HELP!

Talk about a frustrating week! Started out with a scratch on the transparent top on my 2000 coupe that had progressed to a strip about 5 - 6 inches wide from the front to the rear of the top. Found several CF posts and received a couple PMs with refinishing recommendations and procedures, so decided to refinish the top myself. Other posts indicated it should only take a few hours to strip the clear coat off the Lexan top, so I got out the wet/dry sandpaper and started sanding. I wound up with over 20 hours of hand sanding before the clear coat was finally off and the top was clean and free of scratches.

One of the CF posts I had reviewed before tackling this job indicated an adhesion promoter and clear coat, available from Pep Boys, was recommended for the final finish. When I picked up these two products, the Pep Boys sales guy said I needed to use a wax and grease remover before I applied the Bulldog adhesion promoter, so I cleaned and wiped the entire top down and then proceeded to apply the promoter.

When the adhesion promoter was applied, I waited the required time, and applied the second coat. Then, as I watched, the surface turned from smooth to alligator skin. The entire top had crazed! What a mess. Called Bulldog's support 800 number and was advised the wax and grease remover recommended by the Pep Boy sales guy had reacted with the adhesion promoter and there was no way to remove the stuff without sanding it again. When using this product, you must thoroughly clean the surface with water and Dove dishwashing liquid ONLY.

Well, when the finish dried, I proceeded to try to hand sand the top again, but it was such a mess that I finally grabbed my random orbit sander, attached 220 grit sand paper, and stripped the entire top AGAIN. I followed the 220 grit with 400 and then 600 grit paper. The surface looked great, no scratches, and took about 6 hours of sanding and lots of sandpaper.

I thoroughly cleaned the surface and then wiped it down with alcohol, as recommended on the Dupli-Color clear coat spray can, before applying their clear coat. This time, I wasn't going to use the adhesion promoter. My final sanding had been with 600 grit paper which a local body shop thought should provide sufficient "tooth" for the clear coat to adhere to the Lexan.

I sprayed on my first coat of clear, waited the recommended 10 minutes, and applied my second coat. As the clear coat was drying, I noticed what I thought was a couple of scratches that I must have missed in the final sanding process. Well, it got worse - the crazing was back and now I need to completely remove the two coats of clear coat.

Any ideas or recommendations on the next steps to put a final clear coat on the top after my next sanding efforts will certainly be appreciated.

 

Personally, I would not use alcohol on Lexan. If there are any small scratches the alcohol can cause crazing (propogation of tiny cracks). As you are finding out, there are many chemicals out there that will attack acrylics/polycarbonates, and other clear plastics.

 

Yeah, that adhesion promoter will crack plastic. It did it to my DRL's when I was working on tinting them. You have some more sanding to do now in order to get the small cracks it makes.

 

Don't use adhesive promoter. Next time clean it with a soapy solution. Kitchen soap, Dawn, diluted in water will work perfecly.

 

Palm sander?