Hello Håkan,
Last year I damaged the propeller strut on my Albin Nova in a mishap with an anchor line. It broke the strut off the boat and bent the propeller shaft. Repairs have taken some time and been a challenge. After investigating a number of repair options (the narrow width of the hull at the strut location made attaching a metal strut difficult) I decided to reproduce as much as possible the rather unusual original use of a fibreglass strut. The original broken strut piece was ground down to a thin remnant to create a template for the repair and to reuse the portion shaped for the cutless bearing. I then built it up with multiple layers of mat and woven cloth (and sanding) to eventually achieve the overall original shape although I did make it somewhat thicker. The last few outer layers were vacuum bagged to improve the glass/resin ratio and maximize the strength. The broken fragment in the hull was drilled out to create a recess for the new strut. I replaced the 25mm metric shaft with a 1 inch shaft (0.4mm larger diameter) since it was easier to obtain that here. I used a tapered bushing in the motor end of the stern tube to centre the new propeller shaft. A temporary bracket glued to the hull supported the propeller end of the shaft and was used to adjust the shaft position until it was centred in the stern tube at the outboard end. The original propeller shaft had been significantly off centre in the stern tube and getting the new centred shaft aligned required lifting the back end of the engine to remove the engine mounts and cut a slot in the front (originally just a hole with only a slot at the back for adjustment). This allowed additional sideways movement of the engine and the mounts. The rebuilt strut with a new cutless bearing was slid onto the shaft and inserted into the recess filled with thickened epoxy. Fibreglas fragments were pushed into any gaps and the shaft/bracket used to support the strut in proper position until the epoxy had set. I had previously ground the surrounding hull area to original fibreglass and now used a number of layers of glass mat and cloth to join the strut and the hull together (this was also vacuum bagged for strength). The result was faired into the hull and barrier coated with Interlux 2000E followed by antifouling. I also added some additional fibreglass to the interior of the boat in case the drilled recess had somehow weakened the fibreglass block into which the original strut had fitted. The original shaft coupling which had been scored by the shaft when everything came to a sudden stop was replaced and a new shaft seal installed (PSS dry seal). Basically everything back from the engine flange was replaced. A new Flex-o-fold 3-blade propeller replaced the damaged original fixed prop. Unfortunately the battery box now came too close to the rubber of the new shaft seal for comfort so I wanted to move it back and also improve the access to the seal and coupling area. The box contacts the hull after only a slight move so I had to raise the entire level of the quarter berth supports with wood strips to allow more clearance and movement. This of course meant the battery cables had to be lengthened but this allowed me to replace with a larger guage and add some fuses. I don't imagine this is a common repair issue and there are likely some other ways to do it but after bringing the problem to the Albin Nova group I thought I would let you know how it was done. So far the results have been quite satisfactory and hopefully I will never have to do it again!
Regards
Andrew Haill
Nova 341 Sirocco
Thunder Bay, Ontario, Canada
