This report and its appendix present the results of inspections and observations of the performance of selected protective coating systems in submerged fresh water exposure on the Isthmus covering a period of approximately eight years.
The results described were derived from performance tests of panel-specimens continued after immediate information from accelerated and/or short-term tests had been obtained during 1940-1942 for basing specifications for protection of the new locks and other structures planned under the Third Locks Project. The tests were continued until service performance had reached a repaint rating value of 6, or until complete deterioration had occurred if this information was considered desirable or necessary.
Summary information is included covering the performance of the systems selected for protection of two submerged steel lift gates installed in the Panama Canal Locks. Comparison of the protective coating systems on the basis of individual elements which could alter the performance behavior beneficially or adversely has been accomplished wherever possible. In addition, an effort has been made to correlate the long-term performance data with the short-term or accelerated test results. Within the limits of the investigation, it is believed that all significant data and comparisons have been presented.
