Tri-ing? Yes very!

Discussion in 'Multihulls' started by Dodgey_rog, Jun 7, 2006.

  1. Dodgey_rog
    Joined: Jun 2006
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    Dodgey_rog Junior Member

    I'm building a 32' tri using kledgecell, glass roving & vinylester resin. It's my own design. To give myself a legup I aquired a free foam sandwich Y.W. Diamond, which I cut in half longways & spread it out 1200mm at the transom. After turning it upsidedown I attached framework & built a nice skinny hull shape. It's back up the right now & I'm starting to wack in a few bulkheads.
    Sounds kinda wierd but it's starting to look like the real thing.
    Don't know much about boat building- but I ask alot of questions. (justabout driven my local boat builder bananas)- Then I found this great site.
    So all you experts out there, don't hold back.

    Questions. Can you use epoxy over vinylester- I wanted to build the beams using epoxy.
    Anyone got ideas on beam construction- layup etc. Is it better to use ply or foam as a core. HIT ME.
    Dodgey rog. c/o bodgeit & legit- defrocked shipwrights!

    I'd also like to build a carbon? wing mast. What ideas?
     

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  2. hansp77
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    Location: Melbourne Australia

    hansp77

    Hey Dodgey,
    care to post some photo's of your boat?

    I know nothing about building with carbon, other than what I have read here, and it seems to be something that takes a lot of practice, and holds a lot of potential for things to go expensively wrong.

    Did you do the maths on your design to see if it will work properly? (not that I would know how)

    Goodluck,

    P.S.
    Is W.A. Western Australia?
     
  3. Dodgey_rog
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    Dodgey_rog Junior Member

    G'day hansp77.
    Thanks for your interest.

    I;ll post some photo's once I sort out how to do it!

    A while ago I purchased plans for a 22' tri. After studying the plans in detail, I realised it was a complicated little soandso and after many hours of slog I'd still end up with a small boat.

    There's lots of info that I'm scaling up.

    Dodgey rog. BEWDIFULL WESTERN AUSTRALIA!
     
  4. frosh
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    frosh Senior Member

    Kinda weird trimaran?

    Hi Dodgey Rog. Don't into the boat building business with a name like that!
    However getting back to the bisected YW Diamond. As a home trimaran builder myself, what you have posted so far does not completely make sense.
    What are the principal dimensions going to be, main hull, floats and overall beam. This will indicate to all us "experts" if you are on the right track.
    There is a lot more to building a 30ft. tri than whacking some hulls and beams together and sticking a carbon wing mast up. The stresses developed by this size multihull are huge, and it is both a science and an art to engineer the structurally loaded parts so that they can withstand more than the expected stresses, and at the same time not be excessively heavy.
    Your specific questions about epoxy over vinylester is fine, it will work.
    There are many ways of doing beams. Suggest you check out a few websites first. http://www.f-boat.com/ Probably the best allround small/medium tris available. Also this thread on this forum. http://boatdesign.net/forums/showthread.php?t=12015
    I wouldn't tackle your own mast until you have considerable laminating experience, and buying an aluminium mast section is probably a better option.
     
  5. Dodgey_rog
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    Dodgey_rog Junior Member

    Ive posted some photos... They're attached to my 1st post
     
  6. Dodgey_rog
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    Dodgey_rog Junior Member

    Hi Frosh.
    Good to hear from you.
    The hull's going to be wedge shape, With a v large cockpit aft.
    The floats are going to scaled up versions of the 22 footer-unless I can find anything better as I progress. Apart from the basic building principals that I've used from my smaller tri plans this boat is evolving week by week
    I anticipate the overall beam will be 26'.
    Thanks for your wise words about the stress factors. You're spot on there.
    I've owned a 19' Farrier Tramp {U.S. Eagle] for a few years and given it heaps without major drama. Which is surprising considering the mast has had 2.4 mtrs stuck on it and the forestay has been shifted to the bow.
    The poor little thing now flies an Etchell jib, a modified Nacra sq. top main with a luff of 9.5 mtrs and an enormouse lightweight reacher on a prodder.
    Apart from keeping a close eye on the leeward float it's a joy of a ride!
    Gives much bigger boats heaps.
     
  7. waikikin
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    waikikin Senior Member

    holding back[HIT ME}

    Dear Dodgey Rod, sorry, but she looks a horrible creation to me.It might well turn out OK but why invest good foam, resin, glass & effort into a bashed up diamond tri? To save some sqare meters of boat building?Dont make sense to me, resale on tris is hard enough, but that object aint gunna bring much, and every thing gets onsold one day.How about buying some good plans & have most of your building ? anwered & solved by a pro & then you'll more wisely invest materials & time in something much much better that is a proven design with vastly improved resale potential.Mate, tip it or turn it into a flat water party pontoon/ barbeque boat would be a better result. These kind of half baked boats have been holding back the overall good of pro designed multis.Apologies for being a wet blanket but sometimes these things have to be said.Regards from Jeff.
     
  8. frosh
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    frosh Senior Member

    Hi Rog, I am in Perth by the way, not very far from the Swan River where I do most of my sailing. There is a boat moored near my yacht club that is amateur built tri around 25ft. with a massive igloo structure in glass fibre mounted about centre of the craft. Unfortunately the mainsail had to be discarded and I have seen it attempting to sail under jib only. Absolutely terrible! This sort of abomination is maybe what Waikikin is referring to, and hopefully your tri will turn out much better. Some of what he says is quite correct however, although I think from the photos that the main hull is acceptable in shape if high performance is not an issue.
    Are the plans you have a Farrier 22? If so it looks a very nice day sailor.
    Creating something that is uniquely yours as you are trying to do is very satisfying with the following provisos.
    Money spent is almost certainly non recoverable. That is why my experimental projects are quite a bit smaller than yours, and the money is not that much. Also being smaller the crucial part, the engineering for strength and good performance is less critical.
    Assuming that you cannot calculate all the loadings on the crossbeams and rig with real accuracy there will be a risk that the thing could break in heavy weather.
    What are you intending to do about sails? This is a high cost item if you are getting them made, or do you have other options?
    Are you intending to cruise offshore, and who are you going to have aboard?
    If there is a serious breakage offshore in bad weather due to an engineering guestimate being wrong, are you prepared to take responsibility for others on your boat?
    If my experimental boat has a breakage we are only on an enclosed river and usually close to other boats.
    You need to think about all these things before you spend more money.
    There is another thread that is a bit similar which you should read. :)
    http://boatdesign.net/forums/showthread.php?t=7206
     
  9. Dodgey_rog
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    Dodgey_rog Junior Member

    Hi Frosh. Thanks for your input.
    Welll-I've finally crawled out of the corner of my room- stopped rocking to and fro- sucking my thumb etc. and the boot marks are begining to fade!

    I've presided over a few stuff ups in my life, t'is true, but I've got a good feeling about this effort. Still reckon a monumental stuff up is more spectacular.
    The reason I'm doing it my way is mainly because just about every tri design I've seen looks like a mono with floats on. So long as you don't make it too high or too heavy, there's alot that can be done above the water line. This will be fixed not folding. Never liked the idea of dragging a boat down the road- waste of good sailing time!
    Hey man, t'is better to have tried and failed than- you know the rest! And something to do with the journey as well as the destination.
    It also depends on your outlook on life.- I call 22' miniature- 30' small- 60'+ large.
    The plans I have are of a Ray Kendrick 22' Scarab tri- really like it but I can see now that I'm going to need something larger.
    Call me Daffy Duck if you like, but using a Diamond hull was a master stroke- a moment of sheer blinding genius. {being modest again]. I mean why spend hours and hours building a frame to bend stuff over when your frame can actually be part of your boat?
    I'm thinking of buying up all the available Diamonds so I CAN CORNER THE MARKET!- Cos I know there's going to be a rush on this once it gets out!
    As far as loadings go.- Because this is to be a cruising tri, I will err on the side of overbuild, which should not make the boat too much heavier.
    Coastal cruising is my bag which I don't think would present too many problems. The boat will have many water tight compartments, so even if it does break up there will be a fair choice of bits to hang on to!
    As for sails- I'm not too proud to accept charitable hand outs. I've already got my hands on a dacron main - fully batoned - with 3 [three] reefs- in good nick- which cost me alot of flattery and $250. I reckon I can scrounge up a suit of sails including kite for around $1000 . I reckon dacron rules. I've got sails over 20 yrs old that are still worth hanging up, and if you're not tearing round the cans abusing the crap out of your boat and crew- what's 1/2 a knot anyway?
    Still would like stuff about building composite beams and wing masts.

    Cheers Dodgey Rog.
     
  10. waikikin
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    waikikin Senior Member

    Dear dodgey , glad youve come out of your corner etc, a thick skin is the first hand out at our local school of boatbuilding knowledge, combine that with tenacity , integrity & hard work you'll have a fair shot at success with the project. As for a wing mast I can post you a cross sect piece of cedar/carbon wing of a shion wl 1160( featured on bruce hodgdens cd) as an example.The uncool vibe I layed on you- some times people dont come back from adventures at sea & thats pretty sad, could sway my opinion in these matters:(
    Cornering the market - I like that, diamonds are terrific value, how much stock can you get?Regards from Jeff.
     
  11. frosh
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    frosh Senior Member

    Welcome back Dodgey!

    Hi Rog, glad to see that you are able to weather the storm even before you hit the water. As Jeff said being able take some criticism, and take stock of the situation and continue on albeit very carefully shows you have the guts to see the project through.
    I would not build a boat these days to some-elses plans, not because I think I am better, but because I have different ideas about boats to the majority and need the challenge of trying out my own ideas in practice. This we seem to have in common, although I am not into cruising, a small boat is too confining to live in!
    You might like to contact Rob Denney, who lives in Perth and has designed and built multihulls, mainly proas. Really good heplful person who will steer you in the right direction regarding crossbeam and mast construction.
    Rob Denney:
    email: proa@iinet.net.au :)
     
  12. Dodgey_rog
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    Dodgey_rog Junior Member

    Hey Frosh & Jeff.
    I'm overwhelmed. Isn't this a great site.
    From being a cretin of the first order, to a person worthy of encouraging replies in the space of a few days!
    I've thrown away my matches and cancelled the skip. There's Fleetwood Mac and Eagles booming through my shed- the heady smell of resin is again up my nostrils- it's on again for young and old.
    WOOOOOOPPPPPPEEEEEE!
    By the way, I do have some qualifications. [not toadly hignorunt].
    It might surprise you to know that I have an honours degree in pencil sharpening, AND I majored in carpenters and graphite! [very tricky].
    SORRY SORRY SORRY- got carried away by the moment.

    Thank you for your help. You both obviously know heaps about stuff.
    If there's any thing else you think might be helpfull I'd like to hear from you- or anybody out there in ciberspace.
    I remain yours on the water. Dodgey Rog.

    p.s. By the way, all my products carry the famous Bodgeit & Legit 20/20 Warranty- 20 seconds or 20 fathoms- which ever comes first!
    Shouldn't joke about that , but I'm kinda on a roll!

    pp.ss. I'm not smokin or sniffin anything- just getting a belt out of life!
     
  13. frosh
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    frosh Senior Member

    Aluminium for crossbeams and mast.

    Hi Rog, I found these web sites for you that might save you heaps of time and probably money as well. For cruising you would be crazy to spend big bucks on carbon to make crossbeams and a mast when you can manage perfectly well with aluminium. For crossbeams a round tube would be fine. You need to estimate what diameter, wall thickness etc. You probably can get data on stiffness etc from the manufacturer. They come in 6 metre lengths which should be fine for 26 ft. beam. with possibly some wastage.
    http://www.onesteel.com/products.asp?action=showProduct&productID=1027&categoryName=Aluminium
    What about using a Tasker mast section for your mast in tempered anodized aluminium. Theye have people there to advise what section is the best for your boat.
    http://www.taskers.com.au/mastspars/hardware/sections/index.php#newsections
    I hope that this helps, and makes your headache a little better. :)
     
  14. Dodgey_rog
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    Dodgey_rog Junior Member

    Hi Folks.
    I was just wondering about centre boards, dagger boards & such & I was thinking [you know how one does] what about wacking a mini keel on each float? The draft could be about the same as the main hull & the area same as the centre board.
    Would it work? There would be a couple of obvious advantages if so, i.e. no centre case/ d-b case & the boat would dry out on the level.

    Like to hear your thoughts on that.

    CHEERS. Dodgey Rog.
     

  15. frosh
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    frosh Senior Member

    Hi Rog, you didn't say if you had made any decisions on cross-beams, and I was just wondering.
    Regarding foils for lateral resistance, if you are building a cruiser tri, you have a few options. Nothing wrong with not putting a centreboard into the main hull, in my opinion, although this is the usual trend. This may be partly due to the fact that access is better here than on the floats if the board has to be raised quickly, and also that you construct one big one instead of two medium size ones.
    Are you intending to make fixed stub keels for the floats? If you are hoping to go to windward reasonably well then these are contra-indicated. I don't know how much "on the wind angle" you would be prepared to sacrifice, but it has a lot to do with area, and aspect ratio, for starters. How about making drop down timber boards that have an immersed depth of about three times the chord measurement? You would need a case within each float, and once out on the water, drop the boards and leave them. The extra effort to build boards and cases would be worth it in the long run. If you do stub keels you still need to have them penetrate into the floats to support the lateral force that they will be subjected to. :)
     
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