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/
>
|