ASTM_C_741_-_93_1998.pdf

Designation:C 741 93(Reapproved 1998)Standard Test Method forAccelerated Aging of Wood Sash Face Glazing Compound1This standard is issued under the fixed designation C 741;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(e)indicates an editorial change since the last revision or reapproval.1.Scope1.1 This test method covers the testing of wood sash faceglazing compounds for accelerated aging.NOTE1Test Method D 2249 describes a similar procedure for adifferent type of glazing compound.1.2 The values stated in inch-pound units are to be regardedas the standard.The values given in parentheses are forinformation only.1.3 This standard does not purport to address all of thesafety problems,if any,associated with its use.It is theresponsibility of whoever uses this standard to consult andestablish appropriate safety and health practices and deter-mine the applicability of regulatory limitations prior to use.2.Referenced Documents2.1 ASTM Standards:C 717 Terminology of Building Seals and Sealants2D 822 Practice for Conducting Tests on Paint and RelatedCoatings and Materials Using Filtered Open-FlameCarbon-Arc Exposure Apparatus3D 2249 Test Method for Predicting the Effect of Weatheringon Face Glazing and Bedding Compounds on Metal Sash22.2Federal Specifications:TT-P-96A Paint,Latex-base,For Exterior Wood and MetalSurfaces(White and Tints)42.3NWMA Industry Standards:NWMA I.S.4-81 Water Repellant Preservative Treatmentfor Millwork5NWMA M-2-81 Swellometer Test53.Terminology3.1 DefinitionsRefer to Terminology C 717 for definitionsof the following terms:adhesive failure(loss of adhesion),bead,compound,face glazing,glazing,muntin,rabbet,andsight line.4.Summary of Test Method4.1 A section of wood muntin bar and glass,simulating atypical wood sash,is glazed with the compound and exposed inthe accelerated weathering unit for 200 h,then visuallyinspected for degradation or failure.5.Significance and Use5.1 The effect of accelerated weathering will assist injudging the quality and predicting the performance of glazingcompounds.Accelerated weathering devices should not,how-ever,be used to predict the exact number of years of servicelife or the exact type of failure that will occur under all thevaried conditions encountered in actual use.6.Apparatus6.1 Accelerated Weathering Unit,described in PracticeD 822.6.2 Wood Muntin Bar,three,9-in.(225-mm)sections,Standard Wood Sash Muntin Bar.6.3 Glass,three pieces,double-strength Grade B,9 by 1 in.(225 by 25 mm).6.4 Rubber Base Bedding Compound.6.5 Wood Preservative,one gallon,commercial type(waterrepellant),conforming to NWMA I.S.4-81.6.6 Paint,2 floz(59 cm3),white latex exterior,conformingto Federal Specification TT-P-96A.6.7 Glaziers Points.6.8 Putty Knife.6.9 Rule,calibrated to132in.(or 1 mm).7.Sampling7.1 Take the compound to be tested directly from a con-tainer as commercially supplied by the manufacturer.If thereare any signs of separation,mix the compound thoroughlyprior to testing.8.Procedure8.1 Immerse the wood muntin bars in the wood preservativefor 30 s when using a solvent-borne preservative and 3 min forwater-borne preservative in accordance with NWMA M-2-81.Weight them if necessary to ensure complete submersion.Thenremove them from the preservative and dry for 24 h at 73.4 63.6F(23 6 2C)and 50 6 5%relative humidity.8.2 Paint the bars on all surfaces with one coat of whitelatex exterior paint,and allow to dry for 24 h at 73.4 6 3.6F1This test method is under the jurisdiction of ASTM Committee C-24 onBuilding Seals and Sealants and is the direct responsibility of Subcommittee C24.12on Oil and Resin Base Glazing and Caulking Compounds.Current edition approved April 15,1993.Published June 1993.Originallypublished as C 741 73.Last previous edition C 741 85.2Annual Book of ASTM Standards,Vol 04.07.3Annual Book of ASTM Standards,Vol 06.01.4Available from Standardization Documents Order Desk,Bldg.4 Section D,700Robbins Ave.,Philadelphia,PA 19111-5094,Attn:NPODS.5Available from National Woodwork Manufacturers Association,205 WestTouhy Avenue,Park Ridge,IL 60068.1Copyright ASTM,100 Barr Harbor Drive,West Conshohocken,PA 19428-2959,United States.NOTICE:This standard has either been superseded and replaced by a new version or discontinued.Contact ASTM International(www.astm.org)for the latest information.(23 6 2C)and 50%relative humidity.8.3 Prepare three test assemblies as follows:8.3.1 Using the putty knife,apply a thin layer of therubber-base bedding compound over the entire length of thenarrower(3.16 in.or 80 mm)width of the glazing rabbet.Placeone long edge of the glass face on the bedding compound,sothat the length of bar and glass coincide,and fasten in placewith two glaziers points(or equivalent),each located 3 in.(75mm)from the bar end.Allow the assembly to cure for 24 h at73.46 3.6F(23 6 2C)and 50 6 5%