Aleria’s shaft damage and subsequent repair

As they say, "$#IT Happens", and we wound up with a bent shaft, mangled propeller, and a shattered stern tube. As Aleria was careened on the shore near our house, the one saving grace was that the PSS shaft seal kept the briny wet stuff out of our boat.

The plan was to have a fibreglass professional come to do the job, but he got really busy and would not have been able to come for some time. It would have taken him a week to do the job and as he was coming from quite a distance away we would have had to pay for accommodation, travel, etc, etc. So, having thought the project through in great detail, this became yet another DIY project. As the professional is also a friend, we exchanged emails daily. I sent him my progress report, and he sent a laundry list of recomendations - the good part was that most of these were already on my to do list for the next day. But it sure was consoling to have him there in the background steering me along through this major job.

We keep Aleria overwinter in a cradle constructed out of telephone poles. The fore and aft pair of poles each have a sling to keep her balanced. She also has a spiderweb of ropes from her mast tops to aoncrete anchors buried in the shore either side.

The aft sling in Aleria’s cradle had been pushed forward under Aleria's prop during a gale that coincided with a spring tide. When the tide went out she settled onto the sling bending her shaft and prop blades and shattering her stern tube.

Starting to cut out part of stern tube

Stern tube section has been removed

The area areound the cut out section is ground down and beveled to the outside.
The new shaft is inserted

A jig is used to precisely line up shaft in what remains of the old stern tube.
The new tube fits into the old tube and is held centred in position in the old one with some small wedges.

To fix the new tube in position daubs of epoxy filler are pushed into the gap between the wedges.
Further down a pair of tabs are ‘glued’ in place with some epoxy and left to cure.

Over a period of two days the gaps are slowly filled with epoxy filler made out of resin, chopped fibre strands (suitable for use with epoxy) and some colloidal silica.

Then, woven roving is applied – 15 layers each side. One layer a little smaller than the preceding and so on. Then the same all over again, and again. This way, a nice bevel is ensured.

A mix of colloidal silica and resin is then applied over the roving.

The repaired area is then painted with primer and then two coats of anti-fouling

Aleria’s shaft damage and subsequent repair

Further Reading