HEMPEL has during the last three decades coated millions of containers, and more than 90% of these have been painted with our 3-coat system consisting of a first coat of zinc rich epoxy, which is often split into one part being applied as shopprimer and the remaining applied on-line. This is followed by an intermediate epoxy coat, which acts as an inhibiting coat, followed by an acrylic topcoat. The base is usually coated with the same zinc rich epoxy primer as used on the remainder of the container, followed by a heavy coat of underseal, or alternatively same as the exterior coating system.

Advantages of a 3-coat system

The main advantages of a 3-coat system are improved mechanical resistance and general durability. The durability of the end result is obtained by the basic principle that three coats cover better than two coats since minor application flaws in any individual coat have less negative influence. Also, proper drying of each coat is more safely achieved with three thin coats than with a 2-coat system, especially one with a thicker topcoat. Thicker coatings have a tendency to skin-dry, resulting in solvent retention for a longer period. Proper curing creates the optimum film formation and thus the longest protection period.

A typical standard system

Exterior system:	HEMPADUR ZINC 15360 HEMPADUR 15300 HEMPATEX HB 46370 Minimum recommended DFT	20-30 µ 30-40 µ 50-60 µ 110 µ
Interior system:	HEMPADUR ZINC 15360 HEMPADUR HB 45200 Minimum recommended DFT	20-30 µ 60 µ 80 µ
Base system:	HEMPADUR ZINC 15360 HEMPINOL 10220 (bitumen)	20-30 µ 200 µ
Alternative base system:	Same systems as the exterior