Mark,
The problem is that the blue foam there is Spyderfoam (or similar) and is
intended for model airplane wings and things like that.
If you get a core made out of CoreCell or some other foam core which was
intended to be use as a real core material, you wont have
these problems. Without looking it up, I am guessing CoreCell compression
strength (ability to keep those skins apart) is at least
twice than that of the blue stuff. Corecell will also bind to epoxy a lot
better than spyderfoam due to the rough surface it has.
Obviously what you are doing with the cedar/carbon has the same effect, but
its a complex and time consuming process.
I think Phills foil can make a corecell core. They made some spreader cores
for Darius and I a while back.
Having said all that, it really sucks if the board breaks during sailing, so
I would encourage anyone building this stuff to overbuild
or even consider buying one. I can recommend the 29er board as a cheap and
bullet proof board. It also nice and wide to stand on.
HTH,
Christian
On Thu, Nov 13, 2008 at 5:18 PM, Mark White <mwhite4459@xxxxxxxxx> wrote:
> Robert,
>
> I agree, I was thinking about using carbon, or fiberglass laminated
> stringers instead of wood. I think would have a longer life.
>
> Mark
>
> On Thu, Nov 13, 2008 at 3:12 PM, Robert Harper <rharper@xxxxxxxxxxxx>wrote:
>
>> After we talked about this at the last time we got together, I've been
>> thinking of using carbon tape where you have the wood stringers with the
>> edges lapped over the sides of the blank. Attached is a simple drawing. That
>> way you could keep the ultra light board and also have stringers to help
>> hold the skins together/apart.
>>
>> Just an idea. I don't have a good chance to test it out right now.
>>
>>
>> On Thu, 13 Nov 2008 13:57:43 -0700, Mark White <mwhite4459@xxxxxxxxx>
>> wrote:
>>
>> Chris wanted to see some pictures of a failing centerboard, so I
>>> thought an open discussion might be in order, (since I am going to
>>> make another).
>>>
>>> This centerboard was made as per the instructions from Bram and or
>>> Greg, to the best of my ability. I started using it in the 06 regatta
>>> in FL, so it has seen 3 seasons. Before going to FL in 08, I removed
>>> some surface scratches by filling and sanding back to a smooth and
>>> fair finish. The first blister appeared 2 days before the 08 regatta,
>>> and every time I sail, it gets larger, and now is on both sides. It
>>> still works, but has become increasingly difficult to lower and raise.
>>> You can see 1 large bulge on the starboard side, and 2 on the port
>>> side. The origional rudder broke under heavy air just after the 07
>>> regatta. The pictures of the foam core are the new rudder made just
>>> before the 08 regatta, with wood strips inserted to help handle the
>>> loads it incurs, (which I believe are enormous)
>>>
>>> I'm not an engineer, but it seems hybrid and carbon cannot handle
>>> compression very well, or maybe it's just a limited number of cycles
>>> it can handle. I don't know if altitude has anything to do with it,
>>> but these boards were made at 4500' msl. The fact that they are black
>>> probably has a lot to do with failure, although I tried my best to
>>> keep them out of direct sunlight. If you add heat to epoxy resin it
>>> will soften.
>>>
>>> I will build another centerboard with a foam core, but it will have
>>> stringers (4 or 5) to help with the loads the skins incure. Hopefuly
>>> it will last indefinitly, or at least longer than the first.
>>>
>>> If anyone has any ideas on making foam cored boards last longer,
>>> please chime in.
>>>
>>> Mark
>>>
>>>
>>> IMG_7404.JPG
>>> IMG_7405.JPG
>>> 002.JPG
>>> 003.JPG
>>> 013.JPG
>>> 014.JPG
>>>
>>> These pictures were sent with Picasa, from Google.
>>> Try it out here: http://picasa.google.com/
>>>
>>
>>
>>
>> --
>> Live large, love lots, and sail fast!
>> The mark of who you are is determined by what you do when you don't have
>> to do it.
>> USA 050 Fugu
>> 77959 Wasabi
>> Robert Harper
>> This is the Swift Solo mailing list. For unsubscribe instructions,
>> visit here: http://catzooks.com/swift-solo/
>>
>
>
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