You could apply zero rust or por15 or something like it to the seam and then just paint over it if you want the seam to show. Don't bondo over rust, it will come right through. If you are going to weld you have to get the rust off first to get a good bead. It will keep the rust from coming through (but you probably want to protect the back of the seam too)


Paint & Body Shop moderator
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