Am I the only one who skips the epoxy primer on small bumper repairs?

I see everyone online saying you always need epoxy primer over bare plastic on bumper jobs. But I tried two direct-to-plastic adhesion promoters from Sherman and went straight to urethane primer, saved about 45 minutes per repair. Did three bumpers like this six months ago and none have peeled or cracked yet. Anyone else cut corners like this or am I asking for trouble?

3 comments

3 Comments

sarah_hart1mo ago

Yeah but six months vs a year or more is a totally different story. That boat trailer guy probably didn't even scuff the plastic right or used a cheap non-automotive primer. I've seen guys do a full epoxy coat on a front bumper only to have it chip off in a month because they mixed the hardener wrong or sprayed too thick. The Sherman direct-to-plastic stuff has been around a while now and it's designed for this exact use case. You're probably fine, especially if you're doing small repairs where the whole bumper isn't getting beat up constantly.

theac631mo ago

You ever see a buddy skip the epoxy on a boat trailer repair and watch it bubble up like a bad sunburn a year later? I heard about a guy who did that and ended up redoing the whole thing.

elliot_barnes4d ago

And that's the thing, people get caught up in the "one way is the only way" mindset. I watched a guy use that "special" bumper primer from the auto parts store on a plastic fender flare, and it started peeling in three months because he didn't scuff it with anything rougher than a dish sponge. Meanwhile I've got a buddy who just cleans the plastic with soap and water, hits it with some rattle can paint from the hardware store, and his truck bumper looks fine after two years in the sun. It's all about prep and knowing what you're working with, not just the label on the bottle.