In marine use, surfacing wax is a wax dissolved in a styrene solution that is mixed with polyester resins and gelcoats to create a hard, tack-free, and sandable surface by forming a protective barrier that prevents oxygen from inhibiting the resin’s final cure. This additive rises to the surface as the resin cures, and once the surface is hard, the wax layer must be sanded off before any subsequent applications of resin or gelcoat.