Scow Moth Designs

Discussion in 'Sailboats' started by luckystrike, Nov 26, 2014.

  1. luckystrike
    Joined: Feb 2010
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    luckystrike Power Kraut

    I think we both live in different worlds. I want this feeling!
    https://www.youtube.com/watch?v=vpPPYhM_2-U

    A "superb light wind performance" is not my goal. I want a early planing medium wind machine. I want it chaep to build and maintain and I want to have fun building it as well as learning how to construct a extreme lightwheight dinghy with "normal" materials.

    I think due to the simple construction methods of modern boatbuilding plans (fast to build) for amateur builders a lot of boatbuilding knowledge is lost in history.

    For example a 7m Buccaneer Trimaran is specified for 4mm plywood skins and this is a proven solid and long lasting boat. My feeling would be make it 6mm, but thats not neccesary. Iam looking forward to test my thoughts and feelings when I build my Moth with 1,5mm ply (if I can buy some ply so thin) and doing all the tricks of the old to get this skinny stuff stiff. This is living on the cutting edge of 1970' boatbuilding technology.

    Sorry, this was little bit enthusiastic off topic.

    Michel
     
  2. CT249
    Joined: May 2003
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    CT249 Senior Member

    Nah, it's great.

    My last scow had a 1.5mm (I think) deck; there's still some spare in the shed, I think. You could cut it with scissors, which made repairs dead simple.

    Ian Outhred of traditional boat design fame used to sail Moths from my club and did a series on Moth construction eons ago in Australian Sailing mag. If he's still designing it would be great to see his ideas on a modern scow.
     
  3. NoEyeDeer
    Joined: Jun 2010
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    NoEyeDeer Senior Member

    You can easily buy birch ply at 1.5 mm in Europe, but it only comes in 1200x1200 sheets AFAIK.

    Over here we can get hoop pine marine ply, made by Austral, in 1.5 mm (I've just used some for laminated oar blades) and several years ago I remember using some 1.8 mm gaboon ply, although I can't remember the brand (it wasn't Bruynzeel, and wasn't all that good).
     
  4. The Q
    Joined: Feb 2014
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    Location: Norfolk, UK

    The Q Senior Member

    My example of the British Moth site was to:
    A, To show there are a suprising number of different designs Under the "Moth" umbrella,
    B, The Britsh Moth can also be home built and since you are building a Moth to your own requirements you can pinch Ideas from any class.
     
  5. Richard Woods
    Joined: Jun 2006
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    Location: UK, USA and Canada

    Richard Woods Woods Designs

    I raced a scow Moth (Imperium) as well as several skiffs in the UK and Europe in the 1970's. The scow was clearly slower than the skiffs unless it was flat water and over 15 knots. In a short chop it was horrible and very wet. You don't sail one flat, it has to be heeled.

    It has more surface area so is very difficult to make as light as a skiff, hence the 1.5mm ply skins. The skiffs used 2.5mm. So even more prone to damage when beaching, although I assume you mainly sail in sand/mud.

    100kgs is very heavy for a Moth, 70kgs is the norm.

    The tunnel hull had to stop where it did (700mm aft of bow from memory) because the Moth rules do not allow catamarans (although the new boats are essentially trimarans as they have foam buoyancy in the wings)

    I think the British Moth is only ever sailed on rivers and lakes

    Check this

    http://books.google.com/books?id=6g...6AEwAA#v=onepage&q=iain oughtred moth&f=false


    Richard Woods of Woods Designs

    www.sailingcatamarans.com
     
  6. Doug Lord
    Joined: May 2009
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    Doug Lord Flight Ready

    Moth

    As I understand it the latest foiler Moths are about 66lb(30kg) all up(or less). The Mach II Moth has a hull weighing 18.7lbs(8.5kg)!
     
  7. Richard Woods
    Joined: Jun 2006
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    Richard Woods Woods Designs

    I was referring to the crew weight, the OP says he weighs 100kgs

    Richard Woods
     
  8. Petros
    Joined: Oct 2007
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    Petros Senior Member

    go do a search for "classic moth", it sounds exactly like you want. you will find lots of free plans on the internet. A classic moth keeps the design simple using low cost materials, no foils or exotic materials allowed, (keeps cost down) and they make good fast sailing dingys. So the skill level is not nearly that of the foiling moths.
     
  9. SukiSolo
    Joined: Dec 2012
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    SukiSolo Senior Member

    I have managed to find 2mm Gaboon (Okume) marine ply in the UK in 2.5 X 1.25m sheets and this is lighter than the 1.5mm birch aircraft ply. So it may still be available,

    Yes Doug, the weights you quote for the hulls are pretty much correct, but Richard is also right in that even at 80Kg you are a bit too heavy for a foiling Moth. At least that has been what some of the Moth boys and girls have told me. Quite a few sailors are closer to 60Kg, hence the attraction to late teens, early twenties before you 'fill out' a bit!...;)

    Back before the hulls went narrow, I sailed and raced a couple of Moths, Shelley Mk3 and something else. Fairly interesting on the non tidal Thames! but far quicker than the British Moth which is not a good boat for choppy waters.
     
  10. JRD
    Joined: May 2010
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    JRD Senior Member

    Sorry its not a scow but I have been following this blog of a John Shelley moth being built. The author has used nice simple construction techniques. If you look at the dates of his posts you can see he doesn't mess about either.

    http://johnshellymothboat.blogspot.co.nz/

    When I was learning to sail as a kid I always wanted a scow moth, by the time I was old enough they were pretty scarce in NZ.
     
  11. Richard Woods
    Joined: Jun 2006
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    Richard Woods Woods Designs

    I only ever saw one Shelley Mk 3 in the UK. The one in the blog shows how things have changed. It must be very uncomfortable to hike out compared to a modern design. And it's slower and because it is not self draining, more dangerous. Begs the question - why?

    Another problem with the scow Moth is that it has a very shallow hull, which makes it awkward to get under the boom when tacking and, especially, gybing

    Richard Woods
     
  12. JRD
    Joined: May 2010
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    Location: New Zealand

    JRD Senior Member

    The same could be asked of dozens of legacy classes worldwide of course. We have the 11' Zephyr class in NZ designed by Des Townson, a little more refined than the Shelley Moth but designed and mostly built in the 60 & 70s. Most are kept in immaculate condition by doting owners who will sail them until they can't walk anymore... in fact some see sailing as a higher priority than walking.

    I like self draining boats, carbon fibre masts and all that, but I think there is still just as much value in keeping traditional classes going if you're among friends.

    Jeff
     
  13. Moggy
    Joined: Feb 2011
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    Moggy Senior Member

    I raced a scow as a kid @ 6' and 75kg and yes there is not a huge amount of space. A 100kg guy is going to struggle... some of the classic skiff designs would probably be a better choice.
     
  14. luckystrike
    Joined: Feb 2010
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    luckystrike Power Kraut

    Hi Richard and all the others.

    Just a short look at my thread.

    You have missed some informations I gave to you, so here is a short update to stop misleading posts.

    I know that with 100kg Iam far to heavy to sail a (real) Moth. I will design a new boat suited for my physical dimensions. I expect the new "fat-mens-moth" to be 12' or 12.5' long to bring us into planing mode. I started this thread to seek for informations as a starting point for my design.

    I'am not interested in foiling or regatta, The design does not have to be competitive in any way, it's just planing for fun!

    I can handle a Laser or a A-Cat in terms of diving under the boom in tacks or jibes. Is this fit enough to dive under a moth boom???



    My intention for the Fat-Mens-Moth are:

    I want a cheap and light boat as a addition to my quartertonner. I want it to be car topable, so that I can load it alone and drive to the best spots with good wind and no waves.

    I think a Scow Moth is more stable than a lightwheight Skiff Moth, so better for that what I want. ... sailing, not swimming.:p

    I know that 1.5mm or 2mm plywood results in a fragile boat, I want to learn more about lightwheight construction methods. This has something to do with the beauty of such filigree bulkheads and stringers, building them and feeling how the structure works when the boat is on the water... not reading about.

    My normal workshop is not heated, so now in winter I cannot do any serious glueing or laminating. The room I use in winter has very limited space, so the project has to be small to fit into it. (You will see as soon as my building thread starts.) All this votes for the Scow Moth and this what I want to do.

    Best Regards, Michel
     

  15. The Q
    Joined: Feb 2014
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    The Q Senior Member

    I Know you are particluarly Looking at the Moth, but have you considered other designs such as the Phantom for which British champion was a few years ago 114 KG. They have been home built in the past and are known for light weight construction.
    http://www.phantomclass.org.uk/forum/index.php
     
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