I have made a wooden table top and in the centre I have cut out a rectangular shape ( 29cm by 60cm ) and glued down small ceramic tiles. The height of the inlay from top of the tiles to the level of table top is 8mm. Can I use GlassCast 30 to fill in the inlay and coat the table top all in one go, or do I need to use GlasCast 50 to fill in the inlay and pour Glasscast 30 over that and the rest of the table top.