Surface Preparation

Before any coating can be applied to the metal, the surfaces have to be carefully prepared to receive it. For material which has been galvanized before powder coating (recommended) this involves removing surface irregularities in the zinc coating that would otherwise show through the colour coating. Here at Highland we ensure that all the surfaces are prepared to the highest standards to allow for the greatest adhesion and quality in the finished article.

Chemical Pretreatment.

Once the surfaces have been prepared the article is treated chemically to make sure the surface is primed and ready for coating. Here at Highland we use a 12 stage system to produce finishes of the highest quality. After dressing a degreasing bath removes dirt, oil, grease, fingerprints etc. The article is then rinsed twice to ensure that no chemicals are left on the surfaces to be treated and then it is put in an acid bath to etch the surfaces to allow for greater adhesion. The article is then rinsed twice again and put in a conditioning bath, a zinc phosphate bath and then it is then rinsed twice to ensure that the surfaces are chemical free and allowed to dry.

Galvanizing

For an explanation of the galvanizing process, click here to visit the details found on our sister plants site.

Powder coating

The article to be coated is suspended in one of our specialized coating booths (which are scrupulously clean to ensure no contaminants are present) and are subjected to a stream of highly charged coating particles being sprayed at them. Because these particles are highly charged they coat the surface evenly and even wrap themselves round corners.

Curing

Once the article has been thoroughly coated it is is then placed in one of our specialized ovens where it is heated to about 220°C. Dependant on the powder being used the oven temperature is profiled to make sure that the desired quality and finish are achieved.

Inspection

Highland 's quality procedures call for two sample pieces to be coated with every order. One is subjected to a range of multiple destructive tests, measuring the coating performance characteristics, including adhesion, gloss, cure and hardness of coating. The other test piece is kept in our records for any future reference or tests.

Packaging and Delivery

After the article is coated it is packed with the utmost attention to detail to ensure its safety during transit and is delivered back to the customer at a location of their choice.