What is PD CEN/TS 16498 – Assessment of tannin staining about?
PD CEN/TS 16498 focuses on coating materials and coating systems for exterior wood. PD CEN/TS 16498 specifies a test method for assessing the discoloration of coatings on wood by tannin staining due to wood extractives. The method uses an extract from Merbau wood as an indicator. Bleeding of wood extractives is assessed at two specified stages firstly after coating application and secondly after cyclic climate exposure. A qualification of colour differences that can be attributed to three different causes, bleeding of extractives, low opacity of the coating film or general yellowing in climate exposure, is included.
Note: PD CEN/TS 16498 does not specify acceptance values for colour differences that can be tolerated and it is not applicable to staining caused by knots for which there is a different test method.
Who is PD CEN/TS 16498 - Assessment of tannin staining for?
PD CEN/TS 16498 on coating materials is useful for:
- Coating materials manufacturers
- Quality control department
Why should you use PD CEN/TS 16498 - Assessment of tannin staining?
Coatings on exterior wood surfaces have both decorative and protective functions. A valued function of the the coating system is to protect against discoloration caused by the presence of wood extractives in the coating migrating from the wood material. Bleeding of extractives can occur at different stages, including shortly after coating application and at a later stages in use, when driving forces like fluctuating humidity are present.
PD CEN/TS 16498 provides a test procedure to determine the assessment of tannin staining that covers the preparation of wood extract, coating application, and colour measurement after coating application.
PD CEN/TS 16498 will help in the measurement of discoloration that has been caused due to the climatic exposure on the coating applied to the exterior wood. This will help you in the evaluation of the coating manufactured by you.
