Bottom Paint Divet(s) - How to fill/fair

[backcreeksailor]

I have one spot in the bottom paint near the bow where a silver dollar sized divet of paint is missing. It looks to be about 1/16"-1/8" deep and it's covered with last years anti-fouling paint, so I can't really tell if this is just where built up paint came away, or if the barrier coat failed to adhere in that spot.

In any case, my plan is to bottom paint w a couple coats of high quality anti-fouling paint. And then when my next bottom paint is due, soda blast, fair and start from the original gelcoat.

So in the mean time, what type of filler should I use to fair this spot before the bottom gets painted? I want something that's going to stick, but not something that will be impervious to soda blasting down the line.

[sailingdog]

Wash the area well, sand the silver dollar sized divot and a bit of the surrounding area down to the bare fiberglass, then fill and fair with thickened epoxy, and then paint with bottom paint. No real need for barrier coating where the thickened epoxy is, since that is effectively a barrier coat.

[backcreeksailor]

Just so I'm clear before I do this... In the spot where I put the thickened epoxy... When I soda blast in the future, is that going to come off? Or am I going to have a plateau of residual epoxy left in that spot after blasting ?

[Sailormon6]

Originally Posted by backcreeksailor

Just so I'm clear before I do this... In the spot where I put the thickened epoxy... When I soda blast in the future, is that going to come off? Or am I going to have a plateau of residual epoxy left in that spot after blasting ?

I respectfully disagree with SD, who I know is a knowledgeable and experienced yachtsman. I would just sand the area smooth around the divot, so that it doesn't create any significant turbulence when the water flows over it. Then I would sand the spot lightly, wipe it with Acetone to make sure it's clean, and paint over it. Most antifouling paints will bond to gelcoat reasonably well if the gelcoat is lightly sanded. If your paint manufacturer says a primer is necessary to make the antifouling paint bond, then you can apply a little primer to the area. I don't see a good reason to fill the area with epoxy when you plan to strip it all off in a year.

[sailingdog]

If the epoxy comes off due to sodablasting the hull, you did something wrong. This is essentially a permanent way to fix the divot and fair the hull.

Originally Posted by backcreeksailor

Just so I'm clear before I do this... In the spot where I put the thickened epoxy... When I soda blast in the future, is that going to come off? Or am I going to have a plateau of residual epoxy left in that spot after blasting ?