ASTM D4939-89(2020)
(Test Method)Standard Test Method for Subjecting Marine Antifouling Coating to Biofouling and Fluid Shear Forces in Natural Seawater
Standard Test Method for Subjecting Marine Antifouling Coating to Biofouling and Fluid Shear Forces in Natural Seawater
SIGNIFICANCE AND USE
5.1 Effective antifouling coatings are essential for the retention of speed and reduction of operating costs of ships. This test method is designed as a screening test to evaluate antifouling coating systems under conditions of hydrodynamic stress caused by water flow alternated with static exposure to a fouling environment. A dynamic test is necessary because of the increasing availability of AF coatings that are designed to ablate in service to expose a fresh antifouling surface. Because no ship is underway continually, a static exposure phase is included to give fouling microorganisms the opportunity to attach under static conditions. After an initial 30-day static exposure, alternated 30-day dynamic and static exposures are recommended as a standard cycle. The initial static exposure is selected to represent vessels coming out of drydock and sitting pierside while work is being completed. This gives the paint time to lose any remaining solvents, complete curing, absorb water, and, in general, stabilize to the in-water environment.
5.2 This test method is intended to provide a comparison with a control antifouling coating of known performance in protecting underwater portions of ships’ hulls. This test method gives an indication of the performance and anticipated service life of antifouling coatings for use on seagoing vessels. However, the degree of correlation between this test method and service performance has not been determined.
SCOPE
1.1 This test method covers the determination of antifouling performance and reduction of thickness of marine antifouling (AF) coatings by erosion or ablation (see Section 3) under specified conditions of hydrodynamic shear stress in seawater alternated with static exposure in seawater. An antifouling coating system of known performance is included to serve as a control in antifouling studies.
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, health, and environmental practices and determine the applicability of regulatory limitations prior to use. For a specific hazards statement, see Section 8.
1.4 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.
General Information
Relations
Standards Content (Sample)
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.
Designation: D4939 − 89 (Reapproved 2020)
Standard Test Method for
Subjecting Marine Antifouling Coating to Biofouling and
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Fluid Shear Forces in Natural Seawater
This standard is issued under the fixed designation D4939; the number immediately following the designation indicates the year of
original adoption or, in the case of revision, the year of last revision. A number in parentheses indicates the year of last reapproval. A
superscript epsilon (´) indicates an editorial change since the last revision or reapproval.
1. Scope Dry Film Thickness of Nonmagnetic Coatings Applied to
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a Ferrous Base (Withdrawn 2006)
1.1 This test method covers the determination of antifouling
D2200 Practice for Use of Pictorial Surface Preparation
performance and reduction of thickness of marine antifouling
Standards and Guides for Painting Steel Surfaces
(AF) coatings by erosion or ablation (see Section 3) under
D3623 Test Method for Testing Antifouling Panels in Shal-
specified conditions of hydrodynamic shear stress in seawater
low Submergence
alternated with static exposure in seawater. An antifouling
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2.2 U.S. Military Specifications:
coating system of known performance is included to serve as a
MIL-P-24441 Primer, Epoxy (Formula 150, Formula Sheet
control in antifouling studies.
24441/1)
1.2 The values stated in SI units are to be regarded as the
MIL-P-15931B Paint, Antifouling, Vinyl, Red (Formula
standard. The values given in parentheses are for information
121/63)
only.
MIL-S-22698A Steel Plate, Carbon, Structural
1.3 This standard does not purport to address all of the
3. Terminology
safety concerns, if any, associated with its use. It is the
responsibility of the user of this standard to establish appro-
3.1 Definitions of Terms Specific to This Standard:
priate safety, health, and environmental practices and deter-
3.1.1 ablation, n—in this test method, the removal or
mine the applicability of regulatory limitations prior to use.
wearing away of the outer layers of coating caused by the
For a specific hazards statement, see Section 8.
combined action of hydrolysis and hydrodynamic shear stress.
1.4 This international standard was developed in accor-
This action is often, but not necessarily, achieved by the
dance with internationally recognized principles on standard-
combined effects of hydrolysis and hydrodynamic shear stress.
ization established in the Decision on Principles for the
3.1.2 hydrolysis, n—softening or weakening of the outer
Development of International Standards, Guides and Recom-
layers, permitting the hydrodynamic shear stresses gradually to
mendations issued by the World Trade Organization Technical
remove them, continually exposing a fresh antifouling surface.
Barriers to Trade (TBT) Committee.
3.1.3 hydrodynamic shear stress, n—the force tangential to
the surface resulting from water in contact with and flowing
2. Referenced Documents
parallel to the surface.
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2.1 ASTM Standards:
A569/A569M Specification for Steel, Carbon (0.15
4. Summary of Test Method
Maximum,Percent),Hot-RolledSheetandStripCommer-
3 4.1 The antifouling coatings to be tested and a control
cial (Withdrawn 2000)
coating are applied to steel panels and exposed in natural
D1186 Test Methods for Nondestructive Measurement of
seawater at a site where the fouling rate is high. The exposure
consists of alternate static and dynamic cycles of typically 30
days each for a total length of time to be specified (such as one
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This test method is under the jurisdiction of ASTM Committee D01 on Paint
or two years) or until some selected degree of fouling is
and Related Coatings, Materials, andApplications and is the direct responsibility of
reached. The static exposure is conducted in accordance with
Subcommittee D01.45 on Marine Coatings.
Current edition approved Aug. 1, 2020. Published August 2020. Originally
Test Method D3623 except that the panels are smaller and are
approved in 1989. Last previous edition approved in 2013 as D4939 – 89 (2013).
preformed to fit a rotating drum. The dynamic exposure
DOI: 10.1520/D4939-89R20.
2 consists of subjecting the test panels to a shear stress by
For referenced ASTM standards, visit the ASTM website, www.astm.org, or
contact ASTM Customer Service at service@astm.org. For Annual Book of ASTM
Standards volume information, refer to the standard’s Document Summary page on
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the ASTM website. Available from Standardization Documents Order Desk, DODSSP, Bldg. 4,
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The last approved version of this historical standard is referenced on Section D, 700 Robbins Ave., Philadelphia, PA 19111-5098, http://
www.astm.org. www.dodssp.daps.mil.
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