12 metre

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About 12 metre

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    English Bay

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  1. 12 metre

    Old Sails

    If it is, it's a problem I'd love to have...
  2. 12 metre

    Retrofit Composite Chainplates

    Referencing this: https://epoxyworks.com/index.php/if-you-were-just-more-flexible/ Typical strain to failure for CF ranges from 0.5% to 2.0% High modulus CF being at the lower end. Typical strain to failure for WEST System epoxy is 3.5% to 4.5% Typical strain to failure for e-glass is 3.5% to 4.8% Agree that as long as the resin has higher strain to failure than the fibre, it is okay. However, with epoxy/e-glass, the composite can strain more prior to failure, allowing the epoxy to take up more of the load. Admittedly this is a small amount, but it does help. I should have been more specific by saying " If tensile strength rather than stiffness is the desired goal, UD E-glass is almost as strong as carbon", but I thought one would have figured that out by my quote from the article. Nowhere did I say e-glass was almost as good in flexure, but again I thought one would have figured that out when I said "...strength rather than stiffness" since flexure and stiffness go hand in hand. My main point was not to rip on carbon but that some people spend a lot of money fabricating carbon fibre parts when e-glass may be just as suitable.
  3. 12 metre

    Pulsing in rudder/tiller

    Yeah, my bad...but I thought it made for an interesting video nonetheless...
  4. 12 metre

    Pulsing in rudder/tiller

    The rudder will be shedding vortices especially upwind or reaching - kind of like the video below: which would tend to excite any weed wrapped around it - so you can see how it could cause vibration.
  5. 12 metre

    Corby 33 Rebuild

    ;Like this: http://microspan.typepad.com/ircboats/specifications-corby-33.html Typical heavy IRC thingy.
  6. 12 metre

    Retrofit Composite Chainplates

    The chainplate is in tension but the bond to the hull or bulkhead is primarily in shear. IIRC you use 15 MPa (roughly 2200 psi) as the shear strength for epoxy laminates. So in imperial units, the bonding area should be at least equal to total shroud tensile strength x an appropriate SF / 2200. For example if total shroud tensile strength is 15,000 lb and a chosen SF of 3, then bonding area is 15000 x 3/2200 equals about 20 sq inches. Not much really. If wrapped around hull or bulkhead that is 10 sq inches per side.
  7. 12 metre

    Cool fairing tool

    The cabosil makes it harder to sand. Have you ever tried straight microballoons? I have fiddled around with it and I can get it to a decent consistency to apply if you mix in enough, but wondering if it becomes too dry in the process of doing so. I like West 410 and S3 Quikfair (although less so than 410) but both are more pricey than micro balloons.
  8. 12 metre

    Florence

    Probably similar to the explanation of Hurricane Patricia back in 2015. That one was in the Pacific of the Mexican Coast. There is a thread on here somewhere about it. Maximum sustained wind speed of 215 mph which by the time it made landfall in a rather less populated area was down to 150 mph and quickly petered out after that. Meanwhile, over in the Philippines, they are going to soon be dealing with Super Typhoon Mankhut (equivalent to Cat 5 hurricane) https://www.cnn.com/2018/09/14/asia/typhoon-mangkhut-philippines-intl/index.html with current wind speeds of 180 mph.
  9. 12 metre

    Is 'All pink on the outside gear' cool?

    It's definitely cool if you are doing it for the Seattle Pink Boat Regatta
  10. 12 metre

    Mo Bettah Too

    I would prefer the holes to stop short of the vang attachment.
  11. 12 metre

    Foam deck

    Isn't that the 1D35 that was "stolen" a couple of years ago? Any update on exactly what transpired?
  12. 12 metre

    Mo Bettah Too

    Agreed. Here is a repost of a closer shot of the rudder SJB posted a few weeks ago together with the most recent photo. To me it looks like the rudder has dropped 3-4" since then, In the previous photo, it looks like there is very little gap and the notch looks fully contained within the vestigial skeg.
  13. 12 metre

    Retrofit Composite Chainplates

    Further to what Hughes said, I can't figure out why everyone is so hung up on carbon. If strength rather than stiffness is the desired goal, UD E-glass is almost as strong as carbon. https://www.christinedemerchant.com/carbon-kevlar-glass-comparison.html One of the things working in favour of E-Glass is that it is a better match with epoxy than carbon - in the sense of matching elongation to failure. Quoting from this article: "...In the end if Tensile Strength is your only concern, save your money and use e glass."
  14. 12 metre

    shit show (front page)

    I was under the impression KZ7 was solid glass, which was why inspectors drilled small holes to verify thickness and ultra-sounded the hull to check for voids.
  15. 12 metre

    Keel Bolt Questions

    A pound IS a unit of force. A slug is the unit of mass in imperial.