All, I have a project going on that will require a little bit of silver soldering..... Looking through the books it seems that the "kits" are available (containing the silver solder and flux) for about $45 or so, (varies with supplier). Anyone know where I can get a "little bit" of silver solder and flux. Of course I guess I could just buy the $45 worth, and there will be a lot left over for my kids to throw away when I die..... Anyhow... I remember someone years ago (I don't think Weller) used to sell a small plastic tube of solder and a little tiny toothpaste tube of flux as a little kit. Anyone know if a little kit like this is still available? (Or is *this* the $45 kit in the catalogs?). Thanks. Ken.
Ken, What kind of silver solder do you need? And what size (diameter)? I have some that is used for steel to steel work I could send, and I have some that is used for brass/copper to brass/copper also. There is annother type used for stainless to stainless work, don't have that. Both kinds I have use the borax type white flux, which I don't have, you would have to get that yourself. Thats the same type used in brazing, I think. Steve Steven
There are a lot of silver solders so you might say a bit more about your project so someone can recommend which one to use. I would look up welding suppliers in the yellow pages and shop there. You ought to be able to buy silver solder and flux there for less that $45. Sears used to sell silver solder in kits, but I have not looked there for years.
If you want low temp solder that contains a small amount of silver try Lowes or Home Depot. The real deal needs a propane torch to melt it.
I've got some jeweler's sheet silver solder (about 5 thou thick) in both "easy" and "hard" melting temps and could slip a half a square inch or so of each type in an envelope to you if that would help. I could include a plastic envelope with some powdered brazing flux, which when mixed with water and applied with an artist's brush works ok for small silver soldering work.
This presumes you have or will be getting a torch. For small stuff (pencil point sized flame) the little self lighting butane torch that Harbor Freight often specials for less than ten bucks works for me. You gas it up it from a container of Ronson cigarette lighter butane fuel.
It's hard to say what's in that kit. Also, there's silver-soldering and silver-brazing. In my area, if you go down to the welding supply and ask for silver solder, you're going to get handed a roll of tin/silver alloy solder. For the good stuff, you want to ask for silver brazing filler rod. Then they ask you want it's for. There's literally hundreds of alloys out there intended for silver brazing, only a few of which can be used with an air-propane torch. Some fill gaps better than others, some wick into joints better than others, some are stronger than others, it just depends on what the job is. There's no one silver brazing alloy that's going to do it all for you. You also need the matching flux. If you've got access to acetylene gear, you'll have a wider variety of filler alloys that you can use and your results will be a lot better. Propane, ala Bernzomatic torch, sucks for silver brazing. It takes way too long to get up to temperature and you get heavy scaling.
If it's truly silver solder you're looking for, not the higher-temperature brazing filler, you can find that at a real hardware store in the plumbing section. A lot of the leadless plumbing solders are alloys of mostly tin with silver added.
One source for silver solder and brazing fillers by mail is
Not the cheapest place, though. Check with the local welding supply, too. Most can supply you with a line sheet that details what alloys are used for what purposes. Allstate seems to be the brand that a lot of the suppliers handle around here.
Gang..... I guess I should have been a little more specific in my intentions: I'm building (just started) a miniature hit n miss engine, finished length about 12-1/2" with about 6" flywheels. The prints call for machining some parts from brass, and silver soldering them to other brass parts (these are pretty small, like a sight glass oiler), but also going to be turning out a crankshaft from 4140 steel, 1-1/2" by
3/4" by 12". The plan calls for placing two centers in the ends of the bar, one for the connecting rod journal, the other for the main shaft journal, turning out the connecting rod journal first, then silver soldering a small chunk of metal in the "gap" formed by turning out the journal, then moving to the main shaft centers to machine out the main shaft. The little block of metal is to keep the bar from deflecting in the gap that's left by machining out the connecting rod journal. It is only a temporary "brace" and will be removed after the main shaft is turned. I have never silver soldered anything, but have done lots of copper water lines, etc. Also do O/A welding, cutting and Arc Welding with a little Lincoln Tombstone 225A. So knowing diameters, silver content, etc., is an unknown to me. A little help would be appreciated in this area also. Thanks for the post.... I'll have a look at Sears and as others have suggested, places like Lowes, Home Depot, etc., but I don't know how much silver content I need. I'm kinda in the dark here...... Ken.
Thanks Jon, I didn't think about you guys having a use for it. And I hadn't really even thought about a welding supplier before another posted mentioned it. I was thinking ...... I don't know.... I guess I wasn't.... I'm not even sure about what I *need* to do this (silver content, soft, hard, diameters, etc). Never had any experience in this area and never had the opportunity to be around anyone that was doing it. Gotta learn something new everyday.....Thanks for the post. Ken.
YEAH!---I would use the Staybrite, it's probably the lowest melting point of all the stuff listed so far---Heck, since the block you're inserting is just under compression--any kind of solder would do..NOTE--be careful to let the crank blank cool very slowly, (no wind drafts, etc ) as it is similar to 4130 which will harden if cooled too quickly---I mean harden to brittleness! if quenched.
Thanks for the info concerning cooling. I am going to try to keep the heat as low as possible for as short of duration as possible. I know regular brass filler rod wouldn't work because of the heat involved, but the soldering process may be able to be done without any damage - and it's also a pretty good sized hunk of steel so that should work as a "sink" for the very small area to be soldered. Thanks again. Ken.
I would not have thought they would have such a high percentage. I can see some silver content for the work they sometimes have to do on air conditioning systems, etc., which may require silver content for a strong joint in the tubing. I assume when you say "stick" you are speaking of some sort of a pre-fluxed rod? or is it just bare solder? Thanks. Ken.