ASTM D4938-89(2007) - 1.6.2007
 
Significance and Use

This test method is intended to measure the erosion rates of ablative antifouling paint systems exposed to flowing water at velocities designed to subject the paint system to shear stresses experienced in service.

Measurement of erosion rates are necessary to help in the assessment of ablative antifouling paint film thicknesses required for fouling control between scheduled drydockings of ships, in the selection of materials, in producing quality assurance, and in understanding the performance mechanism.

The test data is intended to serve as a guide for predicting the service life of ablative antifouling paints in order to calculate the necessary paint thickness to fit specified deployment cycles. Erosion rates of antifouling paints in service will vary depending on such factors as: berthing location, geographic area of operation, salinity, pH, and temperature of seawater. It should also be recognized that some areas of the ship are subject to different erosion rates.

The degree of correlation between results obtained from this test method and shipboard service has not been determined.

 
1. Scope

1.1 This test method covers the determination of erosion rates for marine antifouling paint systems immersed in flowing natural seawater.

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. For a specific hazard statement, see Section 7.

 
2. Referenced Documents

D1889-00

Standard Test Method for Turbidity of Water (Withdrawn 2007)

D823-18(2022)

Standard Practices for Producing Films of Uniform Thickness of Paint, Coatings and Related Products on Test Panels

A569-A569M-98

Standard Specification for Steel, Carbon (0.15 Maximum, Percent), Hot-Rolled Sheet and Strip Commercial (Withdrawn 2000)

DOD-P-24655

Paint, Underwater Hull, Anticorrosion (Metric)

DOD-P-24647

Paint, Antifouling, Ship Hull (Metric)

MIL-P-24441

Paint, Epoxy-Polyamide

D2200-26

Standard Practice for Use of Pictorial Surface Preparation Standards and Guides for Painting Steel Surfaces