Replace fabric with glass

Stealth Pilot wrote:


polyfiber is nothing to be afraid of. it is the best system going so
far. if you use polytone paint it is permanently repairable.
Stealth Pilot

That's one I agree with totally.

Ease of use, repairability, and a nice high quality finish.

Using Polyfiber with and electric HVLP is about as easy as covering
an airplane can get.

Richard

http://home.earthlink.net/~n6228l

Corky Scott wrote:

Are you trying to save money or weight, or both? When you wet out the
fiberglass fabric, it sometimes takes a lot of primer to fill the
weave, depending on the weight of the cloth. That could make for a
looonnnnggggg time of finishing to make it look good.


Doubt it would be any cheaper. Thought it could be a little lighter.

I guess a benefit would be a simplification in this project. I'm
already having to do a lot of fiberglass work with the wings and
turtleback. The fabric is a whole 'nuther skill set, tool set, and
chemical set. The fabric entails, gluing, shrinking, fabric-riveting
(which I understand is slightly different than metal riveting) then
filling the weave. While maybe all minor skills, they are all something
to be learned and all have their set of pitfalls. For instance, I've
been warned that when sanding the primer, the abrasive pad can easily
slice through the fabric at the edges of ribs or other hard supports.

I'm already doing the FG thing, so I'd get to amortize the learning
curve a little more. As I understand it, a 2oz fine-weave cloth doesn't
need much filling and if you wet it out on plastic, it won't need any.
It will come out as smooth as the plastic. The process would boil down
to wet out the glass between 2 sheets of plastic, pull of the top sheet
and wrap the rest around the part to be covered. Scuff sand and and
it's ready for paint.

I'm really not that concerned about strength, other than the FG is so
much stronger that you should be able to size it down accordingly.
Whichever type you choose, the resulting coverings weight will be
determined in large part by how thick the fabric was to begin with. It
seems that a thinner fabric wouldn't need as much filler to get 'full'.
And 2oz FG has got to be thinner than 4oz polyester. The comments
have been that the Razorback system is heavy, and I don't understand why
that should be. Why not use a thinner fabric since it has the strength
to spare?


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

Ernest Christley wrote:

Corky Scott wrote:

Are you trying to save money or weight, or both? When you wet out the
fiberglass fabric, it sometimes takes a lot of primer to fill the
weave, depending on the weight of the cloth. That could make for a
looonnnnggggg time of finishing to make it look good.


Doubt it would be any cheaper. Thought it could be a little lighter.

I guess a benefit would be a simplification in this project. I'm
already having to do a lot of fiberglass work with the wings and
turtleback. The fabric is a whole 'nuther skill set, tool set, and
chemical set. The fabric entails, gluing, shrinking, fabric-riveting
(which I understand is slightly different than metal riveting) then
filling the weave. While maybe all minor skills, they are all something
to be learned and all have their set of pitfalls. For instance, I've
been warned that when sanding the primer, the abrasive pad can easily
slice through the fabric at the edges of ribs or other hard supports.

I'm already doing the FG thing, so I'd get to amortize the learning
curve a little more. As I understand it, a 2oz fine-weave cloth doesn't
need much filling and if you wet it out on plastic, it won't need any.
It will come out as smooth as the plastic. The process would boil down
to wet out the glass between 2 sheets of plastic, pull of the top sheet
and wrap the rest around the part to be covered. Scuff sand and and
it's ready for paint.

I'm really not that concerned about strength, other than the FG is so
much stronger that you should be able to size it down accordingly.
Whichever type you choose, the resulting coverings weight will be
determined in large part by how thick the fabric was to begin with. It
seems that a thinner fabric wouldn't need as much filler to get 'full'.
And 2oz FG has got to be thinner than 4oz polyester. The comments
have been that the Razorback system is heavy, and I don't understand why
that should be. Why not use a thinner fabric since it has the strength
to spare?

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



Glass is a highly frangible material compared to polyester.
It is strong, yes, but brittle.

While tensile strength is a good thing, it is not the only thing
we need to consider.

My new plane is covered with 1.7 ounce dacron and Poly Fiber finish.
For a lightly loaded, low speed plane, this is quite adequite.

3.2 ounce fabric is twice as strong.
Why _not_ use it? (trick question!)

Because it's FOUR times heavier when finished?


Richard

Many of you have some ideas about glass fabric that may or may not be valid.
First of all, I own the RAZORBACK FABRIC Company. The company started in
50's and the FAA signed a letter in 60's that deemed our glass covering as a
permanent covering that no longer needed testing as all other fabrics do on
certified airframes do. This is due to the fact that all hydrocarbon based
material deteriorate in the presents of UV radiation.

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.

As in a poorly installed rivet, I supposed our glass could frett. Our shop
is dedicated to repairing and recovering frieght aircraft and so far, I have
never seen this ocurrance. I have seen poorly installed fabric wear away
the aluminum, though. It is much harder than aluminum and steel and care
should be taken to protect the rivet and etc. with anti-shafing tape, as
with any fabric installation.

Once installed correctly, it has a much stiffer surface than the more
flexible and stretchy dacron. I have seen many pictures on the covers of
aviation magazines that show the top of the wing with pillows deforming
between the ribs as the fabric stretches under the aerodynamic load of
flight. Properly installed glass fabric does not stretch and will remain
closer to the profile of the ribs than any other covering short of metal.
Many of our customers comment that our fabric has gained them real increases
in airspeed beyond the fact of being covered with a fresh finish. This also
allows your paints to last longer as the flexing really stresses the surface
coatings. Plus, you don't have the worry of falling through it if you
should mis-step on a low wing. You can walk on it as long as the rib
underneath it can handle the weight.

By the way, since our fabric does not rot, deteriorate in acid rain and
sunlight or even burns and is easily applied and repaired, it is still the
only synthetic fabric that is authorized for use by our and other
militaries. It is FAA-PMA'd, FAA-STC'd, MIL SPEC and ISO 9002 rated. Our
biggest sales are still the military. Yes, C-130s and C-141 still have
fabric on them and in them.

We don't own chemical companies and we are not trying to corner the fabric
market. But if you want a permanent awning, aircraft covering, or a
firewall, you might want to find out more about RAZORBACK FABRICS, INC.
Thank you for your time.

Robert Little

"Ernest Christley" wrote in message
m...
Most of the fabric covered aiplanes I've seen didn't seem that hard.
That is, you could walk up to them and push the fabric in with your
hand. The way I understand the fabric process, it is basically a
composite structure. You have a nylon cloth with a paint "epoxy".

Could a much stronger and lighter covering be made by wetting out some
2.5oz glass cloth on plastic, waiting till it's tacky and then wrapping
it around the airframe? The epoxy would be much lighter than paint, and
fiberglass cloth is MUCH stronger than nylon.

I've seen some places where builders used composites in place of fabric,
and it seemed that they all aimed for a multlayer, stiff panel, putting
the weight far above the original. I just don't understand why?

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

We don't own chemical companies and we are not trying to corner the fabric
market. But if you want a permanent awning, aircraft covering, or a
firewall, you might want to find out more about RAZORBACK FABRICS, INC.
Thank you for your time.

Robert Little
-----------------------------------------------------------

To All:

Listen to the man.

Common Sense has become such uncommon stuff in the aviation community that the
antique phreaks give each other extra points for using heavier and less durable
(but All Original) Irish linen, while across the field the fabric experts are
happily selling Polly Needles for rib-stitching Polly Thread thru Polly Holes
in Polly Fabric, knowing they can charge the same inflated prices to the next
Polly Idiot to own the thing.

Razorback has the potential to put all the Polly People out of business, which
is probably the reason it is always damned with faint praise.

-----------------------------------------------------

Fabric is not always stitched. Most homebuilders are aware that it is sometimes
glued to the structure but most are not familiar with the many other
time-tested methods. On some airframes it is attached with canes & nails (!)
and for metal ribs, with spring clips, wire, sheet metal screws and even
rivets. When Razorback is attached with these methods you end up with a
virtually permanent skin.

-R.S.Hoover

Veeduber wrote:

Fabric is not always stitched. Most homebuilders are aware that it is sometimes
glued to the structure but most are not familiar with the many other
time-tested methods. On some airframes it is attached with canes & nails (!)
and for metal ribs, with spring clips, wire, sheet metal screws and even
rivets. When Razorback is attached with these methods you end up with a
virtually permanent skin.

-R.S.Hoover

John Dyke's prototype, N555A (I hope I got that right), has the fabric
riveted to the elevon ribs, rudder and tailfin. It is glued to the belly.

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

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

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