Posted by Michel Capel (mike_c_f35ck@…>)
Kevin,
Although I’m a layman in the field of physics a bit further on that.
Others will probably correct me if I’m wrong.
Carbon fibre is located near the bottom of the Galvanic scale. Gold
is near the top, which means gold does not corrode in any way.
Carbon fibre does, especially when connected to metals that are
higher up on the scale. Even magnesium, zinc and aluminium are
higher up the scale than carbon fibre. When two dissimilar metals are
connected, a current starts running, eating away the metal lowest on
the galvanic scale. In Galvanic terms, carbon fibre behaves like a
metal, because it conducts electricity. I’ve seen a mast top of a
carbon fibre Freedom mast come off completely because of corrosion.
Aluminium poprivets are often usen on carbon fibre and pose a
continuous risk. Many Freedom owners inspect the rivets of their mast
track regularly because they know the holes in the carbon fibre mast
will wear out eventually by galvanic corrosion. Monel is expensive,
so not often used. Monel does not in any way conduct electricity, a
very special characteristic for a metal! That’s why it’s so suitable
for attaching hardware to carbon fibre masts.
hope this is all correctly explained.
cheers,
michel
— In freedomyachts2003@yahoogroups.com, “Kevin Ogden”
<kcogden@e…> wrote:
Michel:
Why is electrical insulation of the carbon fiber important, and why
use Monel? Reason I ask is I replaced some of the pop rivets securing
a halyard exit plate about 3 years ago, and am wondering if there was
any problem with the aluminum pop rivets I used?
----- Original Message -----
From: Michel Capel
To: freedomyachts2003@yahoogroups.com
Sent: Thursday, January 27, 2005 2:47 PM
Subject: [freedomyachts2003] Re: mast exits
The fewer holes the better, and if you can’t do without holes,
space
them as far apart as you can. Insulate every part electrically
with
a liner tape or insulating paste and use Monel rivets if you can
find
them. Don’t expect machine screws to hold well in the brittle
carbon
fibre.
Monel is the only non-conducting metal that can be used to make
rivets of.
b.t.w. - why do you need these exit plates and blocks? You run
less
risks if you leave the carbon alone and figure out an alterative
that
can do without new holes.
just my 2 cents.
— In freedomyachts2003@yahoogroups.com, “etowey001”
<etowey001@y…> wrote:
I am planning on adding another exit plate at the bottom and an
exit
block up higher on my carbon fiber mast. The mast is down so it
will
easy to work on. I would appreciate any information as to what
to
look out for and how to attach these items. Thanks for any help.
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