ASTM D4958-24
Standard Test Method for Comparison of the Brush Drag of Latex Paints (Standard + Redline PDF Bundle)
- Standard No.
- ASTM D4958-24
- Release Date
- 2024
- Published By
- American Society for Testing and Materials (ASTM)
- Latest
- ASTM D4958-24
- Introduction
Analysis of the Standard's Core Content
ASTM D4958-24 establishes a standardized method for evaluating the brush resistance of coatings using a 50mm polyester brush under specific conditions. The test requires coating an area of approximately 1000 cm² in 30-35 seconds at a coverage rate of 9.82 m²/L. Brush resistance is quantified using a subjective 1-10 rating system.
Comparison of Technical Parameters
Parameters Solvent-based coatings Latex paints Test differences Applicable standards Coating parameters need to be adjusted Directly applicable Coating time±5 seconds Viscosity correlation 0.03Pa·s difference can be identified Separate test group is required Rheological properties influence Score sensitivity ±0.5 level ±0.3 level Decimal ratings are allowed
Key Operating Points
Brush Standardization: A 14mm thick polyester brush with 70mm bristles and a chisel-shaped tip must be used. The commercial model of the brush must be consistent within the same test series.
Coating Control: Calculation formula: Paint weight (g) = density (kg/L) × 10.2. For example, a paint with a density of 1.5kg/L would require 15.3g to be weighed for testing.
Standard Evolution Analysis
Main updates of this version of the standard (2024) compared with the 2016 version:
1. Clarified the applicable provisions for solvent-based coatings
2. Added a comparison with D4287 high-shear viscosity test
3. Supplemented inter-laboratory comparison data (9 laboratories and 14 operators)
Implementation Recommendations
- Establish an internal standard sample library and conduct regular operator consistency training
- For critical value samples (such as ratings 5-6), it is recommended to add 3 repeated tests
- Solvent-based coatings need to be tested in separate groups for comparison
Application Cases
A coatings company used this method to find that when brush resistance increased from Level 4 (Medium) to Level 6 (Significant), dry film thickness increased by 18%, and correspondingly, hiding power increased by 23%. However, application efficiency decreased by 15%, and performance requirements must be balanced according to the application scenario.
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
- 2024 ASTM D4958-24 Standard Test Method for Comparison of the Brush Drag of Latex Paints (Standard + Redline PDF Bundle)
- 2010 ASTM D4958-10(2016) Standard Test Method for Comparison of the Brush Drag of Latex Paints
- 2010 ASTM D4958-10 Standard Test Method for Comparison of the Brush Drag of Latex Paints
- 1997 ASTM D4958-97(2004) Standard Test Method for Comparison of the Brush Drag of Latex Paints
- 1997 ASTM D4958-97 Standard Test Method for Comparison of the Brush Drag of Latex Paints
