Robert Little wrote:
With the superior strength of glass cloth, why not offer it in a litter
weight? A very good question that I asked the president of the Ultra Light
Aircraft Association. Because of the very expensive process of getting a
new product "certified" by the FAA, I had that organization do a survey for
interest in a permanent fabric. There was no interest at all. After many
years of instructing rib stitiching and fabric installation at the Oshkosh
EAAFly-In, the survey was not too surprizing.

We realize that we don't have to get the blessings of the FAA to sell to the
home builder and can sell "uncertified" fabric as the other companies do.
But unfortunately, that light-weight uncertifed fabric usually shows up on
certified aircraft, regardless of the regulations and recommendations. And
yes, wing loading, speed and flight regimen does mandate the different
weights of fabric. A good reference is the A.C. 43-13.1B.

So, until I think that I can sell enough of our 1.5 oz that test in at 92
lbs/ inch that will break even with the cost of certification, we will not
offer it to the public. (New Grade A cotton only tests at 80 lbs/inch)

The cost difference of glass fabric is 80% greater than polyester. But it
is glued with butyrate dope (no nitrate-laced glue), taunten with butyrate
dope, filled with non-tauntening butyrate dope and should be topped with
butyrate dope, although, the top coat is the installer's choice. We still
buy MIL SPEC butyrate dope for less than $16 a gal. I'll let you figure the
total cost of a cover job from these figures.

I hope that this has answered some of your questions. All things are based

You answered the questions, very good answers, in fact; however, it
doesn't help me. I hear you paraphrasing Ford. "You can have anything
you want, as long as it is what we sell." Which is OK, it just doesn't
help me any.

What I'm after is a 1) lighter elevon and 2) simpler to build elevon.
If it is stronger or cheaper, we can party on those points, too, but
they are secondary. Your process, while excellent, helps on neither point.

I don't mean to tell you your job here, but did you ever consider asking
the Ultralight Association if they would be interested in a LIGHTER
fabric. My impression of the ultralighters I know is that they look at
their planes as dirt bikes. They are not serious modes of
transportation, they're toys. Why would you EVER worry about a
permanent fabric on a toy! But if those guys think they can cruise 1mph
faster or climb 1fpm quicker they'll ransom their children for pixie
dust. I guess it is equally true for the GA crowd, and especially for
the tube'n'rag crowd. For the most part, tube'n'rag crafts are not
serious transportation; therefore, PERMANENT COVERING means zilch.

Now if you'd like to sell some 1.5oz cloth, I'd like to do some test
with substituting a standard epoxy for butyrate dope.

--
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"Ignorance is mankinds normal state,
alleviated by information and experience."
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