Copper welding question

Yes and yes. Pure copper wire and a argon/helium or pure helium shielding gas.

The most common brazing rod for copper is Sil-Phos-Bronze. It requires no flux on copper.

Only copper will patina like copper.

Thank you, Ernie.

Jack

Hi Jack Copper can be tig'd or mig's, but the most common process for joing it is by brazing. I have done mig welding of some very thick copper (4"x5" solid) used as buss bars on a gantry crane. Mig copper is not particularly hard, but its a very weird looking arc and takes quite some time to get used to setting it up.

Shaun

If the braze is a bit light for your taste potassium dichromate will give a darker colouration . Derek

Silver solder it. Better than either welding or brazing, and it has by far the best visual appearance / required skill level ratio.

Downsides are that the solder is expensive (affordable at this level though) and that it needs a well-fitting joint. It flows by capillary action, rather than manually building up a fillet.

Advantages are that it flows by capillary action. You get it clean, well-fitting and hot, then it just "flashes" by itself. You can even do it in an oven without needing to touch it. The toolign is also cheap - a few firebricks and a natural draught propane torch are enough.