This test method is intended to induce color changes in sealants, as well as their constituent pigments, associated with end-use conditions, including the effects of sunlight, moisture, and heat. The exposures used in this test method are not intended to simulate the color change of a sealant caused by localized weathering phenomena, such as atmospheric pollution, biological attack, and saltwater exposure.

When conducting exposures in devices that use laboratory light sources, it is important to consider how well the artificial test conditions will reproduce property changes and failure modes associated with end-use environments for the sealant being tested. Information on the use and interpretation of data from accelerated exposure tests is provided in ASTM G 151.

When this test method is used as part of a specification, exact procedure, test conditions, test duration and evaluation technique must be specified. Results obtained between the two procedures may vary, because the spectral power distribution of the light sources (fluorescent UV and xenon arc) differ. Sealants should not be compared to each other based on the results obtained in different types of apparatus.

These devices are capable of matching ultraviolet solar radiation reasonably well. However, for sealants sensitive to long wavelength UV and visible solar radiation, the absence of this radiation in the fluorescent UV apparatus can distort color stability ranking when compared to exterior environment exposure.

Note 1—Refer to Practices G 151 for full cautionary guidance regarding laboratory weathering of non-metallic materials.

1. Scope

1.1 This test method describes laboratory accelerated weathering procedures using either fluorescent ultraviolet or xenon arc test devices for determining the color stability of building construction sealants.

1.2 Color stability rankings provided by these two procedures may not agree.

1.3 The values stated in SI units are to be regarded as the standard. Values given in parentheses are for information only.

1.4 There is no equivalent ISO standard for this test method.

1.5 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.

2. Referenced Documents (purchase separately) The documents listed below are referenced within the subject standard but are not provided as part of the standard.

ASTM Standards

C717 Terminology of Building Seals and Sealants

C1442 Practice for Conducting Tests on Sealants Using Artificial Weathering Apparatus

D1729 Practice for Visual Appraisal of Colors and Color Differences of Diffusely-Illuminated Opaque Materials

D2244 Practice for Calculation of Color Tolerances and Color Differences from Instrumentally Measured Color Coordinates

E177 Practice for Use of the Terms Precision and Bias in ASTM Test Methods

E284 Terminology of Appearance

E691 Practice for Conducting an Interlaboratory Study to Determine the Precision of a Test Method

G113 Terminology Relating to Natural and Artificial Weathering Tests of Nonmetallic Materials

G151 Practice for Exposing Nonmetallic Materials in Accelerated Test Devices that Use Laboratory Light Sources

G154 Practice for Operating Fluorescent Light Apparatus for UV Exposure of Nonmetallic Materials

G155 Practice for Operating Xenon Arc Light Apparatus for Exposure of Non-Metallic Materials

CIE Documents

Keywords

artificial accelerated weathering; sealant; color change ; color stability; Accelerated weathering--sealants; Color--sealants; Color stability; Laboratory--building/construction materials analysis; Sealants;

ICS Code

ICS Number Code 91.120.30 (Waterproofing)

Citing ASTM Standards

[Back to Top]