Anti-Fouling prep question...

[abl1111]

Last couple of years I have sanded/feathered some of the black, ablative, antifouling paint in spots where the paint has flaked off w/ a DA ( been fighting a previous owners unknown antifouling for years ).

And, this black paint dust settles on my decks nonskid and leaves a black stain that is a be'atch to get off and can take weeks to come off...

Anybody have a way to avoid this ? Should I wet the non- skid areas before sanding or make sure they are completely dry before sanding ?