Fiberglass vs. Fabric

I am building an wood amphibian and the entire plane is covered with glass.
I covered my wings with 1.4 oz fiberglass which is as close in weight to
fabric as you will get. The thinner glass can be a bear to work with- it is
so light that when working over any substantial area, you will squeegee it
and four feet down the way it pulls and causes a run. You will have a
difficult time covering the plywood with this thin glass UNLESS you also use
a peel ply over it,. I have only done my surfaces when horizontal so I
don't know how difficult or easy a vertical surface would be. This fabric
is so thin and light that after wetting it out, over larger surface areas,
while you are working with the squeegee the fabric will tend to get pulled
by the squeegee and will get a lot of runs and ripples in it, and the resin
to glass mix will tend towards being resin rich.

I had good success by first laying the thin glass over the surface (no resin
underneath) Then wetting out the glass from on top, resin rich, letting
gravity pull the resin through the glass into the underlying wood, as much
as working it through by stippling and some light squeegee work, the glass
can be resin rich at this stage. Then I put a Dacron peel ply over the
light glass/resin and also wetted the Dacron out with additional resin from
on top as if it were a ply of the glass. If you don't wet out the Dacron it
will "blot" too much of the resin off out of the underlying glass. It was
much easier to use the Dacron to help get the light glass to lay down nicely
and get an even resin ratio on the glass. The Dacron is stiffer and has
more structure when wet and helps control the lay of the glass. As long as
the Dacron gets thoroughly wetted out the glass underneath will wet out nice
and even, any excess resin can be left on top of the Dacron as it will get
pulled off after cure. Then let it cure and have fun pulling the Dacron
peel ply off. This method definitely wastes some resin but you will end up
with a better finished product that has a nice tooth for the primer.

Whatever you do, do a 3' x 3' practice lay-up before committing the system
to your project!

Good Luck!

My project can be seen at http://dougnlinap.home.mindspring.com/home.html



"Lou" wrote in message
ups.com...
Ok, I just finished reading Tony Bingelis's "sportplane builder"
section on covering a wooden plane with fiberglass instead of the
intended fabric. Has anyone in this group ever done this or some who
knows someone who has done this? I'm building a wooden place that
calls for
a fabric covering. I've tried to do as much homework on this subject
as I can but still can not come up with a weight difference between
fabric and a thin coat of fiberglass. I know that the fabric is not
structural so why can't I subsitute a lightweight fiberglass for the
fabric?
Any feedback?
Lou