Buffing a Polycarbonate Windshield

I have seen numerous questions on this.  This windshield is toast, but I wanted to clean it up to match the color. 

(warning: some polycarbonate windshields can have a anti-scratch coating.  This may remove that coating)

First step is to clean the windshield.  Dirt will just cause you problems.

To make it smooth, it would have had to be sanded.  If I were sanding it, I'd start with 600 DA or 1000 wet or dry by hand and sand smooth IF REQUIRED, then jump to 1500/2000, than 2000 on a DA sander.   Always sand as fine as you can and still get the job done.

 I skipped the sanding process.

I mounted the windshield to some wood and then put bubble wrap behind it so it had some support and wouldn't get scratched.

You can see that this windshield was quite cloudy with some pretty serious color shifting by the windshield retaining molding.

buffing windshield

I used a medium cut compound.  Any compound that is good for about a 1500 grit scratch should work.  If you go coarser than that, you may then have to go over it with a finer compound to remove the coarse cut compound scratches.  If you need a coarser cut, I'd start sanding.

Some use plastic polishes, and that is fine.  But if you have compound on the shelf, I would just use that.  I also used a high speed buffer with a wool pad.

windshield buff

A picture of the windshield buffed.  As you can see the cloudiness has pretty much disappeared on the half that I buffed.  If you were doing a difficult to buff area, a 3 inch buffer would help.

windshield buff

I then took a 2000 grit swirl remover polish on a medium cut foam pad and final buffed the windshield.

windshield buff


And the final results.

windshield buff