Lighter weight boats ??

Discussion in 'Fiberglass and Composite Boat Building' started by tunnels, Aug 31, 2011.

  1. tunnels

    tunnels Previous Member

    Ok
    Light weight boats for the future . But how light is to light ??
    I work with a sales person sitting in the same office and when i said the boats we are making are way to heavy he just about threw something at me , Boats have got to be heavy !! I asked but why ? Because they dont ride well and uncomfortble if they are to light , That was the only valid reply !!!.Heavy is good !!! POPPY COCK i say !!
    TO many boats out on the water are way to heavy ,
    A brand of motors ,Vee 6 , did a copy of another well known brand of motor and took more than 50 kgs off the weight of just the motor with out getting to carried away , not counting the gear box and other bits !!.
    In a 36 foot hull just simply by changing the laminating schedual its possible to take 100 kgs of resin weight out of the solid glass laminate just doing wet on wet lay ups using the same amount of glass !! simple ??
    So is it time to rethink what we do and how we do it and have a serious look at the shear waste of materials and cost and the cost of those materials wasted and make boat lighter just by doing things differantly ! :D
    There are for's and against's of Cored hulls , if done well they never have a problem so why are lots a manufacutres still making solid glass hulls .
    I have been sitting looking at a set of plans for the next 48 foot boat we will make and the laminating schedual is crazy beyond belief !! (mind you it all came from Australia !!) The designer must have had shares on a resin and glass supply company some where .. :mad:
    So how do we make boats lighter thats my question??? :confused:
    .
    I know what you are going to say resin infuse but for us it like going into space in just your undies and without a space suit !!:eek:

    :p
     
  2. PAR
    Joined: Nov 2003
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    PAR Yacht Designer/Builder

    Boats have gotten dramatically lighter in the last half a century. They got equally as much lighter in the previous half a century. I currently own a 63' LWL yacht that is 12 tons. How light do you want? This isn't the lightest you can get, but it does rival some.
     
  3. masalai
    Joined: Oct 2007
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    Location: cruising, Australia

    masalai masalai

    Tunnels, Your question to be answered needs "qualification" as boats are a compromise and the design is to meet a need or a cruising/racing area...

    Look at the style of boat in the America's Cup before a certain Mr Bond (not James) acquired the 'famous cup' - designed and optimised for the local US round the buoys racing at that time of year...

    It is all a matter of where and for what purpose... What sea state can be expected for the "sailing season"... What type of sailing will be expected - - liveaboard cruising, - motor-sailing, - maximum use of sails, - able to push through any seas/storms, - motor boating at 'displacement' - or - planning speeds and so on ........ Each may be best served by differences in displacement and a myriad other criteria...

    As a manufacturer, you need to look at what the market mood dictates... fuel economy means light and easily driven with perhaps some motor-sailing capability...

    On the pylons up near the botanical gardens on the Brisbane River, would be best served with a relatively heavy catamaran, as the wash from passing boats ensures that skinny hulled mono-hulls never stop heavy swaying from side to side ALL NITE LONG... as one live-aboard complained... or fitting hammocks that are swung in line with the keel... Look at your market, determine what would suit most-new-boat-buyers and market / promote the merits of your design to overcome the perceived advantages a new owner will-appreciate / is-seeking...

    Hard chine using DuFlex, (end-grain balsa with a layer of woven "epoxy-glass" on each side), is about the lightest and cheapest construction for 'one-off' building - it can also look pretty smart as in the new boat built for Stefan (of Queensland hairstylist fame)... That is what was used to build my boat... http://www.boatdesign.net/forums/boat-building/my-little-piece-peace-25962.html
     
  4. tunnels

    tunnels Previous Member

    You are completely missing the point !! do you have trouble sleeping at night ??:eek:
     
  5. groper
    Joined: Jun 2011
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    Location: australia

    groper Senior Member

    well ive just been considering all my options to build my next 1 off boat... considered infusing my own panels and a myriad of other construction methods... but at the end of the day it looks like the duflex balsa core panels are hard to beat... very light, high strength and the cost is around equal for any other composite materials to scratch build a comparable structure using foam cores... add in a small charge for CNC routing service and the amount of labour saved laminating and cutting makes great sense...

    How can you build lighter? easy... with properly engineered composite sandwich structures...
     
  6. tunnels

    tunnels Previous Member

    wow i think the point is being missed here .:eek:
    I am talking about production boats ,ones that come out of moulds and are in every day use the ones our marinas are full of . Those great things you see when you go out fishing with bow wave that are scary to see coming if your in a 14 foot open boat and no where to run from it .
    So lets get our thinking back on a even keel . :D
     
  7. Steve W
    Joined: Jul 2004
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    Steve W Senior Member

    I agree its a problem and i think it is an attitude problem, if everyone in a company has the mantra " Take care of the ounces/grams and the pounds/kgs will take care of themselves" beat into them huge weight savings can be had. In other word, weight savings are cumulative, look at every item that goes into the boat, not just structure.I think that cost is more of what drives the purchasing department in selecting equipment for example,do they even look at weight when ordering a genset? How well does the laminating department control resin/glass ratios in many production shops?
    Steve.
     
  8. tunnels

    tunnels Previous Member

    Yes at last a man after my own heart !! I agree its a accumilative problem and comes as a total package Not just isolated departments but all . Gensets ,water makers,and a great bank of batteries !etc etc Yes you have it !!!:D:p;)
     
  9. masalai
    Joined: Oct 2007
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    masalai masalai

    Only need to return to wander in my boat... Feel "out-of-the-water" and in the wrong place when I am not cruising - (just another confused misfit of society)...
     
  10. masalai
    Joined: Oct 2007
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    masalai masalai

    Ahhhhh Now I see the root of all evil therein...

    Better quality control and an experienced sailor needed to determine choices NOT the accountant...

    I was discussing this aspect the other day, and it seems that many chandlers and "purchasing departments" are needlessly driven by accountants and and the "placement-of-sexy-brand-names" to appease the retail buyers with erectile-dysfunction, who will leave his boat languishing in a marina until the annual 400-litre outing after the bottom has been cleaned in the seasonal haulout...
     
  11. CatBuilder

    CatBuilder Previous Member

    I think there is once sentence that sums it up, given that many people in the new boat market are looking for "something they can afford."

    "Light boats are expensive to build."

    That's pretty much it. If you stick to the old solid laminates, don't look at the lightest new galley stove or toilet (head) seat, you save a lot of time and a lot of money on the build.

    It's much easier and more cost effective to just slap it all together and not worry about weight. This gives the production company a better margin. Heck, they can even use an old mold since the design isn't changing so much! :) The production company gets a good margin and a the customer gets a less expensive boat. Win/win, unless you are interested in efficiency or performance.

    By any chance was it the sales/finance/business guy that nearly threw something at you?
     
  12. PAR
    Joined: Nov 2003
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    PAR Yacht Designer/Builder

    My hull is a solid laminate, though it does have cored bulkheads and internal furnishings. It's D/L is in the mid 60's and it's SA/D is in the mid 30's.

    Again how light do you want to go?
     
  13. Submarine Tom

    Submarine Tom Previous Member

    I'm thinking an inflatable kayak, maybe 22 kg or so...

    -Tom
     
  14. Steve W
    Joined: Jul 2004
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    Steve W Senior Member

    Those are pretty impressive numbers Par, care to tell us a little about it?
    Steve.
     

  15. PAR
    Joined: Nov 2003
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    PAR Yacht Designer/Builder

    It's a mid 80's production boat that I happened into, when a very distressed owner approached me. It was in bad shape as it's life hasn't been good in recent years, but because the purchase was very cheap, I can afford to upgrade her and have some fun kicking local blue blood butt. It's not a boat I would have sought out, but given what I have in it and what I can get, when the markets rebound in a few years . . .
     
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