Standard Practice for
Applying Coil Coatings Using The Wire-Wound Drawdown
Bar1

This standard is issued under the fixed designation D 4147; 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.

1. Scope

1.1 This practice covers a procedure for applying a coating
film of uniform thickness on a flat panel using the wire-wound
drawdown bar.

1.2 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. Summary of Practice

2.1 A flat panel is secured on a firm horizontal surface. An
ample amount of coating is poured across one end of the panel
and the drawdown bar placed behind the coating. The bar is
then drawn with uniform pressure and speed along the length
of the panel toward the operator to apply a uniform film. The
wet and dry film coating thickness obtained is dependent on the
combination of the bar used, the volume solids of the coating,
and the speed of the drawdown motion.

3. Significance and Use

3.1 This practice is useful in the laboratory to simulate
roll-coated films.

4. Apparatus

4.1 Wire-Wound Drawdown Bars—A set of stainless steel
wire-wound drawdown bars of sufficient diameter to prevent
bowing during application. These bars are manufactured so
that the diameter of the wire wound on the bar controls
thickness of the wet film applied. The choice of specific
drawdown bar is dependent on the dry film thickness required
and the volume solids of the coating under test.

4.2 Devices for Securing Panels:

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