ASTM C679-03
(Test Method)Standard Test Method for Tack-Free Time of Elastomeric Sealants
Standard Test Method for Tack-Free Time of Elastomeric Sealants
SIGNIFICANCE AND USE
The tack-free time is a measure of the surface cure time and may generally be correlated to a variety of useful parameters such as the time interval before the sealant (1) resists damage by touch or light surface contact, (2) resists job-site or airborne dirt pick-up, (3) resists impinging rainfall.
The tack-free time is sometimes used as an on-the-job quality assurance test. A quality product that is consistent and reproducible will generally fall within a maximum and minimum tack-free time.
This test for tack-free time can be used at any temperature and humidity. It is important that if a sealant will be used in a climate quite different than the standard conditions called out in this test method, then those conditions be used to test the sealant.
SCOPE
1.1 This test method covers a procedure for the determination of the tack-free time property of single- and multi-component elastomeric sealants commonly used for sealing, caulking, and glazing in buildings and related construction.
1.2 This test method is applicable to self-leveling and non-sag grades of sealant. Sealants requiring slight heating to facilitate extrusion from the cartridge or gun are also described by this test method.
Note 1—See Specification C 920 for type and grade definitions.
1.3 The values stated in metric units are to be regarded as the standard. The values given in parentheses are provided for information purposes only.
1.4 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.
Note 2—Currently, there is no ISO standard similar to this specification.
General Information
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Standards Content (Sample)
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Designation:C679–03
Standard Test Method for
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Tack-Free Time of Elastomeric Sealants
This standard is issued under the fixed designation C 679; 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.
1. Scope sealant does not attach itself to the film and the film appears
clean when peeled from the surface.
1.1 This test method covers a procedure for the determina-
4.2 More specifically a strip of polyethylene film is placed
tion of the tack-free time property of single- and multi-
on the surface of the curing sealant and a 30-g (1.06-oz) weight
component elastomeric sealants commonly used for sealing,
is placed on the film. The weight is left in place for 30 s, then
caulking, and glazing in buildings and related construction.
removed and the polyethylene strip is removed and examined
1.2 This test method is applicable to self-leveling and
for sealant attachment to the film. The length of time from
non-sag grades of sealant. Sealants requiring slight heating to
when the sealant was first applied and tooled into the template
facilitate extrusion from the cartridge or gun are also described
until the time the sealant is no longer picked up by the film is
by this test method.
called tack-free time.
NOTE 1—See Specification C 920 for type and grade definitions.
4.3 With some sealants, interpretation of the end point is
1.3 The values stated in metric units are to be regarded as confusing in that a very thin film of sealant or oil will transfer
the standard. The values given in parentheses are provided for to the film. For consistency of data, record the point where the
information purposes only. bulksealantisnolongertransferredtotheplasticbutignorethe
1.4 This standard does not purport to address all of the very thin uniform film of sealant or the plasticizer transferred
safety concerns, if any, associated with its use. It is the to the plastic test strip.
responsibility of the user of this standard to establish appro-
5. Significance and Use
priate safety and health practices and determine the applica-
5.1 The tack-free time is a measure of the surface cure time
bility of regulatory limitations prior to use.
and may generally be correlated to a variety of useful param-
NOTE 2—Currently, there is no ISO standard similar to this specifica-
eters such as the time interval before the sealant (1) resists
tion.
damage by touch or light surface contact, (2) resists job-site or
2. Referenced Documents airborne dirt pick-up, (3) resists impinging rainfall.
5.2 The tack-free time is sometimes used as an on-the-job
2.1 ASTM Standards:
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quality assurance test. A quality product that is consistent and
C 717 Terminology of Building Seals and Sealants
2 reproducible will generally fall within a maximum and mini-
C 920 Specification for Elastomeric Joint Sealants
mum tack-free time.
3. Terminology 5.3 This test for tack-free time can be used at any tempera-
ture and humidity. It is important that if a sealant will be used
3.1 Definitions—See Terminology C 717 for definitions of
in a climate quite different than the standard conditions called
the following terms used in this test method: caulking, com-
out in this test method, then those conditions be used to test the
pound, cure, elastomeric, glazing, non-sag sealant, sealant, and
sealant.
self-leveling sealant.
6. Apparatus
4. Summary of Test Method
6.1 Cabinet or Room, capable of maintaining a temperature
4.1 Thetestconsistsoflightlytouchingasurfaceofacuring
of 23 6 2°C (73.4 6 3.6°F) and 50 % 6 5 % relative humidity.
sealant with a polyethylene film at regular intervals until the
6.2 Weight, rectangular, with dimensions of 41 by 19 mm
5 3
(1 ⁄8 in. long by ⁄4 in. wide) and mass of 30 g (1.06 oz).
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ThistestmethodisunderthejurisdictionofASTMCommitteeC24onBuilding
NOTE 3—The thickness of the weight should be approximately 6 mm
Seals and Sealants and is the direct responsibility of Subcommittee C24.20 on
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General Test Methods. ( ⁄4 in.) but planed to a thickness that will provide the 30-g (1.06-oz) mass.
Current edition approved May 10, 2003. Published June 2003. Originally
approved in 1971. Last previous edition approved in 1997 as C 679 – 87 (1997).
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Annual Book of ASTM Standards, Vol 04.07.
Copyright © ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959, United States.
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C679–03
6.3 Polyethylene Strips, several (often 6 or more), clear, low described in 8.5. Try to touch a different place on the surface
density w
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