I plan to put the TJ flares on the rear this week and I'm aware that when I cut I'll go through the factory seam and open a hole in the wheel wheel. I'll then rivet sheet metal in the wheel well to fill the gap, and was wondering if you guys think bondo will work to seal it off? I'll just cake it on inside over the sheet metal and rivets. Would it be prone to cracking, and should I go with something like caulk instead?

 

I'd go with something that has a little give to it when cured. They actually make a caulking for auto bodies but regular old silicone from home depot will work too. Bondo will crack off in time.

 

Bondo will deffinitley crack sooner or later ive always used bondo glass. it works the same as bondo but its fiber glass so it has some give and it can be sanded and painted.

 

Most parts place carry a body seam sealer
http://www.google.com/products?sourc...ed=0CBYQrQQwAA

 

i cut out alot and had my buddy weld a big piece of sheet metal as my new wheel well sprayed and primed it black,then went to pepboys and got rtv auto body seam sealer(its black)gunked that on let dry,then i took expanding foam and sprayed the interior inside with it,then put my bushwackers on.