Pretreatment of your products surface before the application of the coating
The role of most powder coating finishes is usually two-fold – firstly to provide surface protection and secondly, a decorative finish.
However, the adhesion of powder coating to an unprepared surface is highly suspect. Dirt, grease, polishing wax, oil, silicone mastics, metal oxides, rust, mill scale, paint, even old powder coatings all prevent the new powder coating from keying to the substrates surface effectively. As a result the typical outcome of which is either a disruption to the new coatings surface resulting in an unacceptable aesthetic finish or worse still the delamination of the new coating from the base structure.
To confirm a quality finish for your product, we therefore prepare the substrate’s surface by either physical and/or chemical means, so as to ensure that the surface is optimised to accept the new coating and provide the highest quality finish. However, by far the best results are achieved when we can work together with the client.
As the protective characteristics of the powder coating are reliant upon a comprehensive attachment to the substrates surface, it is our usual practice to combine chemical cleaning with a degree of surface roughing or etching to promote good coating adhesion during the curing process.
The selection criteria that we use for each product is dependent upon four factors :-
- The substrates chemical composition,
- The type of substrate fouling that has occurred,
- The type of powder coating to be used,
- The end application of the articles which are to be coated.
In many cases, after the substrates surface has been thoroughly cleaned we also combine the application of a chemical conversion coating which provides both protection and further enhances the bond of the powder coating finish to the substrate.