6.3.3- Fabric

Question 1

What are the most suitable conditions for the application of fabric?

Answer 1

Room temperature of 16°C to 21°C and relative humidity of no more than 70%.

Question 2

What is the weft of a fabric?

Answer 2

The threads running the width of the fabric.

Question 3

What is cotton tape often referred to as?

Answer 3

Egyptian tape.

Question 4

For stringing of fabric what is normally used?

Answer 4

Flax cord.

Question 5

How should fabrics be stored?

Answer 5

20°C in dry, clean conditions away from direct sunlight.

Question 6

How do you stop any dope from reacting with the protective treatments?

Answer 6

Adhesive cellulose or aluminium tape, or painted with dope resistant white paint.

Question 7

What angle can the warp or weft of a fabric be fitted to the slip stream?

Answer 7

45° or in line.

Question 8

What are the two methods of fabric covering an airframe?

Answer 8

Prefab Envelopes

Blanket.

Question 9

How does the envelope method of fabric covering work?

Answer 9

Made from the patterns for the various surfaces and are loose enough to slip them over the structure but still achieve the required tautness when doped.

Question 10

How does the blanket method of fabric covering work?

Answer 10

Lengths of fabric are joined side by side.

Question 11

What are the two types of seams?

Answer 11

Balloon

Lap.

Question 12

What is the balloon seam sometimes referred to as?

Answer 12

French fell.

Question 13

What is a balloon seam?

Answer 13

The edges of the fabric are folded back and then fitted to into each other and then sewn. (Page 182 of notes).

Question 14

What stitches are used for repair? And what are the two less commonly used?

Answer 14

Herring bone (baseball) and boot stitch. 
Overhand and lock.

Question 15

Why do you put beeswax on threads?

Answer 15

To protect them from friction, fraying and damage to the eyelets.

Question 16

Where is boom stringing used?

Answer 16

Used on deep aerofoil sections, the cord goes around the rib boom instead of the entire rib.

Question 17

What are the most common methods of fabric attachment?

Answer 17

Strip
Stringing
Adhesives

Question 18

What is strip attachment of fabrics?

Answer 18

Wrapping it around a rod and then securing in a channel or groove.

Question 19

How is fabric attached to plywood?

Answer 19

Dope, it should be rubbed down after it has dried with wet and dry.

Question 20

What methods of drainage and ventilation are there?

Answer 20

Drainage holes
Drainage eyelets
Shielded eyelets

Question 21

How can the ability to inspect the structure be incorporated into fabric covering?

Answer 21

Woods frames
Zip panels
Spring panels

Question 22

What is the major disadvantage of woods inspection frames?

Answer 22

A new patch must be doped on each time.

Question 23

What can be repaired using a darning?

Answer 23

Irregular holes or jagged tears, provided it’s not bigger than 50mm at any point. Stitches should follow the line of the warp and weft.

Question 24

What dimensions are fabric insertions used for fabric repairs?

Answer 24

For damage over 100mm square.

Question 25

Name the two methods used to test fabric?

Answer 25

Seyboth and maule.

Question 26

Describe the principles of using a maule tester.

Answer 26

Spring loaded instrument with a blunt point. Breaking point of fabric is reached on the scale, if fabric is punctured it fails.

Question 27

Describe the principles of a seyboth tester?

Answer 27

The force it takes to pierce the fabric is measured on a coloured scale, all punctures must be repaired.

Question 28

What does doping achieve?

Answer 28

Tautening
Waterproofing
Airproofing
Light proofing

Question 29

What dope is used to protect from UV?

Answer 29

Aluminium Dope.