I ran a quick search and didn't find what I was looking for. I apologize if this has been asked and answered, but what type of plastic is our C3 interiors made out of? I ask mainly because I'm trying to plan out an interior repaint and the Mid America product instructions recommend two different types of "adhesion promoters" This one for TPO, EPDM, PP plastics. Or this one for ABS and PVC plastics . Thank you as always.

 

I am not sure, but post pictures when you do. I am starting on my interior, so let me know how it works out. I am sure others will be able to help once they wake up.

 

I have no idea what substance Mid-America sells for 'repainting' interior parts. But, if your interior parts have not received any aftermarket coatings since they were new, I highly recommend that you recolor those parts with vinyl dye, rather than "paint". I have used SEM liquid vinyl dye exclusively (sprayed on), and have never had any problems.

You can get SEM [or other good brand of dye] at pro auto body paint supply stores (not car parts stores). They can mix it to a color code or mix it to match a part you bring in.

Rattle can paints will not do what you want. They are thick and will fill the surface grain. If they don't adhere well, paint will chip/peel off the surface. Elastomeric vinyl dye will not behave in that manner. With dye, you can easily change colors without any bleed-thru problems; you can re-dye as many times as you want without changing the surface appearance.

Use the right stuff to recolor your interior. You'll be glad you did.

P.S. Even SEM rattle-can spray dye has a different sheen than your interior when it was new. My advice is to stay away from the rattle-cans when doing interior work.

 

While not 100% sure, I think the Mid America products are actually the SEM products re-branded (with the correct colors already mixed). Please don't take that to the bank... lots of other searches turn up the same thing. But, for the sake of argument... which one of these SEM products would you use prior to interior dying? The Plastic Adhesion Promoter for Olefin-based plastics? Or the Sand Free for ABS and PVC Plastics?

 

It is my understanding door and dash skins were ABS. Depending on model year, other plastic interior surfaces could be something else. Have you called Mid-America to ask which product you should use?

 

The door substrate is ABS (replacing the paper/cardboard form uses by GM) the ABS substrate is covered by a vinyl skin as were the original GM door panels.

 

I'm no expert on plastics, but one of the subsidiaries of a company I worked for years ago, was in a field related to plastics. From what I remember, I think that TPO, EPDM & PP plastics are part of the thermoplastic family, and are usually soft, flexible plastics. ABS and PVC are hard, rigid plastics. If I'm right, than the "adhesion promoters" for soft TPO plastics would likely have a flex agent in them, while the adhesion promoter for rigid ABS plastics, wouldn't need or use the flex agent.

Different year Corvettes, used different interior materials, so it would be helpful to know what year the OP is working on.

Most 68-76 interior surfaces were vinyl covered. Though some parts, such as the rear storage compartment frames, seat backs, kick panels and parking brake console, were hard plastic, and painted. Just about everything else was covered in color keyed vinyl.

Starting in 77, the vinyl covered a-pillar moldings were replaced by painted ABS plastic ones, and the rigid plastic parking brake console, was replaced by a flexible "rubber" one. The "clam shell" frames used for 78 Pace Car and all 79-82 seats, were also ABS and painted.

I would think that if you were dying a 77-82 parking brake console, or any vinyl covered interior surface, you would want the adhesion promoter for TPO, EDPM, etc. The adhesion promoter for ABS should be fine if your dying hard plastic parts, like kick panels or seat backs.

 

Awesome, thanks for the replies. Mid America wanted me to do an "acetone test" on the back of the panel to see if it had an effect on the plastic.. I was hesitant to do this mainly because I could tell the back was different from the from the (Vinyl wrapped) front. I mainly just wanted to be sure... now I am.

 

the rattle cans are paint/dye from all companies.

 

The major difference between 'paint' and 'dye' is that dye has elastomeric additives to allow the parts to flex. And, that product will work on ANY item...whether it flexes or not.

But, good quality vinyl dye has OTHER properties that most paints do not have. SEM [liquid] dye is very thin (almost watery viscosity); but it has very dense pigment content. Thus, you can change dye colors at will with very little bleed-thru with only one coat; with 2 normal coats, you can change from black to white, if you want.

And, when dry, it won't fill in surface grain like paint. It won't chip/peel as it bonds with the surface (if that part hasn't been 'painted' previously).

There is a tremendous difference in the results obtained when dyeing interior parts, as opposed to painting interior parts. And, from what has been posted on this Forum (over the years), I suspect that the rattle can stuff labeled "Dye" from the aftermarket suppliers is really cheap paint with some elastomer additive included. Not really what you want for YOUR C3's interior.

You can do it "easy" by just ordering unknown stuff on-line; or you can do it RIGHT by getting the proper vinyl dye from a pro auto body paint supplier. Your choice...

 

So, full disclosure I painted my interior using the Mid America system about 8 years ago and was pleased with the results then, but admittedly I rushed the job a little bit and left (what I now think is) an important final step out. Were I to do it all over again I would look into doing what 7T1 and others have suggested... using the interior dye. That said since I did the Mid America route last time and it lasted almost a decade I decided it would be safe this time (and your always better the second time right?)

First things first. All Mid America stuff is SEM stuff (I pulled the label off to check). What they do is mix the color coat in the spray can for you. I did check and I believe their pricing is very fair.. plus they've done all the color matching leg work for you. The color coat is mixed in with SEM Universal Color Coat (a flexible coating.. not a dye).

Here's the process I used on my first Vinyl piece (the trim underneath the rear window on a 69 Coupe).

1. Cleaned the piece twice with liquid dawn and green dish scotch pad.

2. Next I used Mid Americas Vinyl Prep to further clean and remove all the years of interior cleaning product. I did this x 2.

3. I then used SEM soap to further remove all grease and oils

4. Gave the piece a quick wipe down with tack cloth

5. Next I applied 3 coats (10 minutes apart) of Clear Flexible Bonding

6. Then I applied 3 coats of (in my case) Gunmetal Color Coat Of note I think it took about 1/3 of a can to do the rear trim piece. Once I am completely done with everything I'll let you know how much was required for the car.

7. Lastly (this was the step I skipped 8 years ago) I applied (15 min after the last color coat) Low Luster Clear.

I did not take a before picture.. needless to say it was mainly just dirty and a little faded. But I am very pleased with the results. Only time will tell how well it holds up.

 

I read and reread some of these posts. Good information. I've been involved with some "re-dying" interior parts...changing my black 1970 interior to red. Just to emphasize what has been said...you can't take a can of red "re-dye" and spray over a black piece and you're done. The "re-dye" paint is very thin, it'll take many coats to get a perfect solid color.

One of the reasons you want to learn about "re-dying" original parts to a new color, is that the repro parts in the correct color are often of poor quality with regards to fit. An original interior part, with no cracks. warrants your attention to try to "re-dye" it; i.e. repaint it.

 

For an original interior part (no re-coat of any type), you should only need to CLEAN the part of all oil/dirt/grease, RINSE the part with clean water to get rid of any detergent/soap, DRY the part completely and SHOOT good quality vinyl dye on it.

If you have to do more than that, the "dye" you are using isn't worth buying. I have always used LIQUID SEM dye that was purchased and mixed at a pro auto body paint supply store and sprayed it on....and have NEVER had any peeling/wear-thru/fading/etc. on any part I re-dyed.

Do what you want...it's your car. You may get a few years of service out of it. I've sprayed a leather-wrapped steering wheel with SEM dye and have used it regularly for 5 years without any problems.

The original parts you presently have are over 40 years old and still have the original [dye] color on them. That's how a re-dye should hold up, as well.

P.S. Even SEM spray can products don't have the same appearance and durability of sprayed-on liquid SEM dyes.

This entire topic (as many times as it shows up) always reminds me of the old adage:

"You can take a horse to water....but you can't make him drink."