1、Designation: D 7376 07Standard Practice forOutdoor Evaluation of Wet Stack Storage Conditions onCoil-Coated Metals1This standard is issued under the fixed designation D 7376; 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 (e) indicates an editorial change since the last revision or reapproval.1. Scope1.1 This procedure describes the practice for determiningrelative performance of coil-coated metal in an outdoor wets
3、tack testing environment.1.2 The purpose of this test is to evaluate relative wet stackcorrosion resistance and blistering. Substrates, pretreatments,primers, topcoats, and backers may be evaluated.1.3 This test simulates coil or stacked building panel bundlestorage at a job site in wet outdoor cond
4、itions. The results frompanels tested during the same time period may be used tocompare products as an indicator of actual field performance.Environments with higher temperature and moisture levelsaccelerate degradation.1.4 The values stated in SI units are to be regarded as thestandard. The values
5、given in parentheses are for informationonly.1.5 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 regula
6、tory limitations prior to use.2. Referenced Documents2.1 ASTM Standards:2D 610 Test Method for Evaluating Degree of Rusting onPainted Steel SurfacesD 714 Test Method for Evaluating Degree of Blistering ofPaintsD 1654 Test Method for Evaluation of Painted or CoatedSpecimens Subjected to Corrosive Env
7、ironmentsG7 Practice for Atmospheric Environmental ExposureTesting of Nonmetallic Materials3. Summary of Practice3.1 This practice is for the evaluation of relative wet stackcorrosion resistance and blistering of coil-coated metal. Thetest is to be conducted in an outdoor environment withcoil-coated
8、 panels placed on a flat surface while allowingexposure to environmental conditions such as rain, dew,humidity, and high temperatures.3.2 Panels are evaluated periodically for corrosion andblistering as specified in 6.7.4. Significance and Use4.1 This practice provides for periodic testing to compar
9、ethe relative performance of specific coatings, substrates, and/orpretreatments used on coil-coated metal for resistance to wetconditions during storage.4.2 When performed in south Florida, this practice givesaccelerated corrosion and blistering results relative to otherlocations within the continen
10、tal United States.4.3 This practice allows comparison of different coatings,substrates, and pretreatments when they are tested at the sametime. The results must be considered relative and do notindicate absolute performance.4.4 Because the outdoor environment shows year-to-yearclimatological, season
11、al, and geographic variation, the absoluteamount of degradation based on corrosion and blistering mayvary (see Practice G7).4.5 Temperature, rain, and humidity are important factors inwet stack corrosion. Corrosion and blistering will acceleratewith increased temperature. The preferred test location
12、 is southof 27N latitude in Florida. Other locations may be used, butdifferences in temperature and moisture must be considered,and the amount of corrosion and blistering are expected to vary1This practice is under the jurisdiction of ASTM Committee D01 on Paint andRelated Coatings, Materials, and A
13、pplications and is the direct responsibility ofSubcommittee D01.53 on Coil Coated Metal.Current edition approved July 1, 2007. Published July 2007.2For referenced ASTM standards, visit the ASTM website, www.astm.org, orcontact ASTM Customer Service at serviceastm.org. For Annual Book of ASTMStandard
14、s volume information, refer to the standards Document Summary page onthe ASTM website.1Copyright ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959, United States.considerably with climate. Test sites must have the instrumen-tation to measure and record ambient
15、temperature and rainfallas in Practice G7.4.6 This practice is not meant to support the field storage ofcoil-coated metal in any way other than what is recommendedby the manufacturer.5. Apparatus5.1 The use of a wooden pallet to stack the test panels in ahorizontal position is one way to ensure rain
16、 does not puddlearound the panels. Rainwater and condensation flow down thesides of the stacks, and water is absorbed between panels bycapillary action. Excess water will drain through the slats in thepallet (see Fig. 1).5.2 The pallet is recommended to be 61 cm to 91 cm (24 in.to 36 in.) from the g
17、round and all foliage should be removedfrom the area.5.3 Wooden two by four boards of approximate cross-sectional dimensions, 4 cm by 9 cm (1.5 in by 3.5 in.) and ofthe required length are placed on top of the stacks (see Fig. 1).The pallets and boards shall be composed of untreated wood toavoid any
18、 influence from the treatment.6. Procedure6.1 A wooden pallet or some flat surface with slats for waterdrainage is assembled in the required outdoor environmentalconditions.6.2 Test panels shall be gathered and cut to the required size.A size of at least 15 cm by 15 cm (6 in. by 6 in.) is required.D
19、uplicates of each panel are required to allow contact betweenthe topside and backside of the same coil. Panels to becompared must be cut on the same metal shear with edge burrsoriented equivalently.6.3 It is recommended that a minimum of two extra panelsbe placed at the top and bottom of the stack t
20、o act as a barrierto any influences from the wood or water accumulation.6.4 The test panel numbers shall be recorded along withinformation such as coater, paint code, substrate, primer,pretreatment, and date of test initiation.6.5 The test panels shall be stacked on top of one anotherwith the convex
21、 side facing upward against the backer of aduplicate panel. A second set of duplicate panels may also betested, and it shall be stacked in the same fashion as the first.A second set of duplicate panels is highly recommended aswell as positive and negative controls representing knownperformance level
22、s.6.6 Each stack of test panels shall be no greater than 5 cm(2 in.) in height and shall be weighted down with a singlewooden two by four with cross-sectional dimensions, 4 cm by9 cm (1.5 in. by 3.5 in.) on top of each stack or spanning twoor more stacks.6.7 It is recommended that panels be evaluate
23、d for corrosionand blistering monthly in accordance with Test MethodsD 610, D 714, and D 1654 Procedure B, until a suggested totaltest time of six months has elapsed or until a time agreed uponbetween customer and supplier is complete. Evaluation of fieldcorrosion and blistering is considered to be
24、the most appropri-ate for this test, but edge results may also be assessed. Edgeresults may be significantly influenced by burr differences.Corrosion ratings shall include any visible red or whitecorrosion products.7. Report7.1 Included in the test report shall be the location where thetest is perfo
25、rmed, the start date of the test and the date of theevaluation.7.2 The test report shall include an estimate of total rainfalland number of days with rain during the test period at the testlocation.7.3 The test report shall include the average monthly tem-perature based on daily averages.7.4 The tes
26、t report shall include the manufacturer of theproduct being tested. Include any experimental or raw materialchanges or any changes of the coating process for the product.7.5 Include in the test report the coating paint code, sub-strate, primer, backer and pretreatment used. Dry film coatingthickness
27、 (DFT) and pretreatment weight may also be impor-tant and should be reported, if available.7.6 Samples shall be evaluated for corrosion and blisters.Any notable changes shall be recorded. Corrosion and blisters,including any red or white corrosion products, shall be rated inaccordance with Test Meth
28、ods D 1654 Procedure B, D 610,and D 714.7.7 A statement of compliance shall be noted and anyexceptions to the procedure shall be noted in the report.8. Keywords8.1 blistering; coil-coated; corrosion; wet stackNoteLevel position for test purposes only. Level storage of building panels inwet condition
29、s is not recommended.FIG. 1 Illustration of Wet Stack Test Placed Horizontally (Level)on a PalletD7376072ASTM 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
30、 determination of the validity of any such patent rights, and the riskof infringement 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 reapprov
31、ed or withdrawn. Your comments are invited either for revision of this standard 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 fee
32、l that your comments have not received a fair hearing you shouldmake your views 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).D7376073
