1、 FORD LABORATORY TEST METHOD BI 001-04 Date Action Revisions 2001 03 02 Revised Editorial no technical change A. Cockman 1992 06 08 Printed copies are uncontrolled Page 1 of 3 Copyright 2001, Ford Global Technologies, Inc. MEASUREMENT OF DRY HIDING POWER OF PAINTS RED AND GRAY CHECKERBOARD Applicati
2、on This procedure is used to establish the dry hiding power of paints by determining the film thickness required to completely hide red and gray squares of a standard checkerboard. Apparatus Required Checkerboard Red and gray checkerboard. This is made up of standard color rectangles the red to matc
3、h Munsell color value 7.5R (yR) 3/2; the gray to match Munsell neutral color value N/6 medium gray. These hiding power charts are produced by: Morest Company, Inc. 211 Centre Street New York, New York and are identified by the code number RGF-1. Note: A stock of these charts is maintained by the Aut
4、omotive Assembly Division, Technical Control Department, Paint and Sealer Section or the Glass and Chemical Products Division, Paint Plant, Quality Control Section. Local requirements can be obtained from one of these sources. Masking Tape 1 inch wide. Source: Minnesota Mining & Mfg. Co. (3M) No. 71
5、0 or equivalent. Steel Panels Clean steel panels 4 x 12 inches of the type described in FLTM BI 103-02 are used for this test. Reference Test Methods FLTM BI 103-02, Preparation of Panels for Paint Tests, describes the apparatus and procedure for spraying panels. FORD LABORATORY TEST METHOD BI 001-0
6、4 Page 2 of 3 Copyright 2001, Ford Global Technologies, Inc. FLTM BI 117-01, Thickness Measurement of Paint Films, describes the apparatus and procedure for determining paint film thickness. FLTM BI 109-01, Color Matching with Artificial Light, describes the apparatus and procedure for viewing hidin
7、g power charts under the Macbeth light. Conditioning and Test Conditions All test values indicated herein are based on material conditioned in a controlled atmosphere of 23 +/- 2 C and 50 +/- 5 % relative humidity for not less than 24 h prior to testing and tested under the same conditions unless ot
8、herwise specified. Procedure 1. Cut a section of checkerboard 2 inches wide and 10 inches long so that there are ten alternating 2 x 1 inch red and gray rectangles plus a inch gray border at the upper and lower ends. 2. Position the checkerboard on the steel panel even with the right edge and 1/2 in
9、ch inboard from the upper and lower edge. Tape the cardboard to the panel, using 1 inch wide masking tape. The tape should cover only about 3/8 inch of the checkerboard at the top and bottom ends. 3. Reduce the paint under test with appropriate thinner to the viscosity designated in the Engineering
10、specification. 4. Spray the entire panel and checkerboard with a uniform wet coating of the test color approximately .0005 inch thick. 5. Allow 1 minute flash-off, then spray the lower 3/4 of the panel with an additional .0005 inch coat of paint. 6. Allowing 1 minute flash-off between coats, progres
11、sively spray the remaining lower areas of the panel until complete hiding of the red and gray rectangles is obtained at the lower end of the panel. Note: Some practice may be required to accomplish the object of this test. A gradual increase in film thickness from the top to bottom of the panel is d
12、esired with a dry film thickness gradient of .0005 inch - .0025 inch. A wedge type film thickness with complete hiding of the lower checkerboard rectangles is obtained when the panel is sprayed in increments with successive coats of paint. FORD LABORATORY TEST METHOD BI 001-04 Page 3 of 3 Copyright
13、2001, Ford Global Technologies, Inc. 7. Air dry, or after a 3 minute flash-off, bake the panel at one of the standard cycles designated by the Engineering specifications. Remove baked panel from oven after specified time, and cool to 23 +/- 2 C. 8. Examine painted checkerboard under the North Sky Da
14、ylight of the Macbeth unit. The panel should be held on a suitable rack at an angle away from the viewer and at 45 from horizontal. The lower edge of the panel should be inboard 12 inches from the outside lower edge of the color matching booth. The viewer should stand so that his line of vision is n
15、ormal (90) to the surface of the steel panel which should then be marked adjacent to the point where complete hiding of the red and gray rectangles of the checkerboard is obtained. 9. Remove panel from the Macbeth unit and measure the paint film thickness on the steel panel adjacent to the area of t
16、he checkerboard marked as having complete hiding. Record this measurement and report as the dry hiding thickness of the paint. Chemicals, materials, parts, and equipment referenced in this document must be used and handled properly. Each party is responsible for determining proper use and handling in its facilities.
