Self-inflatable floatation bags

[Joseph]

Seeing the inflatable tubes used to refloat the C22 made me wonder about the pertinence of having one or more self-inflatable floatation bags inside the cabin in order to provide floatation to boats without it (i.e., many CP's) in the event of a mishap. Does anyone know or use any of these devices?

J.

[NateD]

There was a little discussion about adding flotation over on the Trailer Sailor forum a few days ago:

http://bbs.trailersailor.com/forums/trailersailor/index.cgi/read/716815

One solution that was mentioned was making your own float bags to fill otherwise unused crevices on the boat.

http://yostwerks.com/FloatbagA.html

I think the best plan is to keep the water out in the first place. As soon as I start to get any kind of significant heal, the hatch board goes in and latched shut. I also have my life jacket on and waterproof VHF attached to my body. If the boat goes down, I know I will have positive buoyancy. If I were going to add more flotation, I would probably use tractor tire intertubes before I would try to make my own bags though.

[Craig Weis]

I for one realize that the Catalina 22 that swamped because the drop board was not in place was 'rescued' by having a inflatable bag placed beneath it's keel from the out side. I believe this rescue was infinitely more easy by the simple fact that this hull was fitted with a centerboard and not a 800 [C-P19] pound fixed keel on a 2000+ pound boat.

I'm thinking that almost every drop of water would need to be displaced by the inflatables inside my C-P 19 just to stay afloat and lastly I'm afraid that the deck to hull joint may fail and the deck be popped off by the bag floating and the boat sinking. I don't think I want to sacrifice the interior room to stow the inflatable bag.

Best not to get into the situation in the first place through careful and correct seamanship.

skip.

[Craig Weis]

Lifting 1600 pounds dry, [C-P 16] on three points is about 540 pounds per cleat and each cleat is placed within a plywood doubler fiberglassed into the inside of the deck and through bolted, that is maybe 6 inch by 6 inch, or 1/4 square foot, which means about 135 pounds per square foot. I think the deck will stay on given the circumference around the hull and a rivet ever three inches with 3-M 5200 adhesive/sealant.

Bare in mind that each through bolt is steel and the usual working load can be guessed at by knowing the dia or thickness in inches times 10,000 pounds divided by a safety factor of 4.

When I cut and welded up my sampson post I reused the fasteners and same holes. I'm guessing 4~1/4" bolts. Or 625 pounds per bolt [2,500 pound for 4; More then the whole boat weighs] before breaking. I'm thinking that is enough to tie her to the dock.

It's all about spreading out the weight.
We use to hang our 22 foot 7 inch, 1476 pound Star Boat by one bronze eye bolt bolted to 2 keel bolts via a strap when sticking her in the water from the trailer. We dry sailed her at Belmont Harbor, Chicago..

[Joseph]

With respect to cluttering the cabin, the question referred to some auto-inflatable device that would normally be deflated (a kind of inflatable bag similar to those in cars, only bigger). As for ripping the deck-hull joint I guess it is possible, but CP's (at least the SC's) have a screw every 3 inches of their toerail.

J. 

[mrb]

Having a pfd is not only a great Idea it is also the law.   If you really want a float bag do some searching on-line and You will probably find a company in Florida marketing one.

However do you all really think you need this kind of security blanket.  Just do what is proper and you will be OK.  Use drop boards, close and secure hatch when going gets rough. Shorten sail when needed,  not after.  ect.

I don't know about the 19's but my 16 is just not capable of carring the weight of all the safety gear some sailing rags would like me to have.


One of the sailing mags just ran a story about someones voyage and at the end they listed what was don right and what was done wrong.  On the right list they bought a large costly boat advertised one page 3.  Then they outfitted with at least two of every safety item advertised within the last two years.  Every radio, GPS, Spot, ARC, Narc, Farc and what all.   On the done wrong side was the bigest mistake ever.  THEY LEFT THE DDDDDDD IT"S JUST SO HORRIBLE I CAN'T SAY IT BUT IT STARTS WITH D AND HAS AN O, C AND K IN IT.

To end on the upbeat What a great day today was to be on the water.  Good winds, nice sun then a great row back to the dock.

[brackish]

My 23 with motor, anchors, chain, rode, batteries, and other various negative buoyancy stuff I'm carrying probably displaces 3600-3700 lbs.  So if it fills with water, I'm starting with a basic need of 60 cubic feet of flotation to get to neutral.  Subtract from that anything aboard that is neutral to positive such as wooden parts, foam cushions (providing they stay put) the cored part of the of the deck that have a positive core material and maybe you drop off 10 or 15 cubic feet.  That still leaves about 45 cubic feet of area required for a neutral condition.  Not sure I'm willing to give that up for permanently placed or inflatable flotation.  The calculation is simplified because the specific gravity and location of each component part has not been considered, however finding enough room to get to neutral is probably very difficult unless you have something that deploys full cabin.  Am I missing something here?

So, I have a Sterns 4000 auto/manual inflate very comfortable PFD with harness and D rings to attach my wichard one end quick release snap shackle the other end tether, and I use those items religiously when single handling or with inexperienced crew.  On the preventive side, I will install a single line reefing system that can be managed from the cockpit.  I plan to install mid boom sheeting with 6:1 purchase.  And I will put the drop boards in when conditions warrant. 

Oh and I will not let my boat insurance lapse.

Frank

[Craig Weis]

brackish  I might be wrong but I believe the Com-Pac 23 does not have a core in the deck. It's 100% resign impregnated once and ahalf woven cloth. Which is why our C-P's won't rot. And this is the only draw back to me owning a Canadian made 26 foot Hinterhoften Nonsuch sailboat with that giant cat rigged sail and wishbone boom. The on-end balsawood core in the deck and cabin. Yes I can say rot.
Bad enough we need to occasionally fix a plywood hard point buried in fiberglass on C-P's. skip.

[brackish]

Skip, My 23/IV is not cored with balsa or plywood fortunately, but when I made my cut for the nicro solar vent above the forepeak, that area had a polymer honeycomb core material between the glass layers.  Not sure how far it goes.  that material traps air and would create positive buoyancy.  Not unusual to use that type of material to attain high strength while maintaining low weight above the rotational axis.

Frank

[nies]

........A VERY LONG TIME AGO THE COM-PAC PEOPLE HAD A VIDEO OF A CP16 BEING PULLED OVER AT A DOCK TO SHOW THE SELF RIGHTING ABILITY OF THE CP16, IF ANYONE ELSE CAN CONFIRM I WOULD APPRECIATE , SO I CAN CONFIRM I AM NOT LOSING IT.........PHIL

[nies]

THANKS DAVID, I SEEM TO REMEMBER HUTCH BEING IN IT, THE GOOD NEWS IS I HAVENT LOST IT, THE KIDS WILL BE HAPPY ......PHIL

[Craig Weis]

When Hutchins' makes the epoxy to impregnate the glass cloth just like on R/C aeroplanes a product called 'Micro Balloons' is added to diplace the epoxy and lighten the mix. Micro Balloons are 'infused' [yes I watched shampoo commercials because I like the red head model used] with air.

I guess a product like you drilled through is also used. Palmer Johnson Yachts uses a 4' x 4' core board epoxy coated to make our 135 foot yachts, which being made of fiberglass actually weigh 20 to 30% more then our 150 foot, 104 ton, aluminum yachts. Glass is heavy. But can be made thin. It's amazing!


Here she is. Going from one assembly barn to the next door, all 135 foot of her. All core board and fiberglass on the way to be faired with 'All Grip' mud by a troop of Mexicians.

I once posted a April Fools Joke about Micro Balloons being filled with Hydrogen or Helium gas to lighten the load.
skip.