Water in cockpit - Centerboard trunk?

Submitted by Michiganmirror on Sun, 10/16/2016 - 01:47

Forums:

Thanks to all for your previous advice. Mirror 52064 relaunched today after an unknown amount of time out of the water. To see her sail, view https://www.facebook.com/michael.angell.16/videos/10207574754151598/ During her sail, I did notice some water seeping into the cockpit around the base of the centerboard trunk. I didn't actually see it squirt out, but it accumulated there at a slow rate (no water was entering from the scuppers or anywhere else. When I repaired the hull, I didn't see any issues with the centerboard trunk on the outside of the hull. Is this common in 40 year old boats. What is the best way to address it?

mirrorpete

Sun, 10/16/2016 - 12:44

When I put my Mirror in the water for the first time in a season after being in my garage all fall and winter I too get a small amount of water in the cockpit which accumulates around the center board box. This is the low point of the Mirror. However, when I put the Mirror in the water the next day there is no more leak. I suspect the wood just swells and cause the small hole to close.
Pete

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62816inBerlin

Fri, 10/21/2016 - 13:44

The CB trunk - hull joint is one of the parts subject to a lot of stresses. It's worth checking for signs of rot in that area during the winter season. Press on the paint with your fingers, it shouldnt't give. Where I found soft spots, I then used a thick needle to locate the soft wood beneath the paint.
After failing to fix leakage around the CB trunk by injecting epoxy and having sailed with gaffer tape over a crack there, I gave up and tore out my CB trunk and rebuilt the hull joint completely, also strengthening the thwart there. All flexing of the thwart is transmitted to the hull via the CB trunk, after all, and this probably leads to leaks in most Mirrors on the long run.
Wood swelling/shrinkage and leaking, as Pete mentions, is a problem with all wooden boats. However, prolonged dampness in the centre plywood layers will almost inevitably lead to rotting wood.
A description of my repairs is given in the discussion thread http://forum.mirrordiscussforum.org/node/94 . The fix has withstood some very severe conditions since. For that, another minute leak has now developed around the end of one of the patches at the end of a floor batten. So I've got my work cut out for the winter too. Perhaps a new bottom paint job will be adequate.
BTW - Michael - I couldn't see your video on Facebook - is it restricted to "friends only"?

Michiganmirror

Sun, 10/30/2016 - 01:47

Thanks for the information. When I worked on the hull, I didn't detect any rot near the CB trunk (using a awl). I do see that there are gaps around the fiberglass tape at the CB trunk. I've removed the thwart to get better access and will be trying to re-epoxy the area. I will take a look at your repair information as well. Sorry about the video (thanks for telling me). This link may work better: https://www.facebook.com/Sailmichigan.org/videos/1272723052800812/
Thanks again - Mike

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curlew

Tue, 11/29/2016 - 21:39

My CB was pretty sound, or so I thought, although it tended to leak a bit. Then one day I touched a rock with the dagger board and it ripped the CB case away from the hull. This put me in an emergency situation and I called the Coastguard as I tried to reach shore. All was well but it was big stress! I think there was a bit of rot in the wood to allow this to happen.
david

mirrorpete

Sun, 10/30/2016 - 10:51

It looks like you done a good job restoring your Mirror; enjoyed your video.
We have quite a few Mirror sailors in the Greater Toronto Area; our organization is the Ontario Mirror Dinghy Association. Take a look at our website, http://www.mirrorsailing.ca/ , perhaps you can get down to one of our regattas next summer. If you are also a camper, bring your gear. We camp at almost all of our regattas.
Pete

Michiganmirror

Sun, 10/30/2016 - 19:14

You folks look to be about 4 hrs from me, which isn't that bad. I'll need to renew my passport. I have a feeling that no matter who wins our current election, I'll have to wait in a long line.... Thanks - Mike