Standard Test Method for Subjecting Marine Antifouling Coating to Biofouling and Fluid Shear Forces in Natural Seawater

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 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 hazards statement, see Section 8.

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09-Mar-2003
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ASTM D4939-89(2003) - Standard Test Method for Subjecting Marine Antifouling Coating to Biofouling and Fluid Shear Forces in Natural Seawater
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NOTICE: This standard has either been superseded and replaced by a new version or withdrawn.
Contact ASTM International (www.astm.org) for the latest information
Designation:D4939–89(Reapproved2003)
Standard Test Method for
Subjecting Marine Antifouling Coating to Biofouling and
1
Fluid Shear Forces in Natural Seawater
This standard is issued under the fixed designation D 4939; 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 (e) indicates an editorial change since the last revision or reapproval.
1. Scope MIL-S-22698A Steel Plate, Carbon, Structural
1.1 This test method covers the determination of antifouling
3. Terminology
performance and reduction of thickness of marine antifouling
3.1 Definitions of Terms Specific to This Standard:
(AF) coatings by erosion or ablation (see Section 3) under
3.1.1 ablation, n—in this test method, the removal or
specified conditions of hydrodynamic shear stress in seawater
wearing away of the outer layers of coating caused by the
alternated with static exposure in seawater. An antifouling
combined action of hydrolysis and hydrodynamic shear stress.
coating system of known performance is included to serve as a
This action is often, but not necessarily, achieved by the
control in antifouling studies.
combined effects of hydrolysis and hydrodynamic shear stress.
1.2 This standard does not purport to address all of the
3.1.2 hydrolysis, n—softening or weakening of the outer
safety concerns, if any, associated with its use. It is the
layers, permitting the hydrodynamic shear stresses gradually to
responsibility of the user of this standard to establish appro-
remove them, continually exposing a fresh antifouling surface.
priate safety and health practices and determine the applica-
3.1.3 hydrodynamic shear stress, n—the force tangential to
bility of regulatory limitations prior to use. For a specific
the surface resulting from water in contact with and flowing
hazards statement, see Section 8.
parallel to the surface.
2. Referenced Documents
4. Summary of Test Method
2.1 ASTM Standards:
4.1 The antifouling coatings to be tested and a control
A 569/A 569M Specification for Steel, Carbon (0.15 Maxi-
2
coating are applied to steel panels and exposed in natural
mum Percent), Hot-Rolled, Sheet and Strip, Commercial
seawater at a site where the fouling rate is high. The exposure
D 1186 Test Methods for Nondestructive Measurement of
consists of alternate static and dynamic cycles of typically 30
Dry Film Thickness of Nonmagnetic Coatings Applied to
3 days each for a total length of time to be specified (such as one
a Ferrous Base
or two years) or until some selected degree of fouling is
D 2200 Pictorial Surface Preparation Standards for Painting
4 reached. The static exposure is conducted in accordance with
Steel Surfaces
Method D 3623 except that the panels are smaller and are
D 3623 Method for Testing Antifouling Panels in Shallow
4 preformed to fit a rotating drum. The dynamic exposure
Submergence
5 consists of subjecting the test panels to a shear stress by
2.2 U.S. Military Specifications:
rotating the drum underwater at some specified revolution rate;
MIL-P-24441 Primer, Epoxy (Formula 150, Formula Sheet
typically,thatratethatgivesaperipheralspeedof15knots(7.6
24441/1)
m/s). See Note 1 for an example. Photographs and film
MIL-P-15931B Paint, Antifouling, Vinyl, Red (Formula
thickness measurements (made in accordance with Test Meth-
121/63)
ods D 1186) are taken before exposure to seawater and, along
with fouling ratings, at intervals during exposure.
1
This test method is under the jurisdiction of ASTM Committee D01 on Paint
NOTE 1—Consider antifouling paint for a ship about 500 ft in length
and Related Coatings, Materials, andApplications and is the direct responsibility of
that cruises at about 20 knots. From Table 2, the column for 20 knots
2
Subcommittee D01.45 on Marine Coatings.
shows the hydrodynamic shear stress, t varying from 2.01 to 1.40 lbf/ft
Current edition approved March 10, 2003. Published May 2003. Originally
over a flat plate with approximately the same length as the ship. From
approved in 1989. Last previous edition approved in 1996 as D 4939 - 96.
Table 1, a rotating drum with a radius of 0.75 ft with a peripheral speed
2
Discontinued; see 2001 Annual Book of ASTM Standards, Vol 01.03.
2
3 of 15 knots gives a t of 1.72 lbf/ft . To subject the paint to about the same
Annual Book of ASTM Standards, Vol 06.01.
4
rangeof tasontheship,thepaintcanbetestedonthedrumwith tof1.72
Annual Book of ASTM Standards, Vol 06.02.
2
5
lbf/ft . Because t for the plate (and ships) decreases from the leading to
Available from Standardization Documents Order Desk, DODSSP, Bldg. 4,
Section D, 700 Robbins Ave., Philadelphia, PA 19111-5098 the trailing edge, it is considered adequate to select t for the drum as the
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