TIG welding copper?

[Korac MacArthur]

Anyone have any experience welding copper? I believe we are using 110 copper, long machined sections with about 1/4" walls. I have seen that sometimes helium is preferred over argon, but didn't know how well it works in general given the high heat conduction there. Any anecdotes, advice appreciated. I am a novice welder but we have a couple people to turn to with more experience.

Thanks.

Korac

[kelly'$mygirl]

thats some big $$$$$ in copper. I have used helium, i preferr it over argon. I've got a question of my own , can u mig/stick/FC weld copper?

[triggerman]

Tiggin' copper?

What kind of copper? Copper plate or tubing? I do lots of tubing and use my O/A and 15% silphos sticks, for plating I use acetylene turbotorch and silver bearing solder, 95/5 or 50/50 depending on the application. I have to get the high tensile strength of running the flux and stick into the joint.

Hope this helps.

[jmcglynn]

Anyone have any experience welding copper? I believe we are using 110 copper, long machined sections with about 1/4" walls. I have seen that sometimes helium is preferred over argon, but didn't know how well it works in general given the high heat conduction there. Any anecdotes, advice appreciated. I am a novice welder but we have a couple people to turn to with more experience.

Thanks.

Korac

I've TIG welded copper, usually 1/8" and thinner. It welds nicely, but it is an amazing conductor of heat, the whole part gets very hot, so it takes a bit more heat. My old TIG machine (Miller 300ABP) took a while to puddle it on thicker sections/larger parts. The focused arc on the Dynasty series might be a real advantage -- I can weld aluminum at about 2/3 (or less) power with the 300DX than with the 300ABP.

No experience with helium, I think it affects penetration.

[wldrman]

If you use a 75% helium,25% argon mix you can get a much greater heat at lower amperages. This is the only mix we use for copper and aluminum. It definitley increases penetration. It also increases puddling time as well.
I don't know how exactly this works, but I know it does.

[MAC702]

How critical is your color-match? Sometimes you can use left-over pieces of the actual material as filler for TIG instead of copper wire or copper TIG filler.

[steeltoyman]

Welding with TIG and argon

I have used Argon to TIG copper, but I justs used stripped copper wires. I also was able to weld copper to steel, but you must just wash the copper into the steel. It will not work in the reverse (steel to copper). I never used any other gas but Argon though.

[mr. steam]

If you use a 75% helium,25% argon mix you can get a much greater heat at lower amperages. This is the only mix we use for copper and aluminum. It definitley increases penetration. It also increases puddling time as well.
I don't know how exactly this works, but I know it does.

From what I understand, its the helium that gives the better heat / penetration. Argon is good for cleaning while the helium gives penetration. A guy where I work had to do an emergency pump shaft TIG repair out to sea in the Navy (had to use mirrors as nothing is easy to get at). The only gas he had available was Nitrogen. He said it almost blinded him as it was so bright.

[steeltoyman]

Argon or Helium

I havae welded on Xray welds in nuclear plants for over 30 years. We never used anything except Argon. I don't know the reason except that Helium is much more costly, but the welds are certainly critical and the Argon works fine. We usually open butt the root pass and then run a hot pass with TIG. Then we usually fill and cap it with 7018 low hydrogen wire (stick welding).

Vinny