Proa-Cement

Discussion in 'Boat Design' started by DrCraze, May 14, 2010.

  1. DrCraze
    Joined: Apr 2010
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    Location: North America

    DrCraze Junior Member

    Throw all the mud you like....I already did. Its 5.3 meters long and displaces 108 kilos... I plastered the main hull yesterday and now Its time to build the cement ama. The ama is calculated to weigh 27 kilos.

    My method was a mixture of stone age and modern tech. I started by setting 4 hull forms on a strong back staked down to the ground as well as bow side profile forms. I then used a clay mixture similar to adobe to build up a male mold using the forms as guides. I finished the mold by fairing with sheetrock mud then I covered the entire mold with plastic sheeting.

    The hull reinforcement was then stretched over the mold and built up to a thickness of 6mm. A mixture of fiber reinforced cement plaster with the latest in admixture technology was then applied and finished. Bulkheads and decks will be fitted in a few days with the added weight of 13 kilos.

    he's a beast and as far as I have been able to ascertain the first of his kind.(Micronesian proas were all male)
     
  2. Alex.A
    Joined: Feb 2010
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    Location: South Africa

    Alex.A Senior Member

    You have to post pics!!!
     
  3. DrCraze
    Joined: Apr 2010
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    Location: North America

    DrCraze Junior Member

    I took this one this morning. I have it covered in wet sheets and plastic(I gave my patient wife some money from the boat fund:D ) Bless her heart for putting up with me. Tomorrow or later today I will spread on a special non-sanded filler I have developed to fill some of the pits I missed yesterday. Then I will wet sand with 400 grit diamond abrasives after it cures. I will smooth and polish the tubricals on the bow after the cement/filler fully cures

    [​IMG]
     
  4. tugboat

    tugboat Previous Member

    finally!--this is great and open up doors...i experimented a bit with this too--i failed because i used the wrong cement- thinking a topcoat which is stronger would be better--it isnt..i tried 1/4 inch and 1/8th int thick..actaully in my last post on the other forum i said i used plasterers lath--actually i used 1/4 inch mesh one layer and thta wasnt enough to support the cement i SHOULD have used plasterers lath...i didnt take my time during the experiment. otherwise i would have a multihull--i think a cat design would easily accomodate this or a large orca class could be done in ferro cement. would be stronger than anything other than carbon fiber layup at that thickness.
     
  5. tugboat

    tugboat Previous Member

    i think ill start designing plans for a mulithull in ferro--thanks!
     
  6. dskira

    dskira Previous Member

    Tugboat I love your enthousiasm, but now you have to start one project.
    What ever it is, I wish you to go ahead, and hope you will be posting pics very soon.
    Go for it Tugboat.
    Daniel
     
  7. DrCraze
    Joined: Apr 2010
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    Location: North America

    DrCraze Junior Member

    My goal is to build a cruising proa at least 36 feet long out of ferro. I plan on using a product called c-grid. Its carbon fiber mesh made for the countertop industry. There wouldn't be any steel used in the construction not that steel is bad in ferro. The carbon fiber would enable me to keep the thickness down without degrading the tensile strength. I will be building a house this year so any large build will have to wait till our house completed.

    I have to say plastering over a solid inverted mold helped keep the weight down and definitely aided in keeping the hull relatively fair. I didn't want to add any more cement than necessary so there are a few spots that could use a little fairing. I dont plan on painting the hull anytime soon so I colored the skim coat orange. If it comes out looking good after I polish the hull then I will just wax it.

    I think this hull should be pretty fast but when I shunt Im sure it will take a moment for all that inertia to come to a halt and get back up to speed.
     
  8. tugboat

    tugboat Previous Member

    @dskira- How very true...I WILL be laying the keel for either a tugboat or submarine in the summer(within the next two months)...i just had a setback financially so it is delayed one month.

    the multihull ill just wait until i have my first major project finished- when i lay the keel i definitely will be posting the pics.

    but it'll be fun to mess about with some ferro multihull designs in the meantime...
    the sub is a more serious project though...about 50/50 chance that will be my choice.
    so i wont make any guarantees to anyone right now about Which vessel i will choose.

    btw dskira- what boats are you building or have built?..im curious...appreciated the midget subs info you sent me
     
  9. dskira

    dskira Previous Member

    My building was of wood. Not wood composite, but lumber. Some exception in the 70 when I built IOR and other racers in cold molded.
    Every size, from small peanut to large vessel.
    Now I am building for myself a little houseboat. I called it my camp. It will allow me and my wife to spend time visiting the numerous Island and the beautiful coast of Maine at a leisurely path.
    Sub are a beast apart, very difficult due to the fact they react to the slight movement, and every change in longitudinal weight and static weight must be compensated. As for the density of the water and the temperature (density). The speed help to stabilize, but speed is not always possible.
    If you don't set up a fly by wire, you stock with every crew member with a multiple task, meaning no leisurely guest on board but in surface motoring. And even the sail(tower) is never large enough to have more than one or two man. In a small submarine I mean. The number of thru hull necessary are numerous, from the pressure hull to the free flooding hull, and are the Achilles' Heel of the whole system, as the regenerator of fresh air and other things to long to elaborate.
    The tug will be a better bet, mostly if like me, your finance are low. Even with few dollar you will be sure to finish it, even working in the water.
    And tug are beautiful, no doubt about that. A big high bluff bow, a sweeping sheer line going close to the waterline aft, nice bulwark, the biggest engine you can buy second hand, a cabin dedicated as an engine room, a beautiful half round pilot house, your flag painted on the side of the oversized smoke stack, and you are in business. :)
    I think DrCraze it is your thread and I am of topic, sory about that.
    Daniel
     
  10. tugboat

    tugboat Previous Member

    Dskira- you will love the houseboat- i built three. two of them i lived on year round and paid no rent or mortgage. THAT is the reason I love boats..well one of many. I built them for about 5 000. used gensets for power. lived on a river that froze the hull in year round but never hurt the boats. was cold to heat at times but amazign experience...
    to be honest i already got a set of plans for a 30 ft tug. I changed the design a little adding a v bottom. and a single chine since the original design was flat bottom. i beefed up the framing and added thicker longitudinals.

    the plating calls for cor-ten but f___ck that! i will use 3/16th plate.

    The extra bouyancy will bring her to her lines...
    the idea here was that I would build a small tug..then buiuld a huge barge say a40 or fifty ft'er to use the tug to tow and puch through the great lakes and through the canal systems here. year round liveaboard.
    i love the lines of a tug expecially a general purpose design./ i wanted to build a 45 ft'er but the frames (33frames @ 3/8 x 2.5 inches) would have cost me around 10 000!! i can build the whole 30 footer tug hull for half that.
    I estimate two years max construction time and i can work full time on it if needed.


    drcraze- may i ask--what the ridges or some type of cement "U" shapes going vertially on what appears to be the stem or transom in your pics are for? on your ferro cement hull proa?
     
  11. tugboat

    tugboat Previous Member

    Drcraze- sorry i just wanted to reply to Dskira one more time

    Dsikra- I have decided to build the tugboat first, only because i am tired of landlords and idiot neighbours who smoke yell and drink too much and the rules that go with renting etc...so i NEED a home so the tugboat and barge combo is top priority--BUT i am fully convinced, that i can accomplish a workable submarine for around 25 000. out of cement. after this boat gets built i will start the submarine...
    if you have wish i can send you a copy of the sub plans and details -written details but easily understood?...no charge...just pm me. you can see how i worked out all the systems.

    After i get my floating "home" set up WILL be building the submarine...

    I would love to see some drawings of your houseboat design...i like using core cell as a building method or plywood as a core is great too for sailboats like you have built...cold molding i have not yet tried...is it hard to do?..i think you need to vacuum bag to form the surfaces? Kurt Hughes has some great ideas for a type of cold molding process...

    sorry drcraze- i am not trying to hijack your thread...
    keep me posted as to the progress of your hull..this is great!!
     
  12. DrCraze
    Joined: Apr 2010
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    Location: North America

    DrCraze Junior Member

    My submarine...

    [​IMG]
     
    1 person likes this.
  13. tugboat

    tugboat Previous Member

    does she come with the plans??
     
  14. DrCraze
    Joined: Apr 2010
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    Location: North America

    DrCraze Junior Member

    Some has to think this will sink! Or is the possibility of having ones foot in ones mouth too great:p
     

  15. DrCraze
    Joined: Apr 2010
    Posts: 91
    Likes: 6, Points: 0, Legacy Rep: 33
    Location: North America

    DrCraze Junior Member

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