I have also experimented with alternative materials and procedures for
rib gusset making. I commend Bob for his post and recommend that
people do their own experiments. The results will possibly surprise
you.

Consider these emails:

From: "Mark McAtee" Add to Address Book
To:
Subject: Paper Gussets
Date: Wed, 12 Nov 2003 16:34:50 +0000


The paper I used is 140 lb. Medium Weight Bienfang water color
paper.
You're right, I don't know where I got the 20lb thing. This was the
heaviest water color paper I could find at our local store. It really
works
well on light ribs. sucks up the West and does not need much clamping
pressure. I used sand filled beanbags. It also worked well with
normal
wood glue for testing purposes. Weldwood powder glue also worked
very
well. I don't like the gorilla glue because it does "foam" in the
joints.

From: "Nicholas Cafarelli"
To:
Subject: Paper Gussets
Date: Tue, 04 Nov 2003 15:31:24 -0000

Hello.

You mention 20 lb paper in your post. I do not mean to second guess
you, yet was the paper really this light? I suspect it may have been
a much heavier weight paper. I could be dead wrong.

Watercolor paper:

http://www.dickblick.com/zz100/07/pr...am=0&ig_id=754

at a much heavier weight, is another inexpensive option.

I, too, experiment with gussets for much lighter aircraft - not
Tailwinds.

You might consider these other lighter, cheaper gusset forms:

1. Drywall fiberglass tape laminated with epoxy.
2. Drywall fiberglass tape laminated with Gorilla Glue.
3. Other fiberglass laminated with epoxy.

Regarding number two: pressure must be maintained while this type of
gusset cures. The glue wants to expand. This incorporation of air
makes the resulting gusset material very light and suprisingly strong
and cheap.

One thing I have yet to try is drywall fiberglass tape adhered with
epoxy - NOT laminated. If tension can be maintained in the fibers I
suspect that only the fiber area in contact with the rib sticks need
be epoxied. This will NOT be as strong as complete lamination, yet
it likely will be MORE than strong enough. In addition, as you and
your students discovered firsthand, gusset flexibility can be an
ADVANTAGE.

Of course, you are the mechanic in charge, and workmanship and
material choice can result in nonairworthy parts.


I have since experimented with other gussets:

1. cereal box/epoxy
2. cereal box/dollar store "sterling glue"
3. fiberglass drywall tape/epoxy
4. various other paper products/various adhesives

All of these are much stronger than you might think.

The variation I found most interesting involved type 3. I oriented
the strands at 45 degrees and only applied epoxy where the tape
touched the rib sticks and rib caps. Try it.

Based on hands-on work with these seemingly radical formulations, I
concur with Bob that for some lightweight applications they can serve
well.

Sometimes, good enough is good enough.

I should add that the testing I have done involved complete ribs. It
is my opinion that this most accurately predicts the true utility of
alternatives.

nc