10ft flatbottom aluminum jon boat

Discussion in 'Stability' started by tony1177, Apr 25, 2010.

  1. tony1177
    Joined: Apr 2010
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    Location: RI

    tony1177 New Member

    i know this has probably been answered many times allready but ive been goin thru alot of posts and cant find it. i have a flatbottom john boat, its nice for the shallow ponds out here in RI but its very rocky back and forth. whats a good way of stabilizing it so it wont rock as much or make aliitle more stabile. i dont know if theres bolt on's or maybe somethiing i can make just to feel a litttle more secure and i wont have to worry about sneezing and tippin it over.. hahaha
     
  2. Squidly-Diddly
    Joined: Sep 2007
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    Squidly-Diddly Senior Member

    tie a pair of oars at the stern outside corners and tie the

    handles together above the out-board so that the paddles are in the water with flatsides "flat".

    that way you aren't hauling all sorts of extra gear that isn't used otherwise and just using your backup oars you already have, just adding a few short lengths of rope.

    I suppose you could make a couple of little brackets to hold the ends of the oars if tying them together amidships doesn't want to work, and just add a pair of oarlocks as close to transom as practical. Or mount the oar locks wherever on the boat where the handles wont be in the way when fishing. Instead of 'rope' maybe a length of old bike inner tube to wrap the handles together for the gripping friction of the rubber on wood.

    that is sort of how rowers stabilize those skinny 'shell' boats if it gets too rough or a big wake is coming and it works great.

    You shouldn't need to add any extra flotation or ballast, just some 'damping'.
     
  3. Squidly-Diddly
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    Squidly-Diddly Senior Member

    or tie a couple of big ice-chests to the sides, but you would

    need someway of keeping them from flopping to get the most stability.

    Maybe if placed at transom a bar could be installed that would be too much in the way.
     
  4. messabout
    Joined: Jan 2006
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    messabout Senior Member

    Tony; Your boat is not wide enough. I know that is too simple an answer. What to do about it? There is a remarkable difference in the percieved stability of small boat when the weight of the occupant is lowered. For your purposes that means definitely NOT having one of those tall swivel seat things that so many fishermen use. Let us say that some nincompoop power boater has created a big wake that is going to hit your boat. Sit immediately on the floor. You'll probably survive.

    You can increase the initial stability a comforting amount by adding sponsons to each side of the boat. Build a box about 5 or 6 inches wide and as tall as the gunnels on your boat. Finish the ends in the same shape and with the same curve as the boat bottom. Attach them firmly to each side of the boat. Of course the sponsons must be waterproof. You can deck them if you like, I would. That or something similar is about the only hope of making the little boat more steady.
     
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  5. pistnbroke
    Joined: Jan 2009
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    pistnbroke I try

    before we say anything how wide is the boat at the waterline?
     
    Last edited: May 8, 2010
  6. Ike
    Joined: Apr 2006
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    Location: Washington

    Ike Senior Member

    Jon boats are ideal for what they were originally built and intended for, flat calm waters, or what folks in the south call bayous. Actually, if this jon boat (we need pics) has a lot of tumble home, that is, the sides slope a lot, then the boat has what is called reserve stability. That is, as it leans farther it gets harder to lean over. This is typical of jon boats. It also allows them to carry large loads (like cat fish and alligators) and still navigate very shallow water. Also they are inexpensive to build and so cost less than a regular boat of comparable size.

    The unfortunate result is a lot of people buy them and use them for purposes they were never intended for, like open water (I've even seen them going out inlets into the ocean, with breakers ) This has resulted in a lot of unfortunate accidents.

    As was said, keep the weight low. Sit in the bottom if necessary. Don't take them where they don't belong.

    Yes, you can fit them with outriggers, or sponsons, to make them more stable. This has been done with lots of narrow shallow boats, such as canoes and kayaks,. A trimaran is just that, a narrow boat with two outriggers. If you google outriggers you may find some, they are called amas on trimarans and proas. But you'll also find a lot of offshore fishing gear.

    Good luck
     
  7. cummingknives
    Joined: May 2010
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    Location: Cedar Crest

    cummingknives cummingknives

    Jon boat stability problem

    The major problem with a short jon boat is that they aren't very wide. The suggestion to lower the center of gravity by sitting on the bottom is good, but it assumes that you'll continue to utilize the boat as-is. There's myriad solutions to your dilemma, but one that I saw in Bali, Indonesia works wonders on boats that can easily capsize. Slender shallow-draft power and sail craft in that part of the world employ outriggers, much like those seen in Hawaii.

    The Indonesian versions include a pair of long, lightweight booms that extend out over the gunwales some 2 or 3 meters (depending on length of the boat), connected by means of a length of 4-inch diameter Schedule 40 PVC that run parallel to the boat itself. The tubes are bolted to the outrigger booms by means of U-bolt clamp systems, like a muffler is connected to an exhaust pipe, and each outrigger boom is strongly fastened to the gunwales on both sides. Booms are 1-piece and sag so that the bottom of the outrigger is actually about level with the waterline of the boat itself, thus keeping the boat upright at rest.

    You could install a similar system on the stern of your jon boat by clamping a section of 2.5" pvc pipe across the transom (or perhaps slightly forward of the transom if you plan use a small outboard or battery-powered trolling motor), and slide in the outrigger boom that is held in place by thru-bolts slightly outboard of the gunwales. By connecting larger diameter tubes fitted to the boom by means of a T fitting, a greater level of stability is possible. And if you rigged one per side, even greater stability would result.

    Despite the fact that it will work, you'd still have a 10' jon boat that is inherently unstable regardless the imagination necessary to overcome a fundamental law of nature that will, if Murphy takes a look at this Rube Goldberg contraptiion, likely fail when you most need it. An event such as this could be catastrophic if not deadly, so I suggest that you don't do it and instead buy a bigger Jon boat and keep the 10-footer as a tender.

    Bear in mind that there is no substitute for superior intelligence, and that the above is only one of many possibilities that will help to get the most out of a boat you really don't need. On the other hand, if you enjoy taking an idea and maximizing its effectiveness, by all means give it a shot. The worst that can happen is that you'll drive up the stock price at Home Depot or Lowe's, and you'll get lots of attention at the marina. It might even be cheaper to fly out to Bali for a vacation where you'll see few if any marine insurance agencies, but plenty of outrigger boats.

    cheers!!
     
  8. pistnbroke
    Joined: Jan 2009
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    Location: Noosa.Australia where god kissed the earth.

    pistnbroke I try

    as we dont seem to be going to get any measurement or photos I suggest you cut it from end to end and weld in a plate 12 inches wide or whatever is necccessary to increase the beam at the chines to about 48 inches
     
  9. cummingknives
    Joined: May 2010
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    cummingknives cummingknives

    Increasing beam

    To increase Jim's beam, you must raise voltage to something approaching the hypotenuse of the colon multipled by Pi plus 21. This will maintain proportion assuming that LOA is increased by the max factor. Absent that, a recommendation to ignore the adage that bigger is not always better is better than maintaining the status quo vadis (at) infinitum post partum on Tucumcari Beach.

    The lesson here is that gobbeldy-gook is one way to kill a day doing something constructive, like suggesting that a 10' Jon boat is not the best way to get around on water if you plan on hanging a V-4 or straight-6 on the back of it and expect it to go anywhere except down.

    Donate the Jon boat and take the tax deduction, then get yourself a proper and infinitely safer boat that has some freeboard, some beam across her hips, and the right length consistent to enjoying that which we all too often ignore, e.g., the water, and that which lurks beneath its surface. A bad day fishing is better than just about everything else with the possible exception of simply messin' around in boats.
     

  10. WickedGood

    WickedGood Guest

    Canterleverd hyperbolic distrubanic is the limiting facor on Jon Boat disign.

    When one extrapilates the lenght of the waterline by the beam of the dreadge you will find the parobolic Rhumb Line has been squewed.


    The best solution for the tin boat would be to go to Honey Depot and purchace 16 sheets of 3/8 pressure treated Ply and some elers wood glue and a galv deck screws. That and a few six packs of Gansett Ale will allow higher bouyancy of your jon boat.

    Be sur to paint it and dont for get the burgee.




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