Painting and Finishing PowerPoint

What are two critical safety practices when painting?

• Always wear a respirator that has the proper filters for the paint you are using.

• Always read and understand the Material Safety Data Sheet (MSDS).

What should you understand from reading the MSDS (Material Safety Data Sheet)?

• What chemicals are in the paint

• Precautions to be taken

• What to do in case of exposure

• Fire hazards

• Other important information

What are some methods of paint removal? (List 6 methods)

• Chemical Strippers

• Application of chemicals to soften paint

• Dry Strippers

• Blasting of parts

• Sanding of parts

• Pyrolytic Stripping (use of heat to soften layers of paint)

What are hazards of paint strippers? (List 4 hazards)

• Respiratory system damage

• Eye damage

• Skin damage

• Harmful if internally consumed

Always adhere to the MSDS.

What is the process for paint stripping? (List 4 steps)

• Mask all areas not to be stripped

• Apply stripper and remove loosened paint

• Clean with a solvent such as MEK (Methyl Ethyl Ketone) or Acetone

• Blow out all seams and joints

What is MEK?

MEK stands for Methyl Ethyl Ketone.

It is a strong solvent used for cleaning surfaces and removing paint or adhesives.

What is involved in surface preparation before painting? (List 4 steps)

• Surface must be clean of all paint, stripper, oil, dirt, or other debris

• Thoroughly inspect for cracks, corrosion, and other defects; repair as necessary

• Thoroughly clean surface either mechanically or chemically

• Treat with a conversion coating if desired

(Surface preparation is for prepping to paint, not for paint removal.)

What are three types of primers? (List 3 primers)

• Zinc Chromate

• Wash Primer

• Epoxy Primer

What is Zinc Chromate Primer known for?

Good corrosion resistance

Zinc Chromate is a standalone corrosion-inhibiting primer.

What is important to know when using Wash Primer?

• Cures after a half hour (used in high production areas)

• Care must be taken to ensure filiform corrosion is not set up in the application process

Wash Primer is a different type of primer that is acid-catalyzed and used for etching and priming metal surfaces quickly, often with very fast curing (like 30 minutes).

What is Epoxy Primer?

• Two-part primer that gives the best corrosion protection of any modern primer

• Better bond than Zinc Chromate

What are three types of topcoats? (List 3 topcoats)

• Enamels

• Acrylic Lacquers

• Polyurethane

What are characteristics of Enamel topcoats?

Single-stage paint, dries slower, creates a hard glossy finish.

• Produce a glossy finish that does not require rubbing

• Abrasion resistance is not as good as polyurethanes

• Single Stage Coat
  

Do note that ‘Enamel Polyurethane’ is not the same.

What are characteristics of Acrylic Lacquer topcoats?

Dries extremely fast, allows quick application of multiple coats.

• Subsequent coats may be applied very rapidly

• Used in production for a fast-finishing system

• Dry extremely fast

What are characteristics of Polyurethane topcoats?

Very tough coating, requires mixing two parts (base and hardener) for chemical curing.

• Very tough coating

• When dry, polyurethane has a wet look

• Two-part chemically cured paint

Do note that ‘Enamel Polyurethane’ is not the same.

What are types of painting equipment? (List 6 types)

• Regulator

• Pressure pot (still commonly used for large surfaces like aircraft)

• Spray guns

• Suction cup spray gun (older method, less common today)

• Airless sprayers

• HVLP (High Volume Low Pressure) equipment

What two types of respiratory protection are used when painting? (List 2 types)

• Hood-type (Air-supplied) respirators

• Cartridge-type respirators

What is the purpose of an air regulator in a paint booth?

• Maintains correct air pressure for painting operations

• Ensures consistent spray pattern and quality

The air transformer contains a water drain trap, a filter element, a pressure regulator, and the necessary gauges and connection for spray guns.

What is a pressure pot used for?

A pressure pot is used for painting an entire aircraft.

What is a suction cup spray gun used for?

• A suction cup gun is used for applying the trim and for small paint jobs.

What is an air-atomizing spray gun used for?

An air-atomizing spray gun can be used as either a suction cup gun or a pressure pot gun by changing the fluid tip.

What spray pattern is it? What causes it?

Correct Spray Pattern

What spray pattern is it? What causes it?

Insufficient atomizing air pressure

What spray pattern is it? What causes it?

Excessive atomizing air pressure

What spray pattern is it? What causes it?

Material build up on one side of nozzle

What spray pattern is it? What causes it?

One wing-port hole is plugged up.

What is the correct distance to hold the spray gun from the surface?

Hold the nozzle of the spray gun between 6 and 10 inches from the surface being sprayed.

What should you paint first when painting a surface?

• Paint corners and edges first by spraying parallel to the corner

• Then blend into the rest of the surface by spraying perpendicular to the corner

What are six common painting problems? (List 6 problems)

• Runs

• Dry, rough finish

• Blushing

• Fisheyes

• Orange Peel

• Spitting

What causes runs (sags) in paint and how do you repair them?

Causes:

• Application of paint is too thick

• Air pressure too low

• Incorrect viscosity of the paint

Repair:

• Allow paint to dry

• Sand and repaint

If in small area, just redo the job. Large area, sand it.

What causes dry spray (rough finish) and how do you repair it?

Causes:

• Paint is too dry when it reaches the surface

• Gun is too far from the surface

• Improper thinner

• Air pressure too high

Repair:

• Sand and repaint

Pot life can cause this. If the paint sit for too long.

What causes blushing and how do you repair it?

Cause:

• Condensation of water that occurs when solvents evaporate out of the paint

Repair:

• Repaint the surface and add retarder to the paint to slow the evaporation

Blushing is usually caused by atmospheric conditions such as heat, cold, or moisture.

What causes fisheyes and how do you repair them?

Cause:

• Contamination on the surface of the part

Repair:

• Remove the paint and properly clean the part

Caused by contamination on the surface, such as oil, solvent, or hand contaminations.

What causes orange peel and how do you repair it?

Causes:

• Thinners that evaporate too quickly

• Airflow over the surface

• Improper paint mixing or paint too thick

• Insufficient drying time between coats

Repair:

• Polish the surface

What causes spitting during painting?

• Air getting into the fluid because of low paint in the cup

• Air leaking into the air line between the cup and nozzle

What are important steps for applying and removing painting tape?

Applying Tape:

• Use only fine line painting tape

• Use a flat tool or plastic scraper to fully flatten the tape down against the surface

Removing Tape:

• Remove tape when the paint becomes tacky

• Even if the edge is straight, still remove it when tacky; the paint will not overflow, and the edge will remain clean and sharp

• When removing tape, pull it back over itself at an angle away from the paint line

What are the steps to clean a spray gun? (List 4 steps)

• Dump out unused paint

• Rinse out the cup with solvent

• Spray solvent through the gun while moving the trigger through its full travel

• Dip the nozzle into solvent to loosen any paint around the tip

Where is the regulation for painting registration numbers found?

Found in FAR Part 45

FAR: Federal Aviation Regulations

What is FAR?

Federal Aviation Regulations

What are the three rules for ‘Aircraft Identification Plates?’

Clear Understanding: Manufactured Airplanes that apply to § 21.182

• They must mark each aircraft with a fireproof plate that follows the following rules...

1. The plates must include information listed under § 45.13 by using an approved fireproof marking method.

• (This means the markings themselves must be fireproof.)

2. The plates must be secured in a manner where it will not...

• Be defaced

• Be removed during normal services

• Be lost or destroyed in an accident

3. Outside of the exceptions listed in paragraphs (d) through (h), the plates must be secured...

• To the aircraft’s fuselage exterior

  • Needs to be legible to people on the ground

  • Must be either adjacent to and aft of the rear-most entrance door, or

  • On the fuselage surface near the tail surfaces

Additional Clarification:

• Adjacent to the door means next to the door.

• Aft of the door means behind the door toward the rear of the aircraft.

What are the four ‘Registration Mark Size Rules?’

Clear Understanding: Registration Mark Size Rules

• US registered fixed-wing aircraft must have registration marks at least 12 inches high, except under certain conditions...

1. Aircraft built before November 1, 1981

• May have smaller registration marks under old rules.

2. Aircraft with an FAA Experimental Certificate (under § 21.191 d, g, or i)

• Marks can be at least 2 inches high if the aircraft:

  • Operates as an exhibition aircraft, amateur-built aircraft, or light-sport aircraft

  • Has a maximum cruising speed not exceeding 180 knots CAS

3. Exhibition, Antique, or Other Special Aircraft

• Marks may follow § 45.22, allowing exceptions for these types.

4. Aircraft operating after March 7, 1988 through ADIZ or DEWIZ zones

• Must display nationality and registration marks at least 12 inches high, even if temporary or permanent.

• (ADIZ = Air Defense Identification Zone, DEWIZ = Distant Early Warning Identification Zone)