Out of desperation I am thinking of using traffic film remover to remove black streaks on white fibreglass. Has anybody else used the stuff - does it work - is it likely to damage the polish/sealer on fibreglass? Thanks.
Poster hlb sell similar product informally known as "boat remover". I've used tons of the stuff, dilute at least 10-1 but try 15-1 to start. It;s quite caustic so rinse off well. Best results achied by mixing smallish half-bucket qtys and apply with soft (yellow) ragged-bristle Surehold brush ensures loads of lather but no abrasion.