Powder coating: Class 1 or Class 2?

Electrostatic powder coating combines protection and appearance. The quality, however, is not one single thing.

The Qualicoat classes describe neither colour nor texture but resistance to natural weathering: samples are exposed in Florida and measured for how much gloss and colour they keep — one year for Class 1, three for Class 2, ten for Class 3. Class 2 is what is called super durable and is worth having under strong sun. No class, though, replaces the pre-treatment: corrosion resistance is decided by the preparation of the surface, with the Seaside specification near the sea. The minimum coating thickness is 60 µm — less is not a more economical finish, it is outside specification.

Class 1

Standard durable architectural powders, with a wide range of RAL and RAL Matt shades.

Class 2

Super durable systems with better long-term retention of colour and gloss under strong sunlight and exterior exposure.

The powder class does not replace correct surface preparation and correct application.

What the class actually checks

The Qualicoat classes do not describe colour or texture but resistance to natural exposure. Samples are exposed in Florida and measured for how much gloss and colour they keep: one year for Class 1, three years for Class 2, ten for Class 3. Class 2 is what is called super durable.

Pre-treatment decides corrosion

The powder class is about keeping its appearance. Corrosion protection is decided by how the surface is prepared before coating. In a marine environment a stronger pre-treatment applies — in the Qualicoat specifications the Seaside requirement, which calls for more material to be removed in the chemical stage. Pre-anodising before coating goes one step further.

The minimum coating thickness under Qualicoat is 60 µm in the standard specification. Less than that is not “a cheaper coating”, it is outside the specification.

Class 1 and Class 2 side by side

	Class 1 — Standard Durable	Class 2 — Super Durable
Typical use	Ordinary architectural applications	Demanding exterior exposure, strong sunlight
Colour retention	Good	Clearly better over the long term
Gloss retention	Good	Clearly better over the long term
Range of shades	A wide variety of RAL and RAL Matt	Ranges such as AMMOS, SAHARA, Structura / Sablé
Cost	Lower	Higher

Neither class replaces correct surface preparation and correct application.

Frequently asked questions

What does “super durable” mean?

It is Class 2 of the Qualicoat classes. The classes measure resistance to natural weathering: samples are exposed in Florida and their colour and gloss retention is measured — one year for Class 1, three for Class 2, ten for Class 3.

Is Class 2 enough near the sea?

The class concerns the retention of appearance, not corrosion. Corrosion resistance is decided by the preparation of the surface; in a coastal environment the Seaside specification applies, and pre-anodising goes one step further.

What is the minimum coating thickness?

To Qualicoat, 60 µm in the standard specification. Less is not a more economical finish, it is outside specification.