Rossiter Pintail Mortagne sur Gironde, near Bordeaux |
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Laser 28 - Excellent example of this great design Hamble le rice |
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Laser 140101 Tynemouth |
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List classes of boat for sale |
V Twin |
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Steve Clark ![]() Newbie ![]() Joined: 14 Jul 05 Online Status: Offline Posts: 38 |
![]() ![]() ![]() ![]() Posted: 07 Jun 12 at 5:07pm |
I did some test samples with bamboo cloth that was being sold for organic surfboard construction. Pretty unimpressive really. Just a blotter to hold plenty of resin in place. I sourced one or two other styles with similarly unimpressive results.
As a surface laminate or laminate bulker it's probably fine, but as a structural skin, it does not compete with any of the standard reinforcements. The process of turning it into yarn and then weaving that yarn probably damages the bamboo fiber so it really is no better than cotton or hemp. The cloth I tested was for garments,so it's really not surprising that it didn't perform well as a plastic reinforcement. There is more to getting this right than running down to the fabric shop. Bamboo as a structural wood has many fine qualities, but stripped up into veneer and glued together into sheet goods isn't one of the obvious choices. A small stand will provide home grown tiller extensions and ski poles, which can be very green. And to pile on: surface area is the biggest driver in weight. With modern materials, you quite quickly get to the limit of what can be regarded as watertight and strong enough. This is something in the order of 200 g/m^2 carbon cloth on either side of 55 kg/m^3 foam. Depending on the thickness of the foam, you can predict that the best you is about 1 kg/m^2 of surface area. This goes up as you add bulkheads , local reinforcements, trunks and everything else that takes a flat sheet and turns it into something you can use. If you want a robust boat and capable of being slammed around in waves and getting mishandled a bit, the weight goes up. There are advances in fibers, nano toughened resins and processing because reinforced plastics is a fast moving technology with and a dynamic market. For a long time boat building was about 10 years behind aerospace. However in the recent past, the marine industry developed techniques for building larger pre-preg composite parts than was thought possible by aerospace..... so it's possible for industrially significant developments to come from our little leisure sector. SHC |
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alstorer ![]() Really should get out more ![]() ![]() Joined: 02 Aug 07 Location: Cambridge Online Status: Offline Posts: 2899 |
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You're pretty much spot on with the big problem with using non-refined natural products such as bamboo. With heavily refined or entirely synthetic products you can relatively easily produce exactly the same material time after time after time. When your material's properties are heavily dependent upon that month's weather, you've got a real problem- so what if it grows fast if you get entire harvests that are next to uselsss. I'm also sceptical about " tensile strength or weight to strength being not far off carbon"- good E-glass isn't far off low grade carbon and is very cheap.
As for the mystery resin, other than guessing it's likely some sort vinyl ester (it surely wouldn't hurt to mention the commerical trade name of the resin- could probably tell you much more about it this way as a fair bit will be public) I can't really comment.
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Al |
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Chris 249 ![]() Really should get out more ![]() ![]() Joined: 10 May 04 Online Status: Offline Posts: 2041 |
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Actually, you haven't gone to any facts. Windsurfers are not significantly lighter than racing dinghies once adjustments are made for the fact that dinghies are bigger. Only those completely devoid of logic would ignore the fact that boards are smaller and a bit of basic maths indicates how much of their weight advantage is down to that. Ignoring size factors is like saying that lead is lighter than air because 1 cubic centimetre of lead is lighter than 10 cubic metres of air. Kiteboards are smaller than a lot of centreboards, of course they are lighter than an entire boat. I did check kiteboard weights - same thing, they are around 80L volume (raceboard) and weigharound 5kg. That's much heavier, size for size, than at least some dinghies. Amusingly, the first kite site I came across boasted how in this year's model "Full carbon sandwich construction replaces 2011 bamboo sandwich construction increasing rigidity while reducing 1kg of weight". So instead of kiters leading the way, they are actually switching to a material used by dinghies for years. Ooops..... Hollow SUP boards? Again, they have no rig loads and anyone who has installed chainplates and foils knows that those are the heavy bits so it's natural than craft without them are lighter. Although, of course, those accursed dinghy sailors are actually turning out boats LIGHTER than SUPs if you account for the size. Of course, you don't which is like saying that a steel kiddy's bike is more high-tech than a F1 car because it's lighter. It's nice to see that one company is using hydro power. Pity they have to use fossils to ship the stuff around the world. And it's hardly likely to be cleaner than actually cherishing the boats we Once again, you are back to abuse instead of facts. It's quite clear you are just trolling so I'll bail out.
Edited by Chris 249 - 07 Jun 12 at 12:17pm |
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tryinghard ![]() Groupie ![]() Joined: 03 Mar 11 Online Status: Offline Posts: 42 |
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Me too ........
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tickler ![]() Really should get out more ![]() Joined: 03 Jun 07 Location: Tunstead Milton Online Status: Offline Posts: 895 |
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And while you were all arguing ...I was sailing..........
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Andymac ![]() Really should get out more ![]() Joined: 04 Apr 07 Location: Derbyshire Online Status: Offline Posts: 852 |
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Yep, I guess it is, but I bet the dam cost a few $$$ to build, and a few more to maintain.
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Presuming Ed ![]() Really should get out more ![]() Joined: 26 Feb 05 Location: United Kingdom Online Status: Offline Posts: 641 |
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Wasn't it George Orwell who had something to say about minorities of one?
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Steve Clark ![]() Newbie ![]() Joined: 14 Jul 05 Online Status: Offline Posts: 38 |
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So to recap:
The V Twin did not live up to the lofty claims of it's designer. This is the fault of someone other than the designer. The project manager also seems to have been betrayed by incompetents. One has to conclude that the successful completion of development projects is harder than it looks. Maybe that's a clue. Even the blind squirrels occasionally find a nut. SHC |
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G.R.F. ![]() Really should get out more ![]() Joined: 10 Aug 08 Location: United Kingdom Online Status: Offline Posts: 4028 |
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Abuse given to Australians is legal - fact.
At no time is an Englishman expected to back any comment he may have made to an Australian, the Australian should simply accept the wiser and superior words of the Englishman and be humble, in fact be happy he is even being acknowledged as anything other than a convicted felon or a bush dwelling aborigine. This is the Law. So now to the facts. The factory I recently visited sits adjacent to the Bonneville Hydro electric plant on the Columbia river the electricity is free. The resin I told you of's formula is secret it is being kept in the US to protect their intellectual property from thieving Chinese (and Australians). The wood used in blank construction as well as Bamboo is from managed forests from within a 50 mile radius. The Sports that like light stuff as well as Windsurfing, which no longer has the sun filled uplands of a better tomorrow in which to bask in the fires of progressive innovation, are SUP ( a hollow race board), kite twintip and surf boards and wake boards capable of being both light yet capable of sustaining punishment in cable parks. I've no doubt that somewhere along the Gorge folk are using similar stuff to build sailboats and all manner of stuff, but those are the instances that have prompted my latests rants. You may now go to your room and reconsider your position.
Edited by G.R.F. - 06 Jun 12 at 2:21pm |
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boatshed ![]() Far too distracted from work ![]() Joined: 12 Apr 05 Online Status: Offline Posts: 457 |
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Even more innovative in 1956 ![]() |
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Steve
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