Hi all, I'm wondering what the front and back bumper was made of on the 1991 Camaro RS convertible, as well as the full ground effects kit, I believed it be thermoset polyurethane, but it also seems like it could be fiberglass as it has a crystal like texture on the back, same with the bumpers, I need to know because I'm planning on repainting my car, and figured I might as well fix some cracks that are on it while I'm at it, but obviously the material it's mad out of matters very much, thanks for any info and help

 

You talking about the bumper covers? If they're yellow, then it would be thermoset polyurethane. polyvance.com is a good place to start on the various ways to repair this.

I'm sure the ground effects are SMC. I could see the back of the SMC being described as a "crystal" structure, but not the bumber covers.

 

I'm referring more to the ground effects kit, but they both seem to have the crystal texture on the back, they have a slight yellow tint but not like the examples I saw online, also my spoiler had work done on it before I owned it with fiberglass resin and Matt and thats held up but I read fiberglass doesn't work with urethene so it SHOULDN'T of worked, but I can't tell anymore

 

Some examples shots

 

I can see a little bit of yellow under what appears to be black primer on the second photo. I think Polyvance "Flex Fill" would be appropriate here. If the damage under the fiberglass repair is a tear, staples might be an option to help hold it together and let the Flex Fill do its job for the final shaping. Of course, the fiberglass would need to be removed.

Keep in mind I have yet to repair my bumpers and the same front spoiler/ground effect damage you have, so I am a complete novice at this. I will be relying on Polvances tutorials.

 

Yeah I looked and noticed that it's starting to tear on the edge of the fiberglass😐, I believe using an airless welder is probably my best bet?

 

Yes, I forgot about that part of the repair. Polyvance has the correct repair rod for polyurethane.

I've seen videos of someone pulling on the repair and it seems extremely durable. The tutorials are pretty good. I think one way is to tape the rear of the crack to hold it in place while the front is repaired, then go to the back.