MULTI-PURPOSE UNDERCOAT - MASTER PREP - 4 Litres - WATTYLWATTYL MASTER PREP MULTI PURPOSE UNDERCOAT Oil based for Interior Exterior application. Has excellent hiding properties and provides a smooth finish with superior gloss holdout. It is a high opacity oil based undercoat for use on interior and exterior surfaces, providing asmooth even surface for the finishing coats. Suitable for use on bare interior timber surfaces including hardboard, together with previously painted enamel surfaces and suitably