1、 FORD LABORATORY TEST METHOD BI 120-02 Date Action Revisions 2001 03 19 Revised Editorial no technical change A. Cockman 1991 05 28 Printed copies are uncontrolled Page 1 of 5 Copyright 2001, Ford Global Technologies, Inc. DETERMINATION OF “THROWING POWER“ OF ELECTROCOATING MATERIALS Application Thi
2、s test is used to determine the ability of electrocoating materials to extend a protective coating into recessed areas. Apparatus and Materials Required Power Source Zero to 1000 Volt DC Zero to 10 Amp. Note 1: The maximum peak to peak value of the primary AC ripple must not exceed 10 % of the indic
3、ated coating voltage. Note 2: Equipment having a lower voltage range may be used providing voltages higher than the maximum required by the materials are available. Coating Tank Cylindrical non-conducting, acid resistant container, e.g. glass, having a minimum internal diameter of approximately 150
4、mm and a height of approximately 320 mm. Laboratory Stirrer (Acid Resistant) Zero to 700 rpm, electrically insulated shaft of suitable design to give adequate circulation. Throwing Power Box (See Drawing) This is an open ended box made using two 105 x 300 mm test panels and two insulated acid resist
5、ant strips 10 x 4 x 300 mm. The strips are inserted between the edges of the panels which are then fixed together using waterproof insulating tape or clips to prevent deposition beneath the strips. The cathode holder shall have dimensions giving satisfactory electrical contact with both test panels.
6、 FORD LABORATORY TEST METHOD BI 120-02 Page 2 of 5 Copyright 2001, Ford Global Technologies, Inc. Test Panels and Anode Ford Quality Control approved test panels UMA0018005 - (phosphated) or as specified in the relevant material specification. The two panels are electrically connected by a conductin
7、g bridge using crocodile clips. Phosphate coated panels must be dried at 105 C (metal temperature) for 3 minutes minimum, stored in a desiccator up to 24 hours or used within 1 hour. Note: Alternative panels may be used for special test purposes, e.g. Plant phosphated panels, after notification and
8、agreement with Quality Control. The type of phosphate and coating weight used must be stated. This coating must be in accordance with WSK-M3P1-C unless otherwise stated in the material specification. Thermostat Capable of controlling bath temperature to +/- 2 C. Note: A coolant system is necessary t
9、o maintain the bath at 20 C or as currently used in production. The cooling tube must be acid resistant. Mechanical Convection Oven Capable of maintaining temperatures up to 200 C within +/- 2 C. Low Conductivity Water Conductivity must not be greater than 10 uS/cm at 20 C. Electrode Holder (Insulat
10、ing Material) To support cathode (test box) and anode panel (105 x 300 mm) parallel to each other and 50 mm apart. 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 les
11、s than 24 h prior to testing and tested under the same conditions unless otherwise specified. FORD LABORATORY TEST METHOD BI 120-02 Page 3 of 5 Copyright 2001, Ford Global Technologies, Inc. Procedure 1. A paint sample is stirred with a spatula allowing the tip to contact the bottom of the container
12、. Mixing is adequate if no evidence of settling is indicated when the spatula is withdrawn and examined. 2. A suitable quantity of material is made up using the specified formulation. The solids, pH, and conductivity should be adjusted to suppliers recommendation. This sample is stirred for 16 hours
13、 minimum before use. Note: Production tank samples are used as received, without additions. Suitable stirring time after sampling and transportation is required immediately on arrival at appropriate laboratory. 3. Position the stirrer in the tank so that the propeller is at least 25 mm from the bott
14、om. The desired amount of paint is then poured into the tank and stirred. Note: Stirring speed must be sufficiently low to ensure that in this and subsequent operations air will not be induced. 4. Control the bath at an operating temperature of 20 +/- 2 C or as recommended by the supplier. 5. Positi
15、on the throwing power box and anode in the tank so that the lower end is 50 +/- 5 mm from the bottom. 6 Connect the cathode (both panels of box) and the anode to the power source. 7. The voltage is raised from zero to the coating voltage within 15 seconds. Maintain the voltage for 120 seconds and th
16、en reduce to zero in 2 seconds. Note: The coating voltage shall be the same as that determined for preparing test panels at the specified film thickness. 8. Remove the box assembly from the tank. Rinse with the low conductivity water and remove surplus water with oil free compressed air. Separate te
17、st panels, rinse and redry as before. Note: Clean the insulated strips ready for use again. 9. Bake the electrocoated test panels in accordance with the relevant material specifications. 10. Age the electrocoated panels for either 16 hours at 45 +/- 2 C or 72 hours at 23 +/- 2 C. FORD LABORATORY TES
18、T METHOD BI 120-02 Page 4 of 5 Copyright 2001, Ford Global Technologies, Inc. Evaluation 1. Measure the length of the thrown paint film on each metal panel. The average length in mm is the visual throwing power of the paint. Measure the wedge length from bottom edge of panel at 10 micrometre film th
19、ickness along the line of the throw. 2. To determine the “Salt Spray Throwing Power“: Tape the long sides of the test panels to prevent rusting of the unpainted edges. Do not “X“ scribe the panels. Expose the test panels to a 240 hour salt spray test in accordance with ASTM B 117 unless otherwise sp
20、ecified in the relevant material specification. Rinse the panels with water. Remove excess water with compressed air and examine for blistering and rusting. Do not consider edge rusting. Measure the distance from the painted end of the test panel to the point at which blistering and/or rust are evid
21、ent. This distance in mm is the “Salt Spray Throwing Power“ of the material under test. 3. Report the following in mm: a) Visual throw b) 10 micrometre line c) Throwing power corrosion line 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. FORD LABORATORY TEST METHOD BI 120-02 Page 5 of 5 Copyright 2001, Ford Global Technologies, Inc. THROWING POWER BOX
