Specify surface treatment

Most metals can be powder coated. However, substrates require treatment and/or a tailored process to obtain optimum performance from the paint film in terms of both aesthetics and functionality. These are mainly substrates prone to outgassing such as castings, galvanised steels (mainly class 3 and unclassified) and parts with low-melting-point welds (tin). These substrates may require a degassing phase, specific pickling and/or the use of special paints.

Surface treatment serves firstly to condition the surface of the part to prepare it to receive the subsequent coating. Secondly, in conjunction with the chosen protection system, it ensures the durability of the part in its environment of use. The surface treatment and the protection system will therefore depend on the structure’s end environment.

The choice depends on its intended end use (recommendations of NFP 24-351).

Surface preparation and system
Mild Steel

Durability of the selected system according to the environmental conditions

^{(1) Or alternative treatment with equivalent performance. In any case, results depend on type of surface treatment and so must be qualified with salt spray tests.
(2) Type of blast should be chosen according to the blasting technology and the required roughness
(3) The shape of the blast will be controlled regularly to keep it as stable as possible and maintain the performance
(4) Sa is cleanliness and Ra/Rz is the roughness profile with blasting}

^{(A1) Durability is not a guaranteed period. This is a technical concept that can help customers to establish a maintenance program. The warranty period is a legal concept that is part of a contract. The warranty period is generally shorter than durability. Protection and expected performance will vary according to the design of the part to be painted, the quality of the surface pretreatment and application and thickness of the coating system, as well as the maintenance program of the coated surfaces. This information is given as an indication. It is based on our experience and laboratory results, and does not constitute a commitment on our part.}

Surface preparation and system
Hot Dip Galvanised Steel

^{According to the ISO1461}

System
Metallisation

^{According to the ISO2063 standard}

Durability of the selected system according to the environmental conditions

^{(1) Alternative treatment with equivalent performance. In any case, results depend on type of surface treatment and so must be qualified with salt spray tests.}

^{(2) Inert media, angular}

^{The shape of the blast should be controlled regularly to keep it as stable as possible and maintain the performance. A maximum of 10 % of the zinc may be removed by the blasting process.}