Active Standard ASTM D7786 | Developed by Subcommittee: D01.42
Book of Standards Volume: 06.02
Historical (view previous versions of standard)
Significance and Use
5.1 This standard may be used by paint companies and raw material suppliers to assess the interactions of primers and topcoats with respect to their ability to provide good enamel holdout. Primer/topcoat systems with the best enamel holdout will result in desirable gloss in the first coat of topcoat application.
1.1 This standard provides a method for determining the holdout characteristics of a primer and topcoat coating application. A standard topcoat is used to determine the absorption characteristics of a primer. Enamel holdout can be measured as a difference in observed gloss of the topcoat over a primer, relative to the gloss of the same topcoat over a non-porous smooth surface.
1.2 The standard is written in the context that the user will be evaluating the enamel holdout characteristics of a primer. Alternatively, the standard may be used as a method to evaluate the enamel holdout characteristics of primer/topcoat system where the primer is constant and different topcoats are used as test paints.
1.3 This standard may also be used for evaluation of paints other than primers as the first coat. In this alteration the user can test the enamel holdout characteristics of a self primed topcoat, or use of any other type of paint as the primer followed by the use of a standard topcoat.
1.4 The values stated in SI units are to be regarded as standard. No other units of measurement are included in this standard.
1.5 This standard does not purport to address all of the safety concerns, if any, associated with its use. It is the responsibility of the user of this standard to establish appropriate safety and health practices and determine the applicability of regulatory limitations prior to use.
2. Referenced Documents (purchase separately) The documents listed below are referenced within the subject standard but are not provided as part of the standard.
D523 Test Method for Specular Gloss
D823 Practices for Producing Films of Uniform Thickness of Paint, Varnish, and Related Products on Test Panels
D1640 Test Methods for Drying, Curing, or Film Formation of Organic Coatings at Room Temperature
E177 Practice for Use of the Terms Precision and Bias in ASTM Test Methods
E691 Practice for Conducting an Interlaboratory Study to Determine the Precision of a Test Method
ICS Number Code 25.220.50 (Enamels)
UNSPSC Code 31211500(Paints and primers)