ELECTROLYSIS CAUSES MAJOR PROBLEM AT SEA
Marcel Steinz recently reported (6/18/02) that while bringing SOUTHERN CROSS back north from several years in Florida and the Bahamas, and while about 40 miles offshore of South Carolina, the boat began taking on water. Upon investigation, the source of the leak appeared to be in the area of the stern tube/stuffing box. Water was being taken on rapidly, with the bilge pump running almost continuously. Heading immediately for shore, they eventually had the boat hauled at Beaufort, where they found that both of the bronze bolts holding the cutless bearing housing/stern tube/stuffing box, had sheared. Subsequent investigation revealed a severe case of electrolysis in the bolts. All A-37 owners are advised to periodically check the condition of these bolts for electrolysis and replace as required.
(Editor's Note: Several years ago, we noticed deterioration of the heads of the bronze bolts. After replacing the bolts, we attached a small teardrop zinc to the side of the hull immediately adjacent to the cutless bearing housing, and attached the zinc running a small piece of #10 electric cable to one of the bolts. In the subsequent years, no electrolysis has occurred. Additionally, we also found severe electrolysis in ALL the attaching screws of the rudder center gudgeon and the rudder shoe. We subsequently attached small zincs to all of these items, with no electrolysis since that time.)