Meaning and use

5.1 Tannins and other hair colour extracts are naturally occurring substances in wood and wood substrates. Tannins are common in cedar, redwood, oak, and less so in white pine and ponderosa pine. Tannins are also present in varying amounts in wood composition products. These extracts dissolve and darken through water-based paints, resulting in unsightly yellow or brown discoloration. This test method is designed to show the relative ability of coatings to prevent tannin penetration. Typically, cedar or redwood boards are used for this test.

ASTM D6686-19 “Standard Test Method for Evaluating Tannin Stain Resistance of Coatings”

Step 1: Scope

1.1 This test method is an accelerated procedure to determine the effectiveness of latex coatings in preventing the migration of tannin stains from wood substrates.

1.2 Values expressed in SI units shall be considered standard. The values in parentheses are for reference only.

1.3 This standard is not intended to address all safety concerns, if any, associated with its use. It is the responsibility of users of this standard to establish appropriate safety, health and environmental practices and to determine the applicability of regulatory restrictions prior to use.

1.4 This international standard is based on internationally recognized standardization principles established in the “Decision on Principles for the Development of International Standards, Guidelines and Recommendations” issued by the Committee on Technical Barriers to Trade (TBT) of the World Trade Organization.