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Thread: Large Ply on Frame

  1. #1
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    Default Large Ply on Frame

    Not your typical boat in this forum , " JIGSAW " is a 65' Catamaran currently under construction in my garage .



    Each Hull is made up from 4 separate sections , this is the front section of Hull 2 , After 3 years of Weekends I have constructed 5 out of the 8 sections required . I'm so jealous of the equipment and building spaces of the members in your forum , all I have is a 16' x 10'
    car garage .

  2. #2
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    Default Re: Large Ply on Frame

    Nice workmanship.
    How do you intend on joining the sections?
    The loads will be massive.
    Can be done as many ships are built that way but the engineering needs attention.
    Which design is she? A cat I presume?
    Cheers James

  3. #3
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    Default Re: Large Ply on Frame

    Very few very few of us could build a 65 foot anything inside. I've often thought of building a Chris white design in segments in our garage. I'm looking forward to it coming together.
    __________________________________________________ ________________________

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    Default Re: Large Ply on Frame

    Very cool - a project like that is my wet dream..
    Please post more and more pictures; I would love for you to share how it came/is coming all together.

    What design is she? Kurt Hughes?

    Erik

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    Default Re: Large Ply on Frame

    Joining of the sections is the thing that concerns me the most . originally when I conceived the idea of JIGSAW it was going to be build in steel , joining would have been easy , when the decision was made to change to Wood construction then it became more of an issue . The hulls are two layers of 1/2 inch Plywood , joints exist all over the structure , what I decided was to stop the outer layer of plywood short of the joint ( 8 " wide) , the inner layer butts to the next section of the hull . A 16 " section is added over the Butt joint matching the outer skin and a third layer of plywood ( 36 " wide) is added on the inside of the hull between the stringers and between the two transverse frames . This gives a triple skin construction where the hull sections join and should be sufficient to deal with the loads .

  6. #6
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    Default Re: Large Ply on Frame

    Some of Jigsaws Spec's

    LOA 19.8 m ( 66 ' )
    BOA 8.4 m ( 28 ' )

    Wingdeck Clearance 1.2 m ( 4' )

    Light Load Displacement 38000 kg
    Heavy Load Displacement 45000 kg

    Construction is 2 skins of 12mm plywood over Wood Stringers at 200mm ( bottom ) and 300mm ( Side ) Centers ,
    Transverse framing is at 900 mm centers using Sheet frames ( with Solid Timber reinforcement ) , Solid Timber frames and
    Box Section Bulkhead watertight frames ( 4 per hull ) .

    Motive Power is from a Diesel - Electric Hybrid engine system backed up by Batteries and a large Solar array ( 10 KW ) on the upper deck .

    JIGSAW was designed as a Coastal Cruising Houseboat with the looks of a standard MotorYacht that will serve as my retirement home ,
    to be fully independant and self-sufficient from shore services .
    Last edited by dearlovr; 12-05-2015 at 01:51 AM.

  7. #7
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    Default Re: Large Ply on Frame

    Begining of November , Section 1 of Hull 2 was removed from the build garage to see the light for the first time ,



    Unpainted at this time due to space issues in the garage caused by a shipment of timber that was also in this space ,

    Time for a bath and a quick coat of Hempel's light primer , easier to check for any imperfections in the fiberglass sheathing .



    This side connects to the wing deck of the Catamaran thru a 45 degree section .



    This side looks a little weird as the second layer of plywood is held back in places , so that the sections above
    this hull base don't butt at the same points when finally connected .

  8. #8
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    Default Re: Large Ply on Frame

    Line drawings of the design?
    There is no rational, logical, or physical description of how free will could exist. It therefore makes no sense to praise or condemn anyone on the grounds they are a free willed self that made one choice but could have chosen something else. There is no evidence that such a situation is possible in our Universe. Demonstrate otherwise and I will be thrilled.

  9. #9
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    Default Re: Large Ply on Frame

    I know nothing of naval architecture, but this looks like a great project to me. In addition to the overlapping ply at the points joining the sections, you could run a solid piece of wood along the keel, both as a strengthening component and a sacrificial grounding shoe. Also, will there be a stiffening piece of wood spanning the whole length of the boat along the gunwales? This will also reinforce those areas.
    The fact that this is motor vessel and won't be subjected to the twisting forces of sailing probably also eases the stress on those joints.
    I was born on a wooden boat that I built myself.

  10. #10
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    Default Re: Large Ply on Frame

    Very interesting! Thanks for showing us.

    Is there much difference in weight between the original steel version and this one?
    There is nothing quite as permanent as a good temporary repair.

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    Default Re: Large Ply on Frame

    Quote Originally Posted by dearlovr View Post
    Not your typical boat in this forum , " JIGSAW " is a 65' Catamaran currently under construction in my garage .



    Each Hull is made up from 4 separate sections , this is the front section of Hull 2 , After 3 years of Weekends I have constructed 5 out of the 8 sections required . I'm so jealous of the equipment and building spaces of the members in your forum , all I have is a 16' x 10'
    car garage .
    Wow, this is my kind of project! Please keep posting.
    Walt

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    Default Re: Large Ply on Frame

    Welcome and thanks for sharing. I look forward to getting to know you and your boat. If you are not already aware, there was a catamaran built in California a year or three ago that ended up with the boat sinking outside the Golden gate Bridge. If you have a couple of weeks you could read about it in sailing anarchy. I forget the boats name. I only bring this up because you may have people asking you whether you have engineered plans. Looks like you're not planning on sailing this one though. I suspect that makes a big difference. Keep the pics coming!

  13. #13
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    Default Re: Large Ply on Frame

    I read about that one , didn't he build it like a house ?
    My scantlings are based on LLOYDS rules for the construction of Wooden Boats , Plywood for hulls is BS1088 , timber is Malaysian Kauri .
    If anything its Over-Built , but its not ment to cross an OCEAN , its a houseboat , coastal cruising from the Bay of Islands in the north of NZ to the Marlborough Sounds at the top of the South Island is its intended range , most most of the time it will be at anchor in some sheltered bay .
    More construction details will follow as building tech appears to be a big part of this forum , the pictures come from an original blog I created to show
    my workmates what I was up to

    http://houseboat-building.blogspot.co.nz/

    Not alot of tech stuff in that blog , will post the more interesting stuff in this one .

  14. #14
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    Default Re: Large Ply on Frame

    Quote Originally Posted by bluedog225 View Post
    Welcome and thanks for sharing. I look forward to getting to know you and your boat. If you are not already aware, there was a catamaran built in California a year or three ago that ended up with the boat sinking outside the Golden gate Bridge. If you have a couple of weeks you could read about it in sailing anarchy. I forget the boats name. I only bring this up because you may have people asking you whether you have engineered plans. Looks like you're not planning on sailing this one though. I suspect that makes a big difference. Keep the pics coming!
    But this one doesn't look as dependent on liquid nails, 16d nails, and deck screws. Plus it is shaped like a boat, another advantage.
    The skin thickness, the main scantling given, is certainly adequate, and the framing sounds in the ballpark. For the skin thickness the ribbands even look stout.

    My main concern so far, not having seen the design, would be that there are not as many screws visible in the cold molded hull panels as is the norm. Usually screws are on a 4 to 6 inch grid. Perhaps fewer are needed with easy bends on a large, slim hull shape. But avoiding voids is usually considered worth a lot of screws. Was vacuum used?

    If there is a lines plan, do please post it. If you manage to build a boat of this type, this big, without one, and come out right, you will impress everyone who sees it. To be built in sections and even look fair, much less work well, is not easy. The only large, home-built-in-sections boat I have seen was a 50' ferrocement monohull sailboat. It had quite a hiccup amidships and a queasy ripple toward the stern quarters. But at 50', I am sure it made some time, and had evidently put some miles under the keel.

    Many people here are pedigree plans-obsessed. You might just show 'em up, plans or none. Good on ya

    Edit: just saw your last, Lloyds shouldn't steer you too wrong.

  15. #15
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    Default Re: Large Ply on Frame

    It's obvious that you're building this vessel the correct way, not like the Flyin' Hawain at all.
    I was born on a wooden boat that I built myself.

  16. #16
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    Default

    I, for one, am very impressed. Good luck with the build.
    -Dave

  17. #17
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    Default Re: Large Ply on Frame

    No vacuum used , just careful layout of panels and the use of the curve in the boat to hold the panels together . By angling the first layer of plywood in the forwards
    direction it creates a slight concave bend in the panel , the outer layer is angled rearwards and therefore forms a convex shape , this makes the second layer hold against the first quite well . I also use a number of silicon bronze nails to help between the screws . They don't really show up thru the glass in the picture .
    Hull lines were created on a computer and are still in their original formats , will post when I create a picture out of them .

  18. #18
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    Default Re: Large Ply on Frame

    Space problem Dearlovr?
    32 years ago I lived in an apartment with balconies only 36 " deep. Guy on.3rd floor built a Hobie Cat one hull at a time. Hung first hull over the side, finished the second, lowed it all with block & ,tackle. Took it all to the saltchuck and it worked.
    Where there's a will, there's a way.
    basil

  19. #19
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    Default Re: Large Ply on Frame

    To keep costs down I make as much as I can , found some info on the web about making your own Prop shaft sterntubes so I gave it a go .



    Jigsaw is propelled by two 24" dia x 19" pitch propellors running on 1 3/4 stainless shafts ( one in each hull ) housed in semi tunnels in the hull , the tube runs in a solid wood keel and is approx 5' long , main part of the tube is just over 3/8 " thick rolled biaxial and quadaxial fiberglass with the endpiece for the cutlass bearing enlargened to 5/8 " . Inital tube was created in a couple of layers of 12 oz biaxial rolled over a steel pipe ( protected by mums baking paper ) , this was bound tightly as I needed accuracy for the cutlass bearing fit ( same as pipe ) . When set this was then slit off ( to tight to push out ) , then this was rejoined with the cutlass bearing inserted with small dobs of glue along its length , this allowed me to control the fit of the bearing . Once set and confirmed that all was true and tight the additional layers of quadaxial cloth were added to bring it to full size .

    I don't have a 5' boring bar so instead of making the keel and boring the hole I am laminating the keel around the tube , cut 4 pieces of solid timber to a specific size ( to maximise gluing surface ) , fitted the fiberglass tube and shaped the finished item .


  20. #20
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    Default Re: Large Ply on Frame

    Weight difference between the steel version and the plywood one was approx 5000 kg , only the hulls were supposed to be steel , when you start dealing in boats of this size the difference in weight between steel and plywood becomes less and less . The upper structures in the steel version were supposed to be foam core , main aim was to keep the weight under 50 tonne , above this and its required to be a surveyed vessel which would have made construction much more problematic .

  21. #21
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    Default Re: Large Ply on Frame

    re - Rich Jones comment , I chose not to build too large a keel as it would increase the draught of the boat , have transferred these loads internally to a central girder that runs the centerline down the entire boat ( except the engine room ) , it spreads any point load from the keel to the internal framing . As far as the gunwales are concerned , the break only goes part the way up the sides , additional sections get added after the hulls are joined , thats why on one side the outer skin is held back to the previous stringer . The other side has the 45 degree angled section that leads to the wingdeck . Will post cross-section once I create pictures of the CAD files .

  22. #22
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    Default Re: Large Ply on Frame

    The missing detail here, but included in the blog, is about the butt joints on the stringers. Your solution is close to, and frankly better than my idea, so I will spare you the details. http://houseboat-building.blogspot.c...1_archive.html The only thing that I would add, and likely something that you already know, is to orient most of the fibers in the butt joints longitudinally because cross axis or angled fibers stabilize the composite, but do little for axial strength.
    There are some drawings on the Feb. and Mar. pages of the blog. We are never satisfied with the number of drawings, so I will join the chorus asking for more.
    Nice, well written blog, by the way.

  23. #23
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    Default Re: Large Ply on Frame

    Great project , will be following with interest.

    A big , BIG job !

  24. #24
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    Default Re: Large Ply on Frame

    man you have got some balls

    goodonyamate!

  25. #25
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    Default Re: Large Ply on Frame

    JIGSAW was designed to be a Houseboat , it was not designed to Sail , Go fast or cross an OCEAN , the Hull design is Simplistic , due to its size and only one person working a couple of days a week it had to be easy and simple to build . Later when I sell my home and work Full time on her Superstructure and Internals I will be able to afford in both time and money to build more complex and appealing structures . What JIGSAW looks like underneath the water is not my main concern , only function is important . HullShape was created in a computer program called HULLFORM FOR WINDOWS , it created the basic lines of the boat along with displacement and balance considerations , this Data was then exported to various CAD programs to fill in the structual details of the frames etc . The waterline on this drawing is not correct as the correct line starts on the intersection of the chine at the bow ,also we added the curve on the forefoot , the conical stem and the Propeller tunnel later as well .

    Last edited by dearlovr; 12-07-2015 at 02:11 AM.

  26. #26
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    Default Re: Large Ply on Frame

    Using Various CAD programs I then created drawings of the frames to be constructed . This one is a open Timber frame , stringers are checked in at the appropriate locations .



    This one is a Bulkhead frame , checkins are not required as the ply ( both sides of the timber structure ) goes all the way out to the skin .

    Open timber frame constructed in reality ( checkin's and gussets at the chine not yet added ) -



    And bulkhead frame ( still needing second layer of ply )

    Last edited by dearlovr; 12-07-2015 at 03:26 AM.

  27. #27
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    Default Re: Large Ply on Frame

    Jigsaw's Bow section has been sitting aside for a couple of weeks while we build the next set of frames , now this is done we re-position this bow section back in front of the garage .



    This is to enable the construction of the next piece of the hull to be constructed off the first , in this way when the hulls are re-joined we should have a resonable match . All the frames for Section 2 ( including the first frame of section 3 ) are now lined up on a steel frame inside the garage and the keel , stringers and chines can now be added .



    The sections won't be dis-connected until at least 1 layer ( or both ) of plywood have been added so that the structure is dimensionally stable , all things going well this process of building from and including the next frame in the sequence will assist in creating a resonable hull . Section 2 contains one sheet frame ( part of the internal tankage structure ) , One Primary Bulkhead ( box section frame , primary structual item ) and three solid timber frames , the first frame of section 3 is a solid timber frame and is setup at the back of the garage , the stringers etc continue thru to this so that they are in the correct position for the following section , it gets cut off when this section leaves the garage .
    Last edited by dearlovr; 12-18-2015 at 01:37 AM.

  28. #28
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    Default Re: Large Ply on Frame

    This is Jigsaw's latest configuration :


    As can be seen in the hull are some very large opening Portholes that I will need to fabricate , these are basically
    750mm wide by 450 mm high , six in each Hull . I can build these in one of three ways ,

    1) Welded Stainless Steel - possible , but this process can lead to Minor shape inconsistencies due to the heat of welding and my being out-of-practice welding stainless steels

    2) Cast Naval Brass - also possible , been 20 years since I cast anything and that was Aluminium , still have some of the equipment required .

    3) Fiberglass Fabrication , Probably the easiest but will need careful design as these portholes will need to be very strong and have an inner closing storm cover for when Jigsaw leaves the harbours and runs down the coast . ( exposed to open ocean )

    Has anyone made their own portholes ??
    Last edited by dearlovr; 12-23-2015 at 02:16 AM.

  29. #29
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    Default Re: Large Ply on Frame

    I love it! Good looking boat and lots of room.

  30. #30
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    Default Re: Large Ply on Frame

    Wow, that's a lot more boat than I imagined. Is there a prize for the biggest boat built in the smallest space?
    -Dave

  31. #31
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    Default Re: Large Ply on Frame

    Prize , yeah , After enormous amounts of time , Blood , Sweat and tears , hopefully a home . ( Upper deck and flybridge are still only options at this time , depends on available finance after I sell my existing home ) .

  32. #32
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    Default Re: Large Ply on Frame

    That is amazing! I love being able to look over someone's shoulder on something like this. I don't even know anyone over here with enough land to put a boat like that. very pretty looking designs though!

  33. #33
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    Default Re: Large Ply on Frame

    This is audacious, especially since you seem to know how much work it is going to take.

  34. #34
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    Default Re: Large Ply on Frame

    Its one of the reasons Jigsaw is so large and is classed as a Houseboat , The boat itself is initially just large empty rooms , No built-in furniture , etc , no need to custom build internals , is fitted out with Std House bedroom and kitchen items , No fiddly internal structures , I've seen what takes an enormous amount of time to build in a normal boat and attempted to bypass these issues .

  35. #35
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    Default Re: Large Ply on Frame

    Quote Originally Posted by dearlovr View Post
    Its one of the reasons Jigsaw is so large and is classed as a Houseboat , The boat itself is initially just large empty rooms , No built-in furniture , etc , no need to custom build internals , is fitted out with Std House bedroom and kitchen items , No fiddly internal structures , I've seen what takes an enormous amount of time to build in a normal boat and attempted to bypass these issues .


    A good approach I think.

    I gotta tell you though .....

    a boat that large would nag at me ...maintenance , fuel and other issues !

    Why so large ? Big family ?

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