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Question to the paint gurus--how do you get a decent flat black look under lexan? I'll be working on a 1970 AAR 'Cuda body like this one (not this color, though) but I want to do a flat black hood, chin spoiler & rear spoiler. I could've sworn HPI listed part numbers for the flat black & Panther Pink paint colors used for this body, but I can now no longer find that info anywhere on their site...

You have to spray the paint on the outside for a satin look.

HPI used Testors Model Master Lacquers on those bodies... you can get most of the popular original factory colors.

As for flat black, you cut away the masking film and spray the paint on the outside. I use Krylon Semi-Flat black and have used other 1:1 auto lacquers, on the outside, and it works very well. Lately, I have been spraying a first cost of Pactra Black down for better adhesion, then the Krylon, and it seems to be holding up better.



I have been doing SC beds like this for a while now. So far, no complaints.

Does it hold up to actual use, or is it only suitable for shelf-queens? And the Testors Model Masters Lacquer paints you mentioned, do those bond to Lexan like Pactra paints do, or are they also just for show?

If flat black painted on the outside doesn't hold up to driving conditions, I'll probably just go ahead and paint with normal black on the underside...durability is an important consideration for me.

Thanks!

it'll hold up fine. just don't hit anything or roll it over.

The Model Master paints held up to the Vintage Trans Am Nationals, they will hold up to anything. There are guys I raced with who painted their cars flat black and raced them. I didn't see any major issues with the paint durability.

the thing to remember is that the lexan paint has solvents in it to help it bond to the lexan. Doesn't matter if the paint is on the inside or the outside surface. Most lexan paints are flat because they don't need to be gloss, the lexan does a fine job for you. So shoot it on the outside, and touch it up as you would paint if it were on the inside. It will obviously be more fragile because it doesn't have a bulletproof coating(the lexan)

jwscab wrote:the thing to remember is that the lexan paint has solvents in it to help it bond to the lexan.

Nope, Parma Faskolor is water-based acryllic made by Createx/AutoAir for general purpose hobby usage. They aren't Lexan-specific paints, they just happen to bond to Lexan and flex well. These are the same paints you can paint T-shirts with and race cars. Water-based paints are not etching paints. Solvent-based, yes, but water based paints are not going to surface etch the Lexan at all.

hehheh, you are right Doug.....you can tell how long ago I painted a body....

one of these days I'll get to try out that water based paint....

the etching/solvent still holds true with the 'traditional' paint though correct?

Thanks for the info, guys. Maybe I'll do the flat black on top...the upside is, masking will be easier.

jwscab wrote:the etching/solvent still holds true with the 'traditional' paint though correct?

Yeah, anything with a solvent in it will "haze" Lexan. Some make it brittle, some don't. Those that don't are what you would find in older style lacquer Lexan paints and current paints like Spaztix. Most automotive lacquers will do the exact same thing (which is what I believe Spaztix paints to be).

Eau Rouge wrote:

jwscab wrote:the etching/solvent still holds true with the 'traditional' paint though correct?

Yeah, anything with a solvent in it will "haze" Lexan. Some make it brittle, some don't. Those that don't are what you would find in older style lacquer Lexan paints and current paints like Spaztix. Most automotive lacquers will do the exact same thing (which is what I believe Spaztix paints to be).

So if I understood correctly, automotive lacquers *will* haze Lexan? Or they work the same as Spaztix, in that they won't haze Lexan?

If automotive lacquers work great on Lexan, why not paint these bodies with that, because the color selection is endless and the larger rattle-cans are more economical...

Because most rattle cans aren't lacquers anymore, as they are being phased out in many places in the US.

Hazing of Lexan is due to the solvents in paint. Anything with a solvent will etch or haze Lexan for the most part, with few exceptions. That hazing is actually good for paint bonding. You won't see it when painted. If you tried to remove the paint, you would see what the solvent does to the Lexan.

I knew someone who used to paint R/C and he ONLY used automotive lacquers, and nothing else. He never had paint adhesion or cracking problems and swore by the results. Most people could not afford the smallest quantities of auto paints, so it was never practical for R/C use.

Before I posted this topic here, I emailed HPI Support asking what paints were used for the models on their site. As Eau Rouge stated, they used Testors Model Masters. However, I was also informed that these paints are not recommended for Lexan due to the hardness when dry. It was suggested to use Pactra or Tamiya paint. Testors' website states that the Model Masters paints "cure to hard, permanent finishes", which wouldn't seem ideal for flexible Lexan.

http://www.testors.com/category/135232/Model_Master

Only Pactra makes the statement "adheres to Lexan".

Email from HPI:

"Thank you for contacting HPI Racing and Hot Bodies. While we don’t have the exact colors used for those two bodies, I can tell you the paints that are used are generally by Model Masters. The paint used is not specifically for polycarbonate, but used rather because it shows up well in pictures. For durability of the paint adhesion to the polycarbonate, I would suggest either Pactra or Tamiya."

So, it looks like I'll stick with Pactra for my upcoming paint work. I found a color I like that's available in a spray-can. I'll still do the flat-black hood treatment, though, because I think it looks great!

They are basically saying that they won't guarantee Lexan adhesion, but I do know many people who have successfully used it on racing bodies, FWIW.