Small Tri's under 20', any mention of foils is banned..

Discussion in 'Multihulls' started by waynemarlow, Jan 13, 2015.

  1. Bfrancis
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    Bfrancis Junior Member

    patzefran,

    Thanks for your reply.

    I would love to see some pictures of your build if you were able and willing to share some.

    How do you think the boat would be with Hobie 18 parts ?
     
  2. Bfrancis
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    Bfrancis Junior Member

    Makenmend,

    I just had a look at the study plan, I almost think the removable cabin version of the Strike 18 might be much better looking. Does anyone know if this version has been built ?

    I would love to see pictures.
     
  3. makenmend
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    makenmend Junior Member

    Bfrancis, I don't know of a strike 18 finished with the optional cabin, and haven't seen a picture of one to date.
    Hope to have mine done by June, including the cabin. Right now the main hull is done, and working on the pivoting beam box's.

    MM
     
  4. ThomD
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    ThomD Senior Member

    You are right but gliders are a very different thing. That is more like having a discussion about spars. No way you can compete on free standing spars, or maybe much of any other type, wood to composite, meaning wood to carbon. But the vast majority of a trimaran platform is enormously low tech compared to that, and that is why wood can compete. It basically has to do with very thin things that are highly stressed, vs. thick things where the geometry helps a lot.

    One glider that greatly interested me was the Carbon Dragon. It is a microlift glider, which is a type that will float in virtually no wind, hover like a hawk, There are very few of these, two of them are all wood, but I think they got jammed into the cat, and probably are nowhere near the performance. The CD itself uses carbon, but I was rather surprised how little it actually uses, a few pulltruded rods in the spar, and a boom are the most of it. Almost all the rest is standard wood construction. But of course when you get into impossibly high aspect ratio wings and huge speeds wood is left a long way behind. And doubtless a better CD could be made with a more extensive budget of composites.
     
  5. ThomD
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    ThomD Senior Member

    There are so many Trems, it is hard to know which one you are referring to. I would take any trem with built amas over any of the other boats you mentioned except if one specifically wanted a smaller boat, or wanted to trailer, in which case a Scarab. Keep in mind that the Scarab 18 weighs what the Trem or KHSD 23 weigh, and almost certainly costs more, and takes longer to build. Scarab 18 is one of my favourites as far as I can tell without building one, but the reality is as stated.
     
  6. ThomD
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    ThomD Senior Member

    I think the latest Scarabs are nice looking. Not the state of the art, but really, those boats are 10xs the trouble. I remember reading the number of molds that where involved in Richard's Fire... whatever. It was stunning. You can actually do a lot to make some of the boats look a lot better if you detail them better, and that is something you can do over a period of ownership.
     
  7. waynemarlow
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    waynemarlow Senior Member

    I am still not convinced. By going the carbon and foam route, for about the same effort and not a lot more cost, you would end up with a far nicer looking boat, that is lighter, looks like it was designed in 2015 and has far more residual value when you come to trading up or down, when you get bored with this one.
     
  8. patzefran
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    patzefran patzefran

    Bfrancis,
    Thanks for your reply.
    I think original Hobie 18 hulls lacks volume, Hobie Tiger or F18 would be more adequate for Strike 20. I will post a link to puilding progress as soon as possible. All the bulkheads are built now, but I have to wait April to resume building.
    Cheers

    Patrick
     
  9. ThomD
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    ThomD Senior Member

    No way of knowing for sure. But the best way to keep the price down and the performance up is to not use hobie amas, those things are crap. Nice concept, bad idea. Tornado hulls on the right size boat are OK. It only takes a few day's work to make a set of tortured ply hulls, they have a better shape than some of the designs under discussion, are about as light as it is possible to make any material, they will work great. The Hobie rig will pull your boat. It marches my 24 along just fine, it would be a lot for me on a much smaller boat. With decent foils the boat will not be a dog.

    If the main hull is a dory that will be a bit more of a pig than a round hull, but depending on displacement, it should still be very easy to push. It is easy to paddle my 24 round hull with an SUP paddle, and one can't really get into a good position, or use a full stroke. I remember once leaving the sail up while dropping some folks off at the shore. A tiny puff came up and it was all I could do in full tug of war mode to hold the boat from running up on shore, and I weigh 250. So if a 24 is easily paddled but it takes everything one has to stop even a light puff when the sail is up, you can imagine the performance potential there is when it really blows.
     
  10. ThomD
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    ThomD Senior Member

    There is no doubt those are higher performance materials. I have never seen anything in the real world that indicated it would be as fast or cheap to build. Unless 10 fold increases in cost and time are not a lot.

    What we also know is that as sailed by the Gougeons, their ply tris with modest carbon budgets regularly outsail boats that cost a million. You could probably make the structure of an Adagio for 10-20 K. It is less than 3x heavier than the Scarab 18, at 35 feet, and consists of essentially the same materials, glass, epoxy, ply, and primary lumber. There is always a lot of talk about the next great pie in the sky thing, but for the price of a few sea kayaks you can have a decent sized try in the sub 30 range, and actually be a sailor. But what we have is a lot of tire kicking.

    I had an interesting comparison to this with my boat. There was a listing last year of a carbon tri either 22 or 24 foot nominal (actual OAL was 2 feet shorter). So either way it was shorter than my tri., It weighed I think 600 pounds, all carbon, and cost 30 K (announced). You can build my boat for around 3-6K, and it is larger in every dimension, weighs 800. The resale of the carbon boat though it isn't a Farrier, would have to be better than mine, but I can only loose 3K on mine. I doubt that is the case with a 30K carbon tri, nobody has every heard of. You can spend 10 years building a beautiful tri like the Echo, and it still won't hold more value than a Hughes, and you never get that time back.

    Then the next thing they want is a 33 foot spar on the 600 pound boat. Where does the rigting moment come from? You end up having to add in more weight anyway, so what exactly was the point of the large carbon budget?
     
  11. waynemarlow
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    waynemarlow Senior Member

    Interesting how your lifestyle and work dictates your views on things.

    I work restoring and renovating very old houses, half the problems I deal with are wood decay and wood not behaving as it should when put into places, where it shouldn't. It's a really frustrating slow process to chop out the old and replace with new.

    Equally for a while I was restoring composite gliders when the pilot got things wrong when nature threw a curve ball, great fun and where I learnt the benefits of modern materials.

    So you can now see why I lean towards composites, it doesn't rot and I understand how to deal with it. To now learn wooden techniques would be a retro step for me.
     
  12. Gary Baigent
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    Gary Baigent Senior Member

    I'm always astonished at the high boat weight figures published, even if using carbon.
    Sid is 8.5 x 8 metres with a 11.5m wing mast (around 27 feet length/beam, 38 foot mast) and the whole boat weighs 230kgs - built in low technology tensioned ply, glass with some carbon reinforcing, a la Gougeon philosophy. And building it myself, it cost maybe 7 grand NZ dollars including North main and reacher sails.
    A 6 metre version should be easily half that weight - and half the price.
     

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  13. Bfrancis
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    Bfrancis Junior Member

    Thanks all,

    Fun fact, it seems that there are free plans to ply tornado hulls out there. That could be an option.
     
  14. waynemarlow
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    waynemarlow Senior Member


    I could turn your answer around and ask why Sid is so heavy, my A class cat is 6.5m x 2.3m and only 75kgs, if you doubled its size I would expect Sid to be in the 150kgs bracket :cool:

    Gary even you would have to admit you only have a minimilist boat there in Sid, you don't really have any Amas and minimal cabin room. What most boat plans on the market are designed to have large conventional Amas can carry lots of weight and don't have fffffffoils.
     

  15. Corley
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    Corley epoxy coated

    Due to the square cube law twice the size will be much more than twice the weight. As an example a carbon Marstrom 32 catamaran weighs 500 kg
     
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