How to Specify Architectural Powder Coatings
Many failures of coatings are a result of poorly written specifications. Here are some things to avoid:
- Specifying a particular chemistry or ingredient, e.g. “PVDF” or “Polyester Powder Coat” - many poor performing coatings could claim to meet the chemistry requirements, but may not have the technical performance.
- Specifying by warranty period. Technical performance and warranties are separate issues – and warranties have many caveats.
- Failure to specify a pretreatment – corrosion and adhesion failures can result
- Imprecise colour specification. Quoting a RAL or generic shade alone is not enough; parts from different suppliers or batches may not match
Ideal specifications cover as a minimum the following:
- The standard or quality label to be met (e.g. BS EN 12206, Qualicoat)
- The grade of that standard (e.g. BS EN 12206 with alternative pretreatment and enhanced durability coating, or Qualicoat class 2)
- That the coater must be approved by the coating supplier or a quality label (Qualicoat)
- Requirements for cut-edges and damaged parts to be sealed / repaired
- If a warranty is to be mentioned – the duration, the properties to be covered, and that the properties should be as measured on the building
- The exact shade and gloss level, quoting a particular supplier and saying “or equivalent” – ensuring any alternative supplier must match the required version of the shade - . e.g. RAL 9006 GL from AkzoNobel or equivalent matched to AkzoNobel master.
- For metallic coatings, that all parts should be coated from a single batch, by a single coater.
Should you have any questions regarding the correct specification of powder coating, please contact a local Qualicoat member, or contact Qualicoat UK & Ireland on the number below.