Powder Coating

Powder coating is generally used to colour match accessories used with pre-painted steel cladding and rainwater goods. The use of powder coating on metallic coated steel roof and wall cladding and flashings is not recommended for the following reasons.

• It will fade at a noticeably different rate to adjacent pre-painted metal surfaces.
• Powder coated products are length limited by the size of the curing oven and cannot be re-formed after coating.
• Drilling or cutting of the sheet after powder coating will create an exposed edge vulnerable to under-cut corrosion.
• Standard powder coating does not have the corrosion resistance of pre-painted metal and is vulnerable to post coating damage and edge creep corrosion.
• It is difficult to obtain adhesion to powder coated surfaces when overpainting, and the remaining powder coat surface may not provide a good substrate for such.

Power coating may be used to colour match accessories but cannot be relied upon to increase durability, unless specific pre-treatment and powder coating systems are specified and applied.