Glassing wing center section

[Amir Neshati]

Multi layers of lighter glass will yield a stronger part than the same
weight of
one cloth layer....And you will have control over where  the most strength
is needed.

Looking at the wing from a top view, the final glassed section should look
like
a diamond, with the wides point at the thickest part of the wing, keeping
the
front (LE) and rear (TE) about and  inch  wider than the fuselage
sides....the next best thing
is a "V"  viewed from the top, again, nearly an inch outside the fuse at the
TE and get
to the widest part at the LE....

One way to easily control resin weight is to lay the first layer of glass
down and
wet it out sparingly, then add the next layer on it and let it soak up any
excess.
A  little heat will help wet out the overlay cloth. Each consecutive top
layer will
be a little wider than the previous. Usually two layers of 3ish oz cloth and
a final
light layer should do. I fill the weave with a fairly dry mixture of the
same epoxy
and micro balloons spread over with a plastic squeegee.

A shear web would be a good idea too.....1/4" vertical grain balsa about an
inch past
the fuselage sides, then glassed, will do wonders......Another alternative
is Spyder foam.
2.3ish lbs. density and a compressive strength of 80 PSI.....Spyder foam is
what I believe
the Angel's Shadow should have in its wings for spars instead of what
appeared to be white
foam (bead board stuff).

Another thing to consider is the bi-directional cloths that are unbalanced,
which means they
have a slightly higher thread count (and are stronger) in one direction than
the other...lay the stronger
direction with the higher thread count span wise...

And while I have the stage ;-) when using the really light balsa wood for
sheeting wings, take each sheet
by the ends and bend to get a big Uish shape, then reverse direction....the
lighter balsa comes from the
younger trees, which grow fast in storms (swing from side-to-side).... This
causes some microscopic
tears in the very light wood that we can't see! The bending will show these
cracks, which are generally
straight across the grain, as if they were  scored  with a knife.

have fun,
Amir







> I'm glassing the center section of my Elan.  Using 6 oz/yard K&B cloth
> and 30 minute epoxy warmed with a heat gun on application.  The epoxy
> brushes on well and when dry the weave of the cloth is noticeable.  In
> other words the surface is not a smooth glasslike finish.  Is this OK or
> do I need more epoxy applied for strength?
>
> Thanks,
> Jerry Wilson
> Katy,TX
> NSRCA#3107
> AMA#119585
>
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