How do I get started building a houseboat?

Discussion in 'Boatbuilding' started by SomewhereInND, Dec 9, 2003.

  1. SomewhereInND
    Joined: Dec 2003
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    Location: ND

    SomewhereInND New Member

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    I found the following plans for a 30'+ by 12' flat bottom Placid
    houseboat:
    http://www.dngoodchild.com/5670.htm
    I ordered the plans for a few bucks no real detail, I got what I
    expected, and for what I paid for.
    I like the boat design and size, except that I want to build it with
    a metal hull.

    To build this, I need more details, such as:
    Thickness of hull...
    Cross members support...
    What kind of support do I need to build in so that it can be hauled
    out by a trailer (very big trailer)...
    In fact, what kind of trailer do I need to build, so that I can move
    it a few miles when I haul it out...

    Are there any plans out there that have the detail that I need to
    build a flat bottom boat hull of this size?
     
  2. rjmac
    Joined: Sep 2003
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    Location: Burlington, IN

    rjmac Junior Member

    First, if I may….. I worked for a company that tried to build a houseboat without any regards to weight. It was a pontoon platform…., when they got it in the water it sank…., at that point they decided that they needed someone that knew something about boats ( Wakarusa, Indiana, around 1984).

    Second, there are a lot of guys on this forum that make their living in the marine industry and I feel very fortunate just to read about things that they are discussing. They seem to be very helpful but they also encourage one to do the work and they will guide you in that regard.

    Third, I am an amateur, been one for the past twenty-five years or so.

    With this in mind there are some things that you need to do before you even begin thinking about a trailer…..

    The one most important things to start with is weight, how much is the cabinetry, everything going to wiegh…? You can start with a hull form but then you need to calculate the weight and then the hull thickness requirements (from your posting sounds like you want to do a redesign).

    Another thing, by the dimensions, 30’x12’, ND has a limit of 8’6” width (?) without a permit. As soon as you hit the road, no matter how far, you will need permits.

    If you are serious about this project, you need to calculate the weight…., not sure if anyone has a direct conversion of wood to steel or whatever, frame spacing, thickness, whatever changes as you go from one material to another all this changes.

    The trailer, this will also be based on weight, how many axles, suspension, framing size, etc…., something of this size, if you overbuild it, it will take a semi to move it and you will need a Commercial Drivers License or friend that does.

    At this point, do your homework, and safety!!!!!! Don’t cheapy out, it could cost your life and your families….. Maybe the designer of the boat would have suggestions on this..?

    If you are serious, go for it…….

    Bob
     
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  4. SomewhereInND
    Joined: Dec 2003
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    Location: ND

    SomewhereInND New Member

     
  5. SomewhereInND
    Joined: Dec 2003
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    Location: ND

    SomewhereInND New Member

    One other thing.

    I am also looking for information about sheet steel, such as how much does it cost, and how much does it weigh
     
  6. ted655
    Joined: May 2003
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    Location: Butte La Rose, LA.

    ted655 Senior Member

    Good! Glad you joined.Find "Thomas Reginal" in Google and join, Then you can start locating material supplyers in your area.. Use Google a lot. Like,"weights of steel sheets"
    Don't let worrisum posts get to you. I can give you the displacement formula so you don't sink. Something they should have used in Indiana, back in the 80s.
     
  7. gonzo
    Joined: Aug 2002
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    Location: Milwaukee, WI

    gonzo Senior Member

    At that size you'll at least double the weight from wood to steel. Flat metal panels dent and deform which will make your boat look very unappealing in short time. Aluminum would be a better alternative. There are many designers in this forum, me included, that could do the calculations for you. However, any changes, like what you are planning now, change the whole design and construction schedule and techinque. I recomend that you follow the original designers specifications.
     
  8. rjmac
    Joined: Sep 2003
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    Location: Burlington, IN

    rjmac Junior Member

    Bryan and Others,

    I just had to add to that sinking story...ha..... I was working in the commecial truck body division as a product engineer and the managers in charge of the newly created division did not want to talk to anyone that did not tell them what they wanted to hear.... When they finally launched the tub I was working for a different company.

    What's the gameplan for the interior, will you be building cabinets or purchasing them. Depending on if you are going to build certain items, you can use things like shipping weight.....

    Please forgive me if I sounded worrisum,....... :D
     
  9. ted655
    Joined: May 2003
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    Location: Butte La Rose, LA.

    ted655 Senior Member

    If you decide on aluminium, (my personal favorite material), then do a search here in the archives. "Welding aluminium", it has good info.
     
  10. i have 2 30"x20'pipe to make pontoons with if i cap each end how much weight can they hold? as cabin weight (pipe weighs 80 lbs per ft)
     
  11. gonzo
    Joined: Aug 2002
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    Location: Milwaukee, WI

    gonzo Senior Member

    Decide how much freeboard you want. Calculate the volume in gallons above the waterline. Deduct that volume from the total. Multiply the rest by 62. Take the weight of the pipes from that and the rest is the load capacity.
     
  12. bjn66usa
    Joined: Jun 2004
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    Location: Kentucky

    bjn66usa New Member

    bjn66usa

    Imagine a milk jug, fill it half full of water and it floats half way, fill it full and it sinks. Figure the weight of 1 gallon of water, use a circumfrence formula to figure how many gallons of water your pontton will hold, multiply it by the weight of one gallon of water, and devide by 2. this should give you a pretty aqurate weight calculation for the pontoon floating at half depth.

    round pontoons will have a tendacy to sink further in the water at half full than a square type pontoon. square pontoons can hold up a world dude.

    Hope I helped, please e-mail me if you get this thanks alot.
     
  13. Manuel

    Manuel Guest

    Mr

    Hi there!
    OK I am in europe so I work in decimals and liters:
    here goes: 1... weight of object is = to weight of water displaced.

    therefore the volume of water displaced @ 1Kg per 1ltr ( for fresh water)

    you have 2 pipes of (30")=0.9m x 20' =6.0m.

    weight of pipe = 80lb per 0.33m (1')

    according to my quick calcs your pipes will replace 3200 feet3 x(.30x.30 = metric) =28.8mt of fresh water. now you have the weight of the pipe to start with. = 80lbs per .3m run. so you have 12m of pipe @ 80lbs per 0.3 =36x80lbs = 2880lbs weight of pipe. transfet that into Kgs please.
    so.. now you can find the buoyancy of the pipes (alown).
    so your pipes will have to support 1.. their weight... 2 the weight of everything you will put on them i.e. house boat.
    using formula for vol of cylinder = 22 x R2 x H
    7

    I am rusty in my maths and I do not have converssion tables in hand.

    Have fun
    Manuel
     
  14. B. Hamm
    Joined: Nov 2004
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    Location: Rockford, IL

    B. Hamm Junior Member

    Do yourself a favor before you even start thinking about building this in steel. Take a look around at used commercially built steel houseboats on our nation's rivers. Unless they are very heavily built (probably not trailerable) they have a fairly short life span. Not quite the same enviorment as building for the ocean. It's pretty common to see 10 year old boats needing complete new bottoms.

    Bill H.
     

  15. dominoconsultan
    Joined: Aug 2005
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    Location: Murray Bridge, South Australia

    dominoconsultan Occasional Poster

    I've also been racking my brains to find a cheap way to make some pontoon floats. I want to make a fairly large pontoon barge that I can use initially as a party barge. Over time I will be transforming it into a fully fitted out houseboat.

    I've considered PVC pipe but it's expensive, not that strong, and hard to get in the diameter required. Also, I now doubt that it would have the boyancy required.

    I've looked at making a plywood pontoon body with a foam filling and getting somebody to engineer a galvanised steel pointy end so they are collision proof. The foam is expenssive and the plywood, epoxy and fibreglass isn't cheap either.

    The latest brainstorm is old hot water tanks; the ones with styrofoam insulation (some have fibreglass insul.).

    http://www.rheem.com.au/domestic_product.asp?model=111400&cat_id=

    These things are always being replaced so most places should have an unending supply. They are also relatively strong. With all that foam insulation I figure if you can find them the same diameter you can butt them end to end the boyancy should be sufficient. I'd remove all the protrusions and put in a solid metal plug where each of the water pipes enter the tank. That way you can screw into the plugs. Any general voids in the skin can be filled with expandable foam and a thin galvanised steel skin pop-riveted over the surface. In between the tanks you should also join them with a sheet of gal steel pop-riveted on and filled with foam.

    You would still need to have a manufactured pointy end. Any decent engineering workshop would be able to weld this up and have it galvanised for you. Then you'd need to have some metal bracings running the full length of the pontoon to attach the deck to as well as providing general stability. I'd reccommend one along the "keel", one on the outer side as a "rubbing strake", two on top as attachment points for the deck and one on the inside as a balance to the strake. At the rear end you'd need an engineered "transom" to put your outboard onto. Once you have your pontoon you should put a fibreglass skin over the entire surface of the pontoon including the topside. You can see this method being used by many boat builders online

    See the following picture, it's not a picture of the pontoon but it does give you an idea of skinning with fibreglass. It's also a nice cheap way of making two little pontoons for some of the one-person rafts...

    http://galen.smugmug.com/gallery/380563/2/15176927

    You could have two bloody great big pontoons either side with another in the centre. The centre one could even be made with larger diameter hot water services. Using this configuration you could have a single large outboard in the centre or one outboard on either of the outside pontoons.

    Mike Smith
     
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