Sage Creek Gus SASS #64320 Posted January 18, 2012 Share Posted January 18, 2012 I'm trying to silver solder a couple of pieces of steel together with no success. I've done a lot of soft soldering and have no problem silver soldering nickel silver but for some reason can't get the solder to stick to the steel. I clean the steel well, in fact the pieces I'm trying to solder together were both turned on a small metal lathe and I made it a point to not in any way touch the surfaces. There was no cutting oil of any kind used when turning the pieces. I worked the surfaces a little bit with new silicon carbide sandpaper, once again being careful not to touch the surfaces with my hands or anything else. I have two different grades of silver solder with a flux that came with each. I apply flux with a clean cotton swab and wipe the excess off with a clean paper towel. I've tried not wiping the excell flux off with no better results. When trying to solder I know I need to heat the metal itself and then apply the solder to the pieces and have the heat from the metal melt the solder. No matter how I do it I can't get the solder to stick to the steel. I've tried both holding the two pieces together and attempt to get the solder to flow into the joint and applying solder to each surface and then put them together and heat to get the solder to fuse them together. It seems to me that by the time I get the metal hot enough to melt the solder the surfaces to be soldered become discolored and perhaps this is why the solder won't stick. I'm using one of those propane bottle torches that plumbers use to put copper plumbing together. This readily gets the metal hot enough to melt the solder. I've tried holding the metal in different places in the flame thinking this might becausing some kind of contamination. Any ideas? I'd like to discuss this with anyone experienced with silver soldering steel. Thanks in advance. SCG Link to comment Share on other sites More sharing options...
Adirondack Jack, SASS #53440 Posted January 18, 2012 Share Posted January 18, 2012 Sounds like you're overheating the steel. Always try to think of heat flowing. Put the hottest part of the flame where you want the solder to go, not where it is. As the solder flows, take the heat away. Link to comment Share on other sites More sharing options...
Sage Creek Gus SASS #64320 Posted January 18, 2012 Author Share Posted January 18, 2012 Sounds like you're overheating the steel. Always try to think of heat flowing. Put the hottest part of the flame where you want the solder to go, not where it is. As the solder flows, take the heat away. that does sound like it could be my problem, thanks. SCG Link to comment Share on other sites More sharing options...
Garrison Joe, SASS #60708 Posted January 18, 2012 Share Posted January 18, 2012 Yep, agree with AJ (again). Silver solder is very sensitive to over heating. It goes black and balls up or just "runs away" from the joint when it gets too hot. I normally try to get more flux on than it sounds like you are doing. Don't wipe it off after brushing a coat on; the flux has to coat the joint area. Just let heat melt it down to a liquid. Here's a reminder course in silver soldering: http://www.smex.net.au/reference/SilverSoldering01.htm Propane torch won't contaminate the joint. Oil will. Make sure, as you have stated, that the metal is clean. Then, practice. Make sure you are using a really good flux for your brand of silver solder. The cheaper stuff and the soft solder fluxes won't do it. Good luck, GJ Link to comment Share on other sites More sharing options...
Sage Creek Gus SASS #64320 Posted January 19, 2012 Author Share Posted January 19, 2012 Yep, agree with AJ (again). Silver solder is very sensitive to over heating. It goes black and balls up or just "runs away" from the joint when it gets too hot. I normally try to get more flux on than it sounds like you are doing. Don't wipe it off after brushing a coat on; the flux has to coat the joint area. Just let heat melt it down to a liquid. Here's a reminder course in silver soldering: http://www.smex.net.au/reference/SilverSoldering01.htm Propane torch won't contaminate the joint. Oil will. Make sure, as you have stated, that the metal is clean. Then, practice. Make sure you are using a really good flux for your brand of silver solder. The cheaper stuff and the soft solder fluxes won't do it. Good luck, GJ The solder I'm using I ordered online and it was supposed to be the harder solder, at least it cost more, and the flux I'm using came with the solder. Thanks much for your input. SCG Link to comment Share on other sites More sharing options...
Guest Sheriff Pack Wolf, SASS #31917 Posted January 19, 2012 Share Posted January 19, 2012 It has been my experience that a finer tip ox/acetline type will heat up the metal in the target areas. Wide flames will heat the area finally but the heat is so slow it will drain of quickly. You may have mentioned that you tin ( process)both pieces. If you haven't, you might try that. Link to comment Share on other sites More sharing options...
Jacknife Posted January 19, 2012 Share Posted January 19, 2012 JUst apply the heat to the pieces, not the solder. With the solder touching the metal, when metal gets to right temperature, the solder will melt and run in the seam. Overheating will kill ya. Link to comment Share on other sites More sharing options...
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