A question about flotation

[HankD]

How much flotation is enough to keep the weekenders gunwales above water? Currently i have 4 swimming pool noodles stuffed behind each seat back (8 total) but i can get a little more creative and add flotation to other parts of the boat if need be.

I'm gonna try to take some pictures tomorrow so i can share my project with you fine people. I keep meaning to take more pictures of the progress but i tend to just blow and go and not think much about that kind of thing. I have a few shots of the boat with one side on and no cabin roof/cockpit seats from last week and that's it . I started on April 14th and it's really blown by. Currently she sits with a solid hull, complete cabin, and the cockpit only lacks the seat backs. I hope to wrap up all the small jobs tomorrow so i can call in some reinforcement to help me flip this beast over Sunday. I can get her on her side alone but my building space is so tight there's no room to completely roll her over and i don't think i could do it without doing some damage to her anyway.

She'll be called the "Aurora Sing" and will hopefully be launched in June, at my current rate of progress it would be a little sooner but I blew all my epoxy/fiberglass money on a Nintendo Wii which has proved to be a major distraction. Sorry to ramble on, just wanted to share some details about my project and make an effort to contribute a little more to this community.

[RSdaCat]

Holly Moloy! Swimming pool noodles!!!??? What on earth made you think of that? :shock:

Ingenious!

It's like those silly plastic light toys you used to get from Disneyland as a kid..."oooh look the fibers carry light"...you always knew that could be applied somewhere else. The answer seemed just beyond our childhood reach.

Now! geeze.. multi-billion dollar telecommunications industry!

Noodles....y'all slay me!

And yet..if you see a crazy lady with an armfull of "closed cell positive floatation rods" in front of you at target, you might just want to say Hiya!

Awesome!

See ya later...I'm getting some before the industry catches on and they go from 87 cents to 8 bucks a pop!

[HankD]

Holly Moloy! Swimming pool noodles!!!??? What on earth made you think of that?

Hehe, well i can't take credit for that, i read where several people here did it and decided to take that route myself. I also read about someone using the closed cell raft things to line the bottom of the cabin adding more comfort and flotation. I thought that was a really good idea but when i picked up the noodles the only ones i saw were 45 bucks a peice...so i'm looking for a cheaper solution. Sorry i don't remember who to give credit for either of those to but hopefully they'll come comment and recieve their well deserved credit.

Here is a few pictures of my project as it sits right now, you'll probably get a good chuckle out of my building space...but i gotta work with what i got:P.

[Frank Hagan]

Hehe' date=' well i can't take credit for that, i read where several people here did it and decided to take that route myself. I also read about someone using the closed cell raft things to line the bottom of the cabin adding more comfort and flotation. I thought that was a really good idea but when i picked up the noodles the only ones i saw were 45 bucks a peice...so i'm looking for a cheaper solution. Sorry i don't remember who to give credit for either of those to but hopefully they'll come comment and recieve their well deserved credit.

[/quote']

I used solid styrofoam blocks I bought from a plastics place, but that did cost a bit. I like the pool noodle idea a lot!

The flotation you have is in the right place ... up high. The only other place I considered putting more flotation was inside the cabin, under the side deck and forecastle areas ... I thought about putting another 2" under the side decks and then skinning it with doorskin or 1/4" ply to trim it out. In the forecastle, I was going to line the top of the compartment and then trim it out.

I have read that one of the best ways to prevent a boat from going turtle is to have some flotation in the mast, especially at the tip.

[HankD]

Thanks for the advice, I like the idea of flotation under the deck in the cabin, I'm really just aiming for enough to keep the boat bailable in the event of a capsize. I've lived on the water all my life and spent alot of time in "stinkpots" but have never stepped foot in a sailboat . So I'm trying to prepare for what is likely an innevitable capsize somewhere along the learning experience.

I also like the idea of floatation in the mast I'm still debating on my mast building method, it'll either be two 2x4's laminated together or possibly a birdsmouth mast. A straight 16 ft. 4x4 isn't an option, the only thing readily available around here is pressure treated pine and it's impossible to find one straight with no splits or twist. If i go with a birdsmouth mast i think i could easily shave down a noodle to stick in it, the hole through the noodle would still allow room for any wiring. I've seen a few post by Mr. Riccelli saying the first order of business in a capsize is to tie a PFD to the mast to keep her from turtleing so some permanant floatation in the mast might put my mind to ease a bit.

[JeffM]

I vote for sealed chambers, too, since they double as storage space--good to have in a little boat. Having said that, hatches can be forgotten or leak and air spaces can be breached. I have a little of both on my Core Sound. I did the math on one type of pool noodle a year ago: find the volume of the noodle by finding the area of one end (pi r2) and multiply by length. Do it all in feet and you'll end up with an answer in cubic feet. Salt water supports some 65lb per cubic foot. If I recall, the pool noodle I was doing the math on would support about 9lb. I was tying it to the masthead to prepare for a trip in blue water, and figured it would keep me from going belly up in a capsize. (Fortunately never needed to find out.)

[PAR]

If you install 10' of 4" thick x 6" wide, low density, closed cell foam, under each side deck, then you'll have about 750 pounds of floatation, which is enough to keep a Weekender floating. This is about 12 cu. ft. of foam.

In reality, air bubbles will be trapped in several places aboard, so she'll float higher then the number crunching will indicate. Placing foam low in the hull is never wise. You can actually make the hull more stabile inverted. Cockpit sides, under decks, cabin roofs and under side decks are the best locations. The fore peak, aft deck spaces, storage lockers and cabin will trap enough air to keep her afloat, with the additional floatation keeping her from sinking to fast, or too low on her side to right her after a capsize.

[PAR]

If stability is to remain positive in the event of a capsize, (the boat is lying on it's side) the CG must stay below the CB. There's no debate to this. It's then necessary to have the buoyancy (floatation) as high as possible in small craft. This is simply because small boats have a relatively high CG, which forces the buoyancy to be placed immediately under decks, though you'll likely have pretty low freeboard when swamped (like after a capsize), but you can bail when swamped.

The main considerations in properly placing floatation are: to provide adequate freeboard when swamped, reasonable fore and aft trim when capsized and the ability to have the crew, which is holding onto toe rails and comings not upset or sink the boat further (in fact it should still have a postive righting moment). A swamped boat may require twice the displaced volume to maintain reasonable freeboard. If the floatation is too low in a swamped small boat, rolling motions causes by several possible reasons, can cause the righting couple to go negative (beyond a certain angle the CB can't compensate for gravity, a moment is formed and a capsize will occur).

[MikeStevenson]

Well Hank, it's not anywhere near as bad as some of the spots we've built! And I think the Noodles are a clever idea, if a bit small.

Mike

[HankD]

Just wanted to say thanks for all the valuable info, that's why i love coming here. I haven't decided which route i'll take and since it looks like lotsa overtime at work this week and going out of town for a friends wedding this weekend, i have some time to mull it over.

Oh, and thanks to Mr. Stevenson for making me feel a little better about my building space .

[Andrew_Butchart]

I remember Adam Plourde did a capsize test a number of years ago and was quite happy with the result.

Has anyone else tried it? I know that one of the experiments I'm planning on is to pull my cockpit drain plug to see where the boat ends up settling.

[cs]

Just wanted to add here. As you may know I receantly had an "experiance" with the weekender. I wish I had some floatation built in.

Two things for you. If and when you go over I found that once the cabin fills with water the weekender floats with the decks about an inch or two below the level of the lake water.

The other is that with it full of water you may find that you can't get it stand back up. You may get the mast pointed straight up in the air, but as soon as you let go of the boat it will lay back down.

You will find the need to drive it as far up on shore as you can so as to get it sitting on bottom, thus forcing the decks above the water level and making the boat sit up.

Chad

[Andrew_Butchart]

I think that I'll need to cut a hatch into each of the "behind the seat" chambers and fill them with pool noodles and also do something in the forepeak.

I was spoiled by the MiniCup. When it capsized, it would float on it's side in about 5" of water - not enough to fill the cockpit. The only scary time I had with it was when I was sailing in larger confused waves that kept spilling into the cockpit. I always imagined that the Weekender would be similar in that floating on it's side that the water wouldn't be up very high on it. I can see how the cabin could trap a lot of water though. I wonder what could be done to have that drain as the boat rights itself?

With all the "propeller heads" out there, does someone have one of those computer programs that will actually tell us how deep the boat should float on it's side both with and without the cabin filled with water?

[JeffM]

A lot of builders here use expanding foam. I wonder if you wouldn't get more buoyancy from it since it would exclude water more effectively than round pool noodles. (Can't completely fill a space with round objects.) The drawback is that you can't remove foam for inspection, etc., but since it would be well above the water line, maybe that wouldn't be as much an issue.

[ken connors]

I started saving empty gallon milk jugs a few months before i started putting the seats in. Ive got about two dozen jugs crammed in behind each seat with the caps hot glued on. I keep two super size fenders in the front hatch area and make sure the hatch is locked up after I use it so they dont pop out in an emergency. This is on a Vacationer.

[Ken_Potts]

I collected 2 and 3-liter soda bottles and stuffed them into my kayak way up front and way out back. I had 30 liters of flotation in that little boat. The only thing I didn't like about that solution was as the day was heating up or cooling down I would occasionally hear a "pop" as the pressure changed in the bottles and they flexed.

The occasional pop was a very small price to pay for the peace of mind from the flotation