Questions and Answers - Aircraft Painting | Aircraft Systems

Questions and Answers - Aircraft Painting

Study Aid Questions

Fill in the Blanks

1 Paint is more than aesthetics, it affects the __________________________________ of the aircraft and protects the _________________________________ of the airframe.

2. _______________________________________ is at the top of the list when compared to other coatings for abrasion, stain, and chemical resistant properties.

3. There are several methods of applying aircraft finish. Among the most common are: ___            _____________________________, and _________________________________.

4. There are two main types of spray equipment: ___________________________________

and _______________________________________________.

5. The three most common types of spray guns used are: ___________________________, 
___________________________, and _______________________.

6. The HVLP production spray gun is an ______________________________ mix gun. The ___________________ and __________________________________ is mixed inside the air cap.

7. The most important part of any painting project is the ______________________________________________.

8. The ___________________________________ control knob of a spray gun controls the airflow (pattern shape)

9. Primer is typically applied using a ___________________________________________ spray pattern.

10. While painting the second pass will overlap the first pass by __________________________ percent.

11. A quick check of the spray pattern can be verified by spraying some ________________________________ or ________________________________________ through the gun.

12. A pulsating, or spitting fan pattern may be caused by a _________________________, __________________ vent hole on the supply cup, or the ______________________________may be leaking around the needle.

13. Blushing is the dull ________________________________________ that appears in a paint finish.

14. Pin holes are the result of ___________________________________, _______________________________ or ________________________________________.

15. Sags and runs are caused by applying ____________________________ paint to an area, by holding the spray gun _______________________________ to the surface, or moving the gun ____________________________ across the surface.

16. Orange peel refers to the appearance of a _________________________________ surface.

17. Fisheyes appear as _____________________________________ in the coating as it is being applied.

18. Wrinkling is usually caused by _______________________________ and ______________________________ of the paint finish due to excessively thick or solvent heavy paint coats

19. Spray dust could be caused by spray gun held ____________________________________ from the surface, or incorrect spray gun __________________________________.

20. For a spot repair that requires blending of the coating, an area about ___________________________ times the area of the actual repair must be prepared.


1. The top coat applied to external parts of the aircraft protect against corrosion and deterioration. TRUE/FALSE

2. Epoxy primer is recommended for steel tube frame aircraft prior to installing fabric covering. TRUE/FALSE

3. Older type zinc chromate primers are distinguishable by its flat green color. TRUE/FALSE

4. If the paint materials are too thick, they are likely to run or not cover the surface adequately. TRUE/FALSE

5. A HVLP spray gun transfers more paint to the surface of the painted surface. TRUE/FALSE

6. The HVLP spray gun is an external mix gun. TRUE/FALSE

7. Fresh air breathing systems should be used when spraying polyurethane paint because it contains isocyanides. TRUE/FALSE

8. The Zahn cup is used to measure the viscosity of the primer or paint system. TRUE/FALSE

9. Alodine is not used with aluminum aircraft, it is mostly used with composite aircraft structures. TRUE/FALSE

10. The upper control knob of the paint gun controls the airflow and the bottom control knob controls the fluid flow. TRUE/FALSE

11. If the spray pattern is offset to one side or the other, the fluid valve may be plugged. TRUE/FALSE

12. A spitting fan pattern may be caused by a loose nozzle, clogged vent hole or a leaking packing. TRUE/FALSE

13. When painting an aircraft, start painting the large surfaces first and than fill in the corners and gaps. TRUE/FALSE

14. Blushing is the dull milky haze that appears in a paint finish. TRUE/FALSE

15. Orange peel could be caused by not enough reducer or too little flash time between coats. TRUE/FALSE

16. The most effective way to eliminate fisheyes is to ensure that the temperature is above 70 °F. TRUE/FALSE

17. Each operator of an aircraft shall display on the aircraft, marks consisting of the Roman capital letter “U” (denoting United States registration). TRUE/FALSE

18. The registration marks must be at least 10 inches high. A glider may display marks at least 3 inches. TRUE/FALSE

19. One way to test if the old paint is to apply turbine oil to a small area. If the paint softens within a few minutes the paint system is an acrylic or epoxy paint finish. TRUE/FALSE

20. Plastic Media Blasting (PMB) is an effective way of stripping paint of composite structures which causes less damage than sanding. TRUE/FALSE

Knowledge Application Questions

1. What are the common types of paint used on aircraft?

2. Why are old zinc type primers (bright yellow color) not used anymore for modern aircraft.

3. What will happen if the ports in the horn of the spray gun aircap are becoming plugged?

4. What is the purpose of primers?

5. Many of the solvents and thinners used in modern finishing systems are toxic; what health safety precaution should the mechanic observe?

6. What are three methods of applying paint?

7. What is the cause for spray dust?

8. What may cause spray paint sags and runs?

9. What causes orange peel spray mottle?

10. What is a blushing paint finish?

11. What will cause a blushing paint finish?

12. What could be the result of applying a coat of paint when the temperature of the dope room is too high?

13. What areas must be protected from damage when using paint remover/stripper?

14. What is the reason for paint touchup other than appearance?

15. What is the most common finish system for modern transport category aircraft?

16. Name three ways to strip paint from an aircraft

17. Describe how to adjust a spray gun for painting large surfaces.

18. What could cause a pulsating or spitting fan pattern?

19. What is the most effective way to eliminate fisheyes?

20. What is the location of the registration mark on fixed wing aircraft?

Multiple Choices Questions

1. Which of the following is a hazard associated with sanding on fabric surfaces during the finishing process?

a. Overheating of the fabric/finish, especially with the use of power tools.
b. Static electricity buildup.
c. Embedding of particles in the finish.

2. What is likely to occur if unhydrated wash primer is applied to unpainted aluminum and then about 30 to 40 minutes later a finish topcoat, when the humidity is low?

a. Corrosion.
b. A glossy, blush‐free finish.
c. A dull finish due to the topcoat 'sinking in' to primer that is still too soft.

3. Before applying a protective coating to any unpainted clean aluminum, you should

a. wipe the surface with avgas or kerosene.
b. remove any conversion coating film.
c. avoid touching the surface with bare hands.

4. What is the usual cause of runs and sags in aircraft finishes?

a. Too much material applied in one coat.
b. Material is being applied too fast.
c. Low atmospheric humidity.

5. Which defect in aircraft finishes may be caused by adverse humidity, drafts, or sudden changes in temperature?

a. Orange peel.
b. Blushing.
c. Pinholes.

6. If masking tape is left on for several days and/or exposed to heat, it is likely that the tape will 

a. not seal out the finishing material if the delay or heating occurs before spraying.
b. be weakened in its ability to adhere to the surface.
c. cure to the finish and be very difficult to remove.

7. What is used to slow the drying time of some finishes and to prevent blush?

a. Reducer.
b. Retarder.
c. Rejuvenator.

8. Which type of coating typically includes phosphoric acid as one of its components at the time of application?

a. Wash primer.
b. Epoxy primer.
c. Zinc chromate primer.

9. Which properly applied finish topcoat is the most durable and chemical resistant?

a. Synthetic enamel.
b. Acrylic lacquer.
c. Polyurethane.

10. Aluminum‐pigment in dope is used primarily to

a. provide a silver color
b. aid in sealing out moisture from the fabric
c. exclude sunlight from the fabric

11. What could happen if the to be painted surface is not clean and free of any type of contaminants?

a. The surface has the appearance of orange peel
b. The surface feels rough
c. Fisheyes could appear on the surface

12. A rough surface that feels like sandpaper is an indication of?

a. spray dust
b. orange peel
c. fisheyes

13. What could happen if the paint material is not properly mixed?

a. fisheyes
b. orange peel
c. wrinkles

14. The registration marks must be at least _____ inches high. A glider may display marks at least _____ inches.

a. 8 inches, 4 inches
b. 10 inches, 6 inches
c. 12 inches, 3 inches

15. The pressure used for a HVLP spray gun is __________ the pressure used for a traditional spray gun.

a. lower than
b. higher than
c. equal to

16. A spray gun that uses lower pressure and higher volumes of air is called a:

a. HVLP spray gun
b. Siphon feed gun
c. Gravity feed gun

17. With 12” high registration marks, what is the minimum space required for the registration mark N1683C?

Notes: 2/3 x height = character width       1/6 x height = width for 1
           1/4 x 2/3 height = spacing             1/6 x height = stroke or line width

a. 52 inches
b. 48 inches
c. 57 inches

Finishing Materials
Identification of Aircraft Paints
Common Aircraft Paint Troubles
Painting Trim and Identification Marks
Decals Paint System Compatibility