I am going to roll my fenders and want to know what you body pros recommend for sealing the gap between the fender and rolled up lip. I want to prevent water from building up in the rolled lip and causing rust. Will any multi surface waterproof sealer work? Or is there something specific for auto body work?

Thanks for the help.

 

drill holes and under coat or something

 

After fenders are rolled, check the inner lip for any cracks in the paint. If there are any sand them all smooth with 180 grit down to bare metal so you can no longer feel the crack with a finger nail. Go over the surrounding areas that you are wanting sealed with 400 grit. Clean the area with degreaser and spray with self etching primer or epoxy primer. Let dry then brush automotive seam sealer across the two panel joint. Once it is dry you can paint it black or spray rubberized undercoating if you wish.

 

I agree to what Jake said... If you had to split the fender like you have to do in some cases, then you would tack weld the seam closed, epoxy it tight, sand it, prime it and refinish. Any pics?