Rustins quick dry primer and undercoat greywhite rustins gypu2500 this 25l tin of primer and undercoat from rustins is suitable as a primer on new and bare wood mdf plaster brickwork or cement used as an undercoat on primed or painted surfaces and may be overcoated with water or solvent based finishing paints rustins gypu2500 quick dry primer amp undercoat grey 25 litre