Standardization News

Determining Enamel Holdout of Primer

Manufacturers and developers of architectural coatings will be the primary users of a new ASTM International standard, D7786, Test Method for Determining Enamel Holdout. The standard was developed by Subcommittee D01.42 on Architectural Coatings, part of ASTM International Committee D01 on Paint and Related Coatings, Materials and Applications.

Keith Alderfer, associate scientist, The Dow Chemical Co., and a member of D01.42, says that enamel holdout is an important attribute of an architectural primer.

"The enamel holdout characteristic of a primer can have a significant impact on the appearance of the finished painted system, especially if that system is intended to have a semigloss or glossy finish," says Alderfer. "Semigloss topcoats over primers with poor enamel holdout characteristics or unprimed porous substrates can result in lower gloss than is intended from the final coating."

While D7786 is now complete, Alderfer says that interested participants are invited to join in interlaboratory testing on the standard that is planned to begin this year.

To purchase ASTM standards, visit and search by the standard designation number, or contact ASTM Customer Relations (phone: 610-832-9585;

CONTACT Technical Information: Keith Alderfer, Dow Chemical Co. • Spring House, Pa. • Phone: 215-619-1542 | ASTM Staff: Jeffrey Adkins • Phone: 610-832-9738 | Upcoming Meeting: June 24-26 • In conjunction with D02 June meeting • San Francisco, Calif.

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