How to repair scratched vinyl window or patio door by sanding

Deep cuts, scrapes or scratches on PVC /vinyl windows or patio doors can be sanded away by hand with 60-80 grit sand paper to sand away the scratch, then 280-400 grit to smooth the surface, then use a 4,000 grit pad to polish to the shine of the original vinyl. I have done this many times and the repairs cannot be detected even with bright sun showing the gloss of the vinyl. Sometimes I need to blend the final polishing over a larger area because the repair outshines the fine extrusion lines of the original vinyl. 2,000 to 6,000 grit discs are available at Lee Valley Tools.

[@emmafranklin4781]

Is this the same method you would use to fix scratches from a Stanley knife in the plastic part of my upvc ? Tried to get layers of old caulk out that was covering the plastic of the upvc but in the process it’s scratched the plastic. Is it just a case of sanding it down or do I need to use anything else? Someone mentioned t cut ?

[@windowdrbrian2849]

This method of sanding and polishing scratches off of upvc is meant for >2mm thick vinyl walls so that there is lots of depth of vinyl left afterwards for strength. If there is dirt in the scratches try wiping it with Paint Thinner on a rag first to clean the vinyl perfectly before any sanding. Only sand with the course sandpaper enough to eliminate the cut marks, then use the finer 400-600 grit paper to smooth it enough for the final polishing with 3000-6000 grit sand paper to match the gloss of the original vinyl.

[@bree1128]

Thank you. I didn't know they made 3 to 6 thousand grit sand paper.