I have a severly mildewed overhead in my project boat.The overhead is Gel coat and has been left unattended for 10 yrs.I have tried pressure cleaning bleach mixture mildew remover plus others I still have mildew any ideas other thah covering it with something.Thank You all Dave Cameron
Since you have already tried bleach I would consider painting it. The mildew has grown into and stained the relatively porous gelcoat. The only other idea I have is to try SoftScrub with bleach before painting. Let the SoftScrub sit there for a while and try it multiple times.