Message-ID: <01BDE4FB.90B44760.matt@testelectronics.com>
From: Matt TestElectronics <matt@testelectronics.com>
Reply-To: "matt@testelectronics.com" <matt@testelectronics.com>
To: "Lancair [lancair.list@olsusa.com] (E-mail)" <lancair.list@olsusa.com>
Subject: Re:L-IV elevator trim tab
Date: Mon, 21 Sep 1998 01:02:53 -0700
Organization: Test Electronics
Mime-Version: 1.0

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Ed McCauley wrote:
I'm not sure what adding glass on top of the hinge would add structurally 
because the key securing means are the "flox rivets".  After the hinge, the 
cloth would immediately encounter a 90 curve so that no effective tensile 
strength would be obtained.  If anyone knows better, I'm all ears!

I think you should put a 2 bid layer on top of the hinge to give the flox 
ritets something strong to stick to. The fiber is much stronger than the 
epoxy/flox. The forces would tend to pull the fibers through the hole. So 
even though it is a 90 curve, tensile strength still applies. Have you ever 
removed a rivot by carefully grinding the head down paper thin, and then 
breaking it out. This is what is going to happen to your epoxy flox rivots.

About galvanic issues with carbon, you have to have a media such as water 
to make this happen. If you seal the rivots in the carbon fiber with epoxy, 
you will not get galvanic action. What happens is an insulating oxide layer 
will form between the rivot and the carbon fiber. A very thin oxide layer 
that doesn't cause any harm. As soon as this oxide layer forms, galvanic 
action will stop unless something like water washes the oxide layer out. 
Since everything is sealed, galvanic action will never go beyond the time 
it takes for the resin to cure. This short amount of time would be 
insignificant.

Regards,
Ed
Watsonville CA