Hot Rod Forum banner

Process when painting car with urethane bumpers

12K views 16 replies 6 participants last post by  skip99 
#1 ·
I'm painting a 85 Monte Carlo SS with urethane bumper covers and I am considering what steps to go through.

I have planned on only using epoxy and then SS urethane paint on the bumpers which are prepped with 400 grit. While the body is prepped with 180 and will get epoxy, 2K surfacer and then SS. Just curious what process you guys usually use.

Since I don't want to use a surfacer on the bumpers I've considered addressing them separately. I've considered a couple of ways.
1. Shooting everything with epoxy, mask the bumpers while I shoot the body with surfacer. Then after blocking out the body, sanding the epoxy on the bumpers with 400 so they are ready for the SS.
or
2. Shoot the body with the primers and block it out while keeping the bumpers masked and raw. Then addressing the bumpers first by shooting epoxy followed by SS to cross-link. Then I would mask the bumpers up while I shoot the body with the SS.

What is your usual process?
 
#3 ·
When I did my 87 TA; I scuffed the bumper covers and side skirts, minor body work (flexible filler, used a 2 part epoxy suitable for urethane to repair a crack). This is where it gets murky; I know I used Bulldog adhesion promoter, but I can't remember if I applied it to the substrate and then put my epoxy sealer over it, or vice versa. The next day I applied Bulldog (2 very light coats, heavy coats can cause problems) and shot my base clear over the top.
Im not sure if you need the sealer or not; but the base I used didn't cover great, and I wanted an even substrate. 4 years later and the bumpers look great; the rest of the body is starting to show its age now (parked outdoors, sees rain, drive down a dirt road quite often)
 
#5 ·
Chip;

No probs. I repaired a lower valance for a tooner kid; and he was pretty short on bucks (apparently cutting coils to save money, means every time you drive over a bump, you have the extra money to repair the flattened muffler, wrecked rims and ground f/x). This time I wetsanded it, spotted in over some nicks and dings, used DUPLICOLOR adhesion promoter and some left over black semigloss from a snowmobile project. It didn't fail.
 
#7 ·
I know you don't want to hear this but there is no way I would be painting that car without removing the bumpers. The time spend removing them is FAR less than trying to do a different procedure than the body and masking them off over and over and all that, it is MUCH faster to remove the bumper and work with them off the car.

Brian
 
#8 ·
Now that Brian has posted in here. What is your preferred procedure for repairing damage to these urethane bumpers? I had one years ago I fixed and the discolored area of the urethane shone through the paint like a beacon saying lookit what Chip screwed up. It's been so long ago, I cannot remember the procedure or materials I used.
 
#11 ·
I have to say I have zero bumper repair experience if it involves a tear. We send out all bumpers with any kind of structual damage and have at everywhere I have ever worked.

We have them "remanufactured" and they do a pretty darn good job. Check in your area and see what they would charge. If they ask you how much they sell for new always give the the lowest price you can come up with because they usually set their reman price in relation to the new replacement cost.

Brian
 
#9 ·
TOTALLY missed the part where he said leave the bumper on. When I removed my bumper covers, I found all kinds of dirt/trash behind them. This would have been absolutely awesome to have blown out from behind the bumper when you're on your last color coat pass with your spray gun. They take literally minutes to remove. Side note; my TA used different length fasteners for different parts of the plastic, so put em back where you got em
 
#13 ·
Henry, the other day a guy came in and did a demo with a plastic welder that was REALLY good. That sucker worked like magic, but it was damn expensive. I forget how much but it was thousands as I remember.


Brian
 
#14 ·
Since I don't have repairs to do, do you guys think I'm OK with my 400 prep for the epoxy then paint? Or should I go a step courser like a 220 or 180? There is only one place where I'm down to the plastic itself so is there any need for a adhesion promoter before the epoxy?

With 400 my worry is whether the epoxy has enough tooth, with 180 or 220 I'd worry about sand scratches showing through. Perhaps I worry too much. Right now the plan is 400, epoxy, paint.
 
#17 ·
just did a 79 trans am..hate all the palstic...but...had some really dry sun damaged areas, and a few gouges, so, I sanded all the original paint off, down to the plastic, with 180 da, went over it with 220, then used bulldog, lightly, 2 coats, then omni epoxy, thinned slightly, sat overnight, sprayed 1 coat urethane 2k, then da with 320, then wet sand to 400 grit, almost all the urethane was gone by that point, then black base, and 2 light coats clear, 1 coat would do on bumpers, but I buffed these.
if you are just sanding to original prmer, then you really dont need adhesion promoter, 400, is fine to go to epoxy, but thin it down a little,,, you could even skip the epoxy if the original primer is ok, but I would still use bulldog before base color...
 
This is an older thread, you may not receive a response, and could be reviving an old thread. Please consider creating a new thread.
Top