what material better wood metal etc

Discussion in 'Boat Design' started by Garth, Jul 25, 2006.

?

what material to use

Poll closed Aug 18, 2006.
  1. wood

    42.3%
  2. glass

    3.8%
  3. metal

    42.3%
  4. other

    11.5%
Multiple votes are allowed.
  1. Garth
    Joined: Jul 2006
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    Garth New Member

    hi well its been a dream that one day i mite get a chance to build my own yacht. well im just starting to investagate my progect i alway thought metal [not alloy] would be my best option if you could help it would be very help full to now ather oppions and why that over some thing else, on the subject of what, best to build your yacht from wood, metal, etc:) sorry for the short massage its just gives me some where to start as moving back to New Zealand sailing is plentifull. its a cruise around the world at your own pace yacht say 40 to 50ft not a racer as such more family. Iv been in england for eight year,s and can't wait get back sailing as NZ has a rugged coast and a lot can only be seen from the sea. im looking at a 10 year plan to build my own yacht not to say i wont buy one as soon as i get home.
     
  2. CORMERAN
    Joined: May 2006
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    CORMERAN Junior Member

    Wood or Metal

    To Gath,

    there are lots of proponents of the use of metal to build boats.
    However, even though most commercial ships are made of alum. or steel
    - it does not follow - that this is the best choice for vessels under 100'.

    There is a belief that metal boats sink less often. .....Maybe.
    - Check out the history of H.M.S. Sheffield and the " unsinkable " Titanic.

    Also, go down to the seaside - and check out boats that are over 50 yrs
    of age. Or 100 ! They will most likly be made of wood.
    There will be no tupperware ( fiberglass) boats to speak of - of such
    maturity. And not a whole lot of tin boats, either, much past 25 yrs of age.

    ALL materials have a finite life expectancy. However - some last longer
    than others. Like wood.

    Also with the use of epoxies the dreaded dry rot is much less of a concern
    now - than in years gone by.

    A very elegent yacht can be made with the " composites " - of wood
    and epoxy. Using the cold molding process. Which only requires the most basic of carpentry tools and skills.

    Cheers !
     
  3. Toot
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    Toot Senior Member

    I suspect the answers you get will largely be biased by peoples' different applications.

    Personally, I vote that you make the hull out of maple syrup and crackerjack boxes. You can save the crackerjack to give you extra floatation.

    As for the other options... Steel is great for around-the-world cruises but doesn't seem like a very popular material for something sitting on a small lake. Wood is fantastic on small or even mid-sized ships, but is getting more and more expensive as more trees are cut down, but it's a pure delight to work with- I've even made an airplane out of it. Composites, I would say, are the most adaptable though.. they can be used efficiently on the widest variety of ships- from canoes to giant yachts.

    So I would say that, given the absolute dearth of information you've given us upon which to make an informed decision, composites would be the best because they are at least marginally applicable no matter what you might be talking about. However, my choice could change depending on what you would want the boat to do.


    I suggest using the search function on this site to read what has been written countless times before about each of the materials you've listed.
     
  4. MikeJohns
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    MikeJohns Senior Member

    Garth
    Steel is by far the best material for the amatuer builder. It is forgiving, repairable, strong (UTS) beyond all the other materials and easily altered. I would also say it has the greatest longevity of any hull material, barring perhaps quality ferro-cement type construction. Avoid traditional plank on frame wood construction this is now only for the craftsmen and the traditionalists and is the least reliable construction, wood-epoxy is far better approach these days.

    That aside all the materials will produce a hull sufficient to cruise in sufficient safety. There are many other factors that will guide you to your final choice.

    Before you build go buy a sailboat and sail it for a few years.
     
  5. FastLearner?
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    FastLearner? Junior Member

    Least reliable in what sence???

    Steel requires some pretty specialized skills and equipment and is far from the ideal material for many boats. It depends entirely on what boat the good man is intending to build.
     
  6. MikeJohns
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    MikeJohns Senior Member

    .........sense

    Global strength, long term reliability of fixings, poor non isotropic local strength and high maintenance.

    With steel
    You can show a novice how to weld most of the joints required in a few hours. A plasma cutter takes about a minute to master. The result is a much faster project with the massive benefit of tolerant materials to re-work should errors occur.

    Trad timber takes a lot of skill time and effort if you can even obtain good clear grain timber at a price you can afford.
     
  7. FastLearner?
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    FastLearner? Junior Member

    It is a well-accepted fact that wood, in combination with epoxy, glass fiber and perhaps other reinforcements, is a far stronger material for boat building that steel. Wood is easy to work with and easily obtained, and requires less expensive tools. Steel is very heavy and is usually a poor choice for small to medium sized boats. For larger boats (and for professional builders) a case could be made for steel. Otherwise, wood/FPR is usually a better choice.
     
  8. MikeJohns
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    MikeJohns Senior Member

    Depends on size of course. Smaller lightweight boats with smaller scantling numbers benefit from wood-epoxy or ply construction and are considerably stronger weight for weight.

    As the vessel gets larger this changes. Also smaller boats of heavy displacement suit steel construction admirably, smaller light weight designs should not be built in steel and it is entirely unsuitable in this case.

    We need to ask Garth what his intended use is.
     
  9. MikeJohns
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    MikeJohns Senior Member

    Metal yachts tend to take collision with better results due to their reserve strength past yield. The Titanic and Sheffield..........!:rolleyes:

    100 years ago nearly all small boat yards built in wood so this is just what we would expect. Those built in steel were rivited and a large proportion are still around and of course none were built in Plastic.

    Actually wooden boats of some vintage wil have been extensively re-built and re-fixed over their life .

    And yet I see a lot of rot in wood-epoxy laminates. This is often very hard and time consuming to repair well.

    And lots and lots of time. Given the same amount of time you can make an elegant hull out of any boat material.
     
  10. FastLearner?
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    FastLearner? Junior Member

    Consensus shows your experience is not representative. Steel requires care just like wood/FRP, and rust and electrolysis can be a major problem with steel.

    There is no perfect material for boat building, but some are better than others for particular applications. Before making any blanket statements we need to know what the poster plans to build.
     
  11. Redsky
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    Redsky Senior Member

    my vote currently goes to steel.rivited construction...for hull/frameing.wood upperworks.i like clear coat myself,
    under consideration is concrete.ballast/backing/smoothing of hull below reg waterline for a motorsail. which my understanding of recent comments else where adds a ton of impact str and support agianst objects strikeing/grounding agianst hull and provides ballast for a sail component. all exellent engineering points in the eng art of making 1 thing do 2 or 3 jobs at once. and riviting well i wanted to avoid changing the sheet's structure in the area of joining like arc welding does like welding a tang on a already temperd sword is not a good idea,
    so anyway whats the kind of boat? :>
     
  12. Poida
    Joined: Apr 2006
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    Poida Senior Member

    I would love to build a steel boat, mainly because I am in the metal trades and would be the easiest for me to do, but, as stated they are not really worth building unless they are over a certain size and I don't have the room to build it. Also a large boat needs mooring and you are restricted to the area you can use it, if it is not trailable.

    Mike you said that wooden boats have been repaired and altered over their life. That is because they can. That is one of the best points about a wooden boat is, they are easily repairable or altered. I have a timber boat that I am altering to suit myself, something I could not do with fibreglass.

    Another point in what materials to use in construction is insurance cost. Insurance companies don't usually like timber boats because when they catch fire they burn down to the waterline so expensive to insure.

    If I made a boat it would be in steel, especially if I was going long distances as not only fire can be a problem for wood or plastic boats but also floating sea containers can rip the bottom out.
     
  13. MikeJohns
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    MikeJohns Senior Member

    Perhaps your climate is kinder to cellulose , but it is prone to rot where the coatings stress fracture and one layer can rot unseen for a considerable distance leading to subsequent failure and rot and some painful and tedius reconstruction. The last such hull I surveyed (12 year old 25' Top Hat ) had an internal rotten patch around 1 ft square on the quarter/ transom join and it took a shipright over a week to fix it with tent and heater. The bill is going to be high and the hull is not as strong as when it was constructed.

    I do think it is still a good light weight construction method.

    As for rust and Galvanic corrosion (True electrolysis is rare) that comes down to maintenance and quality coatings. The modern epoxy coatings have made steel a very robust long term marine material. One of the attractive attributes of steel is its full welding strength allowing patches to be simply cut out and replaced without any tapering off and internal reinforcement. But well maintained it should never get to that since any Corrosion is external to the material and clearly evident allowing early treatment.
     
  14. Garth
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    Garth New Member

    metal or wood

    Well thanks for all your input looks like wood is your favorit and at a guess wood and epoxy
    i wood use wood for the deck. Is wood epoxy as strong as steel for the hull . is there such a thing as using a lighter gange steel and epoxy or are they not compatable
    i am waiting on a book the priciples of yacht design
     
    Last edited: Jul 29, 2006

  15. FastLearner?
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    FastLearner? Junior Member

    Garth - as I mentioned above, wood/FRP is far stronger than steel, pound for pound. Check out Dave Gerr's book "The Nature of Boats". Specifically, read chapter 47 which is entitled "Believe it or Not, Wood is Best", and subtitled "Why wood is, pound for pound, structurally the most efficient material known / How wood strengths can be maximized and weaknesses minimized in boat construction". In the above statements Gerr is referring primarilly to hull construction. As you may know, Gerr is Director of the Westlawn School of Marine Technology. I trust his opinions!;)
     
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