Surfaces must be clean, dry, free from all defective or poorly adhering material, dirt, grease, wax etc. Previously painted surfaces should be thoroughly rubbed down using a suitable abrasive paper and then dusted off. Any scrapped area should be spot primed. Light sanding on surface would ensure better subsequent intercoat adhesion.
Ferrous surfaces should be sanded or wire-brushed to remove millscale and rust. Remove the rust thoroughly and the area should be spot- primed.
For optimum performance new galvanized and aluminium surfaces should be cleaned and degreased, then pre-treated with an appropriate pre-treatment primer to ensure good adhesion.