Mizzen Mast Step Construction and Reinforcement

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3 years 2 weeks ago #2544 by William Weigel
Mizzen Mast Step Construction and Reinforcement was created by William Weigel
We have been sailing our W42 fairly hard over the past 2 years and I am concerned about the integrity of the mizzen mast step. I have noticed 2 symptoms that make me worried. First, over time the side shrouds seem to develop slack and the mizzen actually rocks ever so slightly on the mast step when in rough conditions. The tell tale sign is a gray streak that develops on the deck as water washes out the aluminum oxide that is loosened by the motion. The other symptom is that the aft head door starts to stick when the rigging is tightened. On my Whitby hull 210 I have an A-frame support below the floor with a jacking screw. I am able to loosen the mizzen rigging and turn this jack screw to push the deck back up until the door closes properly and then re-tighten the shrouds. I have had to do this 2 times in the past 12 months.

I am thinking about a couple of changes. First, I think I may add additional compression support along the centerline bulkhead below the mizzen. I will likely do this on the side of the bulkhead in the head. Secondly, I am considering stiffening the deck with either a heavy stainless plate or cutting up and re-coring the deck. A couple of questions:

Does anyone know what the core material is beneath the mizzen mast step? Is it plywood, balsa, or fiberglass?

Has anyone reinforced the compression support (i.e the bulkhead) and if so how did you build it?

Thanks in advance for any insights.

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3 years 2 weeks ago #2545 by Dale Kramer
Replied by Dale Kramer on topic Mizzen Mast Step Construction and Reinforcement
We have hull 169 which was originally my fathers boat and now mine. Early on my father noticed deformation in the head door and realized that the mizzen was compressing the deck.

He fixed this by reinforcing the side wall of the head with heavy Oak and bolted this to the existing walls. Once this was done he placed a jack up rig which set on the keel and the other on the new oak wall that he constructed. He jacked up the wall until the head door was operating correctly again and there was no deck deformation.

This has been this way for 20+ years and have not had a lick of problems.

Dale Kramer
S/V Puffin
The following user(s) said Thank You: Frank

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