For sheet metal and using a MIG, I usually weld one dot at a time, set the machine a bit hot for a full penetration weld, and bump up the wire feed a bit to prevent blowing holes (due to the extra heat). Here is a thread that is a good read for welding in patch panels:

[color:#CC0000]Welding in patch panels[/color]

Last edited by MPandC; 08/31/2011 11:40 AM.