ASTM D7489, ASTM D7514 Cover Touch-Up Properties, Ink Stainblocking
October 19, 2009 // Published as a news service by IHS
ASTM International Committee D01 on Paint and Related Coatings, Materials and Applications approved ASTM D7489 and ASTM D7514, two standards that cover architectural coating touch-up properties and ink stainblocking of paint systems.
Both standards are under the jurisdiction of Subcommittee D01.42 on Architectural Coatings.
Touch-Up Properties
ASTM D7489 - Practice for Evaluating Touch-Up Properties of Architectural Coatings Under Various Environmental Conditions covers variations in color, gloss and sheen that can affect the touch-up capacity of a paint.
When a home is being constructed, paints are subjected to a variety of drying conditions, which can lead to differences in appearance between the original coat and subsequent touch-up areas after the paint has fully cured.
According to Douglas Mall, D01.42 member, ASTM D7489 brings together a variety of different testing protocols that have been used for touch-up evaluation.
"By using ASTM D7489, it will be easier for contractors to communicate with laboratories what conditions generated product failure, with a much better chance of the laboratory being able to replicate the failure and make changes that would correct the product deficiency," said Mall.
Mall said the standard will be used by chemists in paint laboratories, as well as technical service personnel in the field.
Future work on ASTM D7489 will include reproducibility and repeatability studies, especially in the area of spray application.
"The next step for this standard is to develop it further as a test method, selecting more common application methods and conditions," said Mall. "We would like to get feedback on the current practice and its usefulness."
Ink Stainblocking
Paint companies and raw material suppliers will be able to use ASTM D7514 - Test Method for Evaluating Ink Stainblocking of Architectural Paint Systems by Visual Assessment to assess the capability of architectural coatings for blocking ink stains from bleeding through to a topcoat.
The standard represents a compilation and synthesis of methods that are being used to evaluate stainblocking.
According to Neal Rogers, group leader, ASTM D7514 is the result of a survey taken by Subcommittee D01.42 of various methods for measuring the stainblocking capabilities of coatings.
"The development of ASTM D7514 provides a means to critically evaluate and differentiate between different resin technologies used in the manufacture of stainblocking primers," said Rogers.
Rogers said that while ASTM has a test method for the assessment of stainblocking tannins in wood (ASTM D6686 - Test Method for Evaluation of Tannin Stain Resistance of Coatings), many coatings, particularly interior paints, are applied to previously painted surfaces rather than the bare wood that is covered by ASTM D6686.
Source: ASTM International.