I was reading Skip's article as I'll need to patch the bottom of my fender.

I understand why you need to strip to bare metal to find the rust, then spray it with Etch Primer to make sure it doesn't flash rust. But once you've primered the panel, doesn't i become harder to decide where to cut the panel as you can't see the rust anymore? Or do you leave the back of the panel alone at this point and cut from the back?

I'm just confused as to how you know where to cut after you've painted again.

It looks like my fenders are in really good shape, only pinholes and such but I'm still not sure how you decide how much to cut and where once you've primed the piece?

Sand/grind down to bare metal,cut out the rust,weld in new metal,grind smooth,apply filler if needed,then prime,and paint....OR...some people will..grind smooth,apply ecth primer,then some epoxy primer,THEN apply filler if needed,then reprime with a 2k primer then paint.

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Rick

So it might be a good idea to sand down to bare metal, etch prime the rest of the panel (rust is isolated to the fender bottom), then do to repair work, and grind down the welds and do filler work (or not, depending on the instructions for the primer) and then etch prime the repaired area and then keep going with the rest of the prep work.

To me, that sounds like the way to keep the rest of the panel from "flash rusting" while I work the rest of the panel?

Also, since it'll be a while til i get to work on the fenders, would it be a good idea to get the whole panels to bare metal and etch prime, then sand off the primer in the rust area when I'm ready to do the work?

Just trying to not let the fenders get from surface rust to pitting/wholes.

TTT

Anybody?

Slowpoke,

I am no expert, but I have researched this topic exhaustively on this site. If you want to strip the entire fender to see where your trouble spots are, that's OK, but you need to get a coat of etch primer to prevent flash rusting. Cut out you trouble spots first, then prime. Sand off the primer before doing the welding and filler work. Work one area at a time. When that is complete, re-prime with etch. Don't use epoxy primer as it is difficult to sand. Never apply filler over etch primer. When the body work is complete, 2K urethane prime, paint and clear.

Kevin

Thanks, I think I get it now.