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Floatation

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After reading Garrett6575's topic about pool noodles, I was temped to put my two cents in regarding another idea for floatation. I started a new topic though because this really has nothing to do with the noodle-securing question...

 

sqare_nails and I were brainstorming an alternative to a float bag. Mainly to reduce the over-all cost of the kayak and retain a float-bag's efficiency.

 

Pool noodles are a very practical idea; very cheap and replaceable. I find that pool-noodle-foam does not have as much buoyancy as other foams. You might need a lot of them inorder to get the water displacement and floatation considered desirable. This, of course, uses up stowage space.

 

Personally, I would want more efficient floatation inorder to free-up space for camping gear.

 

We figured that a home-sewn mesh bag, made into the shape of a cone, could be filled with ultra-light plastic balls. It would conform to the kayak's shape when winched up to the stems. It would be removable just like a float bag and you wouldn't have any worries of it developing a leak over time. After all, with 100 to 1000 balls per bag, you have what I think they call... redundancy?

 

I'm guessing a ball-bag would be lighter and more buoyant than noodles. The only problem is, buying ping-pong balls in bulk has proven to be more expensive than we thought. Small water bottles might be a more economical option.

 

A cooky idea?  Maybe.

 

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Ping pong balls sound like a good answer as long as the question is “What is an alternative method of adding buoyancy to my kayak?”.It may not be so good if the question is “How can I reduce the amount of water in my kayak in the event of a capsize?”Certainly the 2 are related but the big problem with rescues is not making sure the kayak stays at the surface but in handling the weight of the water filled hull initially and then removing the water once the paddler is back in the saddle. As far as I know most kayak hulls will float when full unless loaded with gear that is denser than water. Even a plastic kayak hull should float as the plastic has a specific gravity slightly less than 1.So what’s the problem with the ping pong balls? It’s the spherical shape that means when a heap of them are in contact there is always a significant volume of air gap (or water gap if submerged). If you draw a number of same size circles touching each other you can see the 2 dimensional spaces between them. In 3D there is even more open volume than implied by the 2d image.A single large object will always be more efficient at occupying volume so for this aspect solid pool noodles should be a bit better than the balls and the float bag will be best. Of course this is all subject to each method being applied as well as possible, and especially having the right size in the case of float bags.Having said all this I do believe that on a river or lake not too far from land then any form of volume occupier will make reaching shore easier and should be good enough. In these cases go for the balls, plastic bottles or wine cask bladders (these are popular in Aus).Large lakes and the sea are a different bucket of trout.

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It may not be so good if the question is “How can I reduce the amount of water in my kayak in the event of a capsize?”

 

EXACTLY! I think most are thinking of keeping the boat floating and not safety. I am afraid most paddlers, probably the vast majority have never practiced any re-entry skills and have no idea just how much water gets in a kayak. The only real reason for float bags is keep as much water as possible out of the boat in a capsize. NOTHING is going to beat a bag that will fill most of the nooks and crannies and with a Fuselage Frame boat. Even that leaves a huge amount of water in the boat.

 

3 or 4 inches of water in the bottom of a boat can make it extremely unstable. As you rock the boat and that water starts to slosh to one side, all that weight can roll you right over. If you haven't experienced it I HIGHLY recommend going to a shallow spot and trying it.  Then move on to learning how to get the boat empty enough to get back in.

 

Secondly, making float bags isn't  hard or expensive. Ton Yost has come up a good way to make them for a few bucks. The only thing I don't like isn't they are not very durable so I have been playing with heat sealing nylon instead of vinyl. It's more expensive but it is still very reasonable. And what is safety worth??

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Thank-you labrat and Jeff for your knowledgable comments. From reading previous postings from Jeff and others, I was aware of the safety reasons for displacing as much space as possible with floatation inside the kayak. However, both of you here, have convinced me that a proper float bag is worth buying. Also, I figure that by time I have made something comparable, I have spent more time and money than necessary.

 

I am still confused however, as to just how large of a float-bag is practical. Here's what I mean:

 

-Skinboats.org sells Greenland Float Bags that are 23" wide x 57" long. One of these bags in each end of the kayak would certainly fill most of the hull except for the cockpit. If you want stowage, they have a combination float-bag which has a compartment for your gear. I imagine though, that building a hatch in your kayak would be pointless because access to your gear could only be from the front of the bag, through the cockpit.

(This sounds inconveinient to me)

 

-MEC.com sell float bags that are about 30" long. These would tuck up nicely in the bow and stern and leave room for your gear. But, they would not displace much water in the event of a capsize.

(This sounds like a possible comprimise)

 

I'm brand new at this of course, so I have no idea what kayakers prefer. Please chime in everyone...

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Here's an example that might be useful. I have a Ravenswood boat (15.5' x 24"). I've installed a NRS split kayak stern float bag (13" x 33.5") in the bow and a Skin Boat Greenland float bag (23" x 57") in the stern. The bag in the bow is smaller to leave room for my feet. BTW, I'm 5'-11" and 185 pounds. I've practiced wet exits with paddle-float rescues in calm water and this works OK. After getting back in the boat, it takes a while to pump the water out of the boat so as to reestablish reasonable stability. However, if there was any significant chop, I believe that the coaming would be too low to prevent water from swamping the boat while my weight was on the rear deck during reentry. This additional water would make the boat very unstable. So, I don't feel that I can reliably self rescue in rough conditions even with float bags fore and aft.

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I did a little arithmetic and found that a bundle of pool noodles displaces about 77% of the water in a compartment filled with them. Ping pong balls displace about 53% of the water in a compartment filled with them. I'm not an arithmetologist, so please check and correct me if I've missed something here.

 

The point is that when you lay cylinders along side one another, there's a lot of space in the "corners" around them. Pool noodles also have a hole down the middle that will hold water. A bundle of spheres has even more volume in the "corners" which can hold water.

 

Float bags kinda-sorta flex around the frames and stringers to fill more of the volume inside the boat than is possible with the more rigid pool noodles or ping pong balls. I don't know how many ping pong balls it takes to fill the bow or stern of a kayak, but I doubt they would less than the cost of building a float bag, and you'd still have to do a bit of work to contain them. Pool noodles would also take some work and would certainly not be free.

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As for size you just need to measure you boat. I made a set from heat sealing nylon. Measure around the boat and the length, made a sketch to get in my mind what I needed.  If you buying just buy the closest to the size you need. If I could find a used commercial heat sealing machine reasonable I would start making them.

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Another strategy to be used with flotation is the use of a "sea sock", a big "bag", which slides into the fuselage and is held to the cross sections with Velcro tabs or ties. The opening of the sea sock has a bungee in it which then goes over the lip of your coaming. The paddler slides into the sea sock to paddle. This keeps any water from a wet exit contained mostly to the sea sock. If you look through the back issues of the QajaqUSA's online newsletter called The Masik, there are plans for making a sea sock, or just google it if you're having a hard time picturing it. I'm currently making one but don't have any good pics of it.

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Hi Matt,

Just wondering if you have any updates on your sea sock. I've been looking into it lately and can't find any information on construction outside the ones you have given. Seems like a good think to talk about with the float bags now being built for Kudzu craft kayaks.

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Hi Matt,

Just wondering if you have any updates on your sea sock. I've been looking into it lately and can't find any information on construction outside the ones you have given. Seems like a good think to talk about with the float bags now being built for Kudzu craft kayaks.

 

 

Unfortunately I haven't made any progress on the sea sock.  I used cardboard, a big garbage bag, and duct tape to create a mock up of the sock.  Once I put the garbage bag into the cockpit, I used duct tape to create a fuselage shaped bag, tucking in all of the extra material.  Once the "bag template" was made, I took it out of my frame, and cut it down the middle to make a 2D template to be applied to the coated nylon fabric that I purchased for it.  That's as far as I've gotten......I've built 3 more SOFs since starting the sea sock and haven't finished the sock....I should be ashamed of my boat building addiction :D

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I too am anxious to see your sock.... that sounds kind of weird.  :wacko:

 

I have read everything I can on sea socks and thought about making one too. My concern is getting a foot stuck in the sock. I know they have to be tied to the frame to keep it from collapsing. Working on my roll and I got twisted and foot stuck. That was rather spooky but easy enough to get free.

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I used pool noodles along with foam pipe insulation to super insulate some water pipes before, as I recall, the pipe insulation for 1/2 " pipe fits inside a pool noodle tightly, so, if you are going to use pool noodles you may want to try filling the hole with pipe insulstion which would greatly lessen the amount of water inside., you would only have about a 1/2" diameter hole down the center. Now that i think about it, you probably would have less beccause of no pipe, the insulation could be sliced and made to collapse on itself. Just thinking out loud.

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I saw a write up (no pics) somewhere, but cant find it now, where a guy said he made float bags from the legs of XL heavy PVC rain pants, interesting idea, not sure the diameter would be enough at the wide end though.

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There are a lot of ways to flotation a kayak.  But properly flotation limits as much water as possible from entering the boat. It's not just about keeping the boat floating, the wood will do that most likely. Flotation is about keeping the water out so you can get back in. Less water in means less water you have to get out. It's all about safety and being able to empty and right the boat and then get back in.

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I'm glad to see that Jeff has developed a line of float bags for his designs. I imagine that it would take some special equipment to make them and probably not worth the money for just making one or two sets. The learning curve required to work with sealing the plastic might not be worth it either.

 

Way to go Jeff :)

 

I'm curious to know what people's experience is with Kudzu Float Bags. How durable are they? How long do they last?

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I'm curious to know what people's experience is with Kudzu Float Bags. How durable are they? How long do they last?

 

 

I was waiting to see if anyone else chimed in, but they are so new your going to be  hard pressed to get an informed answer.

 

Anything I say is suspect as Sales Talk but..... 

They are made from a medical grade nylon, not plastic sheeting. This is a high quality material and not the cheap heat seal nylon you see online. It is not air tight by the way, I tried it. One bag will work and next one will leak for no apparent reason. Seams fail on one bag and the next is perfect.  So far I have not had a single issue with the fabric I am using.

 

Seams are welded in my shop and I guarantee the seams for one year. If they fail, I will repair of replace it. 

 

Being a nylon fabric of good quality I expect a long life from them but only time will tell. But with normal use there should be practically no wear on the outside of the fabric. Kept out of the sun they should last many years.

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The only feedback I have is they were used every day for a week (inflated before going out on the lake and the valve opened when putting it away, they performed as expected.  They felt heavy duty to me.  I stuck a nail into the end of a broom handle and used that to push the airbags up into the bow and stern as far as they could go (they come with grommets pre-installed in the ends for this purpose). 

 

My wife complained a bit that she had to manually inflate them, but that only lasted a day and is no reflection on the quality of the bags :)

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I bought three sets of float bags from Jeff recently. I thought about how I would fashion then myself and hashed through a lot of ideas

on how to make something better, cheaper etc.. in the long run Jeff's fit perfectly they fill the entire void, he did all the research and calculations and assumed all the expense for the equipment, i don't regret my purchase. Of the six float bags only one is losing a little air but that is only noticeable after two or three days.

I try to remember to deflate them after each use so a slow leak really doesn't matter. I will buy them from Jeff in the future.  Now lets see, how to make them self inflating?

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My husband was thinking of making me float bags out of Truck Tarp material, the really thick stuff. He has the equipment to do it at his work. Would this work?? 

 

Lisa.

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