cleaning and corrosion control

A primary reason why ordinary or otherwise non-approved cleaning compounds should not be used when washing aircraft is because their use can result in?

Hydrogen embrittlement in metal structures

How many magnesium engine parts be cleaned?

Wash with a commercial solvent, decarbonize, and scrape or grit blast.

Which of the following are acceptable to use when utilizing chemical cleaning agents on aircraft?

Cotton fiber wiping cloths when using a flammable agent and atomizing spray equipment

Select a solvent used to clean acrylics and rubber?

Aliphatic naphtha

Which of the following are acceptable to use in cleaning anodizing surfaces?

Aluminum wool and fiber bristle brushes

Which of the following is an acceptable first step procedure to help prevent scratching when cleaning an transparent surface?

Flush the surface with clean water

What should be done to prevent rapid deterioration when oil or grease come in contact with a tire?

Wipe the tire with a dry cloth followed by a wash down and rinse with soap and water

Caustic cleaning products used on aluminum structures have the effect of proceducing

Corrosion

The rust or corrosion that occurs with most metals is the result of

A tendency for them to return to their natural state

Which of the listed conditions is NOT one of the requirements for corrosion to occur?

The presence a passive oxide film

Galvanic corrosion is likely to be most rapid and severe when

The surface area of the anodized metal is similar than the surface area of the cathodic metal

Corrosion caused by galvanic is the result of

Contact between two unlike metals

(1) in the corrosion process, it is the cathodic area or dissimilar cathodic material that corrodes.

(2) in the galvanic or electro-chemical series for metals, the most anodized metals are those that will give up electrons most easily.

Regarding the above statements?

Only 2 is true

Which of these materials is the most anodic?

Cadmium

Which of these materials is the most cathodic?

Stainless steel

Of the following, when and/or where is galvanic corrosion most likely to occur?

At the interface of a steel fastener and aluminum alloy inspected plate in the presence of an electrolyte

Fayed surfaces cause concern in chemical cleaning because of the danger of?

Entrapping corrosive materials

Fretting corrosion most likely to occur?

When two surfaces fit tightly together but can move relative to one another

Which of the following are the desired effects of using Alodine (also known as Bonderite) on aluminum alloy?

A slightly rough surface and increased corrosion resistance

Spilled mercury on aluminum

Causes rapid and severe corrosion that is very difficult to control

For which of the following reasons would a water break test be conducted?

To make certain that a bare metal surface is thoroughly clean

The lifting or flaking of the metal at the surface due to delamination of grain boundaries caused by the pressure of corrosion residual product buildup is called

Exfoliation

Intergranular corrosion in aluminum alloy parts

Cannot always be detected by surface indications

Which of the following may not be detectable even by careful visual inspection of the surface of aluminum alloy parts or structures?

Intergranular corrosion

What may be used to remove corrosion from nightly stressed steel surfaces?

Fine-grit aluminum oxide

When an anodized surface coating is damaged in service, it can be partially resorted by

Chemical surface treatment

A primary cause of Intergranular corrosion is

Improper heat treatment

Corrosion should be removed from magnesium parts with a

Stuff, nonmetallic brush

A non-electrolytic chemical treatment for aluminum alloys to increase corrosion resistance and paint-bonding qualities is called

Alodizing

One way of obtaining increased resistance to stress corrosion cracking is by?

Creating compressive stresses (via shot peening) on the metal surface

Why is it important not to rotate the crankshaft after the corrosion preventive mixture has been put into the cylinders on engines prepared for storage?

The seal of corrosion preventive mixture will be broken

The interior surface of sealed structural steel tubing would be best protected against corrosion by which of the following?

A coating of linseed oil

Select the solvent recommended for wipedown of cleaned surfaces just before painting

Aliphatic naphtha

Nickel-cadmium battery cases and drain surfaces which have been affected by electrolyte should be neutralized with a solution of

Boric acid

If registration numbers are to be applied to an aircraft with a letter height of 12 inches, what is the minimum space required for the registration mark N1683C?

Note:

2/3 X height = character width

1/6 X height = width for 1

¼ X 2/3 height = spacing

1/6 X height = stroke or line width

52 inches

If masking tape is applied to an aircraft, such as for trim spraying, and is left on for several days and/or exposed to heat, it is likely that the tape will

Cure to the finish and be very difficult to remove

What is used to slow the drying time of some finished and to prevent blush?

Retarder

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

Wash primer

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

Polyurethane

Aluminum pigment in dope is used primarily to

Reflects ultraviolet from the fabric

A correctly use for acetone is to

Remove grease from fabric

Which of the following is a hazard associated with sending on fabric covered surfaces during the finishing process?

Static electricity buildup

When the humidity is low, 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 is applied?

Corrosion

Fungicidal dopes are used in aircraft finishing as the?

First coat to prevent fabric rotting and are applied thin enough to saturate the fabric

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

Avoid touching the surface with bare hands

When humidity is low, what is likely to occur if hydration wash primer is applied to unpainted aluminum and then, 30 to 40 minutes later, a finish top coat is applied?

A glossy, blush-free finish

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

Too much material applied in one coat

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

Blushing

Which statement is true regarding paint systems compatibility?

Old wash primer coats may be overcoated directly with epoxy sinuses