[Jonny042]

I've sprayed most of the underside of my tub with Water based SKS stonegaurd and the directions on the bottle say it must be primed before painting.

Would a urethane primer mixed as a wet-on-wet sealer be most apropriate? Top coat is single stage urethane.

I would think adhesion between the paint and primer may be an issue if it's not applied wet-on-wet, as its going to be impossible to sand the primer (due to the texture of the SKS).

Thanks in advance, Jon