Stainless to copper fusion.

[COMachinist]

Hi All
Happy Labor Day. I have a project under way now that my knee replacement is about 3 weeks old. I can get around the shop pretty good again and can already tell I will be spending lots of time out there With out much pain.
Back to the question, I am building a project that needs some 304 stainless fusion welding to copper. It needs to be water tight, and I don’t want to spend $100.00 for a couple 18” silver brazing rod. I have a TIG setup, and have argon, will this gas work for fusion welding the to together? I saw a youtube video doing this but it did not say what gas they used. Any help is appreciate.
CH

 

[Al 1]

CH, Argon and silicon bronze. Braze. Al.

 

[Ulma Doctor]

tig welding uses 100% argon as the shielding gas

 

[COMachinist]

tig welding uses 100% argon as the shielding gas

Yeah I know, that is what I have. But you can also use helium, 80/20 helium/Argon, CO2/argon mix, Nitrogen for deep penetration. There may be more. Even thought I’m 1595 certified I don’t know every thing. Never have welded SS to copper this will be my first go around with this configuration. I have not done copper with copper filler in a long time but will give it a shot and see if it will work on SS/copper.
Thanks everyone.
CH

 

[woodchucker]

Yeah I know, that is what I have. But you can also use helium, 80/20 helium/Argon, CO2/argon mix, Nitrogen for deep penetration. There may be more. Even thought I’m 1595 certified I don’t know every thing. Never have welded SS to copper this will be my first go around with this configuration. I have not done copper with copper filler in a long time but will give it a shot and see if it will work on SS/copper.
Thanks everyone.
CH

cut some coupons and practice and find out.

 

[COMachinist]

Oh yes plan to do this.
CH

cut some coupons and practice and find out.

 

[Ken from ontario]

I work with copper a lot but have never tried to weld copper to stainless steel, if I faced this challenge, I'll try (AL's suggestion, post#2)O/A brazing with silicon bronze first , then reluctantly will try to see if silver soldering would even work, but that's because I don't have a TIG welder, Ulma Doctor 's way sounds promising.

 

[GunsOfNavarone]

I've done it with silicon Bronze. 100% Argon as this is technically brazing, penetration really isn't the goal.
I love silicon brozne..it's like super glue for all kinds of metal....and purdy!

 

[G-ManBart]

Yeah I know, that is what I have. But you can also use helium, 80/20 helium/Argon, CO2/argon mix, Nitrogen for deep penetration. There may be more. Even thought I’m 1595 certified I don’t know every thing. Never have welded SS to copper this will be my first go around with this configuration. I have not done copper with copper filler in a long time but will give it a shot and see if it will work on SS/copper.
Thanks everyone.
CH

I'm not a professional, but I haven't seen or heard of a C02/argon mix being used successfully for TIG welding. Straight argon, straight helium, argon/helium blends, argon/hydrogen blends, argon/nitrogen and even argon/helium/nitrogen blends I've heard of, but some of those are quite specialized.

I only mention this because so many people post on welding forums asking "Hey, I have a MIG and 75/25 gas, can I use it for TIG"....not if you want the tungsten to last more than a few seconds.

 

[pontiac428]

Silicon bronze on stainless will always be best with TIG running pure argon. I don't think I've ever seen an engineered joint from copper to stainless that wasn't silicon bronze "welded"/brazed. Difference in melt temp is really high with those metals.