mast tabernacle - cabin top compression

[alex nemeth]

Does anyone have any experience or knowledge of a problem involving cabin top compression under the area where the mast tabernacle sits? Is this a problem of design common to the boat, or is it specific to my boat? Any ideas as to a fix would be appreciated. Also, I am wondering about the construction of the cabin top. Is there wood sandwiched under the glass? Could this be rotten? Can I install a post inside the cabin to support the area from below?Thanks for any help or info.-Alex

 

[Justin - O'day Owners' Web]

Compression

Alex - what's going on to indicate a problem? That would be helpful to know. The deck is cored with wood so, yes its conceivable that there is some rot in there but it actually doesn't seem to happen all that often. Even when it does the foot print of the tabernackle is large enough that it usually doesn't go through the glass.That said - it can happen. If you are afraid the rig is going to go through the deck I would start by removing the fitting and cutting away the top skin of glass to check out the core. If its bad, grind it out and fill the space with thickened epoxy. The replace the top skin and the fitting. Since the deck is designed to take the load, you should not need to add a compression post.Justin - O'day Owners' Web

 

[Pat Corbett]

cracks around tabernacle

I have some cracking of the glass around the tabernacle. I've removed the tab. and there doesn't seem to be a problem. I believe the weight of the mast and the wind in the sails and lateral movement over the (30) years, causes some slight pressure on the deck. Pour some water onto the area, and see where it goes.

 

[alex]

follow up on symptoms of comptession

Justin, thank's for the info on the wood core. Here is my situation: I am looking at a boat to buy, but noticed a depressed area directly under the mast tabernacle with some fine cracks radiation outwards. The depth of the pushed in area is, I would estimate at between 1 and 2 cm. I do not see any cracking or obvious signs when I examine the area from below. No downwards bulge. Two nuts pass through the tab and the cabin top and into the cabin and appear OK. There is no detectable softening of the area and no up-and-down movement in the base of the mast when I push on it. Sailing stresses are as yet untested.I was thinking about a compression post underneath because I saw on the "restoration of Wireless" website (a very fine article, btw.)that she has such a post (see "the cabin interior" section). I do not know if this is original or aftermarket. My boat has no signs that she might be missing a post. Perhaps the post is a later addition to the boat by O'Day as a fix for a known problem. Just speculation. My boat is 1973, I think.I hesitate to purchase a boat that likley has dryrot under the mast step glass. Sounds like an involved project is needed to do the repair.-Alex