ASTM D5401-2003(2008) Standard Test Method for Evaluating Clear Water Repellent Coatings on Wood.pdf

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1、Designation: D 5401 03 (Reapproved 2008)Standard Test Method forEvaluating Clear Water Repellent Coatings on Wood1This standard is issued under the fixed designation D 5401; the number immediately following the designation indicates the year oforiginal adoption or, in the case of revision, the year

2、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 evaluates the effectiveness of clearwater repellent coatings on wood before or after exteriorexpos

3、ure.1.2 Intralaboratory results with this test method can be usedto compare the effectiveness of clear water repellent coatings.The agreement between results obtained in different laborato-ries may be less satisfactory unless a known water repellent isused as a reference.1.3 The values stated in inc

4、h-pound units are to be regardedas standard. The values given in parentheses are mathematicalconversions to SI units that are provided for information onlyand are not considered standard.1.4 This standard does not purport to address all of thesafety problems, if any, associated with its use. It is t

5、heresponsibility 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:2D 358 Specification for Wood to Be Used as Panels inWeathering Tests of CoatingsD 100

6、6 Practice for Conducting Exterior Exposure Tests ofPaints on WoodD 1193 Specification for Reagent WaterD 3924 Specification for Environment for Conditioning andTesting Paint, Varnish, Lacquer, and Related Materials3. Terminology3.1 Definitions of Terms Specific to This Standard:3.1.1 clear water re

7、pellent coating, na transparent coatingformulated for the purpose of protecting porous substrates bypreventing the penetration of liquid water.4. Summary of Test Method4.1 Five Ponderosa pine specimens are treated with the clearwater repellent under test and allowed to dry for seven days.Five untrea

8、ted specimens serve as controls. The treated anduntreated specimens are each weighed and then allowed to floatin water for 30 min. The specimens are removed, the excesswater is wiped off, and each are reweighed. The effectivenessof the water repellent coating is then calculated.5. Significance and U

9、se5.1 Water is known to penetrate wood substrates, causingdimensional instability and eventual deterioration. Clear waterrepellent coatings are designed to protect wood from damagingeffects of water. This test method is used to evaluate theeffectiveness of water repellent coatings on wood soon after

10、application or after long-term exterior exposure.6. Apparatus6.1 Conditioning Room or Chamber, having a controlledtemperature of 73.5 6 3.5F (23 6 2C) and a controlledrelative humidity of 50 6 5 % as described in SpecificationD 3924. This is used to establish a uniform moisture content inthe test sp

11、ecimens and during the test.6.2 Balance, accurate to at least 0.1 g.6.3 Saw, sharp, fine-toothed, with a minimum of ten teeth/in. to obtain a smooth surface on the test specimen.7. Reagents and Materials7.1 Purity of WaterUnless otherwise clearly indicated,references to water shall be understood to

12、mean reagent wateras defined by Type IV of Specification D 1193.7.2 WoodWood used for these tests shall be randomlyselected standard commercial “two-by-fours,” straight-grained,knot-free, flat-sawn, kiln-dried, Ponderosa pine sapwood, se-lected in accordance with Specification D 358.NOTE 1Species ot

13、her than Ponderosa pine may be used by mutualagreement.1This test method is under the jurisdiction of ASTM Committee D01 on Paintand Related Coatings, Materials, and Applications and is the direct responsibility ofSubcommittee D01.42 on Architectural Coatings.Current edition approved June 1, 2008. P

14、ublished June 2008. Originallyapproved in 1993. Last previous edition approved in 2003 as D 5401 - 03.2For 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

15、Document Summary page onthe ASTM website.1Copyright ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959, United States.8. Test Specimens8.1 Cut away and discard 3 in. (76 mm) of end grain fromthe selected “two-by-four” to avoid any pretreatment that mayhave been

16、applied by the supplier and to ensure an even cut onevery specimen.8.2 Using the fine-toothed saw (see 6.3) to ensure a smoothsurface, cut a supply of 12 in. (305 mm) long test specimenssufficient for the intended test program, with an ample overageto allow for possible discards. Five specimens are

17、required foreach water repellent being tested and five for an untreatedcontrol set.8.3 Weigh each specimen to 0.1 g and calculate the meanweight. Discard specimens that vary more than 10 % from themean and cut additional specimens as necessary to obtainsufficient specimens within the specified weigh

18、t range toperform all of the planned tests.8.4 Store the test specimens for at least six days in aconditioned room or chamber as described in 6.1, on a raisedscreen or rack to provide ventilation around each specimen,and allow them to come to constant weight. (Constant weightis defined as a change o

19、f no more than1gin24h.)9. Treatment9.1 Prior to treatment, weigh the test specimens on twosuccessive days to ensure constant weight.9.2 Immerse each of the five test specimens in the waterrepellent coating for 30 s. To ensure even coverage, allowexcess water repellent to drain longitudinally for 1 m

20、in fromone end of the specimen, then invert to allow similar drainagefor 1 min from the other end.9.3 Allow the treated specimens to air dry on a raised screenor rack for 24 h.10. Procedure10.1 Return the treated specimens to the conditioning cham-ber along with five untreated specimens for at least

21、 seven daysor until they reach constant weight, then record their weight to0.1 g.10.2 Place the specimens in a container of water at 73.5 63.5F (23 6 2C) and allow to float for 15 min, then turn themover and allow them to float for another 15 min. to give a totalimmersion time of 30 min.10.3 Remove

22、the specimens from the water, allow to drainbriefly, wipe the specimens with a slightly dampened cloth toremove excess water, reweigh and record each weight to 0.1 g.10.4 Optional Weathering ProcedureFollowing comple-tion of 10.3, subject the treated and untreated specimens toagreed conditions and a

23、n agreed time period of exteriorexposure in accordance with Practice D 1006, then test asdescribed in Section 10 to determine the water repellentefficiency of the treatment after exposure with respect tountreated wood.11. Calculations11.1 Calculation the water repellent efficiency, (WRE) inpercent,

24、for each specimen as follows:WRE 5 100 A 2 B! 2 C 2 D!#/A 2 B!(1)where:A = weight of the untreated specimen after water contact,g,B = weight of the untreated specimen before water con-tact, g,C = weight of the treated specimen after water contact, g,andD = weight of the treated specimen before water

25、 contract,g.11.2 Calculate the mean WRE value for each five-specimenset.12. Report12.1 Report the following information:12.1.1 Mean water repellent efficiency (WRE) of eachcoating (See 11.2),12.1.2 Mean weight for each five-specimen set both beforeand after water immersion (Section 10),12.1.3 If the

26、 specimens were weathered, report the exposuretime and conditions of exterior exposure, and12.1.4 Any significant deviations from the standard testmethod as described herein.13. Precision and Bias313.1 PrecisionIn an interlaboratory study of this testmethod, one operator in each of five laboratories

27、 measured thewater gain of five specimens of Ponderosa pine, and of threefive-specimen sets that were treated with three water repellentcoatings ranging from moderate to high water repellency.13.1.1 The intralaboratory standard deviation of the weightgains of the untreated panels was found to be 15.

28、46 g with 17df and the interlaboratory standard deviation 14.2 g with 4 df,after discarding one result from each of 3 laboratories becausethey differed widely from the other results from the samelaboratory and other laboratories.13.1.2 The intralaboratory standard deviation of the waterrepellent eff

29、iciency was found to be 2.99 % absolute with 57 dfand the interlaboratory standard deviation 3.9 % with 12 df,after discarding one result from each of two sets from the samelaboratory because they differed significantly from other resultsin the same sets and one result from other laboratorys set,bec

30、ause the range differed significantly from all the remainingsets.13.1.3 Based on these standard deviations, the followingcriteria should be used for judging, at the 95 % confidencelevel, the acceptability of results:13.1.4 Water Absorption by Untreated Wood:13.1.4.1 RepeatabilityResults obtained by

31、the same op-erator using panels of the same wood should be consideredsuspect if they differ by more than 62 g for four panels and 67g for 5 panels at weight gains of 45 to 100 g.13.1.4.2 ReproducibilityTwo results, each the mean offive repeats obtained by operators in different laboratories,should b

32、e considered suspect if they differ by more than 90 gin the same weight gain range.3Supporting data are available from ASTM International Headquarters. RequestRR:D01-1082.D 5401 03 (2008)213.2 BiasBias cannot be established because there is nostandard material.14. Keywords14.1 architectural paints a

33、nd coatings; water repellentsASTM International takes no position respecting the validity of any patent rights asserted in connection with any item mentionedin this standard. Users of this standard are expressly advised that determination of the validity of any such patent rights, and the riskof inf

34、ringement of such rights, are entirely their own responsibility.This standard is subject to revision at any time by the responsible technical committee and must be reviewed every five years andif not revised, either reapproved or withdrawn. Your comments are invited either for revision of this stand

35、ard or for additional standardsand should be addressed to ASTM International Headquarters. Your comments will receive careful consideration at a meeting of theresponsible technical committee, which you may attend. If you feel that your comments have not received a fair hearing you shouldmake your vi

36、ews known to the ASTM Committee on Standards, at the address shown below.This standard is copyrighted by ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959,United States. Individual reprints (single or multiple copies) of this standard may be obtained by contacting ASTM at the aboveaddress or at 610-832-9585 (phone), 610-832-9555 (fax), or serviceastm.org (e-mail); or through the ASTM website(www.astm.org).D 5401 03 (2008)3