upshift4

i replaced my windshield and there is old rubber residue stuck to the paint. I have tried all my tricks ( WD40, Goo Gone, compounding, degreaser, mineral spirits) and i still can't get it off.

Any suggestions!?

PHX

Straight denatured alcohol might do the trick.

And you've already broken out the polisher and tried that? Maybe a plastic razor blade and some Gtechniq W7 tar and glue remover.

Type 2

You did not identify the model of Porsche. I assume from your avatar that it is a G-Body. You missed your real opportunity to remove the old residue when the windshield, black or chrome metal surround, and rubber gasket were out. It would have been far easier to clean the exterior paint surface when you didn't have to worry about damaging the new rubber gasket.

Nevertheless, there are several products, with the right application, that will remove the old gasket adhesive (what you are calling rubber residue). You should start with the most mild adhesive remover, and progress to one that is more "atomic" if needed. Use Oil-Flo Safety Solvent Cleaner, and using a doubled-over (or tripled-over) strip of old T-shirt cloth, saturate the cloth with the Oil-Flow (do not have streams of Oil Flo come down the paint panel) and leave it on for at least twenty minutes. Do not let the cloth dry out! After that time period, rub with the doubled-over cloth away from the new windshield gasket to remove the old residue. You may have to repeat to soften or liquify the old residue. The clean up with Oil-Flo, after the residue is removed, is hot water. Oil-Flo is safe for you and your car.

If Oil-Flo is not doing the job, switch to 3M General Purpose Adhesive Cleaner (3M #08984), and use the same doubled or tripled over cloth technique described above but leave the saturated cloth on for a longer period. If that application does not liquify or soften the residue, you may need to consider using a flat bladed PLASTIC tool (car plastic upholstery tools are great in this regard and a kit is cheap at Harbor Freight) to very gently do a top scrape of the hardened residue. Repeat the saturated cloth technique as necessary. After the residue to removed, use a polish/sealant to clean up the exterior paint area. Unless the original gasket adhesive used is a "permanent glass windshield sealant" (the factory sealant is not), one of these techniques will remove the residue. If the new gasket rubber is dried out or lightened in color just use 303 Protectant several times to treat and darken the windshield gasket rubber. Type 2