Windows and Lenses (week 6-7) Flashcards
2 Types of Plastic
Thermoplastics & Thermosettings
What type of plastic can be softened by heat & dissolved in various organic solvents?
Thermoplastic
types of thermoplastic
Cellulose Acetate Plastic
Acrylic Plastic
Polycarbonate Plastic
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.
Thermosetting
What plastic is used commonly in the construction of A/C windows and lenses?
Thermosetting
When assessing damage to windows, what is the most precise tool?
Optical Micrometer
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.
Crazing
Cause of Crazing
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
A mark or mar of the surface by rubbing, scraping or tearing with something sharp or rough
Scratch
A defect that involves the breaking without complete separation of the part involved.
Crack
A defect that involves a mark or flaw made by the breaking off or gouging out of a small piece.
Chip
is caused by working one small spot and not blending the damage removal over a large enough area
Localized Distortion
________ distortion is almost always a sign of incomplete restoration.
Surface Distortion
What causes Surface Distortion?
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.
In the case of a crack, all of the ends of the crack can be stop-drilled with a?
30 Drill bit (.1285” or 1/8”)
More permanent repairs can be made to acrylic plastic by using a?
Polymerizable Cement
_________ ________ _________ is not commonly used anymore, expands/contracts easily with heat, tints over time
Cellulose Acetate Plastic
_______ ________ are brittle but strong, and cheap
Acrylic Plastic
______________ __________ can also be softened by heat and dissolved in various organic solvents. Can be bent cold
Polycarbonate Plastic
ATA___ Is Windows
ATA 56
What are the steps to cleaning windows?
1) Use water & your hand/fingernail
2) Use commercial window cleanser DON’T USE AMMONIA
3) Acrylic window polish
Should you drill holes bigger or smaller than fasteners?
All holes should be at least 1/3 bigger than the fastener
When cutting acrylic plastics, what should you not use?
Reciprocating saw
0 - 4 degree rake angle is used to?
scrape acrylic sheet
