I was complaining about the non stiffness of my ailerons and asked what
could be done about it. I received a reply from the famous or notorious
Sal. His response was to finish off those two exposed surfaces and gain a
lot in stiffness.
He was right. Finishing off that foam does matter.
Thankyou again Sal.
I simply paint on a layer of West system epoxy then lay on a much wider
layer of glass in about 2 ounce. Then I put enough more of epoxy on the
surface of the new layer of glass to make sure it is filled at the edges.
When it is dry you should have produced a slight bump at each of the two
edges of the narrow strip which you can sand from the top and bottom then
lightly on the exposed side you had before. This is a very easy finish and
produces great results. I normally in addition trying to get the best of
both worlds cut this glass at 45 degrees. But this makes the handling while
doing the job quite difficult so be patient. Put on the other way the grain
probably would end up in the wrong place. The results are strong enough to
use poly tape and pull pull on the rudder without it crushing inwards. The
stiffness gain on the ailrerons is impressive.
The same technique is used for finishing the exposed ends of wings where
they butt together. The finish is put on after the joiner is completed.
The joiner is inserted with a casting of West System epoxy and light filler
as follows for the hardpoints.
Now that this edge is finished I cut out the hole area for the hardpoints.
Cut from one surface down just to the other area. Then pick out the foam
like a dentist doing a good undercutting job. When you are finished; fill
with West System finishing epoxy filled with their lightest filler. I
usually try to undercut the hole so that it extends against the new surface
you have just created. You probably should think in terms of about a three
eighths inch cutout extended under the surface to about half or more. After
doing this a few times I discovered in some kit reviews in QFI that some
manufacturers were beginning to do it this way.
Rick
PS Like many others I have gotten in the bad habit of replying privately.
So how would the rest of you do it differently??.
Date: Tue, 10 Jul 2001 19:00:22 -0700 (PDT)
From: Lee Cox <[EMAIL PROTECTED]>
To: soaring mail page <[EMAIL PROTECTED]>
Subject: Finishing a glass wing??
Message-ID: <[EMAIL PROTECTED]>
I would like to hear some of the pros and cons about
whether or not the edges of the ailerons / flaps &
back side of wing should be finished or left as open
foam.
It seems to me that if edges are sealed with
(glass-epoxy or?? )it would structurally be a stronger
wing and would help to stop any twist. I see a lot of
wings unfinished. HELP!!! LEE
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