As food for thought, if you were going to glue two pieces of aluminum together 
you may want to rough sand the two surfaces to be adjoined so the adhesion 
would be stronger because of the roughness just like anything you glue or 
paint. If you choose to do this then you have probably removed any corrosion 
resistance that may have come on the tube or sheet from the factory that made 
it. In this case it may be advisable to apply aladine to the surface to seal 
the aluminum from corrosion in the future if you did sand the orginal coating 
off.
  The reason I am bringing this up has to do with LongEzes elevators. The 
original plans had you take the aluminum tubing which became your torque tube 
for the elevator, sand it down to rough it up for better adhesion, glue your 
hot wired air foil shaped foam trailing edge to it with epoxy. Then you wrapped 
the fiberglass cloth around the leading edge of the exposed tube and onto the 
foam to mate the two together and form the elevator. All was fine for a few 
years until there were some of the ezes that developed corrosion on the surface 
of the tubes and then there was no adhesion, the corrosion had caused the 
seperation. It seems very strange that an epoxy coated,sanded aluminum tube 
would be able to corrode, but obviously they can. The repair is to remake your 
canard elevator. The procedure now includes sanding the tube as before but now 
you aladine the tube before you glue the foam and fiberglass to it with epoxy. 
The aladine does not remove or fill the roughness sanded
 into the tube for better grip/adhesion it's job is to seal the aluminum to 
prevent corrosion.
  You all may already be doing this but I thought I would mention it just in 
case someone that didn't know may want to do this as an extra precaution. Non 
alidined sanded aluminum glued together parts may last way past our life times 
but never hurts I guess.
  The old saying is "If I knew better then I would do better" !!
  Larry H.

Mark Langford <n5...@hiwaay.net> wrote:
  > That is pretty much what I have in mind, except I would like to find (or
> make) an aluminum flange to replace the clamp collars, then glue AND rivet
> that flange to both the torque tube and the bellcranks. The tube stops
> could be made the same way.

I've used T-88 to glue some aluminum parts together, and I dare say nothing 
is ever going to separate them. It would be interesting to test what 
happens after a few freeze/thaw/hot cycles, but I'm betting they're more or 
less permanent.

The part number for the clamp collars that I used is 6436k72 from Mcmaster 
Carr. They're for 3/4" OD tubing. I don't expect you to order it, but some 
other folks on this side of the pond might be interested. These are 
aluminum, and allow easy adjustment of range, limit, and synchronization 
between the two flaps. Next time I do this I may use a carbon fiber torque 
tube rather than 4130...

Mark Langford, Huntsville, Alabama
see KR2S project N56ML at http://home.hiwaay.net/~langford
email to N56ML "at" hiwaay.net 


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