ASTM D1384 Test Method for Corrosion Test for Engine Coolants in Glassware
7. Preparation of Test Specimens
7.1 Sand the cast iron and cast aluminum specimens on the 25.4 by 50.8-mm (1 by 2-in.) cut surfaces with "coarse" grade (No. 1) emery cloth. Remove any burrs from coupon edges and hole. Scrub all specimens vigorously, using a moistened bristle brush and ground pumice powder or fine silicon carbide grit until the entire metal area is bright, shiny, and free from any visible oxide film or tarnish.
7.2 Rinse the specimens thoroughly with tap water; then rinse with acetone, dry, and weigh to the nearest 1 mg. Cast aluminum specimens should be dried in a 100°C oven for 1 h, to a constant weight, prior to recording the weight.
NOTE 4 - If the test specimens are not to be used immediately, keep them in a desiccator until required.
8. Test Solutions
8.1 The concentration of the engine coolant to be tested shall be as follows:
8.1.1 Engine Coolant - The engine coolant, EG or PG based, shall be mixed with the proper quantity of corrosive water to give a 33 1/3 volume % coolant test solution.
8.1.2 Corrosive Water (Note 4) - The corrosive water shall contain 100 ppm each ofsulfate, chloride, and bicarbonate ions introduced as sodium salts.
8.2 Preparation of Sample - The preparation of the sample shall be done in accordance with the section on Preparation of Solutions Requiring Inclusion of Separated Solids and Liquids in Test Method D1176, except that the corrosive water shall be used for dilution instead of distilled water. Thus, any insoluble materials will be included in the representative sample.
NOTE 5 - The specified corrosive water can be prepared by dissolving the following amounts of anhydrous sodium salts in a quanity of distilled or deionized water.
sodium sulfate: 148 mg
sodium chloride: 165 mg
sodium bicarbonate: 138 mg
The resulting solution should be made up to a volume of 1 L with distilled or deionized water at 20°C.
If relatively large amounts of corrosive water are needed for testing, a concentrate may be prepared by dissolving ten times the above amounts of the three chemicals, in distilled or deionized water, and adjusting the total volume to 1 L by further additions of distilled or deionized water. When needed, the water concentrate is diluted to the ratio of one part by volume of concentrate to nine parts of distilled or deionized water.
9. Test Conditions
9.1 Beaker Assembly - The arrangement of the assembled metal specimens with relation to the aerator tube and other components is shown in Fig. 1. Note that the tip of the condenser just emerges from the bottom of the rubber stopper.
9.2 Test Temperature - The test solution shall be maintained at a temperature of 88 +/- 2°C (190 +/- 5°F) for high-boiling engine coolants.
9.3 Aeration Rate - The aeration rate shall be 100 +/- 10 mL/min. The aerator tube should be located at least 12.7 mm (1/2 in.) away from the test "bundle" to avoid direct contact with the metal specimens.
9.4 Test Duration - The test shall be run continuously for 2 weeks (336 h).
