Harbormaster's boat problems still a mystery
Representatives of Ribcraft of Marblehead, Mass., met with town officials, and chemical engineer and consultant, Professor Otto Gregory of the University of Rhode Island at the police station on Tuesday afternoon to discuss the galvanic corrosion problems plaguing the harbormaster's boat.
Professor Gregory presented the results of his tests and explained the methodology of the procedures used. He reported that the measurements of voltage and current tested in the area where the harbormaster's boat was docked were within acceptable ranges and should not have caused the extensive damage to the boat in such a short period.
Matt Provenzano, director of operations for Ribcraft, listened to Gregory's presentation and asked about the state of the tide when the tests were performed. Gregory said the area was tested at peak high tide as well as two hours before peak high tide. He went on to explain that tests for both current and voltage were made using a copper grounding rod buried into the sediment as well a silver-silver chloride electrode. He brought the multitester device used to measure electrical current and voltage to the meeting and attested that the unit was calibrated before the tests were performed.
Provenzano said that he appreciated all that Gregory had done, but noted that the tests performed by marine surveyor Joe Lombardi, a consultant hired by Ribcraft, did not agree with the professor's findings. "When the tests were performed last July by Joe Lombardi, the voltage measurements he found in the water were dramatically different," Provenzano said. He said that he found as much as a 2000- millivolt shift, which they (Ribcraft) felt caused the corrosion.
Gregory asked why Lombardi only measured for voltage and didn't measure for current, noting that the high measurement of voltage alone would not account for the extent of the damage in such a short period. The boat had only been in the water for two months. Provenzano said that he didn't know, but would find out.
The professor also said that the barrier coat of epoxy applied between the aluminum hull and the bottom paint was a cause for concern. He suggested that the barrier coat could have been too thin, causing the corrosion.
Provenzano rebutted the professor's analysis and said that the manufacturers, who are experts in their field, recommended all materials used. Gregory said that he didn't doubt that the correct materials were used, but questioned the possibility of faulty application.
Provenzano said, "Ribcraft has made many aluminum boats, and I've never seen anything like this happen before." He emphasized that he wanted to work with the town to resolve the problems, but there were dramatic differences in the professor's findings and those of Ribcraft. "We could repair this boat, but when it's put back in the water, the same thing could happen again," he said.
Gregory agreed, and said that something had to cause the sustained difference in the testing. He suggested that the source of the current that Lombardi found could have come from a boat that was no longer in the area. However, he didn't think that was likely.
The men decided that the best course of action would be for Professor Gregory and Lombardi to perform tests together and make recommendations on mutual results.
The meeting was attended by Town Administrator Bruce Keiser, Police Chief Thomas Tighe, Police Lieutenant Bill Donovan, town solicitor Peter Ruggiero, Harbor Commission Chairman Mike de Angeli, harbor clerk Kim Devlin, Professor Otto Gregory, as well as Bob Gray and Matt Provenzano, both of Ribcraft.