[tac]

I primarily weld carbon pipe,and stainless,and do general maintenance. On ocassion we have to fab temporary drip pans to contain leaks until a shut down to repair the leaks properly. We usually fab a pan from carbon or stainless for example a 24"x24" pan and break a 2" lip and weld up the corners and weld a threaded coupling in the center to attach a drain hose. We have tried to weld the coupling hot, cold, several spot welds, letting it cool, clamping them to the table until cool, just about everything possible but always end up with warpage. Does anyone else have this problem, and any suggestions on how to prevent this warpage? I think everyone knows sheetmetal is usually a problem when welding. We usually use 16 ga. or 11 gauge metal. Any input would be helpful. Thanks

[sschefer]

Get yourself a hunk of 1/2" copper bar and position it under and in contact with the piece your welding. You can also use a piece of aluminum but the copper works a lot better. I use it when I weld Al a lot now. Works like a champ at pulling the heat off the material and preventing warpage.

[Sarge]

A carbon block functions well too...