New Bumper Prep


Hi guys, how are you prepping your aftermarket, already primed bumper covers? I typically clean with 700, scuff with scuff paste and gray scotch pad, thoroughly clean with 700, epoxy as a sealer and then base/clear. Do you guys ever add adhesion promotor over aftermarket bumpers that have been primed from manufacturer? I think they use a waterbase primer.


Combo Man
If they are OEM, your procedure is spot on. But aftermarket bumper primer lets go sometimes. We have to be very careful ever doing those because customers don't understand that it wasn't your products or procedures at fault. It's still your fault regardless.


I have used quite a few aftermarket bumper covers before. Typically on higher quality aftermarket covers I think it is ok to clean good, sand/scuff the primer, clean again, seal with epoxy, and paint. However, I will say that I had one bumper cover that was primed that I used these same steps and the paint peeled off on sheets. I literally pushed the bumper into the plastic bumper stay and my hand rubbed the paint off down to the primer. I have never seen that before. Luckily the company replaced the bumper and I was able to fix the issue before the customer even picked up the car.

I do not think I would use promoter over primer. I have always been told that promoter over primer would decrease adhesion, but I do not have any proof of that. Someone might can chime in and correct me if I am wrong.

I guess the full proof way to ensure a perfect job on an aftermarket cover is to remove the primer and start from scratch with a raw platic cover?


Most of my work is bumpers, for already primed ones I scrub them with a red Scotchbrite and
scuffing paste, then wash with Dawn dish soap, dry thoroughly, then spray a reduced coat of epoxy.
(I mix white and black epoxy for the color I want.)
The next day I sand or scuff the epoxy and paint as usual.
The epoxy has made a huge difference in reducing road rash.


New Member
Do you guys use a flex agent in the epoxy primer and/or BC/CC ?? I will be spraying a new aftermarket bumper cover. It is black now.