1、Designation: D6990 05 (Reapproved 2011)Standard Practice forEvaluating Biofouling Resistance and Physical Performanceof Marine Coating Systems1This standard is issued under the fixed designation D6990; the number immediately following the designation indicates the year oforiginal adoption or, in the
2、 case of revision, the year of last revision. A number in parentheses indicates the year of last reapproval. Asuperscript epsilon () indicates an editorial change since the last revision or reapproval.1. Scope1.1 This practice establishes a practice for evaluating degreeof biofouling settlement on a
3、nd physical performance ofmarine coating systems when panels coated with such coatingsystems are subjected to immersion conditions in a marineenvironment. Guidance for preparation or exposure and han-dling of test specimens can be found in related ASTMstandards as noted below (see Section 2).1.2 Thi
4、s practice and related exposure methodologies aredesigned as tools for the relative assessment of coatingperformance, and in no way are to be used as an absoluteindicator of long-term performance under all conditions and inall environments. There can be high variability among andwithin exposure site
5、s with respect to water quality and popu-lation or species of fouling organisms, and coating perfor-mance may vary with these and other properties.1.3 The values stated in SI units are to be regarded as thestandard. The values given in parentheses are for informationonly.1.4 This standard does not p
6、urport to address all of thesafety concerns, if any, associated with its use. It is theresponsibility of the user of this standard to establish appro-priate safety and health practices and determine the applica-bility of regulatory limitations prior to use. A specific hazardstatement is given in Sec
7、tion 6.2. Referenced Documents2.1 ASTM Standards:2Recommended ASTM Methods and Practices for evaluationof antifouling coatings via panel exposure under a variety ofexposure conditions:D3623 Test Method for Testing Antifouling Panels in Shal-low SubmergenceD4938 Test Method for Erosion Testing of Ant
8、ifoulingPaints Using High Velocity WaterD4939 Test Method for Subjecting Marine AntifoulingCoating to Biofouling and Fluid Shear Forces in NaturalSeawaterD5479 Practice for Testing Biofouling Resistance of MarineCoatings Partially ImmersedD5618 Test Method for Measurement of BarnacleAdhesionStrength
9、 in ShearG141 Guide for Addressing Variability in Exposure Testingof Nonmetallic Materials3. Terminology3.1 Definitions of Terms Specific to This Standard:3.1.1 biofilm, nmatrix-enclosed populations of microor-ganisms adherent to each other or to surfaces, or both, orinterfaces.3.1.2 biofouling adhe
10、sion, nqualitative or quantitativeforce required for the successful and complete removal ofmarine fouling attached to the antifouling coating surface (forexample, reference Test Method D5618 for barnacles).3.1.3 corrosion eruptions, nbuild up of oxides, exitingthrough protective paint film.3.1.4 dam
11、age, nlimited destruction of portions of paintfilm due to impact with a foreign article.3.1.5 digging, na term used to describe hard foulingmacroorganisms that are growing “into” the coating. That is,where its calcareous shell penetrates/breaks through the coat-ing surface causing physical damage to
12、 the coating.3.1.6 macroorganism, norganisms large enough to beseen with the naked eye and thus would be noted whengrowing on submerged surfaces.3.1.7 microorganism, norganisms too small to be seenwith the naked eye, which generally include bacteria, protozoa,fungi and microalgae (sometimes collecti
13、vely called “slime”).3.1.8 peeling, nthe phenomenon manifested in paint filmswhere a portion of a film, when pulled, can be removed instrips or relatively large intact pieces, or both.1This practice is under the jurisdiction of ASTM Committee D01 on Paint andRelated Coatings, Materials, and Applicat
14、ions and is the direct responsibility ofSubcommittee D01.45 on Marine Coatings.Current edition approved June 1, 2011. Published June 2011. Originallyapproved in 2003. Last previous edition approved in 2005 as D6990 05. DOI:10.1520/D6990-05R11.2For referenced ASTM standards, visit the ASTM website, w
15、ww.astm.org, orcontact ASTM Customer Service at serviceastm.org. For Annual Book of ASTMStandards volume information, refer to the standards Document Summary page onthe ASTM website.1Copyright ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959, United States.3.1
16、.9 silt, nsedimentary material consisting especially ofmineral particles intermediate in size between those of sandand clay.3.1.10 softness, advthe phenomenon manifested by paintsin transferring some of its pigmentation to a foreign item orsubstance, upon encountering friction on its surface.3.1.11
17、wearing, ngradual loss of the paint film caused byuse or exposure to the environment.4. Summary of Practice4.1 Test specimens or panels are coated with marine coatingsystems and exposed to marine immersion conditions for aspecified amount of time and under specific sets of conditionsas agreed upon b
18、y the producer and user. See 2.1 for publishedASTM standard methods and practices that provide guidancefor exposure of coating systems.4.2 Coating systems are evaluated in terms of fouling rating(percent of coverage of the coating system by biofoulingorganisms), and physical deterioration rating (pe
19、rcent area ofthe coating system affected by physical coating failure(s).These data are useful in assessing and comparing effectivenessof antifouling coating systems.5. Significance and Use5.1 This practice is designed to provide guidance to a panelinspector for quantitative and consistent evaluation
20、 of coatingperformance from test panels coated with marine antifoulingcoating systems. The practice assesses performance of coatingsystems based on both antifouling and physical properties.5.2 The user is cautioned that the results are representativefor the specific region and time of year in which
21、the specimensare immersed. It shall be noted that interpretation of results willdepend on the geographical location where the test is con-ducted, whether the coated specimens are exposed eithertotally or partially immersed, under static or dynamic condi-tions, and position and orientation.5.3 Simult
22、aneous testing of a proven standard antifoulingcoating system (known to minimize fouling accumulation, forexample, containing biocide or active agent(s) to preventfouling settlement/growth) in the specific marine environmentshall be included as a reference to assist in interpretation ofresults. In a
23、ddition, a negative control (inert surface susceptibleto heavy fouling) shall be included on a regular basis. For theexposure to be valid, the surface of the negative control shouldshow heavy fouling relative to the standard system(s).5.4 Marine coating systems that produce positive resultsrelevant
24、to the standard system(s) show potential for use inprotecting underwater marine structures.5.5 The format can be utilized independent of exposureprotocol and coating type, and provides the end user with aconsistent practice and format for reporting of performancerating.6. Safety Precautions6.1 Warni
25、ngCertain marine coating systems containtoxic materials (biocides) that may cause skin and eye irritationon contact as well as adverse physiological effects if ingestedor inhaled. In the preparation, application, and general han-dling of panels coated with various types of marine paints, theuse of a
26、ppropriate protective clothing and equipment is re-quired consistent with local, state, federal government regula-tions and recognized industrial and technical standards.7. ProcedureEvaluation of Fouling Present on TestSurface7.1 Controls should be exposed and assessed at the sametime as the test ma
27、terials. More information about the use ofcontrol materials in weathering tests can be found in GuideG141. (See also 5.3.)7.2 Retrieve test panels and any negative controls andreference coatings from immersion site. Note and record thevisual percentage coverage by biofilm or silt, or both, or lackth
28、ereof in accordance with the guidelines provided below.7.3 Prior to inspection, it is recommended that panels berinsed (see below and 7.3.2 for more information) in order toremove silt (may interfere with observation of attached forms)and unattached forms. Alternatives to rinsing such as eithergentl
29、e agitation of the panels or not rinsing the panels at allmay be done but must be specified in the final reports.Whichever preparation is chosen, it must be documented andperformed on all panels equally and at each inspection. Ifrinsed, the test panel surface is to be wetted using low-pressurewater.
30、 For example, use household water pressures fromgarden hose sized-nozzles measuring 9.5 to 13 mm (38 to12in.) in the form of a gentle shower spray or non-forceful flowto allow for a reliable inspection of what is attached to thecoating/panel. Nozzles that cause water to be forcefully appliedto the p
31、anel shall not be used. WarningRisk in rinsingpanels is that subsequent biofouling attachment may be af-fected. Alternatively, panels may be gently agitated in water toremove loose/unattached bacterial biofilm or silt deposits, orboth. WarningRisk in not rinsing panels is that silt or slime,or both,
32、 may interfere with assessment of biofouling attach-ment on complete panel surface.7.3.1 Test panels shall not be allowed to dry during theentire inspection period. A holding tank is useful for accom-plishing this.7.3.2 Rinse water and holding tank water, shall be takenfrom the immersion site.7.3.3
33、Efforts shall be made to minimize the length of timepanels remain removed from the normal immersion site, and tonot touch the coated surfaces.7.4 Populations and types of organisms will vary by testsite. Some examples of biofouling microorganisms includebarnacles, oysters, mussels, bryozoans (arbore
34、scent and en-crusting), hydroids, tubeworms, tunicates, sponges, and vari-ous types of algae. Each type of fouling organism directlyattached to the test surface shall be reported by (1) theestimated percentage of the panel area covered by all of thesame type of biofouling (for example, colonial form
35、s), (2) thefrequency (number of individuals for the larger and solitaryorganisms; for example, barnacles, mussels, oysters, tubeworms, and some tunicates), and (3) the range of size for theindividual organisms (for larger, solitary organisms). SeeAppendix X1 for guidance on estimating percent cover
36、andFig. X2.1 for a suggested sample antifouling inspection reportform.D6990 05 (2011)27.4.1 Make a note of any fouling organisms found to begrowing into the paint film, also referred to as “digging.”7.4.2 Note that percentage cover of algae and arborescentbryozoans shall be based on the area covered
37、 by the “hold fast”and not the area covered by the “strands” or colony. The typeof algae (for example, brown, red, green) shall also be recordedif known.7.4.3 Only attachment of primary biofouling settlement(that is, biofouling attached directly to the coating system)shall be recorded. Notes on seco
38、ndary fouling (biofoulingattached to other fouling organisms) can be made if desired, butshall not factor into the generation of a “fouling rating.”7.4.4 Percent cover by mud tube-building amphipods shallbe reported as a footnote in Fig. X2.1, but shall NOT factor intothe generation of a “fouling ra
39、ting.”7.4.5 Partial Immersion Test Panels OnlyPanels exposedin accordance with Practice D5479 are partially immersed. Thenon-immersed area will be subject to splash and may showsome fouling attachment, but the area is not included in thedetermination of a fouling rating. Therefore, the fouling ratin
40、gis calculated based on the fully immersed surface area, count-ing the immersed surface area as 100 %.7.4.6 In addition, antifouling performance of coating sys-tems is often different in the immediate waterline vicinity.Therefore, an estimate of coverage along the first 50 mm (2 in.)of the test pane
41、l shall also be made and can then be contrastedwith the overall coverage. Fouling occurring in the “above thewaterline” area, if any, is not considered when generating a“fouling rating.”7.5 Discount biofouling attachment within 13 mm (12 in.)from all edges of the test panel.8. ProcedureEvaluation of
42、 Physical Deterioration/Performance of Test Surface8.1 Prior to the original exposure, inspect all test panels forpossible physical deterioration. Record findings. Continueobservation of predetermined damage during future inspec-tions. See Fig. X2.2 for a suggested sample physical perfor-mance inspe
43、ction report form.8.2 Evaluate individual physical performance failure, quali-tatively and quantitatively, for each test specimen. Observa-tions of erosion, wearing, blistering, alligatoring, checking,cracking, chipping, peeling, flaking, and damage shall bemade. For additional information and guida
44、nce for evaluatingany of the previous physical deteriorations, refer to Sections 2and 3. Record the percent surface area affected by eachphysical parameter.8.2.1 Observations of physical deterioration shall be per-formed for each coat visible to the inspector (for example,topcoat, intermediate, prim
45、er). The percent surface area af-fected by each physical parameter shall be estimated based onthe visible area of each coat.8.3 Discount any physical failures within 13 mm (12 in.)from all edges of the test panel.8.4 Observations of physical deterioration cannot be per-formed on panel surface areas
46、covered by hard fouling. At thetime of inspection do not count this area in the generation ofthe physical deterioration rating (PDR); see also 11.2. At theend of the panel test period, a final evaluation of physicaldeterioration rating can be performed after removal of hardfouling in order to determ
47、ine whether physical deteriorationhas occurred under areas that had been covered by hardfouling.9. ProcedureEvaluation of “Softness” of MarineCoating System9.1 Evaluation of “softness” is intended for marine coatingsystems (excluding silicone coating systems), and is an indi-cator of a coatings pigm
48、ent erosion characteristics. It ismeasured on a subjective scale of 10 to 0 (see 9.2.1), dependenton the amount of pigment transferred from the coating to acotton swab.9.2 After rinsing the test panels (see 7.2), rub a wet cottonswab, exactly 10 strokes in a back and forth motion, over thewet test s
49、urface. The cotton swab is held at one of its ends withthe thumb and index finger. The cotton swab is positioned at45 to the coating surface and sufficient pressure is applied sothat the cotton swab stem just starts to bend. The strokes shallbe made continuously in a back and forth motion, in the samelinear pattern, approximately 50 mm (2 in.) in length. Use ofproper protective equipment, such as gloves, is recommended.9.2.1 Softness shall be evaluated on the following subjec-tive scale, where:10 = no pigment transferred to a cotton swab,8 = trace amount of
