The history of the use of coal tar coatings for the protection of underground structures is discussed briefly. Specifications. are given for the following hot applied coatings: narrow range enamel, moderate range enamel, wide range enamel, AWWA enamel C 203-4 and hot pipeline enamel. Temperature ranges at which these coatings can best be used are shown graphically. Recommendations are made regarding the selection of a coating for a given underground condition.
Specifications are given for a cold applied coal tar coating which has been used successfully by the Bureau of Yards and Docks and by the Bureau of Reclamation. The coating has a variety of names in industry and is a thick, almost non-flowing, thixotropic material produced basically from a coal digestion pitch. 5.4.5
