Learn: Aircraft Painting: Spray Guns, Coatings, and Finish Defects

What is more than aesthetics in aircraft painting?

Paint affects the integrity and protects the weight of the airframe.

What properties does polyurethane have?

It is abrasion, stain, and chemical resistant.

What are the common methods of applying aircraft finish?

Brushing and spraying.

What are the two main types of spray equipment?

HVLP gun and pressure pot.

What are the three most common types of spray guns?

Gravity gun, siphon gun, and pressure gun.

What is the HVLP production spray gun?

An internal mix gun where the fluid is mixed inside the air cap.

What is the most important part of any painting project?

Preparation.

What does the upper control knob of a spray gun control?

The airflow pattern shape.

How is primer typically applied?

Using a cross spray pattern.

By what percentage should the second pass overlap the first pass?

50%.

What can be verified by spraying some reducer through the gun?

A quick check of the spray pattern.

What may cause a pulsating or spitting fan pattern?

A clogged vent hole or leaking thinner.

What is blushing in paint finish?

A dull milky haze that appears in a paint finish.

What causes pin holes in paint?

Moisture or trapped solvents.

What causes sags and runs in paint?

Applying too much paint, holding the spray gun too close, or moving too slowly.

What does orange peel refer to in paint finish?

The appearance of a bumpy surface.

What causes fisheyes in paint?

Small holes that appear due to trapped solvents.

What is wrinkling in paint finish caused by?

Unequal drying due to excessively thick or solvent heavy paint coats.

What could cause spray dust?

Paint drying before reaching the surface.

What are the common types of paint used on aircraft?

Lacquer, enamel, and polyurethane.

Why are old zinc type primers not used anymore?

They contain toxic chromates.

What happens if the ports in the horn of the spray gun aircap become plugged?

The spray pattern becomes uneven.

What is the purpose of primers in painting?

To prevent corrosion and help paint stick.

What health safety precaution should be observed when using solvents?

Use proper PPE, respirator, and ventilation.

What causes spray paint sags and runs?

Too much paint or spraying too close.

What causes orange peel in paint?

Poor atomization or paint being too thick.

What is a blushing paint finish?

A cloudy or milky paint finish.

What could happen if paint is applied when the temperature is too high?

Paint may dry too fast and become rough.

What areas must be protected from damage when using paint remover?

Windows, rubber, and plastic parts.

What is the reason for paint touchup other than appearance?

To prevent corrosion.

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

Epoxy primer with polyurethane topcoat.

What are three ways to strip paint from an aircraft?

Chemical stripping, sanding, and media blasting.

How should a spray gun be adjusted for painting large surfaces?

To achieve a nice even pattern.

What could cause a pulsating or spitting fan pattern?

Leaking into the paint supply or clogged nozzle.

What is the most effective way to eliminate fisheyes?

Clean off all oil, wax, and silicone.

Where is the registration mark located on fixed wing aircraft?

On the side of the fuselage or vertical fin.