I've got a Buccaneer that the playfield inserts are all loose and cupped. I want to pull them out, fill with Automotive clear and sand level. I remember reading about it a few months ago but I can't seem to find anything now... How do I prep the plastic for the clear coat? I guess clean with Iso and lightly sand? I don't want to mess up the existing paint. Wasn't sure if the alcohol would make the plastic more brittle.