I have the flat spoiler believe it is a base spoiler in black (foam). I was wondering how i can paint this white with out the paint coming off in a month or two.

 

Foam!?!?!

 

like anything fiberglass or plastic, sand it and use self-etching primer before painting.

I believe our spoilers are like the 3rd gen trans ams.... plastic injected with a type of foam, or at least that is what it seems like.

-Mike

 

Not to hijack the thread, but How about repainting the S5 Wing spoiler? if the paint is good (wrong color) should you still reprime?

Thanks.

 

well, are you changing colors since you mention it's the wrong color? s4 and s5 dont matter really in this.... painting is painting, prep work is the same. I personally always reccomend removing any loose paint and just roughing up the surface (1000 grit paper) then using some kind of primer.... I happen to like self-etching because it makes a nice surface for paint to stick to.

 

Obviously not someone who has done any real bodywork....

Self-etching primers are meant to bite into uncoated sheet metal, not for use on polymers or 'glass.

For each different type of plastic and each different paint system, there is a different method of prep.
You should talk to a rep from your paint store and find out what steps should be taken in prepping URETHANE FOAM in your paint system.

 

seriously, what the hell? 1000 grit as prep for primer?
self-etching primer as a high-build before topcoat?

This guy has no idea what he's talking about.

 

Has anyone repainted a S5 spoiler themselves with good results?

Thanks for all the replies so far.

Not sure what material the S5 spoiler is, I actually cut out a section to narrow to fit on a vert, see attached picture. Looks like a foam material on the outside with a ? core.

 

I repainted an s5 spoiler sucessfully last summer!
I even switched colors. I had a silver one and I used a scotch brite pad on an orbital sander to rough it up as much as I could. Then I sprayed it with the new base coat (blaze red) a few times, and then the clear coat. It looks fine to me. No problems yet at all.

 

Yeah i forgot what i used on my spoiler, disreguard my previous info. I used 1000 grit and self etch on my fender and somehow got that mixed up with the work i did on my spoiler ....... working on like 100 different things on my car at once an got them mixed up. He is right though, get primer for polymers/plastics to use on the spoiler.


PS they do make special self etch for fiberglass.

 

Yes, I have repainted them successfully. The best thing to do is to read the instruction sheet on how to prep your surface when you buy your paint system.

You don't just buy a primer, buy a sealer, buy a paint, and then buy a clearcoat and throw it all on. You get a paint system from a manufacturer, and you use the list of products from that same manufacturer that is listed to work chemically together. Different brands of paints differ chemically, and won't necessarily bond together.

 

I wouldnt paint it my friend painted his and if you push on it and it is foam it will spider crack and the paint would start to come off in a few months.

 

thanx everyone. I found out that I need to use an epoxy paint, b/c it will go with the flex in the foam.

 

Actually an epoxy primer won't give you much flex at all, the person who told you that is probably confusing this with an epoxy resin, the most flexible of all fiberglass resins.

To paint you PLASTIC spoiler - which happens to be a TPE type of plastic (also known as semi rigid) there are two scenarios.....
1 if the paint is still good, follow these steps:
-simply sand with a 320-400grit and DONT SAND THROUGH ANY EDGES OR CORNERS
-prime with a standard high build polyester based primer only use a flex agent when you mix it (the ratios vary depending on the paint line being used)
BTW flex agent simply slows the curing process so it never actually fully hardens to allow it to flex however-when you sand the primer after its dry it will ball up or clog your paper so be sure to clean it by slapping it on your hand quite frequently
-final sand the primer with 400-600grit the paint, again using flex agent in whatever type of paint you put on, BC/CC will need it only in the clear, but will need hardener in the base (At least with the BASF materials, others may differ)

2- if the paint is, peeling or cracking or body work needs to be done

-strip all of the paint from the part by using either a pressure washer or by sanding it all off - I MEAN ALL OF IT - if you wash the paint off, sand the entire part with blending paste and a fine scotchbrite pad, if you sand it you nothing coarser than 400grit

- repair any dents or what have you with a flexible plastic repair filler (fleixble putty used for repairing bumpers, again it sands like primer with flexagent in it)

-clean the part with a WATERBASED silicone wax remover to prevent the plastic from soaking up any chemicals, let it breathe for 20 min. then apply a very thin, even coat of plastic adhesion promoter (meaning you should not see any wet spots on it when you spray the promoter on) let that flash and then apply you flex'ed primer

-continue as per previous instructions

any questions pm me

Joe Phillips, Classic Auto Body Inc.