Windows and Lenses (week 6-7)

Question 1

2 Types of Plastic

Answer 1

Thermoplastics & Thermosettings

Question 2

What type of plastic can be softened by heat & dissolved in various organic solvents?

Answer 2

Thermoplastic

Question 3

types of thermoplastic

Answer 3

Cellulose Acetate Plastic
Acrylic Plastic
Polycarbonate Plastic

Question 4

What type of plastic are liquid or malleable prior to their final forming and allows to be formed or molded into their final shape? Material then cures either through heat or through a chemical reaction.

Answer 4

Thermosetting

Question 5

What plastic is used commonly in the construction of A/C windows and lenses?

Answer 5

Thermosetting

Question 6

When assessing damage to windows, what is the most precise tool?

Answer 6

Optical Micrometer

Question 7

appears as a fine web like pattern of small scratches, often only detectable in the hangar by shining a flashlight into the window at an angle.

Answer 7

Crazing

Question 8

Cause of Crazing

Answer 8

caused by the porous structure of the acrylic allowing some passage of moisture, sulphides and atmospheric contaminants, accelerated by pressurization and temperature variance. Poor cleaning processes, using inappropriate solvents, also can induce crazing

Question 9

A mark or mar of the surface by rubbing, scraping or tearing with something sharp or rough

Answer 9

Scratch

Question 10

A defect that involves the breaking without complete separation of the part involved.

Answer 10

Crack

Question 11

A defect that involves a mark or flaw made by the breaking off or gouging out of a small piece.

Answer 11

Chip

Question 12

is caused by working one small spot and not blending the damage removal over a large enough area

Answer 12

Localized Distortion

Question 13

________ distortion is almost always a sign of incomplete restoration.

Answer 13

Surface Distortion

Question 14

What causes Surface Distortion?

Answer 14

1) the incomplete removal of one sanding pattern before proceeding to the next step.
2) not working a larger area with each new step .
3) heat build-up.
4) skipping steps.
5) not cleaning the surface between steps.

Question 15

In the case of a crack, all of the ends of the crack can be stop-drilled with a?

Answer 15

30 Drill bit (.1285” or 1/8”)

Question 16

More permanent repairs can be made to acrylic plastic by using a?

Answer 16

Polymerizable Cement

Question 17

_________ ________ _________ is not commonly used anymore, expands/contracts easily with heat, tints over time

Answer 17

Cellulose Acetate Plastic

Question 18

_______ ________ are brittle but strong, and cheap

Answer 18

Acrylic Plastic

Question 19

______________ __________ can also be softened by heat and dissolved in various organic solvents. Can be bent cold

Answer 19

Polycarbonate Plastic

Question 20

ATA___ Is Windows

Answer 20

ATA 56

Question 21

What are the steps to cleaning windows?

Answer 21

1) Use water & your hand/fingernail
2) Use commercial window cleanser DON’T USE AMMONIA
3) Acrylic window polish

Question 22

Should you drill holes bigger or smaller than fasteners?

Answer 22

All holes should be at least 1/3 bigger than the fastener

Question 23

When cutting acrylic plastics, what should you not use?

Answer 23

Reciprocating saw

Question 24

0 - 4 degree rake angle is used to?

Answer 24

scrape acrylic sheet

Question 25

When Cutting plastics u use a?

Answer 25

Bandsaw

Question 26

why do we grind the tip angle to 60⁰ - 90⁰ sharp angle?

Answer 26

allows the bit to easily enter and exit acrylic sheet without chipping.

Question 27

Why do we grind away the surface behind the cutting edge to clearance angles of 12⁰- 15⁰?

Answer 27

reduces metal-to-plastic contact and heat build-up.