Im trying to figure out what the best fix would be to repair a small 1/2'' rust hole in my rear fender. I have been using an expensive rust proofing called "Rust Bullet" that is supposed to chemically bond with the rust and harden, it seems to be working great.

My problem is one of the rust spots is completely rotted through so i need to find some sort of body filler. I have been looking at Bondo "metal fill" which is aluminum based and supposedly is rust/waterproof. However, I wasnt sure if I would have to apply this on bare metal which would negate the rust proofing I did. I have heard that normal bondo will pit, and that rattle can paint touchups come out terrible over it.

I also was considering JB weld because the spot is so small. Any suggestions keeping in mind that I cant weld and am poor? thanks.

 

try fiberglass cloth an resin.