Went to a body shop in Cleveland and saw them using bondo on a frame rail

I stopped into a shop last week to pick up a part and noticed a guy slathering filler on a frame rail of a Jeep. Not a cosmetic panel, the actual frame. I asked the owner about it and he just shrugged and said it's how they've always done it. That's crazy to me because that stuff is gonna crack out first bump or winter salt will eat through it in a season. I get that filler has its place on quarter panels or roof skins, but structural parts? No way. Has anyone else run into shops cutting corners like that or am I overreacting here?

3 comments

3 Comments

the_susan2d ago

Honestly it depends on the situation. If its just a little surface rust or a small dent on a non-critical spot on the frame, some filler can be fine for a daily driver that never sees offroad use. Frames flex way more than body panels though so yeah itll probably crack eventually if its thick. But if its just a thin skim coat on a low stress area its probably not the end of the world.

ryanf662d ago

Yeah you're spot on about the flex thing, that's the real killer with filler on frames. I've seen guys glob it on thick to hide rot and then six months later it's all cracked and falling out anyway. But honestly for a little pinhole or a shallow rust pit on a suburban grocery getter, a thin skim coat is probably fine if you sand it down smooth and seal it right.

jamie_clark2d agoMost Upvoted

Buddy of mine filled a rust spot on his old F-150 frame with Bondo and painted over it. Three months later he hit a pothole and a chunk the size of a half dollar popped right off, exposing the rust underneath. Then he had to grind the whole mess off anyway and deal with a bigger hole than he started with. So yeah, keeping it thin on low stress spots might work, but I've seen that gamble backfire plenty.