I'm getting ready to spray the body side molding and wheel well trim to match my truck paint. While taping up the one brand new OEM wheel well trim pieces, I noticed that the plastic that will actually touch the fender is much more flexible and supple than the 14 year old stuff. It tapers to a thin, flexible lip so that it will mold to contours of the fender.

It occurred to me that this might be a problem after it is painted. So, my question is, how flexible will the overall paint film be? After adhesion promoter, I'll spray one coat of black epoxy primer, two to three coats of basecoat, and two coats of clear. I have both Tamco 2100 and Sherwin-Williams Dimensions Pro to choose from.

It's not like I'll be bending this stuff into 90 degree angles, but in order to get a tight seam, it'll have to flex it a little.

Any opinions?

Use BullDog Plastic Adhesion Promoter, a sealer is optional. I would suggest a 2k sealer, its much thinner. And paint should hold up well till it gets too old and begins to stress crack

You're saying I can forego the epoxy primer? Seems that a thinner film wouldn't be as brittle. Is that true?

Also, I'm thinking if I install the wheel well trim in question just after the clear is dry to the touch, it will still be more flexible because the clear won't reach maximum hardness for several days, giving it a chance to mold to the contour of the fender before it fully hardens.

Sound good?

Personally, I use epoxy (**********) because it is flexible. If you let it dry in a paint cup it comes out like a rubber hockey puck.
Since the pieces are already shaped you shouldn't have any problems.

'68 Coronet R/T wrote:Personally, I use epoxy (**********) because it is flexible. If you let it dry in a paint cup it comes out like a rubber hockey puck.
Since the pieces are already shaped you shouldn't have any problems.

Yeah, I remember you writing about that recently.

Got some more questions.

I'm painting a bunch of trim tomorrow. Here are pictures of the top and bottom bumper valances. The top one has an abrasion from my DA sander. The bottom one is from where the previous owner hit something.

What I have in my workshop right now is polyester glazing compound, body filler, fiberglass resin, fiberglass cloth, adhesion promoter, epoxy primer, primer surfacer, as well as BC/CC.

I want to get this done tomorrow, so the above products are my only options. I'm not looking for perfection. If it doesn't turn out, I'll just order new bumper valances when I order my new front bumper. I've got plenty of base coat left over.

Tell me what you'd do with this, given the above list of products.

I want to paint this chromed plastic the same color as my truck. I did a search and read through all the results. I'm still not clear on what to do.

How would you tackle these? Scuff up with an interface pad on a DA, then self-etch primer, then BC/CC? Again, if it's a total failure, I'll order new mirror covers, so not a lot at stake here.

There was another thread recently that touched on painting chrome plastic parts; hit the search on those two words you should find it. Bottom line is that stuff is tough to get paint to stick to and it really needs to come off. If there is any gloss at all you will not have adhesion. I don't remember hearing how the other guy made out with his.

chris wrote:There was another thread recently that touched on painting chrome plastic parts; hit the search on those two words you should find it. Bottom line is that stuff is tough to get paint to stick to and it really needs to come off. If there is any gloss at all you will not have adhesion. I don't remember hearing how the other guy made out with his.

I read those before. I think someone said to completely remove it. Was hoping for a new and improved easy answer (self-etch primer).

I went back and re-read the pertinent posts. One person said that he used to sand the chrome completely off, then paint as regular plastic, but later switched to sanding with 180 then self-etch primer with good, lasting results. We'll see.

Can you give me any guidance on the bumper valances, noting my list of products on hand?

Another question. Has anyone used Bulldog adhesion promoter as a filler prep on plastic?

This is probably harebrained, but I was thinking about making my own fiberglass reinforced polyester glazing compound (chopping up some fibers and mixing with the Evercoat) and applying to the inside of the cut in the bumper valance after applying some Bulldog. Just experimenting here.

I wish there were a paint store nearby that is open on Sundays. I doubt O'Reilly or Advance Auto Parts would have what I really need.