Which gelcoat cleaners are best at combating waterline yellowing on boat hulls? Ben Meakins dons his rubber gloves and puts 10 products to the test
This oxalic gel mix is applied with a brush and agitated gently where staining is worst. Leave for 20-30 minutes before agitating again and washing off with fresh water. It is a very thin gel which, like the Star brite Hull Cleaner, foams upon application. After 30 minutes it was easy to wash off, leaving behind a very clean hull, and placing it in the top tier of products.