silver soldering

[Tony]

even'n folks,
hoping to get a 'silver-soldering' clarification.

i'm trying to solder together two thin stainless steel wires (1/16").

conventional (plumber's) solder won't work.

i've used silver solder in the past to weld up needles for tattooing, and it worked great.

now i have this stuff made by Oatey (HomeDepot) .. called "lead free silver solder" and i have the (waxy) flux.

i've tried and i've tried but i can't get it to stick. the drops just roll off the stainless wire. if i use a torch, instead of a soldering iron (80W), the flux burns up, turns brown, and i have to clean again.

please note, i'm trying to solder, not braze. i have silver brazing rods and they work great on bigger stuff. this is a low-heat application.

any ideas? why won't it stick?
-tony

[Evan]

I have had good luck low temp soldering SS with 5% silver bearing solder that is sold in hardware stores. It is flux core and has a very high activity flux. I think it is a clorinated flux so it should be well cleaned from the work.

[rotate]

"silver solder" is not soldering but blazing, because of the high temperature involved. However, there are conventional soft solder with silver (like the ones from HomeDepot) which are used for soldering jewlery and SS. I've never had much luck with them for soldering SS eventhough the package clearly states that it's intended for SS. I vaguely recall that muriatic acid works well as flux for soldering SS.

[portlandRon]

I have used the "lead free" solder to solder the seams on stainless steel water tanks.

Had the same problem with a torch that you are having.

It sounds like you are not getting the wire hot enough with your 80w iron.

I had good luck using the older style sodering coppers. Heated them up with a torch. They hold heat for a long time and you don't get the joint dirty from the flame.

I used a liquid flux so it would flow into the joint. Also make sure the metal is clean.

Another thing that helps is to "tin" each piece first. In other words coat each piece at the area to be joined with solder. When still hot wipe off excess with a clean rag. Then join the to pieces together apply heat and a little more solder.

Good luck.

[Tony]

maybe i'll give it a try with a hotter iron.

strange thing, the SS wires will melt the solder, but not pull the solder into the joint.

-tony

[Al Flipo]

You need the right brazing alloy, otherwise it just runs off. ESAB all-state #155 cadmium-free is one of them.

[Randy]

I've soldered a lot of SS bicycle spokes, with an 80W iron, and 4% silver low temp solder, as Evan mentioned. Mine was made by Alpha metals, Kester and Oatey no doubt have similar solders. The flux seems the key. The liquid flux containing hydrochloric (muriatic) acid does the trick. Keep your face away from the fumes! I clean up with a baking soda solution to neutralize the acid residue.

[happy02]

Try Eutectic MG120 Silver Solder tensile stng.15kpsi, working temp.430*F dia.1/16". Just a thought...

[wierdscience]

Too bad you don't have a bandsaw blade welder,thats how I do small wire at work.

[coldformer]

i have some .050 15% that should work email me an addy and i will send you a chunk
use brazing flux and you will be good to go
jerry