AlienJuggernaut

It's sad. I worked for "the search engine" when they were brand new. It worked great back then, because the results were not "gamed".
Now, it's a piece of junk and it only pukes out what the billionaires want you to see.

I cannot use any set of search terms to find very specifically and without conjecture, what type of plastic is the door panel on a 1997 Trans-Am made out of?

All the conjecture: 97 was the year they changed or last year before they changed plastic type. (Ok? And? What is it?) 97's don't crack (they do). Etc.

I would just like the plastic code from a door panel. Mine is covered with glue. Is everyone else's?

If I knew WHERE under the glue it was, I'd clean that part, but I'm not stripping the whole mat out.

I tried searching on here, but there is nothing distinguishing about those search terms that don't bring up hundreds of unrelated topics.

Thanks!

wssix99

iTrader: (5)

The material is Sheet Molding Composite (SMC) https://gm-efi.com/features/gm-efis-...-chevy-camaro/

SMC is a specific material and has it's own repair products and procedures.

AlienJuggernaut

Awesome thanks! GM's choice of plastics is the gift that keeps on giving.

And that's for sure in 1997?

Do you know if that is the "new material" or the "old material"?

Since it cannot be rewelded, has anyone tried polyvance PP/GF rods on it? It's supposed to be "adhesive" and not melty.

And since it's plastic, I presume you can set "plastic staples" into it to stop progression?

==========================================

Ok, based on the SMC info, I "took apart" the broken tab, and looked at it under my microscope.

I do not see any glass fibers in it.

Do I have the "other plastic" from the split year?

==========================================

Alrighty, replying to myself so Google might pick this up for anyone else that needs the info.

Mine is a 04/97, April 1997

I ripped off the matting on the panel and used a very bright flashlight to shadow highlight the plastic stamps.

I found an SAE [PP] stamp

Since I cannot see any fibers in the piece of plastic that I sampled, I cannot verify that it is SMC, the [PP] leads me to believe I have the Polypropylene door panels.

Can anyone else confirm with an early 97?

RPM WS6

iTrader: (3)

I think the OP is referring to the interior door panel - the piece that always cracks near the top on the Firebirds.

SMC is the exterior (actual door) construction material, but not what is used for the interior (trim) panel.

lees02WS6

iTrader: (5)

I thought the interior plastics were ordinary abs plastic. The door panels crack because the combination of thinner material, temperature swings, and the placement of the staples makes them prone to cracking.

A electric plastic welder can be used to pull the crack closed.

Methyl Ethyl Ketone can melt it back together but the stuff is nasty.

AlienJuggernaut

Thanks, I was going to be asking about that in about a month, haha.

Guess I should just look for a good one at a yard.

wssix99

iTrader: (5)

Thanks, yes. SMC is for the actual door. The decorative panel is not ABS. (Otherwise, it would be easy to repair the cracks it gets.) If I recall correctly, its Polypropylene. (I'm not sure.)

If you look on the back of the panel, there will be a stamp with some letters identifying the type of exact plastic : https://en.wikipedia.org/wiki/Resin_identification_code

When the door panel crack issue came up, we found there was no proper way to weld this particular type of plastic. There are only exotic glues that don't bond as strong as the original material.

AlienJuggernaut

Right. If you look at the reason for my original question, mine was covered with glue and I wondered if anyone had theirs exposed. After getting mixed replies, I did what I was avoiding and cleaned off the glue and found a SAE [PP]. Couldn't risk misinfo since mine was a split year.

A little confused on this comment. Do you mean specifically decades ago there was no way to weld PP?
You mention weld, then glue and bond. Not sure which definition you meant of weld, as in plastic welding, or weld (like with glue) to join a seam.

I used both an air welder with PP rod and then an airless and FiberFlex'd over it, with a steel mesh sammich between.

Welded fine, crack abated. 100% stronger than original now. Just have to monitor your heat.

Cosmetic side you have to know some advanced plastic repair, but that's doable also.

Polyvance is your friend. Ask for Scott in Product Development.

Repairing my cracked bumper cover in a few days. Just waiting on a body shop panel stand, those door panels killed my back bending over them.

wssix99

iTrader: (5)

Sorry I missed the comment that you were dealing with the panel cracks. A lot of folks find the SMC slathered with glue and other compounds to repair it and that was the first thing that came into my head.

I expect that you didn't have too much trouble getting the glue off the poly since things don't stick to it well.


It can be done. Compared to other plastics; PP is extremely difficult to properly weld and glues don't work well with it: https://forgeway.com/how-to-weld-polypropylene/


Do you have any pictures to share? I gave up on trying to weld my panels because of this extra step. (Needing to re-finish the front side of the panel.) If the plastic was easier to work with, we would have had the option to have a partial penetration plastic weld on the backside and be done with it.