I have some deep scratches in clear plastic. Now normaly i would sand, cut and polish these out. I was woundering if it was possible to fill the scratches with either UV resistant clear fiberglass resin or 2 pack clear (my prefered option). then sand cut polish. This is regarding very deep scatches only. I was also wouding what magic compound do obrein and simmilar use on car windscreens repairs.