Fiberglass and flexible bumper covers

Does anyone have experience or tips on prep and painting fiberglass and flexible bumper covers? I just purchased a 1982 Camaro Z28 which is a good candidate for a diy paint job. Considering black Rustoleum applied with foam rollers and foam brushes. It has an aftermarket fiberglass cowl hood (pin down/lift off) as well as flexible bumpers made of some kind of plastic. I am just in the planning stage and have not started any prep work yet. The glass hood will be easy to remove and paint separately and may be my first item to try. I can do the hood inside my basement in heated space or in my unheated garage. Any and all advice will be appreciated.

you may end up with some cracking in the bumper as this paint doesnt have a flex agent, but the nice thing about it is that you can always sand it back down some and repaint anytime you get ready. even still unless you curb check that bumper i think just the wind would'nt really crack it for a long time. i will have the same problem on my 86 trans am.

Man I've seen people spend a couple grand on a camaro or vette paintjob and it's not long before the spider cracks come back. I'm not sure how you go about preventing this but I had a truck painted a few years back and the guy said he used a "plastic prep" on the side mirrors, grill, valance, etc... I'm not sure if its a primer or what but I never had any problems what so ever with the paint on the plastic pieces. Might google it and see what turns up

Try going to a Auto paint supply house and get some Flex Agent you can mix it with your paint so it won't crack or spiderweb.

I looked into the plastic bumper prep a little further. 3m makes a product for this- 3M Automix Polyolefin Adhesion Promoter for TPO Repair - 05907. ($20 plus shipping per aerosol can) I believe TPO refers to "thermal plastic olefin" or something like that which is what most bumper covers are made of. Can you really mix flex agent with Rustoleum paint?

I know it's mixed with automotive paints back in the late 60's-70's which was mostly Lacquer paints.I would try mixing a very small amount and try it on a old bumper thats laying around let it cure and see how it does.
I hope this helps.

Yea see if you can find something to test it on. Let it cure and flex it back and forth to see how well it holds up. Be better than painting the whole bumper cover and it crack off.

i believe my 85 cutlass and '86 regal has the same rubber material used between the chrome bumpers and the steel of the body

where the car its self sports a dark blue original paint job the rubber filler panels looked like they were dyed dark blue and are "flat" unlikke the now faded but originally glossy body paint.

You can get plastic primers that have a flexing agent in them, my current car is all ABS plastic and I used one on the front bumper and never had a crack occur, its made by a company called U-Pol not sure what the name would be on your side of the pond though sorry

Hey guys!
Rustoleum does make a plastic primer. (In white) I plan to try it on my 1971 NOS lower front valance...which is plastic. The hardware store (Ace) didn't have it in stock...and didn't know about it until I asked them to look it up in the book. I special ordered it, and I got a case of it in spray cans. I will be trying this on my fiberglass front fenders too. I wasn't sure if the Regal Gloss red paint from the can would stick well to plastic. I figured if it's Rustoleum Plastic primer...it should work. I'll let you know how it turns out if your interested.

I'm not sure about rusto paint but when I had a wrecked Ford Taurus and the junk yard replacement bumper still needed work, I used regular old bondo to fill depressions.Didn't have any spider cracks tho. The guy at the paint shop said I didn't need flex stuff in the paint because they really don't flex much after they are put on. I just sanded it good, primered it and sprayed. Still looked fine 2 years later when I traded it off. However that was with bc/cc auto paint.
Mike

I have seen a lot of factory paints crack up on plastic parks that have flexed. Usually the problem isn't the paint so much as someone hitting curbs, parkinglot stoppers, sidewalks etc.

A lot of companies make rattle can paints specifically for plastic but IDK how well they hold up to flexing.

There is no need to add flex agent if you're not taking the bumper off of the car. Flex agent is only used when the flexible piece is painted off of the car. It keeps the paint "soft" enough so you can bend the bumper without the paint cracking during installation. The flex agent evaporates completely within a couple of weeks.

I painted my daily driver Firebird over a year ago with Rustoleum and no flex agent. I have had ZERO spiderwebs/cracking, and I lean up against the nose of it all the time while I'm under the hood.