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Spray Paint types for Lexan

Posted: Sun Feb 11, 2024 11:50 pm
by GreenBar0n
I'm trying to get a certain color for a 1/10 '67 Corvette body. I can't find the exact color match in Tamiya, or Duratrax polycarb spray paints.

I've seen some people say that if the inside of a lexan body is roughed up with a green pad to produce a scratchy looking adhesion surface, and then de-greased with soap and water, that then nearly any spray paint will stick to that surface. Has anyone tried this, or have experience with this?

Wanting to try color matched Chevy Marina Blue spray paint for autos, inside lexan.
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Re: Spray Paint types for Lexan

Posted: Mon Feb 12, 2024 12:35 am
by Dangeruss
Marina? Not going for Nassau?

Sanding helps with adhesion, but I found if you get very aggressive it'll leave scratches on the Lexan that'll be visible after you paint.

Could spray couple coats of Tamiya PS-55, followed by your automotive color coats, then back coated with the PS color of your choice. The auto paint mixes with the Tamiya clear and becomes flexible while the PS back coat acts as an encapsulator.

Or you could ask your local PPG or Dupont paint store to mix you up a color matched spray can with a flex agent for use on plastic. Effectively making it like Tamiya paint.

Re: Spray Paint types for Lexan

Posted: Mon Feb 12, 2024 3:52 am
by GreenBar0n
'67 Marina Blue Metallic is the factory color this one came with, it has the 976 paint code stamped on the plate under the glove box.
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https://www.corvsport.com/marina-blue-1967-chevrolet-corvette/

I have PS-55, but I used it to dull the outer shine of the ragtop on this VW Bus model, to make the shiny top contrast to the dull vinyl look of the sunroof/ragtop:
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I may have to try the 976 paint-matched aerosol, just to know for certain if it can be done on lexan.

Re: Spray Paint types for Lexan

Posted: Mon Feb 12, 2024 8:19 am
by morrisey0
I would think PS49 could get you there with the correct backing.
tamiya-ps-paint-chips-2e4c.jpg

Re: Spray Paint types for Lexan

Posted: Mon Feb 12, 2024 12:03 pm
by Elkcycles
I've also had excellent luck with Mountain acrylic graffitti paint from art supply stores. Metallics aren't an option, but the pallette is broad.

Re: Spray Paint types for Lexan

Posted: Mon Feb 12, 2024 2:26 pm
by GreenBar0n
morrisey0 wrote: Mon Feb 12, 2024 8:19 am I would think PS49 could get you there with the correct backing.
tamiya-ps-paint-chips-2e4c.jpg
I was checking that PS-49 out, but it has a matte anodized finish, while it could pass if I weren't being too particular, it doesn't have the right blue overall, Sky PS-49 looks like silver over blue, I need blue over silver.
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Marina Blue Metallic is hard to capture in pictures, it's definitely sparkly, but not like an old 70's boat, it has a silver sheen below the blue that moves as you walk around and catch the sun off of it.

I think I may be foolish enough to try actual auto paint inside lexan at this point.
https://paintref.com/cgi-bin/paintdetail.cgi?paintx=1967%7CGM%7CMarina%20Blue%7C79246

Re: Spray Paint types for Lexan

Posted: Tue Feb 13, 2024 9:30 am
by XLR8
There's nothing foolish about using automotive paint on lexan. Just "prime" the body with PS-55 and I think you'll be fine.
Also, apparently adhesion promoter can be used with lexan but I've never tried it.

Re: Spray Paint types for Lexan

Posted: Tue Feb 13, 2024 1:00 pm
by GreenBar0n
XLR8 wrote: Tue Feb 13, 2024 9:30 am There's nothing foolish about using automotive paint on lexan. Just "prime" the body with PS-55 and I think you'll be fine.
Also, apparently adhesion promoter can be used with lexan but I've never tried it.
Tamiya PS-55 is Flat clear, the Flat won't dull the layer beneath it?

I've only used PS-55 on the outside of lexan so far. Will test some plastic bottles with PS-55 on the inside this time.

Re: Spray Paint types for Lexan

Posted: Tue Feb 13, 2024 3:26 pm
by Coelacanth
I'm not sure how well automotive paint will bond to Lexan. For one thing, it's meant to bond to properly-roughed-up primer on a hard surface, and you can't be priming the inside of a Lexan body shell or that's all you'll see, glossy battleship grey. It's also not meant to be flexible so auto paint on Lexan might crack or chip if the Lexan is stressed. There's no harm in trying, of course. :)

Re: Spray Paint types for Lexan

Posted: Tue Feb 13, 2024 4:13 pm
by GreenBar0n
Coelacanth wrote: Tue Feb 13, 2024 3:26 pm I'm not sure how well automotive paint will bond to Lexan. For one thing, it's meant to bond to properly-roughed-up primer on a hard surface, and you can't be priming the inside of a Lexan body shell or that's all you'll see, glossy battleship grey. It's also not meant to be flexible so auto paint on Lexan might crack or chip if the Lexan is stressed. There's no harm in trying, of course. :)
I had heard that lightly scuffing/scratching the inside of the lexan body with a kitchen green pad, not gouging, or deep scratches, just even surface roughness on the entire inside, then degrease, and then paint with nearly any spray paint - that this can work for lexan. Might as well give it a try. I wouldn't expect the paint to survive bashing, or to be flexible like polycarb, this one will be a shelf body, or a scale speed cruiser. I'll test this all on plastic bottles first, for color, then adhesion.

Re: Spray Paint types for Lexan

Posted: Tue Feb 13, 2024 4:30 pm
by mAdMan
I use poly acrylic spray paint. Its cheap and found all over.

I also back with the cheapest white I have laying around. Poly paint first and the white doesn't crack. Don't have to buy expensive white. Just spray white before the poly colors cure.

If you use an acrylic clear first you can put any paint over it while it's still tacky.

Re: Spray Paint types for Lexan

Posted: Tue Feb 13, 2024 10:11 pm
by XLR8
GreenBar0n wrote: Tue Feb 13, 2024 1:00 pm
XLR8 wrote: Tue Feb 13, 2024 9:30 am There's nothing foolish about using automotive paint on lexan. Just "prime" the body with PS-55 and I think you'll be fine.
Also, apparently adhesion promoter can be used with lexan but I've never tried it.
Tamiya PS-55 is Flat clear, the Flat won't dull the layer beneath it?

I've only used PS-55 on the outside of lexan so far. Will test some plastic bottles with PS-55 on the inside this time.
The flat clear won't affect the finish in any way. Assuming, of course, that you are painting the inside of your body shell, the lexan provides a glass-like reflective finish.

Re: Spray Paint types for Lexan

Posted: Tue Feb 13, 2024 10:14 pm
by Dangeruss
Coelacanth wrote: Tue Feb 13, 2024 3:26 pm I'm not sure how well automotive paint will bond to Lexan.
Bonds fine... some brands just doesn't hold up to abuse as well. When we were in school all our Lexan bodies were shot with automotive paint because it was cheaper and more readily available.

What makes Tamiya PS a "lexan paint" is the use of acetone in their carrier instead of say, isopropyl. Acetone etches the plastic and creates more adhesion. Any spray paint with acetone will produce the same results as Tamiya PS.

If color match is the most important factor, auto paint is the easiest solution, with PS-55 acting as a primer if you want a more resilient paint job. I gurgled and found a video... 3:30 in he demonstrates the flexibility of Tamia TS with PS-55 as a base:



In the end there is no wrong type of paint, just multiple options each with their own advantages and disadvantages.

Re: Spray Paint types for Lexan

Posted: Wed Feb 14, 2024 2:20 pm
by GreenBar0n
Dangeruss wrote: Tue Feb 13, 2024 10:14 pm
Coelacanth wrote: Tue Feb 13, 2024 3:26 pm I'm not sure how well automotive paint will bond to Lexan.
Bonds fine... some brands just doesn't hold up to abuse as well. When we were in school all our Lexan bodies were shot with automotive paint because it was cheaper and more readily available.

What makes Tamiya PS a "lexan paint" is the use of acetone in their carrier instead of say, isopropyl. Acetone etches the plastic and creates more adhesion. Any spray paint with acetone will produce the same results as Tamiya PS.

If color match is the most important factor, auto paint is the easiest solution, with PS-55 acting as a primer if you want a more resilient paint job. I gurgled and found a video... 3:30 in he demonstrates the flexibility of Tamia TS with PS-55 as a base:



In the end there is no wrong type of paint, just multiple options each with their own advantages and disadvantages.
Really appreciate that example, thanks for that!

Interesting to see the PS-55 was able to support Tamiya TS, and be that flexible still; that also adds a ton of color and spray-type options. Also makes this video testing metallic blues even more relevant, as these are TS and lacquer.


I have a nearly full can of PS-55 Flat Clear already, I'll get a can of 976 Marina Blue Metallic auto-matched aerosol spray, and we'll see what can be done. Might be a couple of weeks before I can get this going.

Thanks guys!

Re: Spray Paint types for Lexan

Posted: Wed Feb 14, 2024 2:28 pm
by Coelacanth
Dangeruss wrote: Tue Feb 13, 2024 10:14 pm
Coelacanth wrote: Tue Feb 13, 2024 3:26 pm I'm not sure how well automotive paint will bond to Lexan.
If color match is the most important factor, auto paint is the easiest solution, with PS-55 acting as a primer if you want a more resilient paint job. I gurgled and found a video... 3:30 in he demonstrates the flexibility of Tamia TS with PS-55 as a base:

That's cool, I didn't know there was this PS-55 clear primer that will let automotive paints properly bond to Lexan. In my old-school mind, whenever I think of primer, I think of solid grey or red paint primer. :P