Sender: <marv@lancaironline.net> (Marvin Kaye)
To: lml@lancaironline.net
Date: Tue, 30 Dec 2003 10:10:17 -0500
Message-ID: <redirect-2910729@logan.com>
From: "John Barrett" <2thman@cablespeed.com>
Subject: RE: MKII Elevator hinge
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Pine,

Removing the Hysol bonded hinge might be difficult, but I'd suggest trying a
heat gun first.  Warm up the material with the heat gun and use a putty
knife or chisel to cleave between the hinge and the elevator in the local
area you are heating.  In other words,  either have the gun in one hand and
the knife in the other, or have someone else apply the heat while you work.
In any case, I think you can break the hysol if you work in this way - maybe
even without heat.  Perhaps even a small hammer or mallet will help to
fracture the adhesive joint.  Be careful not to split or damage the elevator
or stabilizer skin in the process.  You will definitely destroy the aluminum
hinge as you peel it off, but that should not be a concern.

Before you try this, I would advise asking for guidance from the Lancair
tech reps and also on the LML.  I'll bet others have separated Hysol bonded
pieces before you or me.

Also, try bonding a scrap hinge to a scrap piece of prepreg and see what it
takes to get the two apart without damage to the composite part.  Make sure
you don't use bench cure composite to bond to in your experiment, because it
won't take the heat from the heat gun when you warm it.

One more thought, Pine, if  one half of the hinge is already bonded in and
it is not damaged, or misaligned you might consider leaving it and living
with it.  Our hinges are compatible with aluminum so you could even just use
Carbinge on the other side. You might be just postponing the solution
because over time the aluminum will begin to deteriorate, but this may be so
far in the future that it won't be a problem.

If you're worried about the bond with the current installation, it might not
really be a problem.  If peel ply wasn't removed or you suspect improper
procedures, that's another story.  Do you have reason to believe the bond is
defective?  Hysol actually does make a tremendous bond with aluminum - you'd
be surprised.  Just try a test piece to prove it.  Bond it - let it set
several days, then put shear forces on it and even try peel forces.

Please review my website for discussion of the Carbinge advantages over
aluminum.  Also, look at the hinge testing data (the pictures of the shear
test)  It shows that the hinge sample was bonded to an aluminum bracket in
order to place it in the testing machine.  The Hysol bond that was used did
not fail.  The shear force applied was 1,000# on about a 3" X 2" area of
bond between the aluminum and the Carbinge.

Best of luck and write back if you have more questions.

Regards,
John Barrett
Barrett/Garrett Enterprises, Inc.
PO Box 428
Pt. Hadlock, WA 98339
www.carbinge.com

-----Original Message-----
From: AP Pienaar [mailto:pine@cpro.co.za]
Sent: Tuesday, December 30, 2003 12:43 PM
To: 2thman@cablespeed.com
Subject: MKII Elevator hinge


Hi John

Thanks for your response to my mail on the Lancair list.

My problem is that I bought the tail as a build unit from Ken Covington and
I not sure that he did everything right. It looks as if I'm going to have to
redo the hinge line Stab to elevator and somehow remove the already bonded
in hinge between the trim tab and elevator. To this end do you know how I
can break this Hysol (I think - green) bond.

I would gladly replace this if I can.

Any help would be appreciated. Then of course should I bond your hinge on or
again rivet like the manual suggest and please give me the benefits.

Kind Regards

Pine Pienaar
pine@cpro.co.za
Lancair 360 #664