering electronic components is OK. The gold will colour the Sn-Pb solder and after cleaning, you will not be able to see the connection. Best regards PavelK ------- Date: Wed, 30 May 2001 17:13:09 -0700 From: "Keith Yundt" Subject: sticky situation unstuck! [NOTE: had gotten soft solder in the teeth of a gear and was looking for ways to remove same: Soft solder: heat and use copper wicking, or desoldering bulb or wipe with cloth or blast with compressed air. Some solder colour might remain but will do no harm. For hard silver solder - the real stuff - it may be impossible to remove except by mechanical means such as filing or re-milling.] Just to let everyone know as a follow-up to my silver solder problem, I just finished heating up the gear (had to get it pretty much dull red), and blowing off the solder with air pressure. Worked perfectly, just needs a little polish and I'm ready for a re-match! Thanks to everyone who offered solutions; yet again I have learned some valuable lessons from you all! Keith ------- Date: Thu, 24 May 2001 23:45:16 -0700 From: "YK Chan" Subject: Re: Digest Number 405 There are good and bad quality solder wick. Higher number (qty) of strands per unit cross-section area is higher quality. High quality wicks more and wicks fast, it does not leave any more excess solder behind except metal alloy. Those are not normally stock at Radio Shack. Some research in its sourcing is necessary. An alternative is to mount it on an good fit arbor of 0.125" shank and spin it on a dremel. "Brush" it with flame off a plumber torch. (Wear eye protection and keep kids away.) Try not to over heat it or run heat down the shank. Hope that helps. YK ------- Date: Sat, 07 Jun 2003 08:45:00 +1200 From: "Richard T. Perry" Subject: OT ( a little): Propane torch? Can anyone out there point me in the right direction for something? I know this doesn't have anything to do with Sherline equipment, but metalworking is metalworking, I guess.... I'm looking for a propane torch, but not the standard "Benz-o-matic" screw-it-on-the-top-of-the-cylinder model. I'm looking for something I saw in a video, once (it was the Rudy K video on "Building a Sterling Cycle Engine") - it's a torch head that looks much like a oxy welding rig - a head with a valve, and a hose down to a large cylinder on the floor. I need to do some fairly precise silver-soldering work (clockmaking), and the "top-of-the-cylinder" rig I've got just isn't cutting it (plus, getting those little cylinders is a problem for me out here in the Central Pacific, but the big propane bottles isn't - BBQ's are a full- time deal out here!) Regards, Richard T. Perry ------- Date: Fri, 6 Jun 2003 14:07:27 -0700 From: "Wm. Dubin" Subject: Re: OT ( a little): Propane torch? Richard: You might want to look at what's called "The Little Torch". It's used by jewelers. I use mine with Oxy/propane, and it gets far hotter than the Benz-o-matic. There is also a special 'tip' for melting metals in a flask for casting. I've used this tip on mine to do major silver solder jobs. Rio Grande carries a full line of these, other small torches, and everything you'll need for them. They have a web-site. Hope this helps. Wm. ------- Date: Fri, 06 Jun 2003 17:39:46 -0400 From: RichD Subject: Re: OT ( a little): Propane torch? The Turbo-Torch line has all what you are looking for and is Propane. Maximum heat from propane - blasts the "Bernz-o-matic" out of the water! Silver soldering and light steel forging are no problem. RichD ------- Date: Fri, 6 Jun 2003 16:43:42 -0500 From: Dennis Cranston Subject: RE: OT ( a little): Propane torch? A little larger is a Sievert torch. Sulpher Springs carries them. http://www.sssmodels.com/ Click on machine tools. They have many heads and attachments. Not cheap but good. You may check with some suppliers in the UK or in Austrialia as it is a brand carried world wide. Dennis Cranston ------- Date: Fri, 06 Jun 2003 22:30:43 -0000 From: "n2562001" Subject: Re: OT ( a little): Propane torch? Richard, if you are trying to do small precise joints where you need to control the flow area there is no substitute for the mini oxygen- acetylene torches by Smith or Victor. I am making the assumption that you are using the 1200-1300 degree silver solder. The torches and tanks would be around $300.00 but you would never regret it. They can be purchased at any welding shop and they may know someone in the area that has a set that would be willing to Demo it. Jerry Kieffer ------- Date: Thu, 03 Jul 2003 19:13:57 -0400 From: RichD Subject: Re: Easyflo Solders Alan Marconett KM6VV wrote: > Hi Rich, Tom, > I use the Turbo Torch as well. With a little 2 Lb bottle. I do silver > brazing with it, using a white "Ultra Flux". What's the black? > Alan KM6VV > RichD wrote: >>Tom, I use the silver alloy soft solders as well. They have their place. >>If it's not to large, welding suppliers usually sell 1/16" dia 45% SS >>in coils. I pound it down to small thicknesses or chips as needed >>and place in the joint prior to heating. Also, the "Black Flux" is well >>worth getting. Much better than the white stuff. I may as well add, >>the Turbo Torch (swirl mixing) will almost equal small acetylene >>torches without the expense and higher scale/crud formation. RichD Alan: J.W. Harris p/n 40051 Stay-Silv Black Flux. There may be other brands now. This flux absorbs more oxides and lasts longer than the white. Great for extended heating periods that modelers may have do to fiddling about trying to "get it perfect". Works very well, especially for joining steel. Except for the color it is used the same way. I find it at the welding trade stores. RichD ------- Date: Fri, 04 Jul 2003 14:25:49 -0400 From: RichD Subject: Re: Turbo Torch/silver soldering George: Look at this pdf file: http://www.thermadyne.com/tt/literature/HandTorches.asp?div=tt I use the STK-9 kit with the ST-3 tip. It's hard to see in the pictures of the bubble pack cards. I also use the ST-3 tip attached directly to the bernz-o-matic valve for max output (use a self made adapter). The gas is fully mixed with air before leaving the tip chamber and is already burning. VERY HOT! With this outfit screwed to a 14 oz propane canister I can forge 1/4 steel bar at red heat or silver solder dainty brass fittings with no problem over heating. Propane has the additional benefit that it does not introduce carbon or excess oxygen theyby making the cleanest joints possible. There are many other versions of this torch head using Mapp, Air/Acet, etc. http://www.thermadyne.com/ Sellers are welding and HVAC trade stores, hardware and home centers. The best selection willl be the trade store. RichD ------- Date: Tue, 02 Sep 2003 14:37:11 -0000 From: "askme" Subject: Re: Multiple layers of different metals, how to bond correctly? In sherlinex~xxyahoogroups.com, catboat wrote: > problem. You could not use solder on the stainless or aluminum so Incorrect. Aluminum can be soldered to aluminum with special solders, it just doesn't solder to anything else. Stainless can also be "hard" soldered with high silver content solders but you do run into the expansion rate problem with dissimilar metals and the heat is high enough that brass may start to liquify. Martensic stainless alloys solder easier and better than austenitic alloys. The following will work for all but the aluminum: You could also solder everything he mentions at a lower heat than the high silver content solder needs with indium solder and its special flux. The drawback is cost, indium solder runs about $1000/pound depending on the spot price for platinum group metals and the flux is about $200 per bottle. Of course it is only available from a few places and only sold in one pound rolls. TIX solder would probably work as well, still expensive compared to Sn/Pb solders and low heat silver bearing types but it should work for what he wants. If it was me, I'd abrade each surface of the parts on 600 grit paper while wearing nitrile gloves and then place them in isopropyl alcohol. One piece at a time I'd "tin" the parts with TIX and clean the flux. when each piece was tinned I'd apply a thin wipe of fresh flux to all sides and bind the bundle very tightly with iron wire. When I'm sure everything's right, then I'd place the bundle in a chunk of clean steel U channel just bigger than the part and at least 1/4" thick, then evenly heat the U channel with an acetylene torch until the solder on the work piece flowed. Nice even heating without direct flame contact. Just get it out of the U channel and ontop a firebrick or some similar heat resistant material before the solder sticks to the U channel. Clean the flux, remove the iron wire and you're good to go. BTW-what he's wanting to do is very similar to a japanese jewelry technique called mokume gama. ------- Date: Tue, 02 Sep 2003 21:19:32 -0000 From: "Ron Smith" Subject: Re: Multiple layers of different metals, how to bond correctly? TIX is a brand of solder for dissimilar metals and hard to solder alloys. Indium, iridium, rhodium, palladium and platimun are all platinum group metals...... ------- Date: Tue, 2 Sep 2003 23:10:42 EDT From: catboat15x~xxaol.com Subject: Re: Multiple layers of different metals, how to bond correctly? > solder on the stainless or aluminum I was speaking in general terms. I use ordinary lead/tin solder on aluminum. The trick I learned someplace was to load up a Dremil grinder wheel with solder (Just run the wheel against some wire solder till it becomes loaded). Then use that wheel to grind on the aluminum where you want to solder. Then you can go ahead and solder brass or copper to aluminum. The reason it works is that aluminum forms an oxide almost instantly when exposed to air and most flux will not cut the oxide. But a grinding disk or wheel cuts the oxide and the heat melts the solder so you have a tinned place to solder to. John LBSC Virginia LBSC Tich ------- Date: Sat, 15 Nov 2003 11:18:58 -0500 From: "Carl Corbeau" Subject: Re: hard soldering (silver solder) brass and steel Original Message ---From: silverwaterh To: sherlinex~xxyahoogroups.com Sent: Saturday, November 15, 2003 4:32 AM Subject: [sherline] hard soldering (silver solder) brass and steel >>> I recently purchased a butane microflame locally (in Israel), for simple hard soldering of brass and steel (dissimilar metals). I'm making simple pneumatic engines for educational purposes with my Sherline lathe and mill. The butane tourch advertises up to 1300 C (2372 F) heat. I also bought two silversolder rods, one 20% and one 30%. The rods are 1.5 mm dia (0.06 inch dia) and has the flux caked on. I have had very little success with the hard soldering. I am trying to hard solder a 4 mm dia (.157 inch) soft steel rod into a 4 mm dia hole drilled out of brass 6 mm deep. (For a picture of the part, see: the crank shaft for a "simease engine" http://www.good- fellow.net/twins.html by Dave Goodfellow). The fit is a tad bit larger than a sliding fit...I would estimate 0.05 mm (0.002 inch). Here are the problems: 1. I see that the silver rod does not melt, even after heating the brass and steel rod (as much as 3-5 minutes). 2. On a similair test part, the joint did seem to be held strongly in place (it passed my moderate destructive vise grip twist test), despite that no visible silver solder went into the joint. Did some microscopic capillary action occur?. I did not heat the silversolder... I heated the joint. In another separate experiment I did heat the silver solder and it did bead into a sphere (ball)... after about 30 seconds... (then I cut off that piece since I probably burned off some of the different metals changing the composition and/or melting point). What I think the solution is... 1. use a smaller diameter silver solder rod with a much lower melting temperature. 2. use a separate flux. Where could I purchase this? Am I in the right direction? Any hints for hard soldering the above project? Thanks in advance for your time and effort in reading and answering. Howard Silverwater silverwaterx~xxbezeqint.net <<< Howard, Yes you can buy paste flux separately. What I would try, is........ make a silver solder paste ... mix finely divided solder with the flux and coat your joints. You may be able to buy prepared paste in your area...if not ,you could try filing the solder with a fine file(the finer the better). Another problem is burning the flux........so keep the flame envelope on the joint continually, this will help exclude the atmosphere. One of the nice things about the solder paste is it is protected when down in the joint. Once you have the joint tinned this way, you can add a little more solder with the wire if needed. Also make sure your joints are not too tight. Carl ------- Date: Sat, 21 Feb 1970 16:08:06 -0800 From: "Wm. Dubin" Subject: Re: hard soldering (silver solder) brass and steel Howard, The microflame torches simply do not have the power to do what you want, you need a wider, and hotter flame. You can use them, if you change to soft solder. You also need to set-up a cave like enclosure built of fire bricks to contain your heat. Another thing to try, is put the parts into your oven in a light baking pan, turn the heat to full, and give it a half hour, transfer to your torch area, and apply the torch to your pre-warmed parts. I would recommend whats called "The Little Torch". Check on line, or, if you have a jewelry supply Co. near you, they would know what this is. You can use either butane & oxygen, or oxy-actelyn with this torch. The variety of tips will allow anything from the smallest flame, up to a huge burner I used to solder a 6" dia. tube, 14" long to 2 end caps, each 1/4" thick. This was done with soft solder, and afterwards I dropped it on the floor from app. 5' to see how well it would hold... it held perfectly. If you can't locate this on line, letr me know and I can supply you with some URL's for it. Hope this helps. Wm. ------- Date: Sun, 16 Nov 2003 02:42:46 -0000 From: "mileagemayvary" Subject: Re: hard soldering (silver solder) brass and steel You must use a flux paste designed for silver soldering. Welding suppliers or plumbers supplies carry it. If you cannot get it then you can make similar by mixing powdered borax in water to a creamy paste. Use 1mm 45% silver rod without any flux in or on it. Those coated rods are only used with OA brazing setups. Apply the flux to the joint. Areas where you do not want the solder to go, wipe off the flux. Solder will only flow to areas where there is flux which prevents oxidation. Heat the joint until the white paste goes clear (looks like a layer of water). Give it about 5 seconds more heat. Apply the rod to the joint with just a little of the flame hitting the rod. You will see a lovely shiny silver flow. Apply enough heat so solder wicks into the joint. DO NOT OVERHEAT. This causes the flux to burn to carbon and produces a lousy join. A Mapp gas torch (2500C)is best. The torch you have with that small area may be just doable. Generally 45% silver solder goes liquid state at about 700C IIRC. ------- Date: Sat, 15 Nov 2003 23:44:41 EST From: catboat15x~xxaol.com Subject: Re: hard soldering (silver solder) brass and steel With your small torch, you may reach melting point of the solder but the part being soldered takes the heat away before the joint is soldered. It is not just temperature, but heat supplied that does the job. Look at it this way, a burning match is wood and a fire in the fireplace is wood. The match may burn your finger, but the fireplace warms all of you. I would get a larger torch, one of those where the tank is about 3 or 4 inches diameter and the head is maybe 3/4 inch. Next mate your parts and hold them together in some way. Heat the parts, not the solder (most important) Heat the parts with them laying on a brick or some surface that can take the heat and not conduct it away from your metal. Then when the metal shows a good red heat touch the solder stick to the joint. If your rod is flexible try forming a ring to fit around the rod part, then heat from the side away from the solder and when the proper heat is reached you will see the solder flash into a thin ring around where you are heating. Remember solder follows the heat. Your statement that the solder turns to balls indicate not enough heat and/or the parts are not clean enough for the solder to flow. If some of Kozo Heroka's books on locomotive building are avalable where you are (copies of Live Steam magazine) he has a lot of good info about silver soldering various parts together. This includes how to prepare the work, applying the solder (he often uses short bits of wire solder) setting the clearance for the joint (about .003 inches usually) and where to heat with the torch. When a substance changes phase from solid to liquid it absorbs a certain amount of heat just as you can't melt an ice cube with our afore mentioned match, you need a certain amount of BTUs or Calories at the melting temperature to do the job. Good luck. John ------- Date: Sun, 16 Nov 2003 01:31:29 -0700 From: "Larry Teague" Subject: Re: Digest Number 1348 Howard, I believe you have several issues you need to address. Your microtorch produces a high temperature but not enough heat to get the joint to brazing temperature. Flux serves several important purposes. A. It protects the joint materials during heating B. It cleans oxides from the materials being brazed C. Promotes the flow of the brazing material D. Serves as a temperature indicator. A rod with a flux coating can't fulfil A and probably does a poor job at B and C. It may do D pretty well, but you would need to heat the rod. You can buy two basic types of flux. One is referred to as LTF or low temperature flux. And surprise, the other is HTF or high temperature flux. LTF generally melt at about 550 C and HTF at around 850 C. Assuming you are using Cadmium free rod, your 20% rod will need an HTF. Your 30% rod might work with an LTF. You can probably buy fluxes at either a welding supply dealer or at a jewelry supplier. Heat the joint until the flux melts. Apply a small amount of silver to the joint. The silver will flash into the joint if the joint is hot enough and was fluxed properly. When I heat a joint I apply heat primarily to the heaviest part. I'm not a professional welder (brazier?) but this works for me. Your mileage may vary. Larry Teague ------- Date: Mon, 17 Nov 2003 01:48:41 EST From: catboat15x~xxaol.com Subject: Re: Re: hard soldering (silver solder) brass and steel > I would take one or the other piece and re-do it so you have an > interference fit. Not for silver solder. You need about .003 clearance so the solder will be drawn into the joint by capillary action. ------- Date: Sat, 10 Jan 2004 19:34:18 -0500 From: "Jim Kirk" To: ffmlx~xxairage.com Subject: soldering piano wire trying to solder piano wire to piano wire... torch doesn't work, solder beads and dribbles.... I want to make solder flow on the joining wires and bond. what solder will work? do I need paste? TIA Jim Kirk ------- Date: Sat, 10 Jan 2004 19:54:50 -0500 From: wombat To: ffmlx~xxairage.com Subject: soldering Probably need acid core, Jim, rosin flux isn't very aggressive. Also, you might try wrapping the joint with a few turns of bare copper wire, you can get that from something like speaker wire. Also, I think a good soldering iron (copper) would be better than the torch unless you can use a reducing (NOT oxidizing) flame. wombat ------- Date: Sun, 11 Jan 2004 12:02:30 +1100 From: "Danny Maslowicz" To: Subject: Re: [FFML] soldering piano wire >trying to solder piano wire to piano wire... torch doesn't work, solder beads and dribbles.... I want to make solder flow on the joining wires and bond. what solder will work? do I need paste? < Hi Jim et al. To solder piano wire the following works for me. 1. Clean the wire throughly and scuff with some dry, wet & dry, paper at the join area. 2. Bind the join with soft copper wire (fusewire in the old days, still available here). Solder alone ain't got much strength. Jig the job such that it can't move around. 3. Use a hard (plumbers/tinman's solder), save the resin cored stuff for the electrical work it's designed for. Check trademan's suppliers. 4. Obtain some active flux, if you found the solder they should should stock the appropriate stuff. "Baker's Fluid" is common here in Oz. 5. Use a big enough iron/torch for the job. You want the heat of the job to melt the solder, not the flame itself. I prefer my ancient 80W electric iron with a 3/8" bit as it can deliver heat to the job quickly. Some of the little handheld propane irons with a copper bit work ok. 5. Brush some flux onto the joint, tin the iron with solder, dip quickly into the flux and apply bit to the job alongwith the solder stick. Hopefully the solder will flow/wick into the join. This is a good sign. The result you should be able to see all the bindings, any more solder than this is cargo. 6. Inspect the joint, if all is well clean it with water and a toothbrush and coat with a smear of oil. The flux is corrosive and will rust the wire quickly if excess is not neautralised. 7. Go fly the model. Cu later * Danny M * ------- Date: Sun, 11 Jan 2004 08:17:46 -0000 From: "Graham Knight" To: Subject: Re: [FFML] soldering piano wire The high temperature needed to silver solder softens the piano wire, it will bend easily at the joint. Soft solder is quite adequate if the joint is bound with copper wire then soldered, but the piano wire must be cleaned first with sandpaper or wire wool, and a seperate flux should be used. The joint should be scrubbed with hot soapy water afterwards to neutralise any remaining flux which will corrode the wire. Graham in Shepperton, England S.A.M. Zero, 35 & 1066 Raynes Park MAC Secretary http://website.lineone.net/~raynes.pk.mac/ ------- Date: Sun, 11 Jan 2004 04:03:40 -0500 From: DaMo123x~xxworldnet.att.net To: ffmlx~xxairage.com Subject: Re: [FFML] soldering piano wire Graham Knight wrote: > The high temperature needed to silver solder softens the piano wire, Graham, there's a relatively high strength silver bearing solder available in the USA which has 3% to 5% silver, the remainder being tin. It melts at 430 to 470 degrees F depending on the amount of silver present. I think this is the "silver solder" which is being referenced by Marty. I believe you are thinking of silver brazing, which needs a temperature of 1100 degrees or higher. Easyflo used to be one of the UK brand names of the "solder". The dull red heat needed for silver brazing will certainly soften the wire. I don't believe that the heat required to melt the tin/silver alloy will soften the wire appreciably more than that needed for conventional tin lead solder. Tin/silver is stronger than tin/lead, and the difference in cost here is small for the quantities used in model airplanes. Pete Money Paraippany, NJ ------- Date: Sun, 11 Jan 2004 09:44:02 -0000 From: "Graham Knight" To: Subject: Re: [FFML] soldering piano wire You're right Pete, different terms for different countries! I think most people here here call it silver soldering rather than silver brazing, brazing being a similar process but using brass of course. I've used the tin/silver soft solder myself but found it brittle without the addition of copper wire binding, but if you bind it then ordinary tin/lead soft solder is quite adequate and easier to use! I thought I was being clever a few years ago using silver solder/braze to make undercarriages, until on the first landing the axles bent backwards! I also tried binding the joints with a thin sheet copper or brass strip, or a little triangular clip, but found it was nowhere near as strong as a wire bound joint; it was also harder to do a neat job. I have reels of tinned copper wire from RS Components for binding, it solders really easily and a reel will last a lifetime for our purposes. Graham in Shepperton, England ------- Date: Sun, 11 Jan 2004 17:38:01 -0000 From: "Graham Knight" To: Subject: Re: [FFML] soldering piano wire "Hank Sperzel" wrote: Yes that would work just as well. I usually paint the wire, on larger models at least, and washing with detergent ensures the wire is free of grease and any other contaminates. Graham in Shepperton, England ------- Date: Wed, 19 Oct 2005 19:46:26 -0000 From: "jerigonzacl" Subject: Silver solder [LittleEngines] Hi All: I'm having some problems soldering a boiler. Anybody know a way to seal those pinholes besides beginning all the silver solder again? Andrés ------- Date: Wed, 19 Oct 2005 23:14:45 +0200 From: "Frank Hasieber" Subject: RE: Silver solder When you say "pinholes" do you mean porosity in the solder? There are many grades of silver solder with varying percentages of silver in the alloy. Johnson Matthey UK make a number of grades; in my opinion the best is their "easy silver solder" as opposed to "easy flo", this has a higher silver content and consequently less gassing (vaporization of the alloys). Overheating can also be the cause of pinholes; ideally use no more heat than is required. It is important also to understand the difference of heat and temperature, you can have a very hot flame that is small and does not put out enough heat to bring the boiler up to soldering temp. To make a comparison, water flowing through a small bore pipe may be traveling fast (the temp) but a small volume is flowing (the heat). Through a large bore pipe it would be slower (lower temp) but a much higher volume (the heat). It is also good practice to use a hearth even with a charcoal fire to preheat the boiler, so that you can easily bring the part to be soldered up to soldering temp. Hope this helps. Frank ------- Date: Wed, 19 Oct 2005 18:29:02 -0500 (CDT) From: Andrés Gonzalez Subject: RE: Silver solder Frank: Thanks for your answer. You are right, the real problem is porosity. Here the only silver solder I can find is "hard silver solder" or "soft silver solder". I'm using two torches in a fire brick housing. Both torches have a medium flame, so, I have enough heat; then the problem is I´m probably overheating the solder. Now the question is: How can I repair that porosity. Andrés ------- Date: Thu, 20 Oct 2005 06:01:08 -0400 From: "Robert Breton" Subject: Re: Silver solder Andres: What I have done in the past is use a lower melting temperature silver solder to re-solder those little pin holes and missed spots; that way there is less danger of undoing all your work that has been done. http://www.cupalloys.com/content.php has some good information on different types of silver solders. Bob ------- Date: Thu, 20 Oct 2005 08:36:14 -0500 (EST) From: "Gary M. Reese" Subject: RE: Silver solder What kind of flux are you using with the silver solder? I always liked that yellow liquid stuff. I didn't heat the whole piece cause it was so hard to control where the solder ran to. It never went where I wanted it to go. GaryR ------- Date: Fri, 21 Oct 2005 00:04:57 +0200 From: "Frank Hasieber" Subject: RE: Silver solder Gary, I am a jeweller by trade. The #1 rule is that the solder will flow to the hottest part (unlike oil which goes away from the heat, which is one reason why a bearing seizes when it runs hot). We frequently use a solder pick, a piece of nichrome wire in a suitable holder and filed to a point; this can be used to encourage the solder to go where you want it. Experiment to get the feel, and observe the results you are getting; even a piece of piano wire will work, but builds up an oxide layer very quickly. I am not sure what you mean by "the yellow stuff" but flux from any reputable supplier should be OK. You heat the whole piece up to a temp of a hundred degrees or so below the solder mp; then using the soldering torch concentrate the heat where you want the solder to go. Again this is something you get with practice; after doing this for 46 yrs I don't even think about what I am doing, like riding a bike or driving a car. Frank ------- Date: Fri, 21 Oct 2005 09:09:10 -0500 (EST) From: "Gary M. Reese" Subject: RE: Silver solder Frank: The oxide formation is one of the reasons I didn't use a pick. I think when you're working on a ring 3/4" dia., the whole thing is heated. In the post I was commenting on, it read like he was heating a piece much larger, up to temp of solder flow. Then again, I only worked sterling silver and brass for 20 years so I may be wrong. The yellow stuff is a fluorine based solder. Don't remember the brand name. The fumes can be nasty, but I like it better. GaryR ------- Date: Fri, 21 Oct 2005 16:57:09 -0000 From: "buffaloman97405" Subject: Re: Silver solder Andres: Pinholes indicate, to me, that you are soldering a closed container (or surfaces not clean enough). You should probably have all your boiler fittings holes drilled before you attempt to solder on the end plates. This will allow gases to escape. If the container is completely sealed gas pressure will build up in the container and blow the solder out to form a pin hole. Soldering something like a boiler end on is not easy as Frank said. Solder flows to the heat. Most people use some kind of torch arrangement to solder with, and that puts the flame at one hot spot at a time. As you move the torch the previously heated side cools. It is better that you heat it more uniformly. Build a wall up around your boiler with fire brick to hold the heat in. In refrigeration I used a stethoscope type torch which heated both sides of a tube at a time. The torch was just air acetyline type and it worked great on tube up to two inches in diameter. For miniature glass blowing I made a similar torch but with adjustable length between the two tips so I could work on larger pieces. I don't see why something similar should not work on making a boiler. Bill -------- Date: Fri, 21 Oct 2005 21:24:14 -0000 From: "jerigonzacl" Subject: Silver solder finished Hi: Thanks to all of you for your advice. All of them were useful to get finished with the soldering. There is still a pinhole and I will seal it tomorrow. Maybe I will try with some ginger just to have a good smelling steam :) I think the main problem was that I was overheating the boiler. I started using a commercial flux, then tried with borax and finished using liquid flux. The boiler has all the fitting holes already open so it was not gases escaping. I cleaned and removed all the excess of solder and get back to use only one torch, heated the boiler body instead of the caps and waited until the copper reached the necessary temperature, so, it was also a patience problem. I'm building a little vertical boiler to learn silver soldering. I read in some place that if you rub some soft pencil over some areas you will restrict the alloy flow. Flux will not remove graphite nor will an alloy bond to it; I haven't tried. I almost finished my steam ship and I think my next project will be a little loco like JANET from PPS steam engines. Someone knows where I can found plans for this? If someone wants to see my ship steaming go here: ( 1.9 MB ) http://us.f1.yahoofs.com/bc/6f7b1678/bc/Mis+documentos/Lechalasmovie4 .MPG?CC_8UYDBMD5V4lEO Thanks again, Andrés ------- Date: Fri, 21 Oct 2005 23:38:02 +0200 From: "Frank Hasieber" Subject: RE: Silver solder finished Another very good thing is to use TIPEX correction fluid, this is very good for restricting the flow of solder, I use it on brooch pins and hinges to prevent them being soldered up and useless, simply paint on to those areas you want to keep the solder away from. Frank ------- Date: Sat, 22 Oct 2005 16:11:42 +0100 (BST) From: Kevin Steele Subject: Re: Silver Solder / brazil The web address for Brazil, which someone mentioned recently is http://www.geocities.com/minidampf/brazil_uk/contents.html Well worth a read, even if you don't plan to build that loco. Someone also mentioned recently in a post the use of tip-ex for stopping silver solder flowing where you don't want it. This does work, but be aware that heating tip-ex gives off highly toxic fumes -- so plenty of ventilation would be a good idea (but if you're silver soldering you should have plenty of ventilation anyway). Regards Kevin ------- Date: Tue, 11 Apr 2006 01:53:41 -0000 From: "patmack_1" Subject: Learning silver soldering [LittleEngines] Have pretty well learned the trick of proper heat for proper flow. Have lots of trouble removing the flux remains -- could use advice from experts !!! ------- Date: Mon, 10 Apr 2006 19:20:08 -0700 From: "Tom Faragher" Subject: Re: Learning silver soldering The glassy, hard flux remains will dissolve in hot water. ------- Date: Mon, 10 Apr 2006 23:08:15 -0400 From: Subject: Re: Learning silver soldering I don't know about experts, but I use acetone most of the time. Course it depends on what flux you are using. GaryR ------- Date: Tue, 11 Apr 2006 04:24:36 -0000 From: "patmack_1" Subject: Flux removal Thanks for the tips. I had modest success with hot water before but I seem to develop a charred crusty stuff that sticks pretty tight. If acetone works, MEK might work also. The steel was cleaned and polished to a mirror finish so not sure what is causing the crusty residue! ------- Date: Tue, 11 Apr 2006 08:17:16 -0400 From: Subject: Re: Flux removal Yes, the MEK should work about the same as acetone. The charred crusty stuff sounds like the result of a reaction between the steel and the flux. What is it you are using for flux? GaryR ------- Date: Tue, 11 Apr 2006 13:01:02 -0700 From: "Tom Faragher" Subject: Re: Flux removal It sounds like you are burning the flux. You should try to avoid getting the flame directly on the flux if you can. I use Handy & Harman "Handy Flux" for all silver soldering and never have had a problem getting the residue off. It will get black and crusty if it gets burned by the flame but still comes off with hot water with a little more time. ------- Date: Wed, 12 Apr 2006 03:09:13 -0000 From: "patmack_1" Subject: Re: Flux removal Not sure the brand of Flux-I'm away from the shop. Came with the Solder at the Store. No question but that I put the flame of the torch directly on the joint where I put the flux--didn't know any better--thought that is where I wanted the heat! The flux quickly melted and seemed to disappear. What is the trick to getting it hot enough without putting the flame on the fluxed joint? I've been using a regular gas welding torch. ------- Date: Wed, 12 Apr 2006 08:30:43 -0700 From: "Alan Marconett" Subject: RE: Re: Flux removal Hi Patmack, I assume we're talking about hi-temp SILVER BRAZING (1100+ degree F stuff)? If possible, heat the BACKSIDE of the joint; it will draw the silver solder into the joint. Also saves the flux, as mentioned. Add heat until the flux appears to boil down, then add the silver solder. Do you "flux up" the joint before you apply heat? BETTER, if possible, make a pre-form of the silver solder. Flux up, then snip an appropriately sized piece of silver solder, and place it in the joint. Paint on a little additional flux to hold in place. Heat as mentioned. An acid pickle is often used on copper (and brass) to remove flux afterwards. I use quite dilute sulfuric acid (CAUTIONS HERE!), with hydrogen peroxide. Check the internet for a recipe. Alan KM6VV ------- Date: Wed, 12 Apr 2006 09:48:51 -0700 From: "Tom Faragher" Subject: Re: Re: Flux removal If the gas welding torch you are using is oxy/acetylene then you will have to be very careful about getting the flame on the flux. Try heating alternate sides of the joint, or the back of the joint if possible, and quickly move the flame across the flux area. Oxy/acetylene is extremely hot for silver soldering. Oxy/propane works much better and is much more forgiving about burning the flux. If you have a propane tank handy for your barbecue or other gas appliance, connect your acetylene regulator to the propane tank and give it a try. ------- Date: Thu, 13 Apr 2006 11:40:58 +0200 From: "Frank Hasieber" Subject: RE: Re: Flux removal I now use oxy/propane instead of oxy/acetylene, acetylene is very expensive here. I checked with my gas supplier and they said I do not need to use a regulator with propane, just take direct from the tank; I have been using it like this for several years now with no problems. Frank. ------- Date: Thu, 13 Apr 2006 14:35:49 -0000 From: "patmack_1" Subject: Flux Removal Thanks everyone for the many comments and tips. Clearly, I need a lot more practice, and perhaps convert to Propane. It did appear I was getting too much heat in some places and not enough in others with the torch. Next time it might help if I use the smaller 'aircraft' type torch with a smaller flame. Will get back to it when back home in about ten days. ------- Date: Thu, 13 Apr 2006 08:06:05 -0700 From: "Tom Faragher" Subject: Re: Re: Flux removal Frank: If someone already has a gas welding set with an acetylene regulator it is simpler to use the regulator because it fits right into the propane valve. Otherwise you need to rig something to get the gas to the torch. Also for the small torches it is easier to adjust the flame if you start out with a regulated gas pressure of less than 10 psi. The fixed pressure regulators used for barbecues would work fine if the fittings could be adapted to the torch hose. Tom Faragher ------- Date: Thu, 13 Apr 2006 18:44:55 +0200 From: "Frank Hasieber" Subject: RE: Re: Flux removal Maybe for you, our regulators do not fit our propane bottles; I am using a Micro-Flame torch for jewellery work, particularly soldering platinum at temps of 1100 to 1500 deg C mp. Frank. ------- Date: Thu, 13 Apr 2006 19:35:41 +0200 From: "Frank Hasieber" Subject: RE: Flux Removal I would recommend a larger torch/tip. You need to get more heat into the job as opposed to getting it to a higher temperature; there is a difference to the two. You can have a very high temperature flame that is very small, and cannot get the job up to the required temperature, whereas a larger and cooler flame will do the job without burning the flux excessively. Sometimes, like for soldering copper boilers (which rapidly conduct the heat away) for steam locos one will use 2 torches, one with a large bushy flame or even a charcoal hearth, to bring the entire piece close to the required temp, then a smaller torch to bring the local area to be soldered up to soldering temperature. Remember that the solder flows to the higher temperature area, which is a reason for applying the heat at the back of the joint to draw the solder through. Ideally keep the temperature as low as possible to avoid burning out some of the alloys in the silver solder and so causing an inferior joint. Frank ------- Removing Black Scale [LittleEngines] Posted by: "Ron Gerlach" r7734gx~xxhotmail.com Date: Wed Dec 13, 2006 2:42 pm ((PST)) I'm looking for some advice from all the wise sages out there on removing the black scale from steel parts after brazing. I have removed the glass like flux residue in boiling water but still have to contend with the tough black scale remaining after brazing or silver brazing. A wire wheel usually does little more than turn it into polished black scale. Belt sanding works on accessible parts but there are places sometimes that you just cannot easily sand. Ron ------- Re: Removing Black Scale Posted by: "Tom Faragher" tfaraghex~xxadelphia.net Date: Wed Dec 13, 2006 4:09 pm ((PST)) Ron: What you are dealing with is iron oxide. If it is not too heavy you can remove it with a pickling solution. You can avoid forming the iron oxide if you use a neutral or carburizing flame on your brazing torch. An oxidizing flame (sharp, well defined blue point) will oxidize the surface of the steel when it is hot. Tom ------- Re: Removing Black Scale Posted by: "Brian Lindsay" brian458666x~xxgenext.net Date: Wed Dec 13, 2006 6:33 pm ((PST)) There are a number of coatings available to prevent the scale forming in the first place, and since anhydrous borax makes a great forging flux you may be able to use some regular borax (not boraxo and not soap) to take care of things. If you sprinkle some on a HOT part the water in the (hydrated) crystals will boil off and be ready to go. You said you use boiling water to remove the glassy flux from your parts; does that mean you haven't tried dropping the just-brazed part into water before it has had a chance to cool? Even a spray bottle of some sort should work, like a squeeze bottle for soap or condiments....I once tried using a pot of boiling vinegar to remove scale. Once. Only. Evidently the steel is not nearly as resistant to etching as the oxide layer. Brian ------- Re: Removing Black Scale Posted by: "Ron Gerlach" r7734gx~xxhotmail.com Date: Thu Dec 14, 2006 9:53 am ((PST)) Tom/Brian: Thanks for the suggestions. I used a pickling solution consisting of diluted Muriatic acid and the parts cleaned up nicely. I followed the pickling with a light kitchen cleanser scrub and the parts look great. Muriatic acid is another name for hydrochloric acid and is commonly available for pool use. Ron ------- Re: Progress on the control arm for the Springfield shaper [Metal_Shapers] Posted by: "Jim B." btdtrfandmwx~xxcomcast.net eeengineer1 Date: Sat Jun 2, 2007 7:44 am ((PDT)) Eric wrote: > I need to silver braze a piece of a shifter fork. I've got the > supplies but have never done it. Do you have any advice on technique? Silver brazing is rather easy. 1) Clean everything. 2) Spread the flux liberally. 3) If you want to prevent solder from flowing anywhere, paint it with Milk of Magnesia 4) Heat both sides of both parts uniformly. Use a slightly reducing flame. (One with a bit of a tail). The flux will start of bubble and then turn clear and then runny. At this point the parts are just about at the correct temperature. 5) Start touching the braze rod to the area to be welded. A bit of direct heat from the torch on the rod is helpful but don't over do it or you will get a big blob that just lays there. If the parts are CI [cast iron], they will show just a bit of color. The braze flows by capillary action to the hottest parts so uniform heating is paramount. Jim B. p.s. One more point on silver brazing CI or brazing CI in general. If it's cast iron you must cool it slowly. Have a metal container of vermiculite (best) or sand ready. After the braze is finished, change over to a very reducing flame, very long tail, and take about 5 minutes to cool the part to the point where the braze is solid. Then put it in the container and cover it and let it cool for several hours. Vermiculite is expanded mica; it's used as a pour-in insulation and also used to start potted plants. It should be available at a good lumber yard (HD is unlikely) or a nursery. ------- Re: Progress on the control arm for the Springfield shaper Posted by: "David G. LeVine" dlevinex~xxspeakeasy.net Date: Sat Jun 2, 2007 9:28 pm ((PDT)) You can also use Pearlite (to 2,000º anyway) which is available at Wal*Mart David G. LeVine Nashua, NH 03060 ------- NOTE TO FILE: Some sources of vermiculite may contain significant amounts of asbestos. See: http://www.epa.gov/asbestos/ In some jurisdictions, asbestos may be present up to a low percentage and the product package can still legally carry a label of "asbestos-free". Pearlite or sand is my choice. ------- silver soldering [taigtools] Posted by: "leeharrysouth" EDAVIS93x~xxComcast.Net Date: Mon Aug 13, 2007 6:26 pm ((PDT)) Hi all: Can any one recommend an on line source of information on silver soldering. I need some basic instruction on tools, type of solder, solder paste and/or flux to use for working with brass. A long time ago, I did plenty of soldering on copper pipe for air conditioning and plumbing systems. Would the procedure for brass be about the same? Thanks, Johnny ------- Re: silver soldering Posted by: "kuhncw" kuhncwx~xxyahoo.com Date: Mon Aug 13, 2007 8:03 pm ((PDT)) Hello Johnny: A quick Google brought up a lot of hits on silver soldering. This one may be helpful. http://www.pollymodelengineering.co.uk/global/technical-notes/basic- silver-soldering.asp You might also checkout Harris and their Safety-Silv alloys. http://www.harrisproductsgroup.com/consumables/alloys.asp?id=30 In my opinion, the best info on silver soldering relative to model building is by Kozo Hiraoka and published by Village Press. These are books about building model steam locomotives from scratch. Kozo includes a short chapter on silver soldering in the books. His fabrication techniques can apply to any sort of item, not just locos. Regards, Chuck Kuhn ------- Re: silver soldering Posted by: "Chris Manning" kenricx~xxlozengy.net Date: Mon Aug 13, 2007 10:22 pm ((PDT)) Hi Johnny. What you are asking about is called hard soldering (soft soldering is the kind done for plumbing.) It is used extensively in jewellery fabrication. I do a fair bit of experimentation with brass for my jewellery projects before executing them in silver or gold. Here is what you'll need: Torch- Depending on the mass of the object you are soldering, you can use anything from a cheap propane torch for plumbing, up to an expensive jeweller's torch. For most people who aren't doing a lot of this, I recommend getting one of the Bernzomatic torches that can handle both a gas, and oxygen tank. http://www.bernzomatic.com/bernzomatic/consumer/jhtml/detail.jht ml?prodId=BernzoProd100044 You should be able to find something like that at Home Depot for $50-60. If you start doing a lot of this type of thing, then you can get into an expensive torch with larger tanks. BTW, you can use propane with this torch as well. It doesn't get quite as hot as MAPP, but it's cheaper and the extra heat won't make much difference for you. Flux- You need to use a different type of flux than what is used for plumbing work. This is a high temp flux that will help protect the material from oxidizing during soldering, as well as help the solder flow. I would recommend Handy Flux. You can order it from Rio Grande (PN-504083 8-oz Jar $7.35, 504086 1lb Jar $10.75. The 1lb Jar is worth it since you can go through a fair bit.) Buy some cheap acid swab brushes to apply the flux with. Oh and don't leave the jar open for weeks at a time. It'll dry up and it takes a while to reconstitute. Solder- For brass you will want to use silver solder (you can also get gold solder, but obviously it's a *little* more expensive.) Generally there are three types, hard, medium and easy (there are some other specialty solders but they really aren't useful to you.) The quality refers to the temperature at which it flows (the hard flows at 1450F, medium at 1360F and easy at 1325F.) It is easiest to purchase as wire. I believe Rio Grande has a minimum purchase of 1oz on silver orders so you're looking at roughly $18 for each type of solder, but that'll get you 21' of it (they may sell 1/2oz spools as well, be sure to ask.) If you are only making one solder joint on each piece, you should buy just the hard. If you need to make two or more, then you need the medium and possibly the easy as well (I'll explain further below.) PN- Hard 101704, Medium 101703, Easy 101100. Pickle- It is worthwhile purchasing pickle as well. Pickle is used for removing leftover flux, and firescale from the piece after soldering is finished. It saves you having to clean a lot of the crap off manually. You buy it as a powder, and mix it with water. It works best if heated (I use a crock pot I purchased specifically for this.) Again, Rio Grande PN 5010233 $10. I generally leave pieces in the pickle for at least 10-15mins. Don't leave the piece in over night, and don't stick ferrous metals in it (everything will become copper plated.) To get a hold of Rio Grande, call them at 800-545-6566. You'll need to setup an account, but you don't need a business. You can pay by CC over the phone. They are good people to deal with, and I have had very few problems over the years. I would recommend ordering their Tools and Equipment catalogue while you're on the phone. All sorts of handy stuff in there (they won't charge you for it if you order it with other things.) Now for the how to. First of all, hard soldering differs from soft soldering in a couple of significant ways. First is the heat. You need to get the whole piece up to the flow temperature of the solder before anything useful will happen. It is important to get the whole piece up to temperature. Hard solder flows towards the heat. If one side of the joint is hotter than the other, you won't get much solder in the joint which is where you want it. Be sure to move the torch around while you are heating the piece so that everything heats up at the same time. Don't just hold it in one place and hope for the best. When you use the Handy Flux, you'll see it turn clear and glassy at one point. Once it's done that you know you've reached roughly 1200F. Because the solder follows the heat, you can use the torch to paint the solder around where you want it to some degree. Second, you need to make sure that the pieces all fit very well together. A couple of thou is the most you want as a gap. This solder *will not* fill a gap like soft solder will. Because of the small gap, you also don't need very much. Less is more with hard solder. Two pieces of wire a 1/16th long each will fill a straight joint an inch long with little trouble. Third, make sure everything is clean. The flux will help with keeping things clean, but it helps to clean everything up before soldering. I tend to flux the entire piece. It will help keep the oxidation down (any part of the metal not protected by the flux will oxidize very quickly at temperature.) If you have more than one joint in the piece, you'll have to either solder them at the same time, or use solders with different flow temperatures. Always solder using the hard first, then medium, then easy. If you try to go in the other direction, all your earlier joints will fall apart as the solder melts. As I mentioned above, once the flux gets to 1200F, it'll stop bubbling (that's the water boiling off,) and go glassy. This is generally when I apply the solder. Take a couple of small pieces, and place them along the joint. They'll move around a little so it's often helpful to have something to poke them back into place (remember the temps involved when picking a poker...) When you're getting close to the magic temperature, the solder will melt into a little puddle. You aren't quite at flow temperature yet. Keep going with the heat, and once you get to flow temperature, you'll see the solder get sucked into the joint. I make it sound easy, and it is once you've got it down. In the mean time it'll be really frustrating and slow (while helping a friend with soldering pins on some brooches, I was able to solder a dozen in 30mins, while it took him 2.5hrs to do 4. Nothing beats experience when it comes to soldering.) Take your time with learning it. Experiment on different pieces that are similar to what you want to work with. Try to solder pieces that are similar in mass (they'll heat up at the same rate.) If you have any questions about materials or techniques, or if something doesn't make sense, either email the list, or me directly and I'll see what I can do to help you out. Chris ------- Re: silver soldering Posted by: "benedict-listx~xxhawaii.rr.com" Date: Tue Aug 14, 2007 4:40 am ((PDT)) Some of the best sources of info I've found have been jeweler's references. Tim McCreight did a nice video that included some silver soldering. Kozo Hiraoka had a good bit on silver soldering in his book, "Building the Shay". I don't know of any online sources off-hand, though. Get some brass, grab a torch, get some solder and flux that matches it, and play. That's more or less how I learned. If you've done plumbing, your experience should stand you in good stead. Same principles apply: A good clean joint, proper choice of solder and flux, appropriate clearance (solder won't flow into a press-fit joint), and "solder flows toward heat" covers a lot of it. It's still worth checking up on other references, though. I could solder, but I couldn't solder neatly until I did some reading and some watching. I'm still a work in progress. (And oh in how many ways THAT's true...) Tom ------- Re: silver soldering Posted by: "Tony Jeffree" tonyx~xxjeffree.co.uk tonyjeffree Date: Tue Aug 14, 2007 6:36 am ((PDT)) you wrote: >..."solder flows toward heat" or to put it another way, heat the joint, not the solder. Regards, Tony ------- Re: Silver soldering Posted by: "leeharrysouth" EDAVIS93x~xxComcast.Net Date: Tue Aug 14, 2007 5:29 pm ((PDT)) Thanks to all for your help with silver soldering. Johnny ------- NOTE TO FILE: A conversation about a project involving silver soldering or brazing or welding can be found in the file "Shaper Bits and Toolholders" starting Dec 1, 2007 and titled "Building Shaper Toolholder". It contins some interesting comparisons of the three processes. The silver solder process (which is actually a form of brazing) proved very successful in this application. ------- Date: Mon, 25 Feb 2008 20:41:26 +1000 From: "John Manners" Subject: Re: [OldTools] Restoring the #51/52 - the saga is renewed! James Thompson writes: > Brazing cast iron works, but I have never been able to get silver > solder to flow on cast. What solder are you using? (metals content > of the solder.) > Would you please describe the technique used? Maybe I am using the > wrong material. Baker's fluid for C.I. (cast iron) is a good flux for soldering ordinary cast iron with plumber's solder, i.e. 30/70 tin/lead. No flow problems encountered. Needs pretty hefty cleaning by grinding or, when joining a broken part, a stiff wire brush. Traditional flux was zinc chloride ("killed spirits"?)(15 parts), sodium chloride (salt) 3 parts and ammonium chloride (common name?) (1 part). General purpose Baker's soldering fluid also seems to work O.K. Never tried (told it would not work) hard (silver) solder on ordinary cast iron but it works O.K. on malleable iron. Better to test it before undertaking a big job. There are lots of "cast irons" out there. Main trick is to get the cast iron hot enough to melt the solder and not simply to melt the solder with the blowlamp, torch or soldering iron. Heating the parts from the underside of the joint, if possible, is the way to go. Incorrect to form a bead. Properly sweated joints are quite strong if they are not to be heated much after being made. Regards from Brisbane, John Manners ------- Date: Mon, 25 Feb 2008 14:23:49 -0800 (PST) From: John Odom Subject: [OldTools] Re: Silver brazing Cast Iron The key is the flux. I use Harris Silflow flus and Harris Saftey-Silv filler metal. The liquidus temp is 1200 F. It works well, the metal must be CLEAN and HOT. John L. Odom Chemist/Microscopist ------- Silver solder [sherline] Posted by: "Ron Ginger" rongingerx~xxroadrunner.com Date: Mon Apr 7, 2008 6:29 pm ((PDT)) Please don't confuse the low temp 'silver bearing' solder with what is more properly called silver brazing or hard soldering. The low temp stuff sold in hardware stores is in no way a substitute for the hard solder. Its a 5% sliver, melts around 400F and is no better than old lead-tin solder. The only use I see for it is a temporary holding of a work piece that cannot otherwise be clamped. Hard solder is often simply called silver solder, but its a 1200F product, about 45% silver. Steel needs to be red for it to flow. Real silver solder is stronger than the base metal- 60-70K psi tensile strength. I silver solder my band saw blades for example. Carbide tips are silver soldered to steel shanks for lathe tools. NEVER even think about using that 5% solder for soldering a model boiler. It's not even close to good enough for a boiler. ron ginger ------- Re: Silver solder Posted by: "a3sigma" dcclark111x~xxcomcast.net Date: Tue Apr 8, 2008 7:15 am ((PDT)) Thanks Ron, and Jerry K. for your contributions to this interesting and useful subject area. To be more specific; would one or both of you, or other knowledgeable members, please take a look at http://www.mcmaster.com/ pages 3311-3313 and tell us what products you recommend for hard or soft soldering brass (alloy 360) to stainless steel feeler stock? Also 12L14 to itself and to brass. Substitute gray cast iron for the 12L14 and any machinable brass for the 360 if that would produce a better result. And hard soldering (brazing) structural extruded aluminum. TIA, DC ------- Re: Silver solder Posted by: "n2562001" jlkiefferx~xxcharter.net Date: Tue Apr 8, 2008 8:26 am ((PDT)) DC: Soft solder in general has been pretty well covered in the last few threads. It will work with any type of brass or steel but not stainless unless specified for that purpose. These products are readly available locally at the just about any place that carries tools. Read the instructions for specific uses. High Temp. silver solder is a slightly different animal. First I would suggest all high Temp. Silver Solder products be purchased at a local welding supply shop. This offers the advantage of IN PERSON knowledgeable recommendations for your exact needs. In many cases it will also be your least expensive option. With 1200 degree silver solder it is very important to have the proper heat source especially with small or light work pieces. Personally I have found oxygen/acetylene to be the best option without exception. I use a small Smith Mini touch for small work and a larger common typical torch for larger projects. Anything that will provide enough heat will work, however in many cases high temperature needs to be contained to a specific small area to prevent work piece damage. This is where the O/A really shines especially small pieces. I am able to rapidly heat a small or tiny area and complete the solder joint before heat can spread and damage the work piece from over heating. For larger work pieces in all types of steel and stainless I would suggest 45% silver solder. For all types of brass and small steel/stainless projects I would suggest 56% silver solder because it has a slightly lower melting point. Silver solder Flux will generally and most commonly come in white paste and black paste form. White paste is for general use and black is supposed to offer better performance/protection on small parts. This may be true however I have found that many times it will block visual observation of solder melting points and cause over heating/damage to the part. I now only use white flux on all projects large or small without problems. Like many others I have talked to, I have not truely mastered the art of Aluminum welding. I will leave that to someone else or the welding supply shop as suggested above. Jerry Kieffer ------- Re: Jerry Kieffer Photos Posted by: "rsojerry" gfeldman2904x~xxpacbell.net Date: Mon Apr 7, 2008 8:49 pm ((PDT)) I'm not the Jerry to whom you sent the message, but perhaps I can help. If you are soft soldering with tin-lead-silver solder (the 450 degree stuff), and cannot find any commercial flux, go to you druggest and see if he/she will sell you a bit of Ammonium Chloride. This is the "active ingredient" in most of the old paste fluxes. (A block of "sal amoniac" was also used in the past to clean and help tin soldering coppers. Just mix the crystals with a bit of water and put some on the joint after thoroughly cleaning (as previously mentioned by others). Make sure you clean all the flux off after soldering as it will continue to do a number on the metal. If you are hard soldering with real (high temperature) silver solder and cannot get hold of the commercial acid flux, just run down to your market and purchase a small box of sodium borate (i.e., Borax) and use it instead. Heat the work with your torch, add some crystals of borax and continue to heat until the borax melts, then apply the silver solder. Hope this helps. Jerry Feldman ------- Re: Jerry Kieffer Photos Posted by: "chieftoolmaker" chieftoolmakerx~xxearthlink.net Date: Tue Apr 8, 2008 5:24 pm ((PDT)) From yet another Jerry, Go to the nearest industrial supplier, and buy a jar of "Handy Flux", some "Easy Flo # 3", and you have it made.... Jerry G (Glickstein) P.S. For silver soldering various materials, there are other fluxes and alloys available. ------- Re: Silver solder Posted by: "Ron Ginger" rongingerx~xxroadrunner.com Date: Tue Apr 8, 2008 6:55 pm ((PDT)) Torches are an interesting problem. You must get the work hot enough, but you can overheat it. You can also melt most brass or bronze alloys with an O/A torch. I was once trying to solder together several parts for a carburetor with an O/A torch when I suddenly had a puddle of brass where I used to have parts. I think the real master of silver solder is Kozo Hiroaka. I have purchased all his books, even thought I don't expect to ever build one of the models. His use of fabrications instead of castings is simply brilliant. He often makes a very complicated part by making pieces that are held together with small brass screws until the solder flows. He is also a strong advocate of placing a tiny 'snipet' of solder just where you want it, then heating from the backside until the solder flows. Dabbing at the joint with a piece of solder wire is guaranteed to put to much solder on the joint. Heating the solder and dripping it onto the joint is totally useless, the base material must be hot enough to melt the solder, not the flame. He also suggests a piece of steel wire, filed to a point, used as a scratch hook to draw the solder along a joint. I think silver solder is one of the most important techniques to be learned by a model maker. ron ginger ------- Re: Silver solder Posted by: "n2562001" jlkiefferx~xxcharter.net Date: Wed Apr 9, 2008 8:01 am ((PDT)) Ron: For the benefit of those who may wish to learn the Art of High Temp. Silver Soldering I would like to comment further. You made a couple of very good points. First having the option to silver solder WILL be one of the most valuable options a model builder can have. Second it is NOT HOW one accomplishes the job but that you are able to accomplish a good job. Unfortunately it is one of those tasks where one must teach yourself the methods that work for each of use as an individual. My personal experiece I think is a good example since at least in part has not been the same as you have described. Again we must work with what works for use as an individual. I personally prefer the A/O torch for two reasons. First it offers a more concentrated controlled heat source than other fuels. I find this offers greater control over where I wish to have the solder flow. Second it is used to limit/eliminate any metal damage from overheating. Metal damage is controlled by selecting the proper wide range of tip sizes that are available. For example a .003" jeweled tip on a mini torch will not melt or damage much of anything. While I have used the technique of a small piece of solder on one side while heating the other, I have found it to be a very difficult process to master. One issue is that as the flux bubbles from heating it pushes the solder bit away from the seam. Also on small parts when enough heat is applied on one side to melt solder on the other, you can easily damage detail on the heated side from overheating. Personally I find it much easier to heat the parts and solder from the flame side. With the concentrated A/O torch flame I can heat until almost ready to melt the solder and then melt a drop of solder off of the stick at the edge of the flame. This small drop will then follow the hot flame until it flows in the joint under the flame. Once perfected this process allows one to silver solder detail in small concentrated areas without heating the whole part. This also offers the advantage of being able to solder more than one detail on a part without having others fall off. In many cases holding screws are just not an option. Some excessive solder in most cases when building scale model parts will be desirable. This will allow you to form "Fillets" or "Contours" in the corner of the seam duplicating the original appearance of the part or casting. The solder fillets or contours can then be shaped, sized and or removed as part or whole by Bead Blasting. Of course samples of the above process will be available for inspection by request next weekend at NAMES. Jerry Kieffer -------