Thermal Spray and Powder Coating
Thermal spray provides the perfect base for powder coating due to its textured surface which provides the basis for a strong bond between the powder coated topcoat and the metallic thermal sprayed layer.
Powder coating thermal sprayed steel provides a finished thickness of overall coating in the region of 250-300 microns, as per the European standard EN ISO 14713, this coating system has an expected life to first maintenance of 25 years. Protx guarantee that the powder will not flake off. Our confidence in this gaurantee has been achieved due to the higher quality of bond achieved with powder coating over metal spray as opposed to conventional hot dip galvanising.
We can also achieve a higher quality powder coat finish in comparison to a hot dip galvanised base. Thermal spray eliminates the need for fettling due to its consistant smooth finish which forms the bases for an excellent foundation to the powder coated topcoat finish. The removal of the requirement for fettling also eliminates the risk of removing to much of the protective coating therefore ensures longterm protection.
One of the key advantages of metal spraying over hot dip galvanising is that it is a cold process, which means there is no distortion of the work piece or any risk of ‘spikes’ on handrails for instance, which is a basic critical requirement in the painting and coating of handrails and balconies from a safety point of view.
The specification used by Protx is as follows: - Blast clean with steel grit to SA 2.5. Following the grit blasting, we apply 60 – 90 microns of metal sprayed zinc, which we check for accuracy using a Positest DFT measuring device. The next stage is to apply a coat of architectural grade polyester powder and green bake it so it's not fully cured, before applying a top coat of the same powder and finish bake both coatings. This achieved a perfect finish without surface blemishes with an expected life to first maintenance of 25 years - a standard demanded and expected by our long-standing clients.
