New Test Methods Will Evaluate Side-Bonding Potential of Coatings for Wood Floors
An ASTM subcommittee is developing a standard to evaluate the potential of wood coatings to form gaps and bonding in wood floors.
Standard Test Methods for Evaluating Side-Bonding Potential of Wood Coatings will provide coating evaluation procedures to coating manufacturers in product development, and end-users who apply wood coatings.
ASTM standards developer Mark Algaier, vice president, R&D, Hillyard Industries, Inc., St. Joseph, Mo., describes what can happen to wood flooring covered with misformulated coatings. The wood naturally expands or contracts depending on the relative humidity, he says. If the coating is not properly formulated, it allows bonding of the adjacent strips of wood flooring, called panelization. As the wood contracts, rather than contracting as individual strip flooring, the wood moves as a single panel, breaking at the weak point. The worst case scenario is where the wood itself breaks. Ive seen some floors actually split.
Dependent on the extent of the side-bonding of particular wood coatings, Algaier explains, when humidity drops and the wood flooring gives up its inherent moisture to the ambient air, the wood dries out and shrinks which can cause two primary concerns:
The wood can either split, requiring expensive replacement; or
The wood can move as a panel, rather than as individual strip flooring, allowing the accumulated gappage to occur which aesthetically is not acceptable by end-users.
The proposed standard provides two mechanical properties tests for the quantitative determination of the cohesive strength of wood coatings (tensile and lap shear), Algaier says. It also provides a wood floor simulation test for the qualitative determination of side-bonding potential of wood coatings.
Academic and industry members with ASTM Subcommittee D07.01, Fundamental Test Methods and Properties, welcome participation as they develop the standard. The subcommittee is part of Committee D07 on Wood.
To participate or comment on this activity, contact Mark Algaier, Hillyard Industries, Inc., St. Joseph, Mo. (phone: 800/365-1555, ext. 8322). Committee D07 meets Oct. 13-16 in Madison, Wis. For meeting or membership details, contact Maxine Topping, manager, Technical Committee Operations, ASTM International (phone: 610/832-9737). //
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