Re: [A/S] Re: Today's Repair Question

["Carol and Oliver Filippi" <ofilippi@xxxxxxxxxxxxx>]

The stain is probably iron rust.

Therefore, you might try a fabric rust stain remover (such as Wink), or some
other  reducing agent such as oxalic acid.  The fabric rust removers are
dilute hydrofluoric acid.  Either one is likely to attack the gel coat
surface, so you will probably have to subsequently polish the surface with a
polishing compound.  (Auto paint polishing compound or the fiberglass
polishing compound commonly sold for boats.)

The rust stain removers should be applied carefully and then flushed with
plenty of cold water to remove the reduced iron salt and acid.  Most other
stain removers and bleaches are oxidizing agents and will make things worse.

Oliver Filippi