CSC 30 Catamaran- the coastal passage

Discussion in 'Multihulls' started by peterchech, Nov 29, 2011.

  1. rob denney
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    rob denney Senior Member

    Agree about the model.
    Your call on how you build it, but there is a big difference between conventional building with foam/balsa and infusing flat foam/balsa panels. And an even bigger one between infusing and intelligent infusing, described in my previous post.
    If you have enough room for the finished hull, you have enough room for a table and can build all the panels before you start assembly. If the table is not big enough, add a rebate to the foam edges and glass them together. You can also do this with ply, it is much neater than butt joins.
    Marine ply with the WEST recommended 3 layers of epoxy one side, glass the other is not cheaper than infused balsa and polyester, in Australia.
    The big plus with infusion is the lack of mess, dust and contact with nasty chemicals. And much less (or none) of "all the sanding involved".

    A 32' long, 8' wide table can be assembled in a day from 8 sheets mdf. A full length panel can be cut to shape, set up, infused and removed the next day. No dust, no grinding, no sticky resin on self and tools. If you want to, you can then use this exactly the same way you intend to use ply for your jigsaw assembly.

    Re Polycore: Great stuff, but if you are going to vacuum bag it, make sure you have the sealed version.
     
  2. UpOnStands
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    UpOnStands Senior Member

    any hints on stopping outgassing?

    some builders have had a real problem with outgassing from the balsa.
    lots of pinholes in the epoxy.
    is it a problem?
     
  3. Steve W
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    Steve W Senior Member

    Not with infusion.
     
  4. Steve W
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    Steve W Senior Member

    Outgassing can be a problem in hand layup situations even with glassing plywood if you do it on a hot day with the temperature still climbing. It is best to wait until the temperature has peaked for the day and is trending downwards. I don't use epoxy with balsa preferring VE. I know Bob has complained about a lot of pinholes in the balsa duflex panels. I think they are done with epoxy, I'm just guessing here but I would think they would be press molded in which case I would not be surprised to see pinholes as they would be in a heated press to achieve quick cycle times.I have pressed snowboards with epoxy at 100 degrees c and de mold in 12 minutes which I would think you would need to do if you are making a run of panels for a big cat kit. I am just guessing though.
     
  5. Gus7119
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    Gus7119 Senior Member

    Hey Jeff as I am the one building one of these for myself. I Have built one with a boat builder b4 but now want to start on my own as wifey gets sea sick so sold mono hull. The models great and if you go back a few pages hes drawn up a design in cad also. The coastal passage web site has the full, if limit, plans on their site just search google for frwe csc30 plans.
    Now thats out of the way we are trying to finish the plans started by Coastal and make full cabin not coach house. Isisladelobos has contributed heaps and we must thank Bob who did the origonal starting drawings. But we or I am looking for anyone who has skill qnd ideas about the boat to contribute. Then I'll with the help of everyone concerned put together a comprehensive set of plans and photos from my build and offer them free.
    I have spoken quickly to a boat builder who reckons that you could increase the size of the bulkheads by 400mm at each section making the bottom 800 instead of 400 the second 1200 instead of 800 the 1600 and so on. Youll need to look at the plans to see what I mean as I cant publish the plans as they are copyrighted and do not have permission to publish.
    I have2spoken to a naval architect but it seem logical but would it through all the ratios out such as water line and such.

    O and its being built out of ply as Im a carpenter have limited space and the cost is cheaper. So please take that into account as I cant build it out of anything else.

    Cheers Gus
     
  6. Gus7119
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    Gus7119 Senior Member

    Gday thanks for the info. One reason for the ply is Im a carpenter so wood is good. No I dont have anything against core but the initial cost is what gets me. And I am by far not a rich man and will be do a buy of supplies on a weekly basis so wont get the bulk discounts making it cheaper. But I do understandwhat you are saying.
    But that said I have worked with both at boat sheads and if I could would to core.
    Now a question you may be able to answer. I was thinking maybe of doing fit our with the honeycombed cardboard or foam?? Not sure what it is just that its really lite and easy to work with. Do you know anything about this? Does it need to be soaked all they way through with resin or do you surface paint it if you understand what I mean.
    Also as You know know Im not changing from ply Id love any input and ideas. As you can see isladelobos has really run with it since my first post. He finished his moddel b4 mine and has done some cad drawings. I am hoping to have full plans and photos of the build so we can distribute it free to anyone interested so people without the 3000 to 6000 dollars for plans can get a start.
    Please have a look a Bobs site which has the plans he started but are copyrighted so youll have to search csc30 free plans on the web to find them. We are going for a full cabin instead of a cuddy and looking for input from anyone intrested and with the knowledge.
    So I hope to hear from you again and would recommend that read the thread through from about page 7 I think as thats about the place thw thread started again after its initial posts from around 2010.

    Cheers

    Gus
     
  7. Gus7119
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    Gus7119 Senior Member

    Necessity to use Hardwood of Pine Marine Ply

    Hi all
    Heres a question that may be silly. But as the saying goes there are no silly questions just stupid ones.
    It seems Leon has used pine ply, may be marine grade may be not.
    But could you make the biat out of pine marine plywood with an outxome of a long lasting boat? Because you are west systeming it wouldnt give you a good strong back bone or not?
    Part to to the question is if pine marine ply sucks. Then Im thinking that a mixed hardwood plywood ofcour4marine grade will do the job just as well as any hard wood ply or am I wrong here?
    Ive been searching for an answer on the net but all that is said is 'for god sack use marine ply" which I was always going to do but the price point between the two is huge.
    Also many people say that external ply that is available in Australia would also be fine. But please if anyone has an answer to the pine/hardwood question. And I do know harwood is much stiffer but is the difference when complete a massive one. Please explan the diffrence and pro and cons if anyone out the knows.

    Cheers in advance
    Gus
     
  8. cavalier mk2
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    cavalier mk2 Senior Member

    #1 thing in ply is the glue, is it exterior or some urea formaldehyde etc...? Some pines like yellow pine ply have a natural oil that may resist bonding with epoxy so figure out what you have there is Oz. It is never in your best interest to skimp on the hulls of your boat. Everything else can be bought used and upgraded later but the hull is the foundation and what you are stuck (or unstuck) with. This also means the design, saving a couple of bucks here will never pay off if you ever sell.
     
  9. redreuben
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    redreuben redreuben

    The gold standard in Australian plywood is Hoop pine which is plantation grown and quite a different timber to Radiata type pine. It is top quality but heavy compared to others, then there is imported like Meranti and the beautiful and light Okoume or Gaboon (same thing). Epoxy is good stuff but it isn't magic, rubbish wood is still rubbish, even if it's waterproof.
    The cost of the entire boat is what $30k in materials plus labour, the difference in ply is a few hundred bucks plus the payload loss of using heavier but cheaper ply, you will never get that back.
    I would use gaboon, resale value plus payload.
    Good luck.
    http://boatcraft.com.au/Shop/index.php?main_page=index&cPath=56
    http://www.denmanmarine.com.au/overview.php?id=10
     
  10. Steve W
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    Steve W Senior Member

    The only advantage okuome has going for it over most other spieces is its light weight and this is a big advantage, other than that it is not particularly attractive and is no more resistant to decay than many other lower cost species such as radiata pine but it is built to bs1088. It is rated as non durable as a species and does rely heavily on proper epoxy protection.
     
  11. Gus7119
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    Gus7119 Senior Member

    Any ideas on cost lets say per sheet of composite material?
    And the general take is pine sheets I see. Strange only because in building we recommend hardwood for its strength and longevity. Any reasons why mixed hardwood and hardwood marine ply is the cheapest and not regarded as being as good that anyone can explain.
    Also am I right in thinking that here in Australia due to us being such a nanny state, a bad thing mainly, if it says it marine ply then it is unlike what I read about othe countries where marine ply can end up not being marine grade glue.

    Cheers
     
  12. Mr Efficiency
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    Mr Efficiency Senior Member

    Hardwood will be much heavier for the same thickness.
     
  13. CT249
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    CT249 Senior Member

    Is she definitely less seasick on a multi? People have huge variations in the type of motion that makes them seasick. If someone says "I got sick on a mono but not on a cat" then that's just the way their own vestibular system works and it doesn't mean that a cat is better. It works the same way backwards, of course.

    This came up in the work of my wife, who is a neuroscientist. It explains why people like me don't mind a cat, don't mind a lightweight mono, but dislike the motion of a heavy displacement mono; no one type is better, it's just our own body's individual reaction.
     
  14. Gus7119
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    Gus7119 Senior Member

    Cheers mate. I agree with you and the research. Im sure alot of it is in peoples heads O Im going to get sea sick. But Ive been in monos since I was 5 and only been sea sick once in a force 10 while cooking steak for the crew on a delivery the smell of the meat did it to me.
    But the up and down motion of a cat seems not to make people who suffer motion sickness sick. People who are violently ill on monos seem to be very happy on cats. I think it has alot to do with being able to see everything 360 degrees plus a one directional motion instead of a three direction. As we will circumnavigate its important for her to be comfortable. And the room on a cat is a benefit for long times at sea. Dont know if youve spent more than a month on a mono it can get a little cramped. :)
     

  15. groper
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    groper Senior Member

    Hi gus - i built my 35ft cat in infused foam core panels as per Rob Denny comments earlier in this thread. The cost per 2400x1200 sheet is approx $280 which includes the consumables required to infuse it. Its a bit cheaper to wet lay them, but not worth the extra labour and mess...

    I built my entire boat, peice by peice, in a double garage... Each peice was assembled into the finished boat in my front yard under a makeshift tarp shelter. The benfit of foam core composite is light weight, no rot, and extra stiffness - dont need as many frames/stringers to keep panels stiff enough and this also means a cleaner look, easier fairing job inside unless your happy to line everything and that costs money and weight too dont forget...

    Building in ply is certainly cheaper - one of the other guys up here built his "easy 37" in BB face hoop pine ply cost about $40 per 9mm sheet. Im pretty sure it came from austal plywood, and it seems to be holding up quite well - no problems yet in the 5 years its been in the water... He reckons the hull cost him $40k to complete. After fitting it out, new rigging but second hand sails, the total cost was around $120k...

    If your building a no name brand cat like the CSC 30- use the cheapest of everything and plenty of used gear you can find, otherwise you will never get your money back on it - its financial suicide really... Another cat just got sold down our local marina - went for $140k after sitting there for sale for an eternity asking in the $300k range... bloody nice boat - i would have bought it for that if i had known it was going that cheap... same stories everywhere these days...
     
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