1、Designation: C419 08 (Reapproved 2013)Standard Practice forMaking and Curing Test Specimens of Mastic ThermalInsulation Coatings1This standard is issued under the fixed designation C419; the number immediately following the designation indicates the year oforiginal adoption or, in the case of revisi
2、on, the year 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 practice covers the preparation of specimens ofmastics and coatings in the form of cured sheets o
3、r films thatmay be used in other procedures for evaluation of physicalproperties.1.2 Three procedures are described for casting and curing(Note 1) mastics and coatings of all types for thermal insula-tion.NOTE 1The term “cure” is used primarily to denote the condition thatdevelops as the result of l
4、oss of volatile matter but also to denote possiblesubsequent changes in chemical or physical properties due to crosslinking.1.2.1 Procedure A is intended to provide a specimen ofcontrolled thickness applied to insulation, and equivalent inother respects to that obtainable under field application con
5、di-tions. The thermal insulation intended for field use may bespecified as the backing.1.2.2 Procedure B is intended to provide a free-film speci-men of controlled thickness having smooth surfaces on bothsides. This type is required for some types of physical testing.1.2.3 Procedure C is intended to
6、 provide a free-film speci-men of controlled thickness having one smooth surface (asfield applied).1.3 The procedures of this practice are not intended for theevaluation of application properties. These are covered in TestMethods C461 and Guide C647.1.4 The values stated in inch-pound units are to b
7、e regardedas standard. The values given in parentheses are mathematicalconversions to SI units that are provided for information onlyand are not considered standard.1.5 This standard does not purport to address all of thesafety concerns, if any, associated with its use. It is theresponsibility of th
8、e 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:2C168 Terminology Relating to Thermal InsulationC461 Test Methods for Mastics and Coatings Used WithThermal
9、InsulationC533 Specification for Calcium Silicate Block and PipeThermal InsulationC647 Guide to Properties and Tests of Mastics and CoatingFinishes for Thermal InsulationD6/D6M Test Method for Loss on Heating of Oil andAsphaltic Compounds3. Terminology3.1 DefinitionsFor definitions used in this prac
10、tice seeTerminology C168.4. Summary of Practice4.1 Mastics and coatings are applied by a metal blade tothermal insulation backing material in a thickness regulated byguide bars. Moderate heat is applied to the specimens to dry orotherwise cure them.5. Significance and Use5.1 The method of preparatio
11、n of test specimens of masticthermal insulation coatings can have an impact upon valuesobtained during testing. Testing laboratories should follow thispractice to help ensure the reproducibility of test methods forwhich a cured sheet or film of a mastic thermal insulationcoating is required.6. Appar
12、atus6.1 Guide BarsTwo rectangular steel bars of thicknessequal to the desired wet thickness of the applied mastic orcoating. The guide bars shall be equal in length to the totallength of the specimens. For use on relatively soft backingmaterial, the guide bars may be equipped with pins projecting1Th
13、is practice is under the jurisdiction of ASTM Committee C16 on ThermalInsulation and is the direct responsibility of Subcommittee C16.33 on InsulationFinishes and Moisture.Current edition approved Nov. 1, 2013. Published March 2014. Originallyapproved in 1958. Last previous edition approved in 2008
14、as C419 08. DOI:10.1520/C0419-08R13.2For 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 Internatio
15、nal, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959. United States1from the lower surface at each end, which can be forced intothe backing to hold the bars in position during preparation ofthe test specimen.6.2 Strike-Off BarA flat strip of rigid metal, not less than2 in. (51 m
16、m) greater in length than the width of the specimen.One edge shall be smooth and straight.6.3 Leveling RollerOne section of straight 112-in. (38-mm) stainless steel pipe or any other convenient cylindricalleveling tool. The tool shall have a smooth surface. Minimumlength shall be 2 in. (51 mm) longe
17、r than the width of thespecimen.6.4 Backing MaterialUnless otherwise specified by theprocedure for the test to be made, the backing for the specimenshall consist of commercial block-type calcium silicate insula-tion meeting the requirements of Specification C533 andmeasuring 2 by 18 by 24 in. (51 by
18、 457 by 610 mm). Thebacking block may be prepared by assembling not more thanthree blocks of smaller dimensions by the use of suitableadhesive or pins, in such a manner as to form a solid, rigidblock.6.5 Release PaperA smooth, dense white paper coated onone side with dextrin, or other water-soluble
19、gum. Size shouldbe approximately the same as the backing block.NOTE 2Films coated with PTFE or other suitable nonsoluble releaseagent may be used as an acceptable alternative.7. Preparation of Test Specimens7.1 Stir the mastic or coating until uniform throughout thecontainer before removing the samp
20、le for specimen prepara-tion.7.2 Determine the percent volatile matter by weight inaccordance with Test Methods C461, for use in calculating thedegree of cure in 8.1.2.7.3 Unless otherwise specified, lay down films to a nominalwet thickness of 0.125 in. (3.2 mm).7.4 Procedure A (Adhered Film)For the
21、 determination ofdegree of cure as described in 8.1.2, prepare one extraspecimen in addition to the number required by the otherprocedures in which they are to be used. If a primer orpretreatment of the block is specified, apply to the testspecimen in accordance with the recommendations of themanufa
22、cturer of the mastic or coating. Place and secure guidebars of a thickness equal to the desired wet mastic thickness onthe backing material along each of the long edges. Fill the areabetween the guide bars with mastic and smooth out with atrowel to a level about 0.063 in. (1.6 mm) above the guide ba
23、rs.Place the strike-off bar upon the guide bars at one end of thefilled area and move it slowly to the other end of the specimen,pushing the mastic along the surface of the backing. Asee-sawing motion of the strike-off bar will be found to aid inuniform distribution of the mastic. As the mastic is d
24、istributed,take care to prevent inclusion of air pockets. Move thestrike-off bar from end to end of the specimen in bothdirections, removing the excess material and filling thedepressions, until a coat of uniform thickness extending fromend to end of the specimen covers the entire space between theg
25、uide bars. Remove the guide bars without disturbing the wetspecimen.7.5 Procedure B (Free Film)For the determination ofdegree of cure as described in 8.1.2, prepare one extraspecimen in addition to the number required by the otherprocedures in which they are to be used. Place a sheet of therelease p
26、aper on the backing block so that the coated surface ofthe paper faces upward, away from the backing block. Placeand secure guide bars of thickness equal to the desired wetmastic thickness on the release paper along each of the longedges. Fill the area between the guide bars with mastic andsmooth ou
27、t with a trowel to a level about 0.063 in. (1.6 mm)above the guide bars. Place on the freshly applied masticanother sheet of release paper with the coated surface facingthe mastic, in the following manner: Place a short edge of thecoated paper at one end of the mastic-filled area and graduallyroll t
28、he paper into the wet mastic, using the leveling roller.Take care to prevent formation of air pockets, or bubbles, underthe paper. When firmly in contact with the mastic, roll out thepaper-covered mastic until its thickness matches that of theguide bars. Then remove the guide bars without disturbing
29、 thethickness of the specimen or the position of the paper. Aconvenient method for accomplishing this is to slit the paperwith a sharp blade along the inside length of the guide bars.7.6 Procedure C (Free Film)For the determination ofdegree of cure as described in 8.1.2, prepare one extraspecimen in
30、 addition to the number required by the otherprocedures in which they are to be used. Place a sheet of therelease paper on the backing block so that the coated surface ofthe paper faces upward, away from the backing block. Placeguide bars of thickness equal to the desired wet masticthickness on the
31、release paper along each of the long edges. Fillthe area between the guide bars with mastic and smooth outwith a trowel to a level about 0.063 in. (1.6 mm) above theguide bars. Place the strike-off bar upon the guide bars at oneend of the filled area and move it slowly to the other end of thespecime
32、n, pushing the mastic along the surface of the backing.A see-sawing motion of the strike-off bar will be found to aidin uniform distribution of the mastic. As the mastic isdistributed, take care to prevent inclusion of air pockets. Movethe strike-off bar from end to end of the specimen in bothdirect
33、ions, removing the excess material and filling thedepressions, until a coat of uniform thickness extending fromend to end of the specimen covers the entire space between theguide bars. Remove the guide bars without disturbing the wetspecimen.7.7 When a reinforcing membrane is specified, apply themas
34、tic in two separate coats of equal thickness unless other-wise specified. Immediately following the first coat press themembrane into the wet mastic. Then apply the second coat tothe required thickness.8. Curing Prepared Specimens8.1 Procedure A (Adhered Film):8.1.1 During the first 24-h hold the te
35、st specimens at 60 to80F (15 to 27C). At the end of the 24-h period remove theC419 08 (2013)2specimens to a thermostatically controlled oven having atemperature of 150 6 5F (63 to 68C) and hold in this ovenuntil the desired degree of cure has been reached.8.1.2 To determine the degree of cure, take
36、from the extraspecimen a sample of the coating from an area typical of thatto be subjected to test conditions during later procedures.Determine the percentage of volatile liquids evaporated fromthe mastic during the curing as follows: Weigha1to2-gsample to the nearest 0.001 g and place it for a peri
37、od of5hat220 6 5F (104 6 3C) in an oven conforming to therequirements specified in Test Method D6/D6M. At the con-clusion of the 5-h heating period, remove the sample from theoven, cool to room temperature, and weigh to the nearest 0.001g. Calculate the loss in weight as a percent of the weight befo
38、reheating. Calculate the degree of cure as follows:Degree of cure, % 5 A/B! 3100 (1)where:A = percent loss in weight, andB = percent volatile matter (7.2).8.2 Procedures B and C (Free Film):8.2.1 Do not remove the specimens from the backing block.Allow the specimens to cure for 7 days at 60 to 80F (
39、15 to27C). At the end of the 7-day period transfer the specimens(still on the backing blocks) to a thermostatically controlledoven having a temperature of 150 6 5F (63 to 68C). Hold inthis oven for a minimum of 14 days, and for as long thereafteras may be necessary to reach the desired degree of cur
40、e.Determine the degree of cure in accordance with 8.1.2.8.2.2 Conditioning of Free FilmAllow the specimens tocool, remove them from the backing block, and immerse in tapwater at approximately 50F (10C). When the paper coatinghas softened (usually 20 to 30 min), strip all the paper from thespecimens
41、and rinse them in cool (50F, 10C) water until nowater-soluble gum remains on the surfaces. Blot carefully toremove excess water and allow to dry at room temperature withgood ventilation. Before using the specimens in further tests,remove and discard the outer 0.050 in. (13 mm) of masticaround the pe
42、rimeter.8.2.3 Measure dry thickness at several locations to thenearest 0.001 in. (0.025 mm) with a suitable ratchetmicrometer, and record. The dry thickness at any point shalldeviate not more than 10 % from the average thickness.9. Report9.1 Since this practice covers only the preparation andcuring
43、of specimens to be tested by other methods, no report isnecessary. Data here obtained should be included in the reportof the succeeding test. These data include procedure used, drythickness of specimen, number of coats, presence of primer ormembrane, or both, degree of cure, and any deviation from t
44、hestated procedure.10. Keywords10.1 mastic; thermal insulation; thermal insulation coatingASTM 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
45、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 reapproved or withdrawn
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47、ments 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
48、 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). Permission rights to photocopy the standard may also be secured from the ASTM website (www.astm.org/COPYRIGHT/).C419 08 (2013)3
