TESTS FOR HOT-WATER RESISTANCE OF TANK ENAMELS*

The resistance to attack by hot water of a representative group of commercial enamels, designed especially for use on hot-water tanks, and of several nontank enamels was measured by the following three types of test: (A) loss of gloss after periods up to several hours in a conventional autoclave with distilled water, (B) loss of gloss after one day to two weeks in apparatus which kept the specimens in contact with constantly changing, boiling distilled water, and (C) loss in thickness after periods up to 5000 hours (208 days) in a modified autoclave with circulating aerated tap water under pressure. The tests are described in detail, comparisons are made, and the loss-of-gloss test with boiling distilled water as used in Commercial Standard CS115–44 is discussed.