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Repairing wasted door panels and textured plastic.

Started by Mr Cuda, March 24, 2022, 06:02:42 PM

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Mr Cuda

First, let me say that I don't make nice, flowing threads. I've had this idea floating around in my head, and recently read another thread from kawahonda. Nicely done, good pictures.
Read it here.https://forum.e-bodies.org/interior/6/interior-plastic-restoration-journey/18703/msg239477#msg239477
I was looking to fix some door panels for a barracuda project,  that is truly a mopar.  (Mostly Old Parts And Rust).
That project has a roll cage, and it has cut outs in the door panel  to clear the tubes. Street rod culture says to build up the backside of panel with expanded foam, then cover with vinyl or leather for consistent finish.
I want my cut panels to look stock.....  Second project is to fix speaker holes in convertible panels.
My sample panel has been outside for many years, but not in the sun. I started by sanding with 36grit all the cracked texture off the plastic  base. My first attempt which failed,  showed that all the texture has to be sanded off as it is a softer layer than the plastic itself.
The next issue is adhesion of a coating to the plastic.
From fixing faded plastic,  I thought plastic primer,  and a polyester based paint would stick and I could apply my texture to it. While  I was able to sandwich the texture between the base and topcoat,  the adhesion to the plastic failed. It did allow me to give the coating and texture a good fingernail and scratch test of the surface itself.  In the end a razor blade and air blower stripped the panel back to its base.
Total time on first go round was 1 hr.
15 minutes to sand texture off.
15min primer,  polyester base, texture.
Once  dry, sand texture to give a flat face to the round spatter of texture
Topcoat with  sem formal black interior paint.
I found a can of ppg vinyl additive that I've been saving for years.  It gives the finish a very soft effect and feel.
But it all came off and I started over.
Pictures from the first attempt.
S


Mr Cuda

More pictures with primer and base  showing absorption

Mr Cuda

Shows texture sanded to try and replicate the flat grain .
Not very successful
One final shot of first attempt


Mr Cuda

So a good  45 minutes wasted cleaning  all the edges an places it did adhere, and cleaning all the remaining factory texture.
I sprayed with a 2 part polyurethane to stick to the plastic,  sprayed my texture  and top coated  with the same paint to soak in and encapsulate the texture.  24 hr dry, then  sand the texture down to a flat top.  I used 80 grit dry.. Topcoat with the sem.
Total time to paint, texture and sand and topcoat,  maybe 45 minutes.
Future  plans are to spot sand the black with 220 wet to see if the pebble effect gets better.
Then finish coat with the vinyl additive

7E-Bodies

#4
 Very interesting. Please keep posting.
1970 Challenger R/T Numbers Matching 440 Auto in F8 Quad Green

cuda hunter

Sure does look great compared to them in the dumpster.
No one seems to save these panels due to not being able to save the original texture.
Great job sir.

Love the pics!
"All riches begin as a state of mind and you have complete control of your mind"  -- B. Lee

Jay Bee

I read this over & over and  must be missing something but what was used as the "texture"? Was it the same Stone Guard kawahonda used?


YYZ


Mr Cuda

Jay Bee, we will get to that. I have several alternatives I'm working thru.

I had another batch of machine parts come through which delayed getting the rear panel resprayed. Since I  use the industrial polyurethane in my interior panel coating project I thought I'd try a different process on a seat back while paint was mixed up.
I had a really nasty seat back that the texture was crumbly on. So crumbly,  I had thought the plastic itself was bad. I sanded it with a da, and 60 grit and the chalky surface just flew off leaving a nice plastic back.
So I've changed my mind about any panel being too far gone to reuse for a rescue project.
This time, instead of adding texture to be encapsulated with the coating,  I went with the time honored method of no air cap spatter technique. I was hoping to get the droplets to have the same base size as the factory grain,  so once the heads get sanded off to flat, it would have small valleys.
No pictures of it guide coated and sanded,  as they were too large in diameter. I will sand flat and repeat with a finer spatter.  But today's takeaway was no junk is too far gone to practice on.

The texture method on the rear panel left some pits, like pinholes that make it not like grain.  I think some of that effect might get filled in with another coat, and it's not a bad look,  just not factory.  Not that we will ever replicate that.

Mr Cuda

My seat back sample  has been re texured  with the 2 part polyurethane.
The first time, I had left too many scratches that showed through,  and the texture was too large.
This texture coat was lightly sanded to flatten the round peaks.  Better but too many large/small size variations

Mr Cuda

Trying for something even better,  I scuff sanded  that finish and hit it with another coat of SEM.
To get a finer , and longer texture  pattern,  I took the air cap  off the paint gun, and shot across the panel.
I played with  air pressure to get sufficient force, without atomizingthe spatter too much.
The SEM has a very low viscosity,  so slow to get texture  buildup.
I think this is looking better.
Now I'm going to get a fresh pair of junk panels and test what I've learned,  and do a time study.


7E-Bodies

1970 Challenger R/T Numbers Matching 440 Auto in F8 Quad Green

autoxcuda

Mr Cuda, Nice way to think outside the box. What you are doing seems like the process of putting texture on new drywall inside a house.

Guy in our club put a texture on his with a paint roller.

Had to play with paint consistency and roller texture and/or nap.

Spring Fling April 2024 Woodley Park, Van Nuys CA, 600+ Mopars, 175+ all Mopar swap, Malibu Cruise, Mopar Cruise-In: www.cpwclub.com Date comming...

Flatdad

Thank you for taking the time to test this and post about it  :thankyou:

Swamp Donkey

I'm also going to try this and see what happens.  Not much to loose besides a bit of time and some paint.


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1973 Cuda. 340 4 speed.