ASTM C1253-93(2009)
(Test Method)Standard Test Method for Determining the Outgassing Potential of Sealant Backing
Standard Test Method for Determining the Outgassing Potential of Sealant Backing
SIGNIFICANCE AND USE
This test method is an indicator of a potential sealing problem that could occur if a sealant backing is flawed in manufacture or transportation to the job site, or abused during the installation. If flawed, some sealant backing materials, in combination with certain environmental conditions, can outgas, generating voids in the applied sealant before the sealant cures, thereby potentially compromising the cured sealant's intended performance.
Voids are also known to be caused by other means and under certain conditions such as air entrapment during sealant application, trapped air in the substrate releasing into the uncured sealant, incompatibility of the sealant with the sealant backing or substrate, or inhospitable installation conditions in the field. This test method is limited to identifying the outgassing potential of a punctured sealant backing by formation of a void in the soft uncured sealant under conditions of heat and compression.
SCOPE
1.1 This test method provides a procedure for determining the outgassing potential of a sealant backing when it is punctured during or after installation, with the puncture occurring before the sealant cures.
1.2 The values stated in SI units are to be regarded as the standard. The values given in parentheses are for information only.
1.3 This standard does not purport to address all of the safety concerns, if any, associated with its use. It is the responsibility of the user of this standard to establish appropriate safety and health practices and determine the applicability of regulatory limitations prior to use.
General Information
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Standards Content (Sample)
NOTICE: This standard has either been superseded and replaced by a new version or withdrawn.
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Designation: C1253 − 93(Reapproved 2009)
Standard Test Method for
Determining the Outgassing Potential of Sealant Backing
This standard is issued under the fixed designation C1253; 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 (´) indicates an editorial change since the last revision or reapproval.
1. Scope temperature for 1 h and then removed. The specimen is
compressed12 ⁄2 %ofitsdiameterandinthecompressedstate
1.1 This test method provides a procedure for determining
returned to the oven. The specimen is removed after another
the outgassing potential of a sealant backing when it is
hour in the oven and compressed another 12 ⁄2 % and returned
punctured during or after installation, with the puncture occur-
to the oven, where it remains for another 2 h. The specimen is
ring before the sealant cures.
removed from the oven, and the sealant is allowed to finish
1.2 The values stated in SI units are to be regarded as the
curingatroomtemperature,whileinthecompressedcondition.
standard. The values given in parentheses are for information
The sealant is then removed from the specimen, and the back
only.
face (the face against the sealant backing) is examined. The
1.3 This standard does not purport to address all of the sealant is slit in half along its length and the size of any voids
safety concerns, if any, associated with its use. It is the
estimated.
responsibility of the user of this standard to establish appro-
5. Significance and Use
priate safety and health practices and determine the applica-
bility of regulatory limitations prior to use.
5.1 This test method is an indicator of a potential sealing
problem that could occur if a sealant backing is flawed in
2. Referenced Documents
manufacture or transportation to the job site, or abused during
2.1 ASTM Standards: the installation. If flawed, some sealant backing materials, in
C717 Terminology of Building Seals and Sealants combination with certain environmental conditions, can
C1193 Guide for Use of Joint Sealants outgas, generating voids in the applied sealant before the
sealant cures, thereby potentially compromising the cured
3. Terminology
sealant’s intended performance.
3.1 Definitions—Refer toTerminology C717 for the follow-
5.2 Voids are also known to be caused by other means and
ing terms used in this test method: sealant, cure, sealant
under certain conditions such as air entrapment during sealant
backing, joint, substrate, non-sag sealant, tooling, and outgas-
application, trapped air in the substrate releasing into the
sing.
uncured sealant, incompatibility of the sealant with the sealant
backing or substrate, or inhospitable installation conditions in
4. Summary of Test Method
the field. This test method is limited to identifying the
outgassing potential of a punctured sealant backing by forma-
4.1 A sample of sealant backing material is placed between
nonporoussubstratesinacompressedcondition,simulatingthe tion of a void in the soft uncured sealant under conditions of
heat and compression.
placing of sealant backing on a job site. The sealant backing is
then punctured at intervals along its exposed face. A sealant is
6. Apparatus
applied immediately after puncture, and it is tooled to make a
typical butt joint as described in Guide C1193. After tooling,
6.1 Air Circulating Oven,capableofmaintainingatempera-
the specimen is placed in an air circulating oven at elevated
ture of 122°F (50°C).
6.2 Test Frame and Stylus, as described in Annex A1.
ThistestmethodisunderthejurisdictionofASTMCommitteeC24onBuilding
7. Test Specimens
Seals and Sealants and is the direct responsibility of Subcommittee C24.20 on
General Test Methods.
7.1 Sealant backing should be 307.8-mm (12-in.) long and
Current edition approved June 1, 2009. Published June 2009. Originally
of a width appropriate for use in 12.7-mm ( ⁄2-in.) wide joints.
approvedin1993.Lastpreviouseditionapprovedin2005asC1253–93(2005).DOI:
The proper width will be as specified by the sealant backing
10.1520/C1253-93R09.
For referenced ASTM standards, visit the ASTM website, www.astm.org, or
manufacturer.
contact ASTM Customer Service at service@astm.org. For Annual Book of ASTM
Standards volume information, refer to the standard’s Document Summary page on NOTE 1—The test method is specifically for 12.7-mm ( ⁄2-in.) wide
the ASTM website. joints and sealant backings used in such joints. The procedure is adapted
Copyright © ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959. United States
C1253 − 93 (2009)
easily to either wider or narrower joints if all compression is considered
9.8 If a clear sealant was used, bubbles will be evident if
as a percent of the joint width.
they occurred. In all cases, slit the sealant along its entire
length at the mid point of the joint width using a sharp razor.
8. Conditioning
9.8.1 If properly performed, the slit will pass through any
voids that have formed. Cut the sealant away from the edge of
8.1 Condition all sealant backing and sealants at standard
conditions for a minimum of 12 h prior to testing. Standard the substrate (a knife generally works better than a razor).
Remove the two sealant halves from the joint and examine the
conditions for this procedure are 23 6 2°C (73.4 6 3.6°F) and
50 6 5 % relative humidity. size of the voids.
10. Report
9. Procedure
10.1 Report the test results and observations on the form
9.1 Prepare the test specimen by placing the sealant backing
shown in Fig. 1.
in the simulated joint apparatus (Fig. A1.1 and Fig. A1.2),
which has been adjusted to a 12.7-mm ( ⁄2-in.) wide opening.
Exercise care not to abuse or puncture the sealant backing
during installation.
9.2 Use the stylus (Fig. A1.3) to form six 9.5-mm ( ⁄8-in.)
deep punctures starting 38-mm (1 ⁄2-in.) from the end, spaced
25.4-mm (1-in.) apart, and centered on the width of the sealant
backing. The marks on the channel, used to form the joint, aid
in locating the quick, even placement of the punctures.
9.2.1 If the sealant backing has a tendency to slip down in
the joint during the puncturing, slip a temporary
...
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