Welding Copper Kettle. It sounds like your are building a copper kettle I have a 50 gallon copper kettle from circa 1800 I use only white vinegar at a ratio of 2 gallons to 30 gallons of water and boil for 20 minutes I would not risk muriatic acid thats pretty harsh stuff. Copper tea kettle with brass weld one of vintage tea pot kettle on antique copper bronze tea kettle.
Youll also want to use either argon or helium gas. If not heat up further till solder flows. Can you use a TIG for copper or is the arc to hot.
Had a customer call this morning inquiring about repairing a pin hole in a copper cooking kettle.
I have welded a lot of materials with my old Miller Dialarc TIG but never attempted copper repair. Where joints may still be needed in the production of deep modern copper cookware overlap and brazing has been replaced as a jointing technique by mechanised arc welded MIG - metal-inert-gas butt joints. First up the two metals have substantially different melting points. A forging operation is applied after the workpieces are heated up.