Interior paint films often become soiled, especially near doorways, windows, and play areas, and frequently need to be cleaned by scrubbing. This test method covers the determination of the relative resistance of paints to erosion when scrubbed.

The precision of scrub resistance measurements in absolute physical values, such as Test Methods D 2486 cycles-to-failure or this test method, microlitres per 100 cycles, is poor due to the relatively large effect of subtle and difficult-to-control variables in test conditions. The test method described herein minimizes this problem by using a standard calibration panel as an integral part of each scrubbing operation and relating its weight loss to that of the paint film under test to establish the latter’scrub resistance.

Note 1—The numerical scrub resistance values obtained by this test method are of significance only in relation to the specific calibration panel types with which the value is obtained. Thus, for example, a scrub resistance value of 83 with a Type X calibration panel would be reported as 83X.

Results obtained by this test method do not necessarily represent the scrub resistance that might be determined if the test film is allowed to dry before testing appreciably longer than the seven-day period specified herein.

Results obtained by this test method do not necessarily relate to ease of soil or stain removal (also referred to as “cleanability” or “cleansability”). To test for those characteristics use Test Methods D 3450 and D 4828.

FIG. 1 Alignment of Panels for Scrubbing

1.1 This test method covers an accelerated procedure for determining the resistance of paints to erosion caused by scrubbing. (Note: The term wet abrasion is sometimes used for scrubbing, and wet abrasion resistance or scrubbability for scrub resistance.) Although scrub resistance tests are intended primarily for interior coatings, they are sometimes used with exterior coatings as an additional measure of film performance.

1.2 The values stated in SI units are to be regarded as the standard. The values given in parentheses are for information only.

1.3 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.