ASTM_D_3806_-_98_2011.pdf

Designation:D380698(Reapproved 2011)Standard Test Method ofSmall-Scale Evaluation of Fire-Retardant Paints(2-FootTunnel Method)1This standard is issued under the fixed designation D3806;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 determines the protection a coatingaffords its substrate,and the comparative burning characteris-tics of coatings by evaluating the flame spread over the surfacewhen ignited under controlled conditions in a small tunnel.This establishes a basis for comparing surface-burning charac-teristics of different coatings without specific consideration ofall the end-use parameters that might affect surface-burningcharacteristics under actual fire conditions.1.2 In addition to the experimental flamespread rate,theweight of panel consumed,time of afterflaming and afterglow,char dimensions and index,and height of intumescence may bemeasured in this test.However,a relationship should not bepresumed among these measurements.1.3 This standard should be used to measure and describethe properties of materials,products,or assemblies in responseto heat and flame under controlled laboratory conditions,andshould not be used to describe or appraise the fire hazard or firerisk of materials,products,or assemblies under actual fireconditions.However,results of this test may be used aselements of a fire risk assessment which takes into account allof the factors which are pertinent to an assessment of the firehazard of a particular end use.1.4 The values stated in SI units are to be regarded as thestandard.The values given in parentheses are for informationonly.1.5 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:2C220 Specification for Flat Asbestos-Cement SheetsD344 Test Method for Relative Hiding Power of Paints bythe Visual Evaluation of BrushoutsD1475 Test Method For Density of Liquid Coatings,Inks,and Related ProductsD2196 Test Methods for Rheological Properties of Non-Newtonian Materials by Rotational(Brookfield type)ViscometerE84 Test Method for Surface Burning Characteristics ofBuilding Materials2.2 Federal Standard:Fed.Spec.TT-V-119 Varnish,Spar,Phenolic Resin33.Significance and Use3.1 A number of laboratory procedures are used to evaluatethe effectiveness of fire-retardant and fire-resistant treatmentsand coatings.In general,these methods measure the threestages of fire development:(1)ignition;(2)flame spread(rateof growth of the fire);and(3)conflagration extent.While allthree are of extreme importance,flame spread has beenrecognized as the main factor associated with testing fire-retardant coatings.3.2 Flame spread ratings based upon Test Method E84 haveacquired common acceptance by regulatory agencies,but suchlarge-scale tests are seldom practical during the developmentor modification of a fire-retardant coating.3.3 This test method provides the relative flame spread ofexperimental coatings using small test specimens.By calibrat-ing the 2-foot tunnel with Test Method E84-rated fire-retardant1This test method is under the jurisdiction of ASTM Committee D01 on Paintand Related Coatings,Materials,and Applications and is the direct responsibility ofSubcommittee D01.21 on Chemical Analysis of Paints and Paint Materials.Current edition approved June 1,2011.Published June 2011.Originallyapproved in 1979.Last previous edition approved in 2004 as D3806 98(2004).DOI:10.1520/D3806-98R11.2For 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.Copyright ASTM International,100 Barr Harbor Drive,PO Box C700,West Conshohocken,PA 19428-2959.United States1 paint,results obtained by this test method should be indicativeof those obtained with a large specimen in the Test Method E84tunnel.4.Apparatus4.1 Flame Tunnel4(see Fig.1A)610-mm(two-foot)flametunnel consisting of asbestos-cement board mounted on an ironframework and supplied with natural gas fuel of uniformquality.4.1.1 The framework is constructed of 3 by 25 by 25-mm(18by 1 by 1-in.)angle iron,the top of which provides a 610by 100-mm(24 by 4-in.)specimen holder inclined at 28 to thehorizontal.The framework is mounted on a 250 by 610 by13-mm(10 by 24 by12-in.)steel base.The specimen holder iselevated 185 mm(73