ASTM_D_5618_-_94_2011.pdf

Designation:D561894(Reapproved 2011)Standard Test Method forMeasurement of Barnacle Adhesion Strength in Shear1This standard is issued under the fixed designation D5618;the number immediately following the designation indicates the year oforiginal adoption or,in the 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 test method covers the measurement of barnacleadhesion in shear to surfaces exposed in the marine environ-ment.It is used to establish the ability of a surface to reducebiofouling adhesion.Surfaces with known barnacle adhesionstrengths are included to serve as controls.1.2 The values stated in SI units are to be regarded as thestandard.The values given in parentheses are for informationonly.1.3 This standard does not purport 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.2.Referenced Documents2.1 ASTM Standards:2D3623 Test Method for Testing Antifouling Panels in Shal-low Submergence2.2 U.S.Military Specifications:MIL-P-24441/1 Primer,Epoxy(Formula 150,FormulaSheet 24441/1)33.Summary of Test Method3.1 Test surfaces and coatings are immersed in the marineenvironment according to Test Method D3623.When barnaclesare observed to have settled on the surface,the strength ofadhesion of individuals is measured.Barnacle adhesive shearstrength is calculated by dividing the shear force required toremove the barnacle by the surface area of the barnacle baseplate.This test method is most suited to small barnacles(generally with base diameters between 5 to 20 mm).3.2 The diameter of the barnacle base is measured and anincreasing shear force is applied to the base of the barnacleuntil it is removed from the surface.4.Significance and Use4.1 This test method is designed as a screening test in theevaluation of coating systems and other materials designed toresist biofouling attachment.4.2 The degree and type of barnacle fouling will varyaccording to the geographic location of test sites and the timeof year when tests are implemented.Surfaces with knownbarnacle adhesive shear strength should be exposed to providecomparative data.5.Interferences45.1 Variations in barnacle adhesion strength may occur dueto differences in species,age,and physical condition.5.2 Incomplete removal of the barnacle base plate from thesurface during testing may lead to erroneous adhesion values.5.3 Care must be taken not to dislodge the barnacle duringbase diameter measurements.6.Apparatus6.1 Hand-Held Probe,used to apply force to the barnaclebase.It is recommended that a 14-by 14-mm stainless steelplate be attached to the end of a 8-mm diameter stainless steelrod that is attached to a force measuring device(see Fig.1).6.2 Force Measuring Device,maybe a spring scale or forcetransducer.6.2.1 The force measuring device should be capable ofrecording values between 0 to 150 N(0 to 34 lb)to an accuracyof 60.5 N(60.1125 lb).7.Procedure7.1 Test and control surfaces are immersed in the marineenvironment according to Test Method D3623.Control sur-faces should include polytetrafluoroethylene and MIL-P-24441primer epoxy.1This test method is under the jurisdiction of ASTM Committee D01 on Paintand Related Coatings,Materials,and Applications and is the direct responsibility ofSubcommittee D01.45 on Marine Coatings.Current edition approved June 1,2011.Published June 2011.Originallyapproved in 1994.Last previous edition approved in 2005 as D5618 94(2005).DOI:10.1520/D5618-94R11.2For referenced ASTM standards,visit the ASTM website,www.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.3Available from Standardization Documents Order Desk,DODSSP,Bldg.4,SectionD,700RobbinsAve.,Philadelphia,PA19111-5098,http:/dodssp.daps.dla.mil.4Swain,G.W.J.,Griffith,J.,Bultman,D.,and Vincent,H.,“BarnacleAdhesionMeasurements for the Field Evaluation of Candidate Antifouling Surfaces,Biofouling,”Vol 6,1992,pp.105114.Copyright ASTM International,100 Barr Harbor Drive,PO Box C700,West Conshohocken,PA 19428-2959.United States1 7.2 Barnacles between 5 to 20 mm in diameter are selectedfor testing and identified with regard to species and condition.Test only barnacles that are at least 20 mm from the edges ofthe test panel and not in direct contact with other barnacles.7.3 The barnacle base area is estimated from an averagebase diameter,da.This is obtained by measuring the barnaclebase with calipers in four directions(0,45,90,135).Thebarnacle base area,A,is then calculated as follows:A 514 da2(1)7.4 The probe is placed at the base of the barnacle.7.5 A shear force is applied with a hand-held probe to th