Description Upol Acid #8 Etch Primer Aerosol, Spray Can, Adhesion, Spray Paint, Bare Metal ACID #8 is a 1K ready to use etch primer available in aerosol cans. It is uséd for priming bare metal surfaces, this promotes adhesion of paint and prevents steel from rusting. ACID #8 is chromate free. Typical applications are over rub through areas prior to painting, on new bare metal panels or over bare seams before sealant is applied. ACID #8 can be applied to the following surfaces:- Bare steel. Aluminium. Galvanized and Zinc coated steels. Fully cured paint. Polyester bodyfillers and G.R.P.