Cleaning & Corrosion Control

Question 1

2. Name at least three factors that influence corrosion.

Answer 1

Temperature
Type of metal
Condition of protective coating

Question 2

3. What are the two general conditions that may cause stress corrosion cracking?

Answer 2

Sustained tensile stress & a corrosive environment

Question 3

5. What is the principal cause of filiform corrosion?

Answer 3

Surfaces that been cleaned properly before painting

Question 4

6. Where is intergranular corrosion most likely to occur?

Answer 4

Along grain boundaries of extruded materials

Question 5

7. What is another name for dissimilar metal corrosion?

Answer 5

Galvanic corrosion

Question 6

8. What are the factors which affect the type of corrosion?

Answer 6

Atmospheric conditions
Size & shape of metal
Type of metal
Corrosion producing agents present

Question 7

9. What methods are used for removing rust from aircraft materials?

Answer 7

Abrasive papers & compounds
Small power buffers
Hand wire brushing & steel wool

Question 8

10. What is an acceptable method for removing surface corrosion from titanium?

Answer 8

Stainless steel brush
Aluminum oxide sandpaper
Scotch brute
Abrasive blasting using glass beads

Question 9

11. What specific operations are part of corrosion preventative maintenance?

Answer 9

Adequate cleaning
Periodic lubrication
Detailed inspection
Prompt corrosion treatment
Touch up damaged paint
Sealing
Protective covers

Question 10

12. Name the steps for corrosion removal.

Answer 10

Clean & strip corroded areas
Remove as much corrosion as possible
Neutralize any residual material remains in pits or cracks
Restore protective surface films & paint

Question 11

13. What tools are approved for cleaning corroded anodized surfaces?

Answer 11

Fiber bristle brushes
Aluminum wool
Aluminum wire brushes

Question 12

14. What is used to keep corrosion from forming on aluminum alloy?

Answer 12

Oxide coating or aluminum cladding

Question 13

15. What can be used to repair the anodized surface of an aluminum alloy part?

Answer 13

Aldine or other chemical conversion coatings

Question 14

16. What products should be used to clean aircrafts engine?

Answer 14

A fine spray of kerosene or solvent

Question 15

17. What should be use to clean grease, fuel, or other oil from aircraft rubber tires?

Answer 15

Soap & water

Question 16

18. Why should only recommended cleaners be used on aircraft fabric & plastics?

Answer 16

Causes less degradation of material

Question 17

19. Name five areas of an aircraft that are more prone to corrosion.

Answer 17

Battery compartments
Wheel wells & landing gear
Lavatory
Valley
Flap recesses
Bilge areas

Question 18

20. What form of corrosion can be found in battery compartments?

Answer 18

Direct chemical corrosion

Question 19

21. Why are piano-type fingers prime locations for corrosion?

Answer 19

Piano hinders use dissimilar metals and tend to trap contaminant between them

Question 20

22. What is used to neutralize a lead-acid battery electrolyte?

Answer 20

Baking soda & water

Question 21

23. What is the difference between “wet wash” and “dry wash” aircraft cleaning?

Answer 21

Wet Wash - water & agent

Dry Wash - compressed air & cloth

Question 22

24. What are types of light duty and heavy duty aircraft cleaning agents?

Answer 22

Light duty - soap & synthetic detergent

Heavy duty - solvents & emulsion type cleaners

Question 23

25. What would you do before cleaning a wind screen?

Answer 23

Wet the surface to prevent scratching

Question 24

26. What does filiform corrosion look like & where can it be found?

Answer 24

Looks like craters on the moon. It occurs between metals surface & protective coatings

Question 25

27. How is the inside of structural tubing prevented from corroding?

Answer 25

Hot linseed oil coats the inside