NOTICE: This standard has either been superceded and replaced by a new version or discontinued.Contact ASTM International (www.astm.org) for the latest information. Designation: D 1653 – 93 (Reapproved 1999)e1 Standard Test Methods for Water Vapor Transmission of Organic Coating Films1 This standard is issued under the fixed designation D 1653; the number immediately following the designation indicates the year of original adoption or, in the case of revision, the year of last revision. A number in parentheses indicates the year of last reapproval. A superscript epsilon (e) indicates an editorial change since the last revision or reapproval. This standard has been approved for use by agencies of the Department of Defense. e1 NOTE—Editorially changes made throughout in December 1999. 1. Scope 3.1.1 water vapor transmission rate, WVT—the steady wa- 1.1 These test methods cover the determination of the rate at ter vapor flow in unit time through unit area of a body, between which water vapor passes through films of paint, varnish, two specific parallel surfaces, under specific conditions of lacquer, and other organic coatings. The films may be free films temperature and humidity at each surface. Accepted inch- or they may be applied to porous substrates. pound unit is grains per square foot per hour. Accepted SI unit 1.2 Two test methods are covered as follows: is grams per square metre per 24 h. 1.2.1 Test Method A—Dry Cup Method, and 3.1.2 water vapor permeance, WVP—the steady water va- 1.2.2 Test Method B—Wet Cup Method. por flow in unit time through unit area of a body (WVT) 1.2.3 Agreement should not be expected between results induced by unit vapor pressure difference (Dp) between the two obtained by different methods or test conditions. The method surfaces of a coating. Therefore, WVP 5 WVT/D p. Accepted that most closely approaches the conditions of use should be inch-pound unit is grains per square foot per hour per inch of selected. mercury (called a perm). Accepted SI unit is grams per square 1.3 The values stated in inch-pound units are to be desig- metre per 24 h per millimetre of mercury (called a metric nated as the standard. Factors for conversion are stated in perm). 13.2.1.2 and 13.2.2.2. 4. Summary of Test Methods 1.4 This standard does not purport to address the safety concerns, if any, associated with its use. It is the responsibility 4.1 In Test Method A (Dry Cup Method), the test specimen of the user of this standard to establish appropriate safety and is sealed to the open mouth of a cup or dish containing health practices and determine the applicability of regulatory desiccant, and the assembly placed in a test chamber with a limitations prior to use. controlled atmosphere. Two sets of exposure conditions are acceptable for this test method. 2. Referenced Documents 4.1.1 Condition A, consisting of 50 % relative humidity at 2.1 ASTM Standards: 73°F (23°C), and D 823 Practices for Producing Films of Uniform Thickness 4.1.2 Condition B, consisting of 90 % relative humidity at of Paint, Varnish, and Related Products on Test Panels2 100°F (38°C). D 1005 Test Methods for Measurement of Dry-Film Thick- 4.2 In Test Method B (Wet Cup Method), the test specimen ness of Organic Coatings Using Micrometers2 is sealed to the open mouth of a cup or dish containing water, D 1193 Specification for Reagent Water3 and the assembly placed in a test chamber with a controlled D 4708 Practice for Preparation of Free Films of Organic atmosphere. Two sets of exposure conditions are acceptable for Coatings2 this test method: E 104 Practice for Maintaining Constant Relative Humidity 4.2.1 Condition A, consisting of 50 % relative humidity at by Means of Aqueous Solutions4 73°F (23°C), and 4.2.2 Condition C, consisting of very low (near zero) 3. Terminology relative humidity at 73°F (23°C). 3.1 Definitions of Terms Specific to This Standard: 4.3 In both methods, periodic weighings of the cup or dish are made to determine the rate of water vapor movement 1 These test methods are under the jurisdiction of ASTM Committee D-1 on Paint through the specimen. and Related Coatings, Materials, and Applications and are the direct responsibility of Subcommittee D01.23 on Physical Properties of Applied Paint Films. 5. Significance and Use Current edition approved Dec. 15, 1993. Published February 1994. Originally 5.1 One of the factors affecting the performance provided published as D 1653 – 59 T. Last previous edition D 1653 – 91a. 2 Annual Book of ASTM Standards, Vol 06.01. by an organic coating is its capability of resisting or aiding the 3 Annual Book of ASTM Standards, Vol 11.01. passage of water vapor. In some services, for example, exterior 4 Annual Book of ASTM Standards, Vol 11.03. Copyright © ASTM, 100 Barr Harbor Drive, West Conshohocken, PA 19428-2959, United States. 1 a standard manufacturer. NJ 07430 .1. If calcium chloride will react with the test water vapor transfer through coatings that range in permeabil. Form NWK. prepare free films.org) for the latest information. greater the increase in transmission when tested in and exposed 7. whenever possible to the barrier material. used but the moisture gain by this desiccant during the test manufacture. weight from. It must not lose weight to. The calcium chloride should be dried at 400°F 5.1 Perm Cup or Dish. please provide this information to ASTM 6. 6. roller coating or other special methods. remove it from the substrate and allow the tive humidity as specified in Section 4.1. Such support would occur in drier environments... days in a room preferably maintained at 73. known to the committee at this time is the Leneta Co. and marketing.3 Analytical Balance. for preparing films that are too brittle or to high humidities. with a controlled temperature and rela. 6 The sole source of supply of paper charts. If you are aware of alternative suppliers. Test Specimens 6. a soft rubber gasket may be inserted between the film temperature in accordance with manufacturers’ instructions. 15 Whitney Rd. bake for specified time and surface. In general. dwellings where high relative humidities are not anticipated. that would affect the test results by more than test method for obtaining values that relate to conventional 2 %. Apparatus 8.1 Purity of Water—Unless otherwise indicated.2 Air dry the coated material in a horizontal position for 7 6. 6. impermeable to water or water vapor.4 Values of water vapor transmission rate (WVT) and and is subsequently heated to regenerate the anhydrous salt.5 Test Method A—The Dry Cup Method is the preferred period of time.1 It is very important that the test specimens be smooth. it must be anodized or out the test area. where high relative humidities are anticipated in the vicinity of 7.5 6 3. Apply air drying coatings to substrates using given a protective clear coating to prevent corrosion. reference Your comments will receive careful consideration at a meeting of the responsi ble to water shall be understood to mean reagent water conforming technical committee. on release is to the passage of moisture as is typical of many water. please provide this information to ASTM Headquarters. consisting of a container made of a 8. responsi ble technical committee. Mahwah.. and shall not vary by more than 5 % of the total thickness in any test film is in position. over the required 5. specimen. tested as a free film. It must be highly resistant to closely controlled conditions of temperature and relative hu. of water vapor to pass through the film without damage to it. or films having a very rough NOTE 3—When applying baking finishes. The contacting faces coating applied shall be within normal range for the type of material under of the flanges shall be ground to such flatness that when the test. Use caution in handling magnesium 5. known to the committee 7. NOTE 1—Among acceptable sealants are (1) a 60:40 mixture of 5. consisting of either anhydrous calcium chlo- Hence. 8. the atmosphere in an amount. throughout the chamber to maintain uniform conditions at all The drying schedule may be modified as recommended by test locations. such as wax for attaching the test specimen to rating of coatings only if the coatings are tested under the same the top of the perm cup or dish. the coating has to allow moderate amounts to Type IV of Specification D 1193. paper5 or glass substrates following procedures outlined in reducible coatings. the passage of water vapor.2 Test Chamber.5 Film Support. the greater its affinity for water and the Practice D 4708. 15 Whitney Rd. an adsorbing desiccant such as a silica gel may be ity from high to low.2 Desiccant. (CLO4)2). If the material is to be 6. one of the methods described in Practices D 823 or D 4708. For low or high humidity conditions. 2°C) and 50 6 5 % relative humidity. temperature or relative humidity.5°F (236 lar dish to which the test film can be sealed with wax or sealant. 7.6 filter paper. For hard films.2 Another suitable cup is any open circular or rectangu. Air shall be circulated previously unexposed surface to dry for an additional 7 days. 7. These values are for use in design. The sole source of supply of release Paper. If and completely continuous films of uniform thickness through- the cup or dish is made of aluminum. and the flange.3 The water vapor transmission is not a linear function of perchlorate because of possible chemical reaction that may be film thickness. NOTICE: This standard has either been superceded and replaced by a new version or discontinued.1 One type of cup that is suitable has a flanged edge and NOTE 2—Special test conditions may require that the coating be applied is equipped with a separate corresponding flange. water vapor permeance (WVP) can be used in the relative 7. the water vapor transmission characteristics of coatings ride (CaCL2) or anhydrous magnesium perchlorate (Mg- are important in assessing their performance in practical use. can have an effect on the test results. and if their thicknesses are equal. noncorroding material.4 Release Paper. D 1653 wood and masonry.astm. Your comments will receive careful consideration at a meeting of the weight of the test cups and a sensitivity of 1 mg. Contact ASTM International (www. desiccator or other suitable cabinet may be used. For maintain- 5 ing constant relative humidity by means of aqueous solutions.6 Test Method B—The Wet Cup Method is the preferred microcrystalline wax and refined crystalline parafin wax. It must not affect the vapor pressure in a water-filled dish. The flanges shall then be held together with suitable clamps.. Form RP-1K. having an adequate capacity for the Headquarters. so that the by brushing.1which you may attend. Support less dense. Absorption of water may make a coating otherwise unsatisfactory for handling as free films. The thickness of the test specimen can be held between them.2 The purpose of these test methods is to obtain values of (200°C) before use. If refer to procedures outlined in Practice E 104. must be limited to 4 %. and glass cloth much higher moisture vapor transmission rate. or gain midity. exposed film area. and (3) a 50:50 mixture of beeswax and rosin. Mahwah. thus allowing moisture to diffuse easily and cause a materials such as paper charts. ( 2) tissue test method for obtaining values that relate to applications embedding wax.3 Sealant. produced if it comes in contact with some organic materials 5. Reagents and Materials at this time is the Leneta Co. (WVTR) than have been found satisfactory in some instances. you are aware of alternative suppliers. NJ 07430 . moisture transfer can occur only through the series.1which you may attend. the more permeable a coating eliminate the potential interference of substrates. 2 . Permeance may vary with the baking schedule or the time of air drying. 3 If the cups are not equipped with flanges. weigh the cups every 24 h for a period of 3 G 5 weight change.1.1 Condition A—Test chamber or cabinet maintained at 12. WVT: 10.4 In general. 12. (6 mm) of water in the cups. Procedure specimen over the opening of the cups between the flanges and 10.org) for the latest information.1.1 Unless other conditions are agreed upon between the the service environment. the cups for periodic weighing to 13. size of the frame. place the test specimens to the top edge of the cups with wax in accordance specimen between the flanges and adjust the clamps to hold it with procedures in 10.2. It may be advisable to apply the test surface saturation of the material. Calculations a substrate or support. over 10 perms.1. the tests shall be performed under one 12. When a straight line adequately fits the plot of at NOTE 5—Imperfections in the film that are not readily visible may least four properly spaced points. 13. WVT 5 ~G/t!/A 5 grams per m2 per 24 h (2) 3 .1. temperature. the water vapor transmission characteristics to be determined: Record time. and relative humidity. seal the test the cup. 9. Coatings should not be applied to purchaser and the seller. Thus.1. Glass cloth is preferred for coatings of the following conditions: that are cured by baking. If the coating material as follows: is on a substrate or support. if weighings are made every day. 11.1.2 In metric units as follows: nearest 15 minutes would be allowed.3 Remove if necessary. follows: 9.4 When coatings are applied to support materials.3.1 Unless other conditions are agreed upon between the purchaser and the seller. or until the weight change versus time becomes t 5 time during which G occurred.6.3. place the coated side away from the 13. 1 g 5 15.1 Condition A—Test chamber or cabinet maintained at TEST METHOD A—DRY CUP METHOD 73 6 1°F (23 6 0.1 In inch-pound units as follows: determine weight gain. a time to the 13.3 Measure the thickness of the test specimen in several weighing.3 If the cups are not equipped with flanges. TEST METHOD B—WET CUP METHOD 8.1 Fill the cups with desiccant to within 1⁄4 in. place the coated side towards the 10.1.1.2 If the cups are equipped with flanges. Test Conditions the desiccant or towards the water in the cup.1.43 grains. place the coated side towards the water in 10. where: 10. transmission. wax.3. applying the second coat perpendicular to the first desiccant exceeds 20 % of the desiccant weight. Coatings expected to have high WVT WVT 5 ~G/t!/A 5 grains per ft2 per 1 h (1) ratings.3.3 Return the cups to the test chamber immediately after 10. on a thin cardboard ring soaked in molten Follow procedures outlined in 10. the test. Procedure or more of the following conditions: 9.2 Condition B—Test chamber or desiccator maintained 12.1.2 If the cups are equipped with flanges.6°C) and 90 6 2 % relative humidity. perform the test(s) under one or more both sides of a support. h.1 Fill the cups with water to within 1⁄4 in. NOTICE: This standard has either been superceded and replaced by a new version or discontinued. discontinue coat and allowing for an adequate drying period between coats to achieve the desired film thickness.1. temperature and relative humidity. 12. weeks.5 and 10. Test Conditions 11. place them in the test cabinets or desiccators.2.2 Condition C—Test chamber or desiccator maintained at 73 6 1°F and very low (near zero) relative humidity. 10.6°C) and 50 6 2 % relative humidity.1. may require weighings more frequently than once a day.2 Calculate one or more of the following.1 Prepare at least three perm cups or dishes for each test adjust the clamps to hold them firmly in position. Record the time that weighings are taken to the A 5 test area.1 Prepare at least three cups for each test material as 73° 6 1°F (23 6 0.astm.1. ft2.1 and 10. places with a micrometer using procedures in Test Methods D 1005 to ensure a uniform thickness. seal the test 10.1. If the coating is on a firmly in position. 10. the top edge. Thoroughly seal the frame to the edge of the cup at the temperature to be used in the test.6°C) and 50 6 2 % relative humidity. 9.2. depending on not being used. substrate or support. plot the weight change against desiccant in the cup.5 Shake cups containing desiccant everyday to prevent defects before commencing the test.2. a nominally steady state produce inconsistent results.1.2 Then place the specimen-covered frame over the weighings. precision of approximately 1 % of the time span between weighings. Contact ASTM International (www.1 Calculate the water vapor transmission rate. place the test 10. depending upon 11.6 Return the cups to the test chamber immediately after 8.1 For each material tested. Record time. and constant. the coated side of the test specimen should be placed away from 11. specimen to the top edge of the cups with wax as follows: 12.1 First carefully place the test specimen.2 Weigh the loaded cups to 1 mg and place them in the 10.1. If moisture absorbed by the material in two coats. cut to the test chamber. 12. D 1653 NOTE 4—Examine test films for the presence of pinholes or other 10. grains (from the straight line). If the coating is on 13. elapsed time. consequently make sure that the test is exists and the slope of the straight line is the rate of water vapor always run at least in triplicate. top edge.2 Weigh the loaded cups to 1 mg and if a test chamber is 13. (6 mm) of the at 100 6 1°F (38 6 0. mouth of the cup. 565 72.774 interest for vapor barrier coatings.1.1. at wet-cup permeances of 5 to 30 perms.25 perms at WVP 5 WVT/Dp (3) dry-cup permeance of less than 1.010 51.102 14. The American Society for Testing and Materials takes no position respecting the validity of any patent rights asserted in connection with any item mentioned in this standard. and 7 Supporting data are available from ASTM Headquarters.815 14.914 48.2 Calculate the permeance. WVP 5 WVT/Dp (4) 15. and the risk of infringement of such rights.157 15.816 20. 4 .astm.1. R1 5 relative humidity at vapor source.54 % relative with 6 df.845 21.800 20.0 23.988 50.894 48.2 0.0 perms.1 Test Method A—Two results. Contact ASTM International (www.5 2. mally better than interlaboratory precision.324 14. h.323 perms with 6 df and the interlaboratory wet-cup coefficient of variation 21. Your comments will receive careful consideration at a meeting of the responsible technical committee. of mercury ~perms! 15. Hg (saturation vapor pressure at test temperature).8 0. Hg mm Hg 14.3 38.2 In metric units as follows: fairly long intervals between tests.7 1.6 2. 74.805 20.840 21.1.2.3 Type of film support used. 2 5 grams per m per 24 h per millimetreof mercury.4 0.453 chamber.3 0. water Dp 5 S (R1 − R2). the following criteria where: should be used for judging. 99.855 21.845 either in inch-pound or in metric units. NOTICE: This standard has either been superceded and replaced by a new version or discontinued. g (from the straight line).1 Repeatability: A 5 test area.925 48.1.5 38. ences when the same coating was tested in quadruplicate with 13. 73. and 15.1. ~metric perms! 16.4 38.1.834 21. each the mean of 13.068 73.6 0. This standard is subject to revision at any time by the responsible technical committee and must be reviewed every five years and if not revised.7 0.978 50.021 51.5 Test temperature and relative humidity in the test 74. water vapor permeance.231 101.999 50. 99.9 0. 72.9 37.3 1. (see Table 1).5 22.2 % relative Dp 5 S (R1 − R2).0 1.5 0. Request R 2 5 relative humidity at vapor sink. vapor transmission S 5 mm Hg (saturation vapor pressure at test tempera- ture).961 which one operator in each of three laboratories determined in 100.8 1.5 1.2. However.1 In inch-pound units as follows: considered suspect if they differ by more than 0. Report Temperature Pressure 14.440 14.2 37.2 23.1.7 37.316 used. either reapproved or withdrawn.8 38.2.3 37. which you may attend.2 Test Method B—Two results.6 23.1 In an interlaboratory study of these test methods in 100. the G 5 weight change.5 23. 15.8 23.850 21. at the address shown below.824 20. acceptability of results: t 5 time during which G occurred. 2 5 grains per ft per 1 h per in. 73. and participant in this exchange has noted relatively large differ- R 2 5 relative humidity at vapor sink.935 49. with no results having been discarded.714 14.1 permeance.941 14.627 metric units. obtained by the same operator should be 13.1 38.692 15.4 23. 73. D 1653 TABLE 1 Saturation Vapor Pressure 14. each the mean of triplicate runs.1 Method of coating application and curing procedure 72.048 deviation for the dry-cup procedure was found to be 0. perms.2 Mean film thickness of the test specimens for each 72.956 49.2.3 22.4 1.4 1.2 Reproducibility—Intralaboratory precision is nor- (see Table 1).org) for the latest information.2.1.946 49.819 20.6 38.4 23.6 Computed rate of water vapor transmission (WVT).1.196 Method B (Wet Cup)).860 21.6 1. Based upon these values. Users of this standard are expressly advised that determination of the validity of any such patent rights. at the 95 % confidence level.073 101.0 0. one R1 5 relative humidity at vapor source.4 Method used (Test Method A (Dry Cup) or Test 73.424 100.1 1.9 22.904 48. RR:D1 – 1064.3 22. 15.5 0.7 22. Keywords where: 16. are entirely their own responsibility.1 Report the following information: °F °C in.690 material. m2.1 37.1.810 20. Your comments are invited either for revision of this standard or for additional standards and should be addressed to ASTM Headquarters.1 22.583 74.891 100.7 The computed permeance in terms of both perms and 99. obtained by the same operator should be where: considered suspect if they differ by more than 74.502 triplicate the permeance of three coatings covering the range of 101. 74.1.0 38.1 0.4 0.967 49. the interlaboratory standard 101. if any.6 0. WVP: triplicate runs.5 37.1. S 5 in.2 1. Precision and Bias 7 100. If you feel that your comments have not received a fair hearing you should make your views known to the ASTM Committee on Standards.2 Bias is not applicable to these test methods.9 1.364 99.829 21. or through the ASTM website (www. D 1653 This standard is copyrighted by ASTM.org) for the latest information. Contact ASTM International (www. PO Box C700. West Conshohocken. United States. Individual reprints (single or multiple copies) of this standard may be obtained by contacting ASTM at the above address or at 610-832-9585 (phone).astm. PA 19428-2959.org). or
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