Coating

The quality and service life of a piece with a powder coated finish is determined not only by the surface treatment technology but, well before that, by the design and manufacture of the piece itself. Inadequate material preparation, manufacturing defects or inadequate design details can later lead to coating faults and thus can also reduce proper protection against corrosion.

It is advisable that silicone-containing materials be avoided: they can cause cratering and adhesion problems on the surface to be coated, and can also damage the equipment. Oxygen-based cutting processes can result in scaling and an oxide layer, which may prevent proper adhesion and be detrimental to the durability and evenness of the coating.

Metal particles embedded in the surface during grinding can become starting points for corrosion, and grinding marks and uneven properties may be even more prominently apparent on a powder coated surface.

Proper edge preparation is also of critical importance, because the coating is thinner on sharp corners, which can lead to the untimely corrosion of edges.

In case of the use of a spray pre-treatment method, the geometry of the part should be designed in a way that the liquid used for pre-treatment could not collect anywhere inside it, but could surely reach enclosed or hard-to-access areas.

Choosing the proper points for suspension is another important issue to consider, since they affect the pre-treatment and the evenness of the powder application.

When creating the design of a part or piece, one must also take into account that the surface has to be accessible not only for the pre-treatment solution but for the powder as well, particularly in including recesses, cavities and more complex geometries. A carefully designed and properly prepared part is essential in order that the finished coating could be aesthetic, technically adequate and long-lasting at the same time.