Replace fabric with glass

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
on economics. As I've said before, I wish all fabric was permanent so that
we didn't have to hide our beautiful airplanes deep in dark hangers. It
doesn't make very much sense that the owners of the most economical and most
fun to fly aircraft are afraid to come out into the sun and fly. The
temporary fabrics that are on the market today have stolen a great heritage
from us. Most of these airplanes are so rare in flight that insurance
ratios are astronomical. and training is getting quite rare. there are tens
of thousands of ragwings hiden away in hangers that are afraid to come out
and stay current. It is sad.


"Ernest Christley" wrote in message
.. .
Robert Little wrote:
It is true that our fabric is heavier than the choices that are now
available. It was originally designed for agricultural aircraft,
Stearmen
to be exact. It weighs 3.6 oz. and uses less dope than Grade A cotton
that
weighs 4 oz. So technically, it weighs 17% less than the original
fabric on
J-3s, BC-12s, and etc. So with 35 yards for a average project, the
total
weight difference from a temporary dacron fabric of 2.4 oz per yard and
the
less expensive, but 200% stronger, permanent glass fabric system doesn't
add
up to all the negative talk about weight to the economists.


So, why do you not offer the process in a lighter fabric?

The application that I'm looking at is an elevon that is hinged from its
leading edge. The top speed is limited by the possibility of speed
induced flutter in the elevon. A lighter elevon corresponds to a higher
top speed, so this is one of the few places on this airplane where I'm
actually concerned about ounces ('cause flutter stories scare me more
than all the others).

It's late, and way past my bedtime, but 3.6oz FG sounds like a lot more
strength than is needed and way stronger that the specified fabric.
I'll do the math tomorrow. But is there a reason that a lighter fabric
can't be used? Since the fabric is 200% stronger, why couldn't you
replace the 2.4oz Dacron with 1.2oz Razorback?

BTW, I haven't seen any prices listed, but LESS expensive than Dacron?
Dacron is fairly cheap as far as coverings go.

--
http://www.ernest.isa-geek.org/
"Ignorance is mankinds normal state,
alleviated by information and experience."
Veeduber

On Wed, 14 Apr 2004 00:17:15 -0500, "Robert Little"
wrote:


I hope that this has answered some of your questions. All things are based
on economics. As I've said before, I wish all fabric was permanent so that
we didn't have to hide our beautiful airplanes deep in dark hangers. It
doesn't make very much sense that the owners of the most economical and most
fun to fly aircraft are afraid to come out into the sun and fly. The
temporary fabrics that are on the market today have stolen a great heritage
from us. Most of these airplanes are so rare in flight that insurance
ratios are astronomical. and training is getting quite rare. there are tens
of thousands of ragwings hiden away in hangers that are afraid to come out
and stay current. It is sad.

owner of the company or not you do write some bull**** robert.
if you have never seen the fiberglass fretted away so that only the
finish remained then you need to get out more. expletive deleted

my tailwind has a 19year old polyfiber finish that just will not die.
I will eventually rip it off in airworthy condition so that I can
check for cracks and recoat the steel tubes.

btw the problem with these modern fabrics is that they are so
permanent that the underlying structures are not getting the regular
maintenance attention that they would have in the days of cotton. that
is the problem. not the BS you write.
obviously ymmv
Stealth Pilot
Australia

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.

--
http://www.ernest.isa-geek.org/
"Ignorance is mankinds normal state,
alleviated by information and experience."
Veeduber

On Wed, 14 Apr 2004 18:03:49 GMT, Ernest Christley
wrote:

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.

I'm building a rag and tube airplane and I sort of break the mold I
guess. I'm interested in outdoor storage, because it's a lot less
expensive, and I'm also interested in traveling places.

I won't go anywhere enormously fast, but I'll get there.

So a permanent fabric REALLY interests me.

Corky Scott

Question for the Razorback Fabric guy:

I'm currently finishing up the training for my A&P certificate at the
school here in Anchorage, and as it so happened, the lecture this
morning was about fabric covering. The instructor brought up Razorback
fabric, mentioned that it is great stuff, but then added that we don't
see much of it here in Alaska because it tends to sag in cold weather
compared to the shrunk-on polyester fabrics. As I recall from the
lecture, he said it was due more to contraction of the underlying
airframe in sub freezing temperatures, than any change in the fabric.
The heat shrunk fabrics apparently don't suffer as much from this
because there is enough extra tautness is added during the shrinking
process to make up for any dimensional change in the airframe at low
temperatures.

I was just wondering if you have any comments in this regard?

----------------------------------------------------
Del Rawlins-
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Unofficial Bearhawk FAQ website:
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Del Rawlins wrote:

Question for the Razorback Fabric guy:

I'm currently finishing up the training for my A&P certificate at the
school here in Anchorage, and as it so happened, the lecture this
morning was about fabric covering. The instructor brought up Razorback
fabric, mentioned that it is great stuff, but then added that we don't
see much of it here in Alaska because it tends to sag in cold weather
compared to the shrunk-on polyester fabrics. As I recall from the
lecture, he said it was due more to contraction of the underlying
airframe in sub freezing temperatures, than any change in the fabric.
The heat shrunk fabrics apparently don't suffer as much from this
because there is enough extra tautness is added during the shrinking
process to make up for any dimensional change in the airframe at low
temperatures.

I was just wondering if you have any comments in this regard?

----------------------------------------------------
Del Rawlins-
Remove _kills_spammers_ to reply via email.
Unofficial Bearhawk FAQ website:
http://www.rawlinsbrothers.org/bhfaq/

Just one. Thanks for passing that on to the group.

In actuality, we do sell quite a bit of fabric to the Northern reaches. ERA
has worn our fabric on their DC-3s and the military sure has used it on a
lot of cargo planes in the northern frontier over the years. We are always
sending out belly repair kits to Maules owners there, as well as a large
contigent of Stinson owners. It is plausible that there could be a problem
with improper installation or very poor conditions during istallation.
Cellulose Acetate Butryate dope is an organic laquer that is sensitive to
atmospheric conditions (usually needing 70 plus degrees of heat during the
application) but is usually very stable once it dries. Again, dope on cotton
and linen has been used for the 50 years prior to the introduction of the
newer fabrics.

I know that a cannon ball drop test was performed on our fabric at many
different sub temperatures and published. Nothing was printed about loss of
tautness due to temperature, only poor application due to following the
instructions. Even an aircraft manufacturer was repremanded for not
following the installation manual by not reinforcing the stress points over
longerons and formers (also as per the A.C. 43-13) with reinforcing tape.
They were saving time and labor by not doing so. The owners paid for the
time saving twenty to thirty years later.
"Del Rawlins" wrote in message
...
Question for the Razorback Fabric guy:

I'm currently finishing up the training for my A&P certificate at the
school here in Anchorage, and as it so happened, the lecture this
morning was about fabric covering. The instructor brought up Razorback
fabric, mentioned that it is great stuff, but then added that we don't
see much of it here in Alaska because it tends to sag in cold weather
compared to the shrunk-on polyester fabrics. As I recall from the
lecture, he said it was due more to contraction of the underlying
airframe in sub freezing temperatures, than any change in the fabric.
The heat shrunk fabrics apparently don't suffer as much from this
because there is enough extra tautness is added during the shrinking
process to make up for any dimensional change in the airframe at low
temperatures.

I was just wondering if you have any comments in this regard?

----------------------------------------------------
Del Rawlins-
Remove _kills_spammers_ to reply via email.
Unofficial Bearhawk FAQ website:
http://www.rawlinsbrothers.org/bhfaq/

In Robert Little wrote:

very stable once it dries. Again, dope on cotton and linen has been
used for the 50 years prior to the introduction of the newer fabrics.

Yes, but both of those fabrics have built in shrinking ability and will
continue to shrink as they age. How can you make fiberglass cloth
shrink? Maybe I just don't understand enough about your process to get
it. Do you have a website with technical information, or could you post
an excerpt from the relevant part of your application manual?

----------------------------------------------------
Del Rawlins-
Remove _kills_spammers_ to reply via email.
Unofficial Bearhawk FAQ website:
http://www.rawlinsbrothers.org/bhfaq/

Del Rawlins wrote:

In Robert Little wrote:

very stable once it dries. Again, dope on cotton and linen has been
used for the 50 years prior to the introduction of the newer fabrics.

Yes, but both of those fabrics have built in shrinking ability and will
continue to shrink as they age. How can you make fiberglass cloth
shrink? Maybe I just don't understand enough about your process to get
it. Do you have a website with technical information, or could you post
an excerpt from the relevant part of your application manual?

----------------------------------------------------
Del Rawlins-
Remove _kills_spammers_ to reply via email.
Unofficial Bearhawk FAQ website:
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Del,

Check the model airplane supply houses.
You can find glass down to 1/2 ounce per yard.

Butyrate shrinks quite a bit.
Even the "non-taughtening" variety pulls up a bit.

So a glass skin would rely on the coating for taughtness
(not in the MS dictonary?) - just like linen does.

In Richard Lamb wrote:
Del Rawlins wrote:

In Robert Little wrote:

very stable once it dries. Again, dope on cotton and linen has been
used for the 50 years prior to the introduction of the newer
fabrics.

Yes, but both of those fabrics have built in shrinking ability and
will continue to shrink as they age. How can you make fiberglass
cloth shrink? Maybe I just don't understand enough about your
process to get it. Do you have a website with technical information,
or could you post an excerpt from the relevant part of your
application manual?

Del,

Check the model airplane supply houses.
You can find glass down to 1/2 ounce per yard.

I'm not sure what this has to do with the effects of cold weather on the
glass cloth. I think you are confusing me with Ernest.

Butyrate shrinks quite a bit.
Even the "non-taughtening" variety pulls up a bit.

So a glass skin would rely on the coating for taughtness
(not in the MS dictonary?) - just like linen does.

I thought that the natural fiber coverings like linen or cotton were
primarily shrunk using water? I.E. they get most of their tautness from
natural shrinkage as the water dries, prior to the coating being applied.
Or am I all wet? I don't know a lot about fabric covering and am just
trying to get a clear understanding of the various systems.

----------------------------------------------------
Del Rawlins-
Remove _kills_spammers_ to reply via email.
Unofficial Bearhawk FAQ website:
http://www.rawlinsbrothers.org/bhfaq/