Auto body repair & detailing: fiberglass repair., willys pickup, fiberglass repair

Question
I am restoring a "56 Willys pickup. There is fairly extensive rust with some holes
on the door sill. Is fiberglass strong enough to fill this holes?

Answer
Hello Jim! Jim, fiberglass has no place on a steel body part. I know it's tempting to just glass and mat it, but that isn't a good way to repair rust- ever. It doesn't last, and it's not strong enough. There are a ton of body parts available for Willeys jeeps, I firmly believe you should check and see if a suitable replacement part is available. If not, parts will need fabricated from steel. Have a  great evening. bill