since 1940

Aircraft Fabric Frequently Asked Questions      

How do I remove Aerothane overspray

Try a very light wet sanding with 1200 or 1500 grit sandpaper. Then buff out with an automotive polishing compound by hand, or with a foam pad on a machine buffer.

Poly Fiber fabric weights

Poly-Fiber Heavy Duty Fabric
Polyester fabric. Each style is identified with the trade name and fabric style. Example: "Poly-Fiber Aircraft, FAA PMA." The fabric description is stamped at three-foot intervals. Refer to current fabric product data sheet for a complete list and description of all fabric styles available. Our Heavy-Duty is for more rigorous operations such as aerobatics, agricultural, bush aircraft, and former military aircraft. Its large filament size and high strength provide excellent resistance to rock penetration and tearing.

Specifications:
Width -- 70 in
Thread Count -- 65 x 58/in
Weight -- 3.4 oz/sq yd
Breaking Strength -- Over 125 lb/in
Bursting Strength -- 304 psi
Tear Strength -- Warp 30.1 lb, Fill 33.8 lb
Tension -- 57 oz/in
Elongation at 70 lb/in -- Warp 13.0%, fill 8.6%.

Medium Fabric
Considered the standard fabric, it is recommended for normal service and is widely used on all types of aircraft, regardless of wing loading or horsepower. Recommended Aircraft: all classics, antiques, and contemporary designs that anticipate normal on-airport operations.

Specifications:
Width -- 71-72 in
Thread Count -- 68 x 68/in
Weight -- 2.7 oz/sq yd
Breaking Strength -- Over 116 lb/in
Bursting Strength -- 226 psi
Tear Strength -- Warp 14.0 lb, Fill 14.8 lb
Tension -- 54.2 oz/in
Elongation -- Warp 8.5%, Fill 9.6%

Poly-Fiber Uncertified Light Fabric
Our light-weight fabric is recommended for covering plywood surfaces on any aircraft and any ultralight aircraft that is not certified. This fabric will be unstamped. It is not approved for certified aircraft.
Specifications:
Choice of Width -- 60 in or 64 in
Weight -- 1.7 oz/sq yd or 1.6 oz/sq yd
Thread Count -- 1.7 oz. is 98 x 98 in
Tension -- 35 oz/in
Breaking Strength -- 67 lbs (average)

Questions about the Stits Poly Fiber Process -

Answers to about every question you might have.

Poly Fiber Recovering Questions

Difference between Stits and Poly Fiber and Consolidated products

There the same. Ray Stits, the founder of Stits sold the company. The name Poly Fiber name was used by Ray to describe his products and is being used more frequently to describe the "Stits" process. Consolidated Aircraft Coatings owns Poly Fiber and Randolph.

How do I increase the glossiness of a dope finish

Dope finishes are not suppose to be glossy but if you must the glossiness of the butyrate color coats can be improved by using butyrate blush retarder. The slower the dope dries, the glossier it becomes. Blush retarder slows down the drying of dope.

Mix one part retarder with three parts butyrate dope reducer. Use this mixture to thin the butyrate dope one to one.

Be aware that the dope is drying slower so it is more susceptible to running and collecting assorted airborne contaminates.
 

Why is it important to calibrate the iron used for shrinking fabric

All polyester fabric, Ceconite, Stits, Superflite react the same way. At 250 degrees F they shrink about half as much as they are capable of shrinking or about 5%.

At 350 degrees F they shrink all the way they are capable of shrinking or about 10%

Above 350 degrees they begin to permanently loosen

Above 425 degrees the fabric begins to melt

You therefore need a good iron with even heat and to have it calibrated. The iron we sell from experience
produces the most even and consistent heat.

How many steps are in the Stits process

There are just six basic steps:
1. Glue on the fabric with our Poly-Tak fabric cement; tighten it with the heat of a calibrated clothing iron.
2. Brush on a coat of Poly-Brush fabric sealer.
3. Riblace, then apply gussets and finishing tapes with more Poly-Brush.
4. Spray on two more coats of Poly-Brush.
5. Spray on three cross coats of silver Poly-Spray to block ultraviolet radiation.
6. Spray on two coats of top coat paint, either Poly-Tone or Aero-Thane.

I want a really shiny finish. Can I use Imron or my favorite auto paint?

Revision 20, July 2001, of the Poly-Fiber Procedure Manual No. 1 allows only Poly-Tone or Aero-Thane topcoat paint over the fabric-covered components of certified aircraft. This is a major change to the STC. Use of any other topcoat paint over fabric will void the STC. The old rule that the STC was valid only "up to the silver" and that any available topcoat paint could be used has changed. The increasing use of brittle automotive polyurethane paints over the years has caused enough cracking and delimitation to cause the FAA to rethink approving untested topcoat paint over fabric. Failed topcoat paints expose polyester fabric to sunlight and UV damage. Poly-Tone and Aero-Thane have long service records over fabric as well as established test data on file with the FAA. Additionally, both paints have an FAA Parts Manufacturing Authority (PMA) which allows their application on certified aircraft. This has no effect on the non-fabric components. For instance, a J-3 Cub must have only Poly-Tone or Aero-Thane over the fabric parts, but you could use enamel or anything else over the metal struts, cowls, doors, etc. The key word is FABRIC. Experimental aircraft are not bound by these changes; however, we do recommend using products with a known track record on fabric.

Do I have to rib lace? My kit manufacturer says it's not necessary

Lift acts like a giant vacuum cleaner, exerting a peeling force on the top of your wing. You have to do something to hold your fabric on other than just gluing it. Pop rivets, screws, clips, and rib lacing are designed to secure fabric for long service lives. Rib lacing is kindest to the rib structures, and it's really pretty easy to learn. It takes only about five hours to lace a wing. This is great insurance and it costs very little. Yes Virginia, you have to rib lace. But it is really a piece of cake to do. Glue alone does not hack it.

How much does fabric covering weigh? What is the lightest system?

When Cubs rolled off the line, they had 75 pounds of Grade A cotton and dope on them.

A Ceconite and dope finish on that same Cub will probably weigh about 50 to 60 pounds.

A Cub done in Poly-Fiber has 40 to 45 pounds of finish weight.

A Cub done in urethane can get pretty heavy if you lay on the thick coats. Urethane is not known for its light weight.

Ultralights can be done in as little as 12 to 15 pounds.

Of these systems, which is cheaper? How much will it cost to cover my plane?

If you got a price quote on each of the three systems, you'd see that they all total about the same. Only the cost per can is different. For instance, dope costs about $40.00 a gallon, Poly-Fiber is about $65.00 a gallon, but you need twice as much dope as Poly-Fiber. The urethanes can get as high as $200.00 including catalyst and flex agents. Here you use fewer gallons, but at a much higher price.

No matter which system you use, the final cost for the fabric, tapes, coatings and paint is about the same.

Cub sized airplanes will cost $3,000 to $3,500, depending on the color you choose.

Ultralights run about $700 to $1,200 on average.

I'm confused about the different covering systems. Please explain them

There are really only three basic systems, and they all start with heat-shrunk fabric:

CECONITE FABRIC (Ceconite is a fabric brand), applied with nitrate and butyrate dopes. Our brand of dope is called Classic Aero. Randolph dopes are also widely used on Ceconite. Dope is easy to repair and has been around since aviation began.

POLYURETHANE. These are two-part polyurethane systems using automotive coatings with flex agents added to reduce cracking of the dried paint. Major brands are Superflite II and Air Tech. Their finishes are high gloss, but are hard to repair and must be sprayed with the precaution: urethane spray mist is very toxic.

POLY-FIBER. The "Stits" system, using Poly-Fiber fabric and all-vinyl coatings. Our vinyl coatings do not support combustion. The basic Stits system consists of the build-up coats Poly Brush, the "silver" coat Poly Spray, and the color coat called "Poly Tone.
 

How long does fabric covering last

This business about recovering every few years comes from the old days of covering with cotton and linen. That's ancient history. Today, all covering is done with heat-shrunk polyester fabric. With proper application, today's fabric systems last 20 to 30 years, even outdoors.

Sometimes the covering can outlast the supporting structure.

How do I remove gas stains from Poly-Tone and Aero-Thane surfaces

dissolve 1 level tablespoon swimming pool granular chlorine in 2 liquid ounces of water for about 10 minutes, then add 2 liquid ounces of BR-8600 Retarder and 2 liquid ounces MEK.

Apply 3 to 5 minutes with a sponge or brush.

Caution: Avoid contact with eyes, skin and clothing. Use eye and skin protectors. If exposed wash with water. Develops chlorine gas - do not store in closed containers. Pot life is 2 hours, then discard.

How much should I order

Naturally, your list depends upon what you're covering and we can help you determine what your plane will require. For example, you want to cover a J-3 Cub; you would need the following

45 yards of Poly Fiber Medium fabric
6 rolls of 2" medium finishing tape
1 roll of 4" medium finishing tape
1 roll of rib lacing cord
2 rolls of 1/2" reinforcing tape
2 rolls of inter-rib bracing tape
1 roll of cloth anti-chafe tape
100 plastic or aluminum drain grommets
30 inspection rings
25 inspection ring covers
8 gallons of Poly Brush
1 gallon of Poly Tak
11 gallons of Poly Spray
5 Gallons of reducer
11 gallons of Poly-Tone color

Ceconite Fabric Specifications

Copyright 2003 by Sacramento Sky Ranch Inc. All rights reserved.  Prices subject to change without notice. Not responsible for typographical or misprint.
Disclaimer: sacskyranch.com contains abundant information relating to aircraft maintenance. The information provided  is not intended to supercede or supplement the F.A.A. approved  maintenance and/or operator’s manuals. Those F.A.A. approved manuals must be utilized when performing maintenance and/or operating aircraft.