From: "Marvin Kaye" <marv@lancaironline.net>
Subject: Re: AFS AOA
To: lml
Date: Mon, 22 Aug 2005 19:46:44 -0400
Message-ID: <web-678376@logan.com>
In-Reply-To: <BJEAIKOJDCKOJHHPCCAPAEEMCKAA.marknlisa@hometel.com>
References: <BJEAIKOJDCKOJHHPCCAPAEEMCKAA.marknlisa@hometel.com>
MIME-Version: 1.0
Content-Type: text/plain; charset="ISO-8859-1"; format="flowed"
Content-Transfer-Encoding: 8bit

"Mark & Lisa" <marknlisa@hometel.com>:

  Gang,
  
For those of you who've installed the Advanced Flight Systems AOA: How did
  you bond the aluminum donut (into which the upper-port drain valve screws)
  into the phenolic tube?  The aluminum donut is a very tight fit--tight
  enough to wipe all the flox I applied off the inside of the tube and pile it
  up on the donut.
  
  Maybe I'm going about it all wrong.  My thought was to install screw the
  drain valve into the donut and use it (the drain valve) to hold the donut in
  place while the bond cures.  After applying the flox and insterting the
  donut it just didn't feel as though any flox was between the donut and tube,
  so I pulled it out and found that the flox had been scraped off the tube
  into a mound on the inside of the donut.  I'm afraid that I might actually
  block the drain valve if I use too much flox, but if I don't use enough I
  won't get a good air seal.
  
  Any ideas?
  
  Thanks,
  
  Mark & Lisa Sletten
  Legacy FG N828LM
  http://www.legacyfgbuilder.com


[Mark... first of all, bonding in the drain should be the last thing you do, 
after paint and everythng else.  If you're to that stage, the best bet is to 
use a triangular file or a cutoff wheel in your Dremel to cut a series of 
grooves around the perimeter of the doughnut.  Do them on the diagonal so they 
spiral up the wall of the cylinder... cut 4 or 5 in one direction, then 4 or 5 
in the other direction so you have a cosshatch pattern.  Use some 36 grit to 
really scuff up the remaining surface.  Don't worry about putting a lot of 
flox in the epoxy, just enough to give it some body... runny is OK.  Better 
yet, mix up some JB weld and use that as is.... it's already a little "stiff". 
 IT works great for bonding metal things to composites, BTW.  Wipe a thin film 
of your epoxy on the scuffed up interior of the phenolic tube (just enough to 
wet out the surface) and do the same with the doughnut, filling in the grooves 
with your mixture.  Install the drain into the doughnut, slide it home and 
hold it in place with a piece of duct tape.  There will be so little epoxy on 
the internal wall of the tube that you should have virtually no squeeze out 
onto the end of the doughnut.  If you're really concerned, grind a chamfer 
around the upper edge of the doughnut so the epoxy that gets wiped off the 
inside of the phenolic tube.  Voila! Done!  I hope this helps you out. 
   <Marv>    ]