I am repairing some rust on my core support. The patch piece will overlap another piece just like it did from the factory. I am wondering what is the best method to prevent this from rusting? Should I paint it with that through primer then weld the patch in? Or my second option was to paint it with do primer then grind away the paint to bare metal where so I can plug weld it? My guess is that even though some of the primer would burn away I think it would protect better than the weld thru primer but that's just my theory. What are your thoughts? Thanks in advance!