ASTM_D_4688_-_D_4688M_-_14.pdf

Designation:D4688/D4688M14Standard Test Method forEvaluating Structural Adhesives for Finger Jointing Lumber1This standard is issued under the fixed designation D4688/D4688M;the number immediately following the designation indicates theyear of original adoption or,in the case of revision,the year of last revision.A number in parentheses indicates the year of lastreapproval.A superscript epsilon()indicates an editorial change since the last revision or reapproval.1.Scope1.1 This test method is designed to evaluate adhesives forfinger jointing lumber used in the manufacture of a variety ofbonded structural wood products such as structural gluedlaminated timber.It tests the tensile strength of joints under thefollowing treatments:dry with no treatment,wet after onevacuum-pressure soak treatment,and wet after cyclic boil-drytreatment.1.2 This test method is intended neither for quality controlas the test assemblies are selected for the absence of defectsusually found in run-of-the-mill finger joints nor as a substitutefor in-plant qualification of end joints,including full-scale jointtests.NOTE1This test method is specifically designed to evaluate adhesivesfor use in finger jointing lumber using small scale test specimens cut fromcarefully selected finger joint assemblies.In contrast,plant qualificationand quality control require tests of full scale end joints selected randomlyfrom production,designed to evaluate parameters beyond adhesiveperformance which affect the performance of the end use product.1.3 The values stated in either SI units or inch-pound unitsare to be regarded separately as standard.The values stated ineach system may not be exact equivalents;therefore,eachsystem shall be used independently of the other.Combiningvalues from the two systems may result in non-conformancewith the standard.1.4 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:2D907 Terminology of AdhesivesD2559 Specification for Adhesives for Bonded StructuralWood Products for Use Under Exterior Exposure Condi-tionsD5266 Practice for Estimating the Percentage of WoodFailure in Adhesive Bonded JointsE4 Practices for Force Verification of Testing Machines3.Terminology3.1 DefinitionsMany terms in this test method are definedin Terminology D907.3.2 Definitions of Terms Specific to This Standard:3.2.1 billet,na piece cut from a vertical finger jointassembly as an intermediate step in making specimens.3.2.2 horizontal finger joint,na joint formed by bondingtwo precut members shaped like fingers where the profile isvisible on the edge of the lumber(see Fig.1a).3.2.3 vertical finger joint,na joint formed by bonding twoprecut members shaped like fingers where the profile is on thewide face of the lumber(see Fig.1b).3.2.4 finger joint assembly,na short portion of two boardsjoined at their ends by an adhesively bonded finger joint tocreate a longer piece,frequently referred to as an assembly.3.2.5 sample,na group of finger joint assemblies obtainedfrom a finger joint production line or laboratory prepared fingerjoints selected for statistical purposes.3.2.6 specimen,nan individual test piece prepared tospecific dimensions for the purpose of determining the adhe-sive performance in accordance with the tension tests describedin this test method.4.Significance and Use4.1 This test method is specifically designed to measure theperformance of adhesives in finger joints manufactured underproduction line conditions.4.1.1 The test method can be adapted to evaluate theadhesive performance of laboratory produced finger jointsusing commercial finger joint cutting heads with finger jointsproduced following the adhesive manufacturers recommenda-tions.The conditions under which the finger joints wereproduced,including any limitations,are to be reported in9.1.2.2(see Note 2).1This test method is under the jurisdiction of ASTM Committee D14 onAdhesives and is the direct responsibility of Subcommittee D14.30 on WoodAdhesives.Current edition approved Nov.1,2014.Published January 2015.Originallyapproved in 1987.Last previous edition approved in 2013 as D4688 99(2013).DOI:10.1520/D4688_D4688M-14.2For 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.Copyright ASTM International,100 Barr Harbor Drive,PO Box C700,West Conshohocken,PA 19428-2959.United States1 NOTE2If laboratory prepared finger joints are to be produced,recorddetails related to adhesive used,its preparation,application to the cutfinger joint,appropriate bonding parameters and limitations in theproduction of the finger joint assemblies.4.2 The results of the