patching hole in sheet metal-seal w/butyl rubber ?

850forum · Post by **850forum** » 06 Aug 2010, 19:31

I need to patch a hole that rusted thru some sheet steel on the underside.

I can get to it from above.

I'm thinking of "gluing" it in place using the kind of butyl rubber sealant made for rain gutters, because I have some on hand and its probably the same stuff used to seal windshield glass in place...

What I want is something that will remain flexible against vibration, so the patch stays in place.

I think this would be better than Bondo -- also I think Bondo is somewhat porous.

This does not need to be painted. I could even use a piece of plastic instead of aluminum for the patch...

I will prime the outside edge of the hole & put some kind of topcoat on it because you can't leave primer exposed... color is not an issue. Then maybe I'll glop some more butyl over the edge just to help keep water & grit from abrading the area.

Does this sound reasonable?

Post by **pkc303** » 15 Aug 2010, 07:43

Bondo is the preferred choice. It is not porous, nor does it shrink. It was designed for just such a project. The butyl rubber would eventually shrink, and crack. If it is not painted, and doesn't show, you might be ok with the rubber. The bondo would be a permanent repair.

850forum · Post by **850forum** » 15 Aug 2010, 15:55

I don't think Bondo is meant to be used a an adhesive. Its sandable & paintable hard plastic.