Sandblasted areas of my car that opened up small pinholes and areas with maybe 1/4" irregular holes max. I've blasted BOTH sides, metal is clean, rust is gone and treated with metal prep. I'll be cutting and replacing w/patches the larger areas (lower quarters). My question is on these smaller pinholes : why can't I repair with epoxy putty (I've heard JB will even work) I know lead is used, and some may still cut out small little patches and weld. Why not epoxy putty ? Someone stated the expansion/contraction variances between metal and epoxies, but how would that be any different than body fillers? I'm sure some old die-hards will use nothing but metal, but I need theory and application experience regarding the newer methods. Sorry so long, but I'm about to start the repairs ! Thanks