QUESTION OF THE MONTH. Correctly Coat Powder-coated Components

Powder coatings are used in many areas: whether inside or outside, on components, containers, machine or vehicle parts. Most often, powder coating forms the final layer of a surface and cannot be treated further. If an additional coating is nevertheless required, appropriate measures must be taken when processing the surface.

A coating of powder-coated components is carried out when the powder coating has only been applied as a primer, e.g. B. a two-component epoxy paint. Because these surfaces tend to chalk and have to be painted over. If objects are worn, it may also be necessary to revise an existing powder coating.

Depending on the additives contained and the type of powder coating, liability problems must be expected. Therefore, the surface must be checked in advance for dirt, type of binder and adhesion of the powder coating.

The load-bearing capacity and liability can be clarified quite easily by a scratch test or a cross cut. Which binder the existing powder coating contains can be determined with the help of solvent swellability, laboratory testing or research by the manufacturer. Information on this may be found on stickers on components. An examination of the coating in the laboratory is fundamentally safer than the usual on-site tests.

Once the essential aspects have been clarified, the surface to be processed should be carefully prepared. Cleaning by washing or sanding are recommended methods. Depending on the persistence of the coverings, you can use a sponge, sanding fleece or paper.

With regard to the warranty, it is important to use a product that is expressly suitable as a "coating for powder coatings". Otherwise, a concern notification should be submitted to the client.

It is definitely advisable to create a test area. It enables the executing company to carry out appropriate scratch and cut tests to check the adhesive strength. However, the following also applies here: Behavior after weathering cannot be determined with this method. A laboratory test would be necessary for this.