Fiberglass vs. Fabric

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

On 16 Jun 2006 19:57:02 -0700, "Lou" wrote:

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

Lou,The glass that tony referred to is model airplane glass which is
very light and thin. I used it as the outside layer on my leading
edges and tips, however that was over aircraft grade fiberglas not
plywood. Apparently Tony had good luck with it. I think if you did a
Sport Aviation search for Tony's articles on building the Emeraude you
could get a little more information.

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

Lou wrote:
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

The fiberglass you're refferring to goes by the name of RAZORBACK.
Various military planes used it like the PT-19B

Lou wrote:

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?

Doug Palmer said all you kneed to know.
The most important is the peel ply, it also save finishing time.

By
--
Pub: http://www.slowfood.fr/france
Philippe Vessaire Ò¿Ó¬

Doug, thanks. You said that the 1.4oz is close to fabric in weight. Is
that finihed weight
with the epoxy against finished weight of fabric all doped up?
Lou

I was unable to find a difference in weight between a 2' x 2' sample of
each, this was using a postal scale accurate to .1 OZ. That said after
finishing, painting each system there might be some difference, but I would
think that it would be very small.

Good Luck

"Lou" wrote in message
ups.com...
Doug, thanks. You said that the 1.4oz is close to fabric in weight. Is
that finihed weight
with the epoxy against finished weight of fabric all doped up?
Lou

Lou wrote:
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


I assume you're applying it over plywood. In that case just get a book
on building wooden canoes and follow the glassing process used for them.
They usually use a layer or two of light weight cloth and West system
resin.

You can also go to the Wittman Tailwind list on Yahoo and search the
archives for posts on it. I believe most Tailwind builders glass their
ply wings instead of fabric.

John

"J.Kahn" wrote in message
...
Lou wrote:
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


I assume you're applying it over plywood. In that case just get a book on
building wooden canoes and follow the glassing process used for them. They
usually use a layer or two of light weight cloth and West system resin.

SNIP
John

One of my former chapter (EAA 315) members built a Pulsar and did not like
the fit of the plywood wing skins after flying it for a while. In
particular, he complained about the plywood skins sagging in humid weather.

He routed out the plywood 'tween the ribs/spars/... He then fabricated
sheets of fiberglass/epoxy skins on a large sheet of plate glass (dunno the
thicknesses, etc.) and applied them over the surface of the wing in lieu of
the routed out plywood wing skins. His approach appeared to resolve the
humidity-induced sagging problem he had experienced with the plain plywood
and also had a sleeker finish.

Of course, he had to engineer the new "skin" system,. test fly it (after
having flown the plywood skinned version), etc. IIRC, he was quite happy
with the outcome. I don't know if the builder is still active as I moved
from the area, but I would be happy to check to see if he was available, had
lessons learned, etc., available.

Michael Pilla

Michael Pilla

What you described is what my plans call for. Wooden ribs with plywood
over but
routed inbetween. Then on top of the plywood I'm to install the fabric.
This is just one
of the areas that I want to replace the fabric with fiberglass. It is
obcviously not structural.
So replacing with fiberglass should give me a smoother, harder finish.
Also, I would like to know if this finish will give me a better gph for
trips not to mention maybe, just maybe a few more knots. Yes I would
love to talk to your friend.
Lou