Hello, I have recently defretted an Ibanez RB690. Filled the slots with black epoxy filler and coated the fingerboard with Ronseal 'Diamond Hard' (water-based) floor varnish. I have done this once before and had good results with on a defretted rosewood fingerboard. 3 months with roundwounds and minimal marking on the surface. Has anyone else tried water based coatings for this purpose?