Tried a 3M panel bonding adhesive on a rust repair and it pulled the surrounding metal into a low spot.

I learned that even a high-strength structural adhesive can telegraph underlying flaws if the substrate isn't perfectly flat, so what's your preferred method for dealing with minor warping before an adhesive repair?

3 comments

3 Comments

danielr9412d ago

Read a forum post a while back where a guy had the same issue. He ended up using a thin layer of epoxy filler over the low spot first, let it cure fully, then sanded it flat before the panel bond. The idea was to build a solid, level base so the adhesive has even pressure. I mean, it makes sense because that glue is so strong it'll just copy whatever shape is underneath. For really minor stuff, I've also heard of people using a stud welder and a slide hammer to gently pull the metal back, but that's getting more involved. Maybe it's just me but getting the metal as straight as possible before the glue seems like the only real fix.

finleyw9911d ago

Saw a video where they used a two-part filler made for metal, not regular body filler. It stays a bit flexible so it doesn't crack like some epoxies can. That extra give might help with the low spot issue.

piperb933d ago

Used to think chasing the perfect filler was the answer. Reading what @danielr94 said about the glue just copying the shape underneath really made it click for me. You can use the best flexible filler in the world, but if the base metal is wavy, the bond will be too. His point about getting the metal straight first is the real fix. Now I see all the filler does is smooth the final surface over a solid foundation. It changed how I look at the whole process.