Painting a Polycarbonate/Lexan Windshield
From what I can tell, most windshields are a Polycarbonate type of plastic (lexan). While the hoods that some of the snowmobile's used are polycarbonate also, I am guessing there is a difference in chemistry due to the nature of the needs for the different applications. Plus many Polycarbonate hoods are a Polycarbonate/ABS mixture. The windshield shown is newer than the vintage sleds, but the procedure is the same.
Acrylic (Plexiglass) can also be used in windshields, but this material shown is Polycarbonate.
Today I am painting a 1996 Ski-Doo Formula windshield. I am painting both sides because the windshield pieces were colored and smoked. Plus there was some wear that I wished to hide.
In a clear application, you can choose to paint only the inside letting the windshield material be your clear. I will be doing one this way in the near future.
Tips, Clean. Clean. Clean. do not use real aggressive sand paper!
The Start
Pictures one and two. Using hot water with my plastic cleaning paste and a grey scuff pad. Scuff completely keeping it nice and wet. A small amount of the paste is all that is needed. You then rinse and repeat using the cleaning paste and scuff pad again. The paste helps to scuff, but it also includes a cleaning agent to remove plastic mold release agents which is the painters enemy.
Please use safety gear not limited to gloves and eye protection along with a respirator.
This Plastic cleaning kit along with adhesion promoter is available here!
When done, you should have a nicely dulled surface with no gloss in any areas as illustrated in pictures 3 through 6. There are some scratches in the smoked section that you can see, filler could have been used to remove them, but they actually filled in pretty well with paint. This is not for a show sled. Once masked, hung and ready to start spraying, I used a liquid plastic cleaner to final clean. DuPont 2319S or RM 902 would be some examples.
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The spraying process
I will recommend an adhesion promoter. DuPont 2322/2330S or RM 868 would be some candidates. I also am repackaging a kit which includes an EXCELLENT adhesion promoter for plastics that is also flexible, along with the cleaning paste and a grey scuff pad in a home user sized package.
My product recommends two light coats with 5-7 minutes flash times between coats. Do not use to big of a tip for the paint gun, or you can end up larger orange peel than you probably desire, plus use excessive product.
After the adhesion promoter is flashed, it is time for color or if desired sealer. In this example I used my basecoat with added hardener. Hardener will give you better metallic control, adhesion and flexibility even in basecoat paints. Not much hardener is needed, one ounce to 32 ounces sprayable in this product. Well worth the investment.
I then cleared using flex additive in the clear. Some will argue that flex additive evaporates when the paint dries. This was true with Lacquers and some cheaper variations of product. This is not true of the adhesion promoter that I use and sell. Painting an older extremely flexible windshield would require flex additive in my opinion.
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The finished product without any buffing yet.
The adhesion test.
24 hours after spraying, I ran this adhesion test. This is scribed with about 1/8 inch "boxes" left. Duct tape is then pressed firmly and ripped off. Any paint not adhering properly would pull off the sample You will notice a bit of lifting in the scribe. But remember paint is not cured for 30 days and continues to increase it's adhesion as it cures. After a week, none of that lifting existed. This is getting super adhesion.
