ASTM C1257-04

NOTICE: This standard has either been superseded and replaced by a new version or withdrawn.
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Designation:C1257–04
Standard Test Method for
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Accelerated Weathering of Solvent-Release-Type Sealants
This standard is issued under the fixed designation C 1257; 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.
1. Scope 5. Significance and Use
1.1 This test method provides an accelerated procedure for 5.1 It is difficult to establish a precise correlation between
predicting the effects of ultraviolet light, heat, and moisture accelerated and natural weathering because of geographical
exposureoncolor,chalking,cracking,andadhesionofsolvent- climatic variations, local weather variation from normal, and
release sealants. local pollutants. This test method is used to determine the
1.2 The values stated in SI units are to be regarded as the relative weathering performance of a sealant against an unex-
standard. The values given in parentheses are for information posed control or a reference material for which the outdoor
only. weathering characteristics are known.
1.3 This standard does not purport to address all of the 5.2 Thistestmethodisconductedusingaluminumchannels.
safety concerns, if any, associated with its use. It is the Other substrate materials may show different results.
responsibility of the user of this standard to establish appro-
6. Apparatus
priate safety and health practices and determine the applica-
6.1 Fluorescent UV and Condensation Apparatus, comply-
bility of regulatory limitations prior to use.
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ing with Practices G 151 and G 154.
2. Referenced Documents
6.1.1 The UV light source shall be UVA-340 fluorescent
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2.1 ASTM Standards: lamps as described in Practice G 154.
C 717 Terminology of Building Seals and Sealants 6.2 Four-Mill Finish Aluminum U-Channels, 76 mm long
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G 151 Practice for Exposing Nonmetallic Materials in Ac- by 19 mm wide by 9.5 mm deep (3 by ⁄4 by ⁄8 in.) inside
celerated Test Devices that Use Laboratory Light Sources dimensions. Additional substrate materials may be specified.
G 154 Practice for Operating Fluorescent Light Apparatus 6.3 Steel Spatula.
for UV Exposure of Nonmetallic Materials
7. Procedure
3. Terminology
7.1 Condition sufficient compound in an original closed
3.1 Definitions—Definitions of the following terms are container for at least 24 h at standard conditions. Standard
found in Terminology C 717: adhesive failure (adhesion loss), conditions are to be a temperature of 23 6 2°C (73 6 3.6°F)
compound, cure, sealant, solvent-release sealant, substrate. and relative humidity of 50 65%.
7.2 Prepare four sealant test specimens in aluminum
4. Summary of Test Method
U-channels.
4.1 The test specimens are prepared in U-shaped aluminum 7.2.1 Thoroughly clean channels using a suitable solvent
channels. After curing, the specimens are exposed to alternat-
such as methyl ethyl ketone (MEK).Allow to dry before filling
ing cycles of ultraviolet light at elevated temperature and with sealant.
condensing humidity at elevated temperature.At the end of the
7.2.2 Block the ends of the U-channels with masking tape
exposure period, the specimens are examined for chalking, and overfill the entire channel with conditioned compound
color change, center cracking, edge cracking, and loss of
from the bottom up being careful to avoid air entrapment.
adhesion versus an unexposed control sample. Strike the channel off flat with a spatula. Do not remove the
masking tape. It is to stay in place for the entire test. Removing
it may disturb the uncured or cured sealant.
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ThistestmethodisunderthejurisdictionofASTMCommitteeC24onBuilding
7.3 Cure the test specimens at standard conditions for 21
Seals and Sealants and is the direct responsibility of Subcommittee C24.40 on
Weathering.
days.
CurrenteditionapprovedMay1,2004.PublishedJuly2004.Originallyapproved
in 1994. Last previous edition approved in 2000 as C 1257-94(2000).
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For referenced ASTM standards, visit the ASTM website, www.astm.org, or
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contact ASTM Customer Service at service@astm.org. For Annual Book of ASTM Apparatus and lamps from Q-Panel Co., 26200 First St., Cleveland, Ohio
Standards volume information, refer to the standard’s Document Summary page on 44145; and Atlas Electric Devices Co., 4114 N. Ravenswood Ave., Chicago, IL
the ASTM website. 60613, have been found satisfactory.
Copyright © ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959, United States.
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C1257–04
NOTE 1—The producer may request conditions other than those speci-
8.1.4 Quantitative visual description of edge cracking, cen-
fied in 7.3 for the curing per
...