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Water ingress top of keel

Posted: Thu Jan 14, 2016 6:27 pm
by seanslife
Hi everyone
Removing the centreboard today for some much needed beadblasting I noticed that when I punctured the fibreglass covering the CB bolt head there was some water in the cavity directly below it, seems to be sitting on top of the keel. The water is salt water (I last sailed at Batemans Bay) and clear. I used paper towel to dry it up but it saw off 6 hand towels before I ran out, and no visible reduction in the water level. Obviously there's some type of cavity there but I can't feel the bottom of it or penetrate it with a torch. It's next to the forward part of the centreboard case. See pics... first is an attempt to show place of water (hard to photograph because it's directly below the bolt head). The second is of the paper towel sucking the water out.

Where does this cavity extend to and what's the possible point of water ingress?

Cheers
Sean

Re: Water ingress top of keel

Posted: Thu Jan 14, 2016 10:06 pm
by atles
put some red food dye in it and see if you have a crack near the keel
should run out

Re: Water ingress top of keel

Posted: Mon Jan 18, 2016 6:00 pm
by seanslife
Checked, and nothing running out, no signs of cracks or osmosis. I've resealed the hull fittings such as cockpit drains, rudder pintels, and hull bungs ( none were loose) but I doubt any of these are the source of seawater ingress because the water ends up inside the CB and Keel casing not in the bilge trough atop that which would normally accept runoff from the stern hull fittings. Anywhere else I should look?

When I removed the CB from its case there were two small, shot, rubber grommets that fell to the ground. Am I right in presuming these sit in the seawater between CB case walls and the CB cheek pads? I ask because when doing trial fitting of the new CB pivot bolt ( 3/8 SS) I noted there was significant play of the bolt in its through-hole perhaps as much as 1-2 mm. Is that normal? I also note there were hard plastic spacers sealed with silicone against the nut and bolt head, no soft rubber seal here. A poor seal there would mean seawater entry around the bolt and into the CB and Keel casing - unseen because it would be below the fibreglass covering that area that acts as the bilge trough.

Should I make big changes to bolt size to remove play?
Is there supposed to be inner seals in seawater between CB case and CB cheeks? (Not according to picture from Andrew of fame: http://teria563.blogspot.com.au/2014/01 ... refit.html
Should the outer seals between face of hole and faces of nut and bolthead be soft rubber?
Is this play in the bolt and hole a good candidate as the culprit for seawater ingress below the fibreglass cap sitting on top of the keel and CB?

Any help is appreciated

Re: Water ingress top of keel

Posted: Fri Jan 22, 2016 9:39 pm
by atles
HI
some were round here their is a photo of it the bolt and the nut and sizes
but yes your right there are washers on the in side to stop the cb from moving around
but they are not to keep the waters out the inside one do that the bolt go in.

some of us put caps with silicon on top of the nut and bolt
too seal them up see if i can find a photo
regard atles

Re: Water ingress top of keel

Posted: Sat Jan 23, 2016 8:06 am
by Greg
I've had issues with moisture hiding inside the keel on my boat. A lot of it is addressed in these threads.

viewtopic.php?f=4&t=732

viewtopic.php?f=4&t=744

I ended up getting all the muck out, allowed the area to dry out over a few months, took it sailing a few times to make sure there was no water coming in then temporarily sealed over the top with plastic and silicone until i've got the time to pull the ingots out and fix it properly (Pictured here - https://www.facebook.com/photo.php?fbid ... =1&theater )

There is also this thread about getting the ingots out -

viewtopic.php?f=4&t=770

Re: Water ingress top of keel

Posted: Mon Jan 25, 2016 9:16 pm
by seanslife
Thanks Greg,
Pulling out the ingots? Boy, that sounds like an involved and dangerous task.

I sucked out the water today, I got about 600ml, so I'd say the cavity held about 1Lt of saltwater before I punctured the top and removed it.

I'll keep an eye on it for now and hope that by reseating skin fittings with new skaflex I have addressed the root cause.

Cheers
Sean