Best type paint for lexan/acrylic

[Guest]

Can anyone tell me what is the best type of paint to use to put a black out strip around the edge of my windows? I am using acrylic at Mark Clapp's suggestion for it scratch resistance.

 

[Guest]

Well, I think I can tell you what paint not to use. I followed this technique described by Greg Heacock:
"To get the nice black edge...
When you get the perspex or Lexan sheet stock, it will have a protective plastic coating on it. Leave that in place! Cut your window pattern and trial fit everything to the door. When you are satisified with the fit, make a depth gage with small blocks of wood that has a razor blade for the scribe. Run the blade around the INSIDE of the window keeping the depth stop tight to the edge, slitting the outer most 20 mm of the protective plastic. Then peel the 20mm protective plastic edge off. Paint the exposed inside window edge. When the paint is dry, peel all of the protective coating off,,, you'll have a nice black trim. Good luck. Greg

This worked great. I had some black Vinyl paint that I had used to refurbish a treadmill I bought my wife some time ago. I thought Vinyl/Plastic/Acrylic, that ought to be perfect. And, for the most part it was. But, for some reason, on the two side edges, which were horizontal when painted, the Vinyl paint wrinkled the edge of the protective film and allowed a serated looking edge to form. I am going to see if I can use a long razor along the desired edge and then buff the paint off of the clear side. If this doesn't work, I guess I'll buy another piece and make another one. At least, I have a very good pattern this time, so it should only take about 20% of the time the first one took.

 

[Guest]

Well the razor and Qtips with a little lacquer thinner got the paint off, but the vinyl paint (and the thiner to a much lesser degree) actually got into the acrylic. The rear window is good enough for track use, but is too messed up to use otherwise.

I will make another window, but I still need some input as to the best type of paint to use for the black out strip on the acrylic window? If you haven't worked with acrylic, what did you use on your polycaronate (lexan, perspex, plexiglass)?

 

I used regular old everyday crylon(sp?) spray paint.
Had no problems at all.
John

 

[Guest]

Cool, thanks John. I was going to default to that. I have used it in a couple of places so far and have been pleased with it.

 

Sounds like the vinyl paint contined some solvents that chemically bonded to the plexiglass. These same solvents apparently also lifted the protective cover. If want somnething to really stick, use an epoxy or two-part polyurethane, although you need to use a vinyl type of tape to keep the paint from getting under the tape. If you want something like the Krylon, either the waterborne acrylics or oil-based enamels should work, although I would think they would not adhere very well long-term.

And then again I don't paint a lot of plexiglass, so these are just guesses based on other painting we do.

 

I painted the inside of the windows and lenses. It looks nice and glossy though the plexi and since it isn't exposed it should last as long as the windows.

 

You might want to look at radio controlled car paint - RC car bodies are made out of lexan and the paint you use is specially formulated to bond well to lexan but still be flexible enough not to crack and split when you bash your RC car into something.

As for masking, people generally airbrush the lexan RC bodies from the inside and so there are lots of masking products available which can yield a very fine edge (remember they're designed for a 1/10th scale paint job) - I've used a vinyl masking tape that works pretty well.

You should also consider sealing the edge of your mask with a transparent laquer of some sort beforehand (also many available for lexan RC cars) - at least if that creeps under the edge it won't show up as badly as black!

ciao

Ian

 

[Guest]

Thanks guys! Once again, some great advice. I think part of my creep problem is operator error. I am just too d@^^ impatient to be a painter. Rather than using several light coats, I want it to cover in one shot and this puts too much paint on the work at one time giving it too much time to sit wet and wick under. I have heard of sealing the edge of the mask and that is great advice!! I think with a little self control, I'll get it right this time.

 

[Guest]

Well as it turns out, short of buying somewhat expensive paint made specifically for painting on sheet acrylic, the vinyl spray paint is probably what should be used because it etches into the acrylic and bonds to it. What is needed though is several fogged on coats rather than trying to do it all in one coat like I did. I made a second rear window and it turned out fine.