Cleanup on aisle three ...

[Simon Sexton]

Not even gasoline and matches, just needs Jesus.

 

[Jacktar]

Most likely actually mildew, after cleaning spray once more with 10% bleach and let dry , do not rinse off again. This will kill any spores left in tiny cracks in the surface.

 

[Mr Fox]

The mildew in my used boat (due to P.O. neglecting a leak) was cleaned by a very good detailer who has dealt with mold here in the northeast for years. They used vinegar which (after a liberal application of elbow grease) was allowed to dry, the acid in it kills the spores and vinegar can work effectively on a porous surface. This was followed by a mildew killing spray to minimize new growth. These are readily available. Worked like a charm and my situation was dire.

They don’t recommend bleach for cleaning on fiberglass, which is porous and therefore cannot be penetrated by the bleach (which kills mold very effectively on non-porous surfaces). You wind up killing only the surface mold, the chlorine evaporates and leaves some moisture behind for the mold in the fiberglass, and your mold returns.

Edit- further reading if you want more info

http://aellabs.com/bleach-myth/

 

[glaufman]

The "tacky after cetone" sounds typical of fiberglass and gelcoa alike, as both are often from a polyeter resin, and softened by acetone. We always coat old glass in acetone before adding new resin as the softening helps the adhesion between old and new... Acetone can likely soften many other substances as well.