Removing A Stern Tube
Posted: May 25, 2010
Boats with inboard power have a tube that runs from the point where the propeller shaft exits the hull to the place where the stuffing box is mounted inside the boat. 30 years ago these tubes were typically bronze pipe, but modern days use a composite material. This boat had developed a leak, and the source could not be determined. We pressurized the stern tube and found that it did not hold the pressure, and concluded that it leaked. Further inspection revealed a flaw inside the tube, which allowed seawater to leak into the keel sump, and then into the bilge.
In order to remove the shaft tube, we fabricated a 15' drill bit - basically a hole saw welded to a length of exhaust tube. This rig slides over the outside of the shaft tube, allowing us to run the hole saw along its entire length, cutting it loose from all attachments.
The shaft tube is then removed, and a new one installed. ZMI tech Mike Demers is shown above manning the super drill.
Category: Current Repair Projects
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