Steel hull wooden everything else?

Discussion in 'Metal Boat Building' started by treeclimber@xtr, Sep 28, 2008.

  1. treeclimber@xtr
    Joined: Sep 2007
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    Location: Auckland New Zealand

    treeclimber@xtr Junior Member

    Wow I just read "Teak Decking Over Steel - Bad Idea??" I guess there are certain similarities to my situation. That being I do not have any plans for this hull and I am adverse to buying them. Am I a cheap *******, maybe, do I want to understand more about building this boat with a view to long term strength, minimal maintenance and making the most of the planning phase to address my forseable needs into the future ie. wife and two small children - absolutely.
    It is going to be a family sailing this boat, my family and I dont want to screw it up.
    This will make you laugh and I hope my wife doesn't see this thred. She wanted to build the boat like a pirate ship like on Pirates of the Cariabian - a raised cabin at each end with a flat deck in the middle. It took me a long time to convince her ......who am I kidding she still isn't convinced and still wants a dead flat deck, easier for walking on she says "we don't have to do what everyone else does" .....no darling ofcourse not...... She's never been to sea. I really hope she enjoys sailing in the ocean including the rough weather. Anyway back to business.

    But first here are some lovely photos. The first one is the day we lifted said hull over the old milking shed. The alarm went off on the crane and we worked out she must weigh about 2 to 2.4 tonne as is.
    12.2 meters long 3.6m wide and 3.7m high. Note the rust stains, it is minimal surface rust only.
     

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  2. treeclimber@xtr
    Joined: Sep 2007
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    treeclimber@xtr Junior Member

    Considering I don't have any plans to get plans for this build I would really appreciate any imput I realise I will need to draw somthing and conceptualise etc but first here is my situation. I'm looking at beginning work next winter as this is the onlt time of year when I have any spare time.
    I am currently milling timber and have a good supply of quartersawn macrocarpa and one very large straight and clear log of Pohutukawa.
    That has got to get you excited LazyJack.
    I know pohutukawa was used on ships a long time ago before epoxies and laminating etc. It is a very hard heavy dense wood. Hopefully somebody has an opinion about how well it laminates and epoxies. I'm not sure if you would remember this LazyJack but at the end of Lincoln Rd in Henderson, Auckland now there is a ferry being restored called the Toroa its the only double ended ferry left in the world apprently(kiwi's are always saying this or that is the only thing left in the world or biggest in the world etc) and I have some peolpe who want to use my Pohutukawa log in that restoration for some major structral componant something to do with the drive system but I think stuff them they can use Jarra.

    I'm realy waffleing on. What I need to know is can I build the rest of this boat in timber is there an advantage to that or should I lay out some of the interior framework in steel, hatches ,cabin, helm etc and finish in timber over the steel. I can work in both wood or steel It is just I would like to take into consideration.... Weight , Strength , rust prevention , how to attache the
    wood to the steel.
    Whats the best way to make a housing for the mast, I'd like to have a mast that can fold down (unless a fixed mast is going to save me ludicrous amounts of money) do I use steel beams where the mast is going to go for strengh of attachment and save on the bulk that wood will otherwise need to have to support such a structure or will a laminate of say Pohutukawa do the trick. I've got lots of timber at my disposal. It is practically free for me which is the sort of thinking that got me into this mess in the first place.

    Basically folks and I'm not afraid to say it.... I would like to be held by the hand and told what to do every step of the way so long as I can ask the questions I need to ask and recieve answers that make sense to me. I'm am willing to pay for this service. As I said before the build begins next winter or March 09 and I realise that somone with knowledge of my materials and an understanding of my needs/design intentions can save me a fortune in money and heartache. Applications welcome
     
  3. Manie B
    Joined: Sep 2006
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    Location: Cape Town South Africa

    Manie B Senior Member

    serious mistake

    very serious mistake

     
  4. treeclimber@xtr
    Joined: Sep 2007
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    treeclimber@xtr Junior Member

    Would I need to purchase the plans from Alan Mummery who originally designed this hull or could I get them from someone with equal an skill level. The reason I ask this is I have spoken to Mr Mummery and although he living in Auckland about 15 Klm away he isn't even interested in coming to see the hull in person. I have a friend who is a shipwright and very skilled has been building boats in steel and wood all his life about 40 years restores classic ships for museums and is invloved in the multimilliom dollar restoration of the Toroa as a consultant. When I said I didn't want to purchase plans I really meant I did not want to deal with a naval architect who has no passion for the project take his fee and walks away. I don't care if he designed it originally and I'm sure he's a great guy but I don't think he is really interested at this point in his life. Can't be bothered drive 15 klms what does that tell you?
    Couldn't anyone with the skills pick up where he left off and maybe have a fresh opinion with todays more comtemporary build procedures.

    Also on another level I think a list of Bargins to look out for over the next few years would also be very useful. Not that I want to do this totally on the cheap but for example if someone was say wrecking a boat what would you salvage?
     
  5. Butch .H
    Joined: Apr 2008
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    Location: South Africa

    Butch .H Senior Member

    Hang in there some one will pop in with all the info you need .Wynand and co are probebly still sleeping:D
     
  6. Wynand N
    Joined: Oct 2004
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    Location: South Africa

    Wynand N Retired Steelboatbuilder

    I a bit further away than 15kms but here go;

    Why bother with a wooden deck on a steel hull - not the best of ideas in my opinion and you always have leaks with that setup. Why not keep it steel and it all forms one structural unit, free of leaks and virtually indestructible.
    Usually a steel hull is designed WITH a steel deck and you should not be worried about the little bit of weight off a steel deck over a wooden one - and honestly, not much between then anyhow.

    A boat your size I would go for angle iron deck beams of 50x50x6mm and longitudinal deck stringers of 40x5mm flat bar. The deck stringers can be spaced about 300mm over centres away from the centreline. Deck plating is 3mm plate. Get that stage done and I then can advice you further.
    In the meantime, I would suggest you check out my website and you may pick up a few pointers along the way.

    Good luck with your project:cool:

    BTW, where are the longitudinal stringers in the hull??
     
  7. Arvy
    Joined: Jun 2005
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    Arvy Senior Member

    It is not only the longitudinals I am missing, but also some limberholes (or ratholes, never can remember which is which). See all the water accumulating at each frame? how are you going to pump that out, one bilgepump at each frame?
     
  8. treeclimber@xtr
    Joined: Sep 2007
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    treeclimber@xtr Junior Member

    Thanks Wynard that sounds like sound advice and alot easier to do really. I will check out your website. I'm going to need to finish the keel and put the motor in fist really do you think. Whta size motor and where do I put it in relation the prop placement?
     
  9. Brent Swain
    Joined: Mar 2002
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    Location: British Columbia

    Brent Swain Member

    Steel hull, etc

    Putting a wooden deck on a steel hull would be a huge mistake for several reasons.
    1 structural
    Take a tupper ware container out of your locker. Take the lid off and twist it. It twists easily. Now put the lid on and try again. The top , like decks on a boat, takes almost the entire twisting load. Trying to attach wood strongly enough to stop movenent and thus maintain the a seal would be impossible matching a material that swells and shrinks with one that doesn't .
    2 time
    The last time I put a deck on a 36 footer it took me 8 hours , and another ten do do the cabin and wheelhouse. In wood it would take far longer and be far weaker and far less watertight over time. Welding cleats , hatch frames, hatch hinges , etc takes a tiny fraction the time it takes to bolt things on a wooden deck and they always seem to work loose eventually , then leak. This simply doesn't hapen with welded on fittings. Instead of the retail price of stainless cleats, they cost me under a dollar in scrap materials.
    A teak deck with frames weighs more than a 10 guage steel deck , especially when you count the sheer clamps and other structural members, ancosts far mor ein both time and money when you count all the bolts , screws ,glues , etc involved, eating up cruising time, which is what it's all supposed to be for .
    3 watertight integrity
    There is nothing more watertight than a welded steel deck with all the fittings welded down.
    4 Maintenance
    Maintaining a well painted steel deck with a stainless trim on all outside corners, would be a fraction the amount of maintenance of a wooden deck ,especialy where the wood meets the steel, which is impossible to deal with once problems begin between the two surfaces.
    If you like fancy woodwork , keep it below decks ,where it doesn't make a slave out of you.
    Brent.
     
  10. lazeyjack

    lazeyjack Guest

    actually go out to Bos and Carr they have done as I have done, steel decks, flange at cabin trunk and all wood
    there are numerous layouts, also 3 of that boat is Ak one in Wellington and one in Coro
    go see em
    , the two I built are great, one was to lloyds, built under lloyds, get onto yahoo messenger I will help you ,by mic
    the trickiest will eb your ballast ratio
    dont be mean use lead, start 3.5 tonne, plate up the keel, then do most of your fitting out, then you can pour lead, then you can find balence by pivot method
     
  11. treeclimber@xtr
    Joined: Sep 2007
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    treeclimber@xtr Junior Member

    BTW, where are the longitudinal stringers in the hull??[/QUOTE]

    I don't know I bought the hull as is. Maybe thats the next thing I need to do?
     
  12. lazeyjack

    lazeyjack Guest

    THE BOAT WAS BUILT ON THE AWTHARTSHIPS FRAMING Method, it does not need stringers, it is the older way and best way, the short intercostals were put into the pounding slam zone forwards
    and you can not do much until you make a dwg of the deck c/l, giving you the crown height, from the crown height you work out the rest of the deck shape
    so you either have to draw what you have, ie the sheer H AND BREADTH and then draw in your cl, deck, OR you have to go to Mummery and pay him to do it
    to do it your self, you need to dumpy up the sheer at whatever your beam centres will be, and measure the beam at those points and then make a scale dwg
    Without a dwg you can not draw the cabin etc

    What many people have not read here, is theat I built two of these boats
     
  13. Brent Swain
    Joined: Mar 2002
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    Location: British Columbia

    Brent Swain Member

    Steel hull

    As long as the hull is fair , she has enough framing. Short longitudinals can be used to force out any hollows in the hull.
    This is a good stage to build in keel cooling .
    A wooden cabin is OK as long as it is new. It is only after ten or more years that the troubles begin. Advice of advocates who have never maintained a single steel boat over more that ten years for any one boat, should be taken with a grain of scepticism.
    It is impossible for any bedding compound to hold together indefiniltly while the wood over it is constanly shrinking and swelling. once it breaks free it is nearly impossible to deal with it easily.There is no way you can build a wooden cabin, hatches , deck fittings etc as strong and as watertight as in welded down metal . If you want to save weight, an aluminium cabin on a steel hull works well.
    Brent
     
  14. lazeyjack

    lazeyjack Guest

    here is the last we built was underlLloyds, smallest ever Llyods yacht in NZ, now they don't do under 80
    the beauty of Mummery yachts is they run very quietly the owner was avery well respected bridge and mech eng, and also very exp yachtsman, navigator on Flyer, now Alaska Eagle for cruising, , why he chose this older design I do now know, but she sails very well indeed
     

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  15. lazeyjack

    lazeyjack Guest

    I have a lot of pics, but they dont scan too well in the book form
    she is really quite colourful, can see it here, all panels come down, satin painted
    part of Lyoyds test was a fire hose on the hatchway
     

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