Small floatation chamber ventilation

[L.W. Baxter]

I'm about ready to apply paint and varnish to my light batteau, but have one issue left to resolve.

Gardner calls for styrofoam packed into the ends for floatation, but I went for air tight compartments. Here is a picture of one before I put the lid on it:

http://www.imagestation.com/picture/sraid161/p34b7621800446d323a5760b2bd9fe13a/f4d089b9.jpg

You can see a little square of plywood glued onto the back of the bulkhead down at the bottom. I had thought to install a plug, like a baitwell or drain plug, through the plywood there, to alleviate "oil canning", and to provide air circulation when the boat is not in use.

Like this:

http://www.imagestation.com/picture/sraid163/p86dde5b947c37e8c5350eecdda21bfa1/f494d5b4.jpg

In this location:

http://www.imagestation.com/picture/sraid161/p96b53efc510bf78b6c00066f2e269645/f4c554f7.jpg

But now that it comes to it, I'm not sure it's such a hot idea. Might be more likely to introduce water where it will be difficult to drain or dry out.

I didn't want one of those fist sized plastic vents.

So what do we think? On a chamber this size, can I just do away with any sort of vent hole? Should I go ahead with the small plug? Or do I need to install a regulation inspection plug/port?

Thanks, Lee

[mmd]

No compartment should be permanently closed up - it'll become a rank, smelly, rot-pocket in short order. I would initially reccommend one of those "fist sized plastic vents", but since you don't like 'em, ponder this option:

Install the transom stopper you have shown in your photos, and install a fuel vent fitting on the deck at the far forward end away from the bulkhead, facing aft. If you play regularly in waters rough enough that water entry becomes a problem, mount the vent facing forward and cover it with one of hose little clamshell cowls that are used to shield below-deck line entrances. When the boat is not in use, open the stopper to allow air to circulate.

[Venchka]

...and every once in awhile stick the suction end of the Shop-Vac over the stopper hole to suck clean, dry air through the compartment.

Wayne
In the Swamp. :D

[Gary E]

How about a cantalope size ball, cut a hole to suit that and when needed stuff the ball in there, when the dog wants to play, ya got a ball handy.

If you really need floatation why not styrofoam under a seat open at the bottom, so ya dont see the foam and it's open to the air.

[dmede]

epoxy seal the inner surfaces then pour in some expandable foam to fill the void. That should reduce the effects of thermal expansion from air.

you could also make your own wood hatches for that space if you wanted to be able to use it for storage but dont want to use a plastic hatch. Harry Bryan has some details for a pretty simple water tight hatch in his Fiddlehead plans. It could be scaled down to use in your space.

[ 04-04-2005, 06:19 PM: Message edited by: dmede ]

[Bill Childs]

I love the cantelope size ball idea - simplicity, ahh. Short of that I would use a 5-6" dia waterproof inspection cover so you can stuff your camera and a pbj in there and make good use of the space and still have flotation.
I can't stand the thought of foam in a sealed-off compartment. It's Trouble with a capital T that stands for you and me - or something like that.

Bill

[almeyer]

Lee,
My Penobscot 14 has two supposedly watertight floatation compartments, with access hatches to allow for air circulation when not in use. Allowing air circulation is a very good idea, given the hot and humid environment down here. But if I were to do it over again, I think I'd prefer making the bulkhead solid, the top decking removable, and stuffing the interior with pool noodles, buoyancy bags or whatever that could be removed and installed at will.
Just my thoughts,
Al

[Steve Lansdowne]

I've seen some kayak hatches of wood that are secured to the space below using bungee cords. These can be large enough to allow use for storage if you want, or to air out the compartment if needed. If you carefully cut the hatch out of the existing end of the compartment, you can re-use it for a cover. You would need to install a gasket between the cover and an interior lip. This fellow also added a slight recess to allow him to pry off the cover using his finger. A small exterior handle could also be fitted. Here's the idea:'

http://www.imagestation.com/picture/sraid152/pe14b84e1f554e00783c3b91e2ad247aa/f5b20365.jpg

This particular arrangement allows each bungee to be detached from one hook to allow access but each bungee is also permanently attached to the other location so that the hatch can't fly off.

[ 04-04-2005, 10:25 PM: Message edited by: Steve Lansdowne ]

[L.W. Baxter]

Okay, I kinda figured as much, my idea of just covering it with paint was wishful thinking. I'm going to make some sort of custom hatch, probably on the bulkhead, we'll see how the spirit moves me when I've got the keyhole saw in hand.

Too bad I didn't decide on it earlier, it will be fiddlier now with deck and coaming in place. Live and learn.

Thanks for the advice and ideas.