Wheel Well Rust Repair

I did some body work with a mig. It's doable, but since the sheet metal is so thin, you can't really do more than tacks. Otherwise it will burn through and warp the metal, even on lowest settings.

1/4 inch between tacks

 

I'm new here and about to buy an 02. first tacoma. anyway, Eastman and others have copper "backing" plates and paddles that can help. theory is it spreads the heat and helps prevent blow through. Not tried it yet but sounds reasonable.

 

Small quick tacks is the right way to avoid warping. Just keep adding one here, one there, one over yonder. Let them cool and repeat until the panel has been fully welded.

Copper backer plates will help to some extent, but much much more time consuming to use. A short blast of cold compressed air will quickly cool the spots welded to allow for continued work. Body panel repair is tedious at best. Not fun!