Designation:D358–98StandardSpecificationforWoodtoBeUsedasPanelsinWeatheringTestsofCoatings1ThisstandardisissuedunderthefixeddesignationD358;thenumberimmediatelyfollowingthedesignationindicatestheyearoforiginaladoptionor,inthecaseofrevision,theyearoflastrevision.Anumberinparenthesesindicatestheyearoflastreapproval.Asuperscriptepsilon(e)indicatesaneditorialchangesincethelastrevisionorreapproval.ThisstandardhasbeenapprovedforusebyagenciesoftheDepartmentofDefense.1.Scope1.1Thisspecificationdesignateswoodsforweatheringtestsofexteriorsolvent-borneorwater-bornepaintsandothermaterialsofsimilarpurpose.Suchtestsmayincludeeitheroutdoorexposuretestsoracceleratedlaboratorytests.Itisthepurposeofthisspecificationtominimizetheinfluenceofvariationofwoodofagivenspeciesontestresults.1.2Thevaluesstatedininch/poundunitsaretoberegardedasthestandard.Thevaluesgiveninparenthesesareforinformationonly.2.ReferencedDocuments2.1ASTMStandards:D3924SpecificationforStandardEnvironmentforCondi-tioningandTestingPaint,Varnish,Lacquers,andRelatedMaterials23.GeneralConsiderations3.1Avarietyofdifferentspeciesshouldbeusedfortestingfinishesbecauseofthewidevariationsintheanatomyandthedensitybetweenwoodspecies.Thefactorshavetremendousinfluencesonfinishperformance.Latewoodbandwidthanddensityareespeciallyimportanttofinishperformance,andtheseparametersvarysignificantlybetweenwoodspecies.Cedarandredwoodhaverelativelylowproportionsofhardsummerwooddistributedinnarrowbandsandcontainextrac-tivesthatdiscolorsomepaintfilms.Southernpinehasalargeproportionofhardsummerwoodinwidebands.3.2Theanglebetweenthegrowthringsandthesurfaceofthespecimenisverycriticaltofinishperformance.Commer-cialpracticeutilizesthefollowingclassificationsystem.Boardsinwhichgrowthformanangleoflessthan30°withthewidesurfaceofthepiecearesaidtobeflat-sawnorflat-grained;thosewiththeringsintersectingatanglesbetween30°and60°aretermedbastard-sawn;andthosewithanglesgreaterthan60°aretermedquarter-sawn,edgegrain,orverticalgrain.3.3Someindustrialprocess...
