Mast Step
It looks like the support under Mischief's mast step has compressed. The rigging has lost tension and there is a distinct dip in the deck around the mast base. I have reached out to others on the Achilles Owners Forum as I believe that this is a common problem. Updates and pictures to be posted here.
The head lining in place, above, and the head lining down, below. This where the webbed step will go and be through bolted to the additional beam in the forward cabin.
The forward cabin looking aft, port and starboard. This is where the additional beam will go.
The plan as it currently stands in early March is to lower the mast, remove the deck beam. cut out the inner skin, replace the core with oak wedges. The epoxy in a new skin, fit the old and new deck beam plus section to fill the gap between them and the webbed mast step. The restore the head lining. Then possibly fit strengthening pieces to the inner edge of the bulkheads to transfer the load to the keel.
The Repair
Over the spring tides I used the club's scrubbing dock to lower the mast.
This, coupled with moving the mast to the forward end of the step, relieved the pressure on the mast step. A doubler plate was bolted to the forward face of the deck beam and holes drilled for the support bracket. The deck was then raised from inside with a car jack and a length of timber until it was back to its original shape.
As much of the deckhead as necessary to reach the affected area was cut out using an angle grinder and chisel. The original deck beam was left in place as it was epoxied in. The mast was supported on a plywood plate which was totally saturated and compressed. This was cut out as far forward as possible. The area was dried out and structural foam was inserted and epoxied in.
A plywood plate was epoxied in under the foam and them a pre-made sheet of glass reinforced epoxy. This was held in place until part cured. Then the support bracket was bolted in and torqued up.
The aft bolts on the mast step were replaced and longer bolts run through the support bracket. These were gently torqued up. The void above the liner sheet was filled with foam and the head lining replaced.
The mast was raised and Mischief was put back on her moorings. A measurement was taken from the floor timber below the mast and a point on the support bracket. This will serve to identify if the mast step bracket has dropped. On deck the rigging was tightened to 75% tension and a check in a week will show if anything has changed. At this point it appears to be a good repair. Four days on the scrubbing dock was knackering as each time the boat landed as the tide dropped the mooring lines were adjusted and the boat held upright.
The head lining in place, above, and the head lining down, below. This where the webbed step will go and be through bolted to the additional beam in the forward cabin.
The forward cabin looking aft, port and starboard. This is where the additional beam will go.
The plan as it currently stands in early March is to lower the mast, remove the deck beam. cut out the inner skin, replace the core with oak wedges. The epoxy in a new skin, fit the old and new deck beam plus section to fill the gap between them and the webbed mast step. The restore the head lining. Then possibly fit strengthening pieces to the inner edge of the bulkheads to transfer the load to the keel.
The Repair
Over the spring tides I used the club's scrubbing dock to lower the mast.
As much of the deckhead as necessary to reach the affected area was cut out using an angle grinder and chisel. The original deck beam was left in place as it was epoxied in. The mast was supported on a plywood plate which was totally saturated and compressed. This was cut out as far forward as possible. The area was dried out and structural foam was inserted and epoxied in.
A plywood plate was epoxied in under the foam and them a pre-made sheet of glass reinforced epoxy. This was held in place until part cured. Then the support bracket was bolted in and torqued up.
The aft bolts on the mast step were replaced and longer bolts run through the support bracket. These were gently torqued up. The void above the liner sheet was filled with foam and the head lining replaced.
The mast was raised and Mischief was put back on her moorings. A measurement was taken from the floor timber below the mast and a point on the support bracket. This will serve to identify if the mast step bracket has dropped. On deck the rigging was tightened to 75% tension and a check in a week will show if anything has changed. At this point it appears to be a good repair. Four days on the scrubbing dock was knackering as each time the boat landed as the tide dropped the mooring lines were adjusted and the boat held upright.
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