I got a little time to work on the UV rotted section of the quarter trim today.
I used 80 grit to sand the area first. Then took my die grinder to put some heavier scratches in the plastic.
I used that dry wall mesh i used to repair the rear bumper again. That plus some panel bonding adhesive to rebuild the plastic.
I started by building up the under side and then let that harden for about six hours. This picture was right after i put the PBA on the mesh, about three hours later, it was a very thick goo that allowed me to push the mesh into the shape of the panel and would hold itself in the shape.
About fifteen minutes before i went home tonight i removed the yellow tape i used to support the initial application of the PBA in place and applied another coat on top to level it out.
Tomorrow i'll cut the repair to the original shape of the panel, sand it smooth and put Polyflex in any voids i may have. I started sanding the rest of the panel to remove the dried out plastic, what a powdery mess. Bright side is that there is lots of solid plastic underneath. I really think i can make these panels almost new looking.
I'll cover the rest of the steps as i go along.