sealed floatation tanks

[Charlie Jones]

Just made an interesting discovery. My Sharpie, Traveler was built with a sealed tank in the stern, of about 4 -6 cubic feet. Since I have converted the boat to a trimaran, that tank is no longer quite as important as floatation, and becomes more attractive as stowage. So I'm adding a hatch in the deck, which will still keep it fairly watertight, but allow access.

Traveler has bee stored in a shed for the last three years, unused, and when I cut into the deck, I was quite surprised to find several pints of water in there. This in a chamber carefully epoxy coated when I built the boat. I expected total dust.

I figure it to have come from condensation, since it's been dry stored for 3 years.

Point is-I'd advise having some sort of access opening in sealed wooden tanks, to allow air in the when the boat is unused- small effort to avoid rot inside sealed sections. Deck plates, whatever.

[brigait1]

Hi Charlie, yeah I have been wondering about that myself. It seems like completely sealed tanks present a couple potential problems. Condensation is one. The other is the potential to pop a seam when we have those sudden 40 degree temperatures swings that we get once or twice a year. I think the inspection hatch is a good idea. And if you are especially worried about positive flotation on longer expeditions you can always stuff the compartment with one of those flotation bags like they use in Optis.

Pete

[Charlie Jones]

Hi Pete- you doing the 200 this year? Don't see your name on the list.

[Tom Lathrop]

Charlie,

I don't know how the water got in your tank but condensation it ain't. In order for water to condense (meaning it condenses out of the air when the conditions pass the dew point on a surface), it has to have already been there. I have had experience with water vapor passing through a shell and collecting in a "sealed" space due to temperature/pressure cycles but not ever in the volume you find. Look for the obvious leaks because there is at least one for sure. Still, inspection ports as well as drain outlets in air tanks make sense. Ports should also be left open when the boat is under cover.

All this "expertise" reminds me that I have not yet folowed my own advice on Lapwing. Intended to do that but have not gotten to it yet.

[Charlie Jones]

I suppose so Tom, but the last time this boat got capsized was about 7-8 years ago. Really can't figure it out. It was sailed in the Tex200 in 2008, again in 2009, then stored. So if it leaked in, had to be 7 or 8 years ago. Sure surprised me to find it.

But for sure I'll never have another "sealed" space I can't air out.

Edited-

Thinking back, that one capsize was the ONLY time this boat has been over since being built, back in 2002. We did that on purpose to see how it self rescued, and found it didn't. That's when we first started making mods, and a few years later, Laura suggested the tri modification. So it beats me. But now I can dry it out

[hokeyhydro]

"sealed" is right up there with "encapsulated." It could happen, with numerous coats of epoxy, but that only works if you never get that wild eye look and holler, "Hey y`all, watch this!" as you drive your rig through mondo seas and cause a itty bitty crack.

For "sealed" compartments I go with a minimum of a drain bung and prefer an access hatch so I can use the air space for storage. And of course, ventilation.

[Charlie Jones]

ME?? Get a wild eyed look? On a 14+ knot boat? Not me

This chamber was VERY well sealed, because when the boat was built it was a primary flotation tank, and the boat NEEDED it. NOW it's a trimaran, and the tank isn't nearly as critical, which is why it's now a stowage area-Nee - floatation chamber. Already added a new watertight box as stowage/floatation up in the bow. Cause it was critical- couldn't bail the boat after a capsize as designed, so unless you were in stand up depths, you needed help rescuing- much like the SeaPearls are.

It just really surprised me to find THAT much water, after the boat had only been sailed twice in 5 years, and was stored under cover.

[Tom Lathrop]

ME?? Get a wild eyed look? On a 14+ knot boat? Not me

This chamber was VERY well sealed, because when the boat was built it was a primary flotation tank, and the boat NEEDED it. NOW it's a trimaran, and the tank isn't nearly as critical, which is why it's now a stowage area-Nee - floatation chamber. Already added a new watertight box as stowage/floatation up in the bow. Cause it was critical- couldn't bail the boat after a capsize as designed, so unless you were in stand up depths, you needed help rescuing- much like the SeaPearls are.

It just really surprised me to find THAT much water, after the boat had only been sailed twice in 5 years, and was stored under cover.

I used to race a lot on the boat that the hull of your boat was an outgrowth of. Early capsizes called for tossing the anchor and bailing with a bucket while in the water hanging on to the side until the water level was low enough fro one crew to get back in and continue bailing. this quickly led to side air tanks and eventually to full and very quick self rescue to continue the race.

Finding that much water in there after 5 years only shows that you did a good job of sealing

[Charlie Jones]

LOL- Yeah- I spent an afternoon with John Harris at CLC, talking about this and that. He told me about the origins of the design, and no longer sells the kits, nor does he push the design. A little too HOT for many, so he deemed it wisest to let it fade.

Nice guy. Interesting place.

He knew me by name as the person who turned it into a trimaran, and was sorta pleased it was a great boat.

[Scott Dunsworth]

I built a Penobscot 14 back in 2000 , the plans called for an inspection port in the stern and bow seat. The only time I would get water in the tanks would be if it rained or I washed the boat out. Obvious I had an inside leak to my tanks somewhere. I could never locate them.

I always left the ports open when stored as the designer suggested.

This boat would swamp if you ever capsized it. The flotation was enough to just have the centerboard trunk at water level. I test capsized it once and thought man I hope this doesn't happen out on the water. If I couldn't stand up and bail her out the only other option was to stuff rags in the centerboard case to slow the water form entering while I bailed her out.

If I would have kept her I would have added some 1 1/2 inch blue board under the side seats and the center one.

Inspection ports are the way to go if possible. I put one in my Belhaven cabin, where I could see what was going on under the cockpit also. I have put them in the spindrifts also. Not because I had foresight, but just because stuff always seems to happen to me.

[brigait1]

Charlie, I'm not going to make the Texas 200 this year. I've got way too many irons in the fire right now. But I'd like to take Goodfoot down your way some time in the fall for a run out to Army Hole for the weekend. I'll keep ya posted on those plans.

[Charlie Jones]

Git'r'done and bring her on down. I'll launch Necessity and we'll have a cruise