(14) Bird Applicators are specified by their film width and the approximate wet film thickness they are intended to apply. The latter value is engraved at one end of the applicator. To calculate the approximate spreading rate in square feet per gallon, divide 1604 by the indicated wet film thickness.
Bird Film Applicators® is a registered trademark of Bird Film Applicators, Inc.
This Applicator was originally designed for latex paint scrub test procedures on a 6-1/2 x 17 in. glass surface, in which a 3-1/2 mil thick test coat is applied over a 5 mil primer. Although the use of primed glass in tests of this type has been largely discontinued, the applicator continues to be widely used for its individual clearances.
(2) Each of these instruments has a 6 mil and an 8 mil gap clearance, laying down wet film thicknesses of approximately 3 and 4 mils, respectively. These are the thicknesses most often recommended for the testing of solventborne and waterborne architectural coatings, hence their characterization by Leneta as "Trade Sales" applicators. The film widths of 4 and 6 inches take advantage of the most popular Leneta test chart widths of 5-1/2 and 7-5/8 inches. Their "U"-shape structure retains a substantial volume of test coating to assure completeness of drawdowns.