On Sat, 10 May 2008 14:22:24 -0500, Brian Whatcott
wrote:

On Sat, 10 May 2008 11:07:42 -0700, Gordon wrote:


Talked to a cruiser back from 4 years in the south pacific on an
Oceanis 43 with a Cape Horn windvane. He reports the vane worked well
with a couple of exceptions.
1) The tube transversing the transom is not watertight and following
seas do push water thru it.
2) His unit started sticking where the rod passes thru the plastic
bushing. After several emails with Cape Horn, they finally admitted that
the plastic they used had a tendency to absorb water and swell up to 15%.
The fix was to disassemble and bore out the bushing using the proper
sized drill.
Cape Horn told him the were "thinking" of going to delrin or something
else.
His unit is 5 years old and he didn't know if they have since upgraded.
The only other problem he encountered was a failed block. He reported
no abraded control lines.
BTW, his unit was installed by a Cape Horn rep.
Gordon


There's a board used in aircraft still - been round for ever, that
looks like SRBP (synthetic resin bonded paper) that is called SRBF
where the fabric layers are made of linen. It's used for cable
fairleads. It turns out it has an unexpected property - it is durable
against frictional wear because it is self-lubricating. Who would have
guessed?

I think you are talking about Micarta, dates back to 1910 or
thereabout, and is still being used.


When I have proposed high density polyethylene for similar purposes
I have heard something like "we KNOW this works, how long does HDPE
last?". You can buy HDPE cutting boards at Walmart for peanuts -
and SRBF is expensive and hard to gert any more, But the Cape Horn
plastic bush story make this jump right back to mind!
(Nylon swells and weakens I believe?)

Brian Whatcott Altus OK



Bruce-in-Bangkok
(correct Address is bpaige125atgmaildotcom)