3. Terminology
1.1 This test method is a standardized brushout procedure for comparing the brush drag of architectural type solventborne paints.
3.1 Definitions of Terms Specific to This Standard:
3.1.1 brush-drag, n—resistance encountered when applying a coating by brush.
1.2 With slight modifications this test method is also applicable to solvent-borne paints. 4. Summary of Test Method
4.1 A 50 mm (2 in.) polyester brush is used to apply the test paint on a test area, approximately 1000 cm2 (1.076 ft2 ). The application is made at a spreading rate of approximately
9.82 m2/L (400 ft2/gal) and is completed in 30 s to 35 s. The degree of brush drag is rated subjectively using a series of standard descriptive terms corresponding to numerical values of 1 to 10. The rank order of a set of samples is thereby established.
1.3 The values stated in SI units are to be regarded as the standard. The values given in parentheses are for information only.
1.4 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, health, and environmental practices and determine the applicability of regulatory limitations prior to use.
1.5 This international standard was developed in accordance with internationally recognized principles on standardization established in the Decision on Principles for the Development of International Standards, Guides and Recommendations issued by the World Trade Organization Technical Barriers to Trade (TBT) Committee. 5. Significance and Use
5.1 As the brush drag of a paint increases, any natural tendency on the part of the painter to overspread the paint is reduced. When all other factors are held constant, increased brush drag will result in greater film thickness with consequent improvement in durability and hiding. Conversely, sometimes it might be preferred to have a lesser degree of brush drag for easier application (that is, the amount of time and effort in applying a paint to a specific area is reduced with a lesser degree of brush drag).
ASTM D4958-24 Referenced Document
ASTM D1475 Standard Test Method For Density of Liquid Coatings, Inks, and Related Products
ASTM D3924 Standard Specification for Standard Environment for Conditioning and Testing Paint, Varnish, Lacquer, and Related Materials
ASTM D3925 Standard Practice for Sampling Liquid Paints and Related Pigmented Coatings
ASTM D4287 Standard Test Method for High-Shear Viscosity Using a Cone/Plate Viscometer
ASTM D5068 Standard Practice for Preparation of Paint Brushes for Evaluation
ASTM D4958-24 history
2024ASTM D4958-24 Standard Test Method for Comparison of the Brush Drag of Latex Paints (Standard + Redline PDF Bundle)
2010ASTM D4958-10(2016) Standard Test Method for Comparison of the Brush Drag of Latex Paints
2010ASTM D4958-10 Standard Test Method for Comparison of the Brush Drag of Latex Paints
1997ASTM D4958-97(2004) Standard Test Method for Comparison of the Brush Drag of Latex Paints
1997ASTM D4958-97 Standard Test Method for Comparison of the Brush Drag of Latex Paints