10030 painting test 1, sem 4

“Alodine is an example and produces a golden brown finish on aluminum” 1. It is a protective coating formed on the surface of materials 2. Produces an aluminum oxide protective layer created by a chemical reaction between the metal and the chemical solution 3. Protects the metal from further oxidation 4. Excellent paint adhesion and corrosion resistance

You identify different alloys by using diluted hydrocloric acid 7075 - Will turn black 2024 - this alloy will not be affected

Occurs between two dissimilar metals (anode & cathode) in the presence of an electrolyte “Pitting and surface corrosion can be caused from galvanic corrosion”

Is an attack along the grain boundaries of an alloy “Results from a lack of uniformity in the alloy & during heating and cooling of the alloy”

caused by adhesion between SLIDING surfaces “Occurs when metal surfaces are in contact sliding against eachother”, especially with poor lubrication 1. Common in bearings, pistons, cylinders and also in screws and bolts causing the threads to seize

Permanent indentation of a hard surface Named after the brinell scale of hardness

1. Brushing 2. Spraying 3. Immersion

let the coating soak to perform

1. They are extremely thin sheets of pure alumminum laminated onto each side of the aluminum alloy Improves the corrosion resistance with little impairment of strength 2. Trade name is Alclad

1. Electrolytic passivation process used to increase the thickness of the natural oxide layer on the surface of metal parts 2. Increases corrosion resistance & wear resistance 3. Provides better paint adhesion

The spray guns require a pressured air

1. Air-Purifying - used during exposure to specific chemicals described on the cartridge as well as sanding 2. Cartridges are only good for limited time and replaced when; You start to smell the vapors in the mask 3. They become difficult to breathe through They have exceeded their specific lifetime

1. Siphon Feed 2. Gravity Feed 3. High Velocity Low Pressure Productin Gun

1. Viscosity is determined by measuring the efflux (drain) time of the liquid coating through the cup orifice 2. The measurement determines if the mixed coating meets the recommended viscosity for spraying

typically 40 to 50psi

Proportions the airflow Which adjusts the spray pattern of the gun

Fluid passing through the needle Controls the amount of volume of paint delivered through the gun

8-10 inches

Spray a light tack coat before spraying on the second coat “A tack coat holds the second coat from sagging and running”

50% “Accomplished by aiming the center of the spray pattern at the outer edge of the first pass and continuing on”

“Because constant air flow through the gun maintains a constant pressure rather than buildup of pressure each time the trigger is fully released” 1. Not doing this could cause a build up of paint at the end of each pass causing runs and sags in the finish

the deterioration by chemical or electrochemical attack

the result from direct exposure to caustic liquid or gaseous agents “ex. battery acid leaking”

appears as general roughening, etching or pitting of surface, frequently accompanied by white powder. caused by direct chemical or electrochemical attack

galvanic corrosion

result of combined tensile stresses and a corrosive environment

two mating surfaces normally at rest subject to relative motion “characterized by pitting of the surfaces and debris”

true

true

true

uses regulated air which passes the gun and draws/ siphons the paint from the cup

paint is located at the top of the gun and is supplied by gravity

true, created by either chemical or electrochemical

process of coating a surface with metal or alloy by spray equipment. “guards metals from corrosion”

cold working process used to produce a COMPRESSIVE residual stress layer “used to relieve tensile strength, replaced with beneficial compressive strength”

1. used for peening small areas on new or repaired parts 2. can be done in field 3. developed by US army in Vietnam

refers to a protective coating, not paint colour “corrosion resistant agent called zinc chromate” highly toxic

1. superior anti corrosive properties 2. exceeds one part zinc chromatic primers in terms of performance 3. “provides solvent proof barrier coat, protects from fabric cements and dope”

1. abrasive pads 2. don’t use same pad on different metals 3. aluminum wool / scotch brite

water break test, ensures no debris on contamination on surface

blueing