Tried patching a rust hole with that spray foam stuff... what a disaster

So I've got this old 2002 Ford Ranger with a rust hole in the floorboard the size of a baseball. Figured I'd get clever and use that expanding spray foam insulation to fill it, then sand it down and slap some bedliner over top. Seemed like a great idea after watching a couple youtube videos... well that foam did NOT bond to the metal like I hoped. After one good rain the whole patch just popped loose and now I've got a bigger hole and foam crumbs all over my floor mats. Learned my lesson about taking shortcuts on rust repair, guess I'm breaking out the welder this weekend. Anyone else try something like this and end up making it worse?

2 comments

2 Comments

joelwells10d ago

Start spraying that junk and within 10 minutes you realize it's just gonna make everything worse. Did the same thing on a 99 F150 where the cab corner was Swiss cheese - packed it with foam, let it cure, then tried to bondo over it. The bondo cracked before the primer even dried. It's like trying to fix a leaky pipe with duct tape, you're just delaying the real fix and creating a bigger mess for future you.

grant_hart10d ago

You tried filling rust with spray foam?