Designation:D358−98(Reapproved2012)´1StandardSpecificationforWoodtoBeUsedasPanelsinWeatheringTestsofCoatings1ThisstandardisissuedunderthefixeddesignationD358;thenumberimmediatelyfollowingthedesignationindicatestheyearoforiginaladoptionor,inthecaseofrevision,theyearoflastrevision.Anumberinparenthesesindicatestheyearoflastreapproval.Asuperscriptepsilon(´)indicatesaneditorialchangesincethelastrevisionorreapproval.ThisstandardhasbeenapprovedforusebyagenciesoftheDepartmentofDefense.´1NOTE—Correctionstotheunitconversionfor10mmweremadeinJuly2012.1.Scope1.1Thisspecificationdesignateswoodsforweatheringtestsofexteriorsolvent-borneorwater-bornepaintsandothermaterialsofsimilarpurpose.Suchtestsmayincludeeitheroutdoorexposuretestsoracceleratedlaboratorytests.Itisthepurposeofthisspecificationtominimizetheinfluenceofvariationofwoodofagivenspeciesontestresults.1.2ThevaluesstatedinSIunitsaretoberegardedasstandard.Thevaluesgiveninparenthesesareforinformationonly.2.ReferencedDocuments2.1ASTMStandards:2D3924SpecificationforEnvironmentforConditioningandTestingPaint,Varnish,Lacquer,andRelatedMaterials3.GeneralConsiderations3.1Avarietyofdifferentspeciesshouldbeusedfortestingfinishesbecauseofthewidevariationsintheanatomyandthedensitybetweenwoodspecies.Thesefactorshavetremendousinfluencesonfinishperformance.Latewoodbandwidthanddensityareespeciallyimportanttofinishperformance,andtheseparametersvarysignificantlybetweenwoodspecies.Cedarandredwoodhaverelativelylowproportionsofhardsummerwooddistributedinnarrowbandsandcontainextrac-tivesthatdiscolorsomepaintfilms.Southernpinehasalargeproportionofhardsummerwoodinwidebands.3.2Theanglebetweenthegrowthringsandthesurfaceofthespecimenisverycriticaltofinishperformance.Commer-cialpracticeutilizesthefollowingclassificationsystem.Boardsinwhichgrowthformsanangleoflessthan30°withthewidesurfaceofthepiecearesaidtobeflat-sawnorflat-grained;thosewiththeringsintersectingatanglesbetween30°and60°aretermedbastard-sawn;andthosewithanglesgreaterthan60°arete...
