Manual copper welding is tricky but it is not as laborious as smithery. Often used in connecting pipes and making exchanger grids, welding copper saves huge stashes of raw material from running into recycling. Copper has excellent heat and electrical conductivity; it is cryogenically temperature resistant, non-ferrous, corrosion-resistant, strong, ductile, malleable, and has a melting point of 1083C. Where all these properties make copper a versatile and reliable option for many functions in the industries, these properties also make its thick sheets somewhat difficult to weld with classic methods. The conventional method was to use bronze or low O2 copper consumables on the preheated base metal. Often alloy filler used in joints leave defects, oxidation pockets, and patchy off-color. The defects in these joints get severe upon sudden changes in temperature during the product’s regular use. The modern automated methods are efficient in reducing these odds and strengthening the joinery.
MIG welding uses metal wire feed to submerge into the base metal at the weld point. The flow of inert gas sort of cocoons the puddle during the process and keeps the contaminants and the adverse temperature away from the feeding tip.
TIG welding directly heats the base metal at the joint and inert gas covers the puddle. Here the fillet wire or plate (optional) is placed externally of the welder, if not absent. Not a surprise that this technique can even weld gold, has no fumes, no spatter, and is easy for overhead and linear works.
How to MIG
- Use alloy fillet for the economy, De-Oxidised Copper wire for perfection.
- Only Aragon won’t work well. The gas mix will need some Helium.
- Cut out a little butt for deeper penetration and to avoid bead flakiness.
- Use additional plates for curvy bends.
The wire should have a greater heating capacity/ electrolytic pitch.
MIG welding copper needs more scientific accuracy than blazing or soldering the same, but it is not impossible. Computerized controls can meet such accuracy around the contact tip. Robotic handling further eases the job as the robotic arms can handle the hot metals in a way human hands cannot.
How to TIG
- The gas mix must be nearly pure Helium.
- Preheat the base and watch for the heat sink to maintain the required temperature.
- Avoid base warp and temperature leakage.
- Speedier the weld, better will be the bead quality.
- Let the base cool gradually.