A proposed new ASTM International test method will combine existing in-house methods for dirt pick-up resistance for architectural paints and stains in an effort to standardize testing for dirt repellency throughout the industry.

The proposed standard, ASTM WK38233, Test Method for Dirt Pick-Up Resistance for the Films of Architectural Paints and Stains, is currently being developed by Subcommittee D01.42 on Architectural Coatings, part of ASTM International Committee D01 on Paint and Related Coatings, Materials and Applications.

According to Amanda Andrews, chemist, Wacker Chemical Corp., and a D01.42 member, the proposed standard will focus on: Standardizing a dirt composition; how to apply dirt; the removal of dirt; and a rating technique for an exterior coated substrate compared to many years of outdoor exposure.

Andrews notes that primary users of ASTM WK38233, once approved, will be coating suppliers and manufacturers.

Andrews invites all interested parties to participate in the ongoing development of ASTM WK38233. “We are particularly interested in participation from those who already have in-house dirt pick up test methods with formulated dirt,” said Andrews. “We are also looking for participation from anyone who has interest in appropriate accelerated methods such as artificial UV and water conditioning.”

In addition to its work on ASTM WK38233, D01.42 is currently working on a revision to ASTM D4446, Test Method for Anti-Swelling Effectiveness of Water-Repellent Formulations and Differential Swelling of Untreated Wood When Exposed to Liquid Water Environments, as well as another proposed new standard, ASTM WK32143, Test Method for Visual Assessment of Water Beading on Horizontal Coatings.