Here is an old link that might help. When I made the cord for my 220v MIG welder years ago, Home Depot carried a nice bright orange 8ga wire and it was EXPENSIVE! I bought enough to go from my garage outlet to the street so I could weld on my race car trailer and I think I bought 60 feet. I paid about $5 a foot I think in that was 10 or 12 years ago. Industrial places are probably cheaper? It never got warm even running at full load a few times welding thick aluminum.
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