Plugging emblem holes in fenders

It will help reduce panel heating if you use .023 wire in your MIG. I made a magnetic copper backer by drilling four holes in a 3/16 copper piece and epoxying in some small neo magnets. Works really well and frees up a hand to steady the gun. Also, leave a little more wire than usual (maybe 3/4 of an inch) sticking out of the MIG nozzle when you make the tacks. This also helps reduce the heat. Filling a 1/4" hole will take roughly 6-8 small tacks. Let it cool down, or cool it with an air hose every couple of tacks. A bit of practice first and you'll find it pretty easy to do.