I know that when I was in the Navy we used to mix the non-skid right in with the paint, then roll it onto the area that we wanted to treat. I could be wrong, but know it was not sand... I think it was pumice.
Personally, I'd check with the guys at a paint store.. (NOT Home Depot or Lowes...they just sell paint).
What I'm talking about is a Sherman-Williams kinda place.. where all they do is sell paint. They usually can answer any question you have as to what kind of paint, how to apply, etc. etc. Go to the pros for this one... it's free and it will save you cursing and a ton of paint removal later on.
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1987 V20 w/1987 150HP Yamaha on a Shoreland'r Trailer
1978 16.5 Airslot w/1996 120HP Force on a Four Winns trailer
1996 V21 w/1993 200HP Mercury on a Shoreline Trailer
All towed by a 5.7L Hemi Durango.
If God didn't have a purpose for us we wouldn't be here, so
Live simply, Love generously, Care deeply, Speak kindly.
(Leave the rest to God)
Silence, in the face of evil, is itself evil. Not to speak is to speak, not to act is to act. God will not hold us guiltless.