COMPLIANCE INFO_COMPLIANCE INFO 1983-2007

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MII,C-11796B arrangement. Apply a 100-gram load on top remove a 1-inch strip of the coating along �of each of the three assembled panel sets, one of the long edges of the panel, after cut- And place them in a horizontal position for ting the film parallel to the edge of the panel, ; 24 hours in a forced-draft oven maintained and at a right angle to the surface of the .at 180 ± 2° F. At the end of the heating panel. A straight line shall then be drawn or period remove the panels from the oven and scratched on the panel, parallel to the cut decoat using naphtha. Inspect the panels for edge of the film, and 1/8 inch away from it. evidence of stain, discoloration, or corrosion, The panel shall then be suspended vertically, disregarding the outer 1/8 inch edges of .the with the exposed area downward, for 4 hours panels. in a gravity convection oven maintained at 150 ± 2° F. for Class 1 or 1A compound; 4.6.9 Low temperature adhesion. A test 1450 ± 2° F. for Class 2 compound; or 130° ± 2° F. for Class 3 compound. The panel shall be cleaned and polished (see panel shall be .removed from the oven and 4.6.8.1), and coated (see 4.6.8.1.2) with a allowed to cool to room temperature. The film of 1.5 --±:,0.2 mils. After standing for approximately 16 hours, the panel shall be position of ;the cut edge of the coating, rela- tive to the reference line drawn or scratched cooled to —40 ±3° F. and maintained at this temperature for a minimum of one on the panel, shall then be observed. The compound shall then be considered to fail hour. While at this temperature 4 parallel the flow point requirements if any movement scratches, approximately 1/8 of an inch apart and 1 inch long, shall be made on the film in of the coating toward the reference line has one direction, and 4 other similarr scratches occurred as a result of heating at the ap- made at right angles to them, so as ,to form plicable specified temperature. a checkered pattern on the coating. A 4- bladed instrument, shown in figure 3, is 4.6.11 Removability. recommended for making the scratches. The tool shall be kept at ambient room tempera- 4.6.11.1 Apparatus. A satisfactory appara- tuTe. In making the scratches the tool shall tus for determining removability property be held in such a position that the cutting of the compound is illustrated in figure 4. edges make a 45° angle with the surface of The essential component of the apparatus is ` the film, and shall be drawn at a rate of the rubbing device, which is shown in detail approximately 1 inch per second through the in figure 5. The device consists of a glass film. The compound shall be considered un- tube having an open bulb at one end, and a satisfactory in adhesive qualities if there is felt plug at the other end. A felt plug, which any flaking of the film within the areas protrudes approximately 1/8-inch from the bounded by the scratches. Flaking shall be end of the tube, serves as the rubbing mem- -defined as chipping of the film for a distance ber. The rubbing tool is supported vertically greater than 1/32 of an inch on either side of and is drawn back and forth across the sur- the scratch marks. If a retest is authorized face of the coated panel. A continuous flow by the Government in case of failure, new of dry-cleaning solvent, conforming to Speci- blades shall be used in the cutting tool to fication P-S-661, is maintained through the eliminate wear of the blade edges as a factor tube, the felt plug, and over the test panel in the outcome of the retest. as the rubbing action Makes place. The rub- bing tool is free to exert its own weight, plus 4.6.10 Flow point. A test panel shall be that of the solvent it contains, upon the cleaned and polished (see 4.6.8.1),and coated surface of the panel. A constant head of with a film of 50 to 55 mils (see 4.6.8.4). solvent is maintained during the entire test Using a stiff spatula, knife, or razor blade by means of the assembly shown in figure 4. 9