UltraCut Rubbing Compound is a good choice for removing heavy oxidation from gelcoat prior to application of wax.Removes heavy oxidation safely from fiberglass and painted surfaces. Before compounding, we recommend that youfirst wash the surface with West Marine Boat Soap, then remove oxidation with West Marine Ultra-Cut RubbingCompound. When done, protect the finish with West Marine Advanced Marine Polish with AFP. For light oxidation,use West Marine Color Restorer Finishing Compound or one of our one-step polishing products.Key featuresUltra-fast cutting removes grit or finer sanding marksRemoves scratches, defects, acid rain and severe swirlsRestores marred or oxidized finishesCompound quickly removes oxidation, stains, etching