Block 8

What are the two types of viscometers

#2 Zahn cup and #4 ford cup

All HVLP guns use between what air pressure

1-10 psi

Top coat removal is what grit?

120 grit

What is the required viscosity of the #2 zahn cup

17 to 23 seconds

Motor driven abrasives primer removal

240 grit

Primer removal is what grit?

240 grit

Clean up HEPA vacuum is preferred compressed air no greater than what

30 psi

After applying alodine How long can you wait to apply the final paint system?

48 hours

When using alodine touch-n-prep application how long must you wait for it to dry?

5 mins within the 5 mins of the first coat apply a second coat

all sources of ignition how far away?

50 feet minimum

Alodine proper adhesion is indicated but what color?

A brassy yellow color

Type 5 PMB

Acrylic plastic commonly used

Chemical paint remover is not authorized on what?

Advanced composites iaw T.O. 1-1-8 and T.O 1-1-690

What does the nozzle assembly consist of

Air cap and fluid tip

Do not agitate coating before an alodine is done drying how long does the alodine take to air dry?

Air dry 2 hours minimum

Equipment adjustments

Air pressure, metering valve, nozzle pressure, respirator/ helmet adjustments

PPE

Air purifying respirator with ov/HEPA cartridges, disposable nitrile gloves, safety toe boots, ear plugs, safety goggles, tyvek or cotton coveralls

How long does a alodine take to force dry and at what temperature

Alodine takes 1 hour at 140 degrees

What is alodine used on

Aluminum and it's alloys

Abrasive mats

Aluminum oxide bonded to nylon mesh

Warning all attachments must have what

An rpm rating higher than drill/grinder being used

application of alodine

Apply immediately after rinsing corrosion removal compound from surface

Split spray

Atomizing pressure high fan pattern too wide

Fluid needle adjustment screw location

Below spray pattern adjustment screw

Blasting Booth major components

Blasting unit, blast/reclaimer assembly and dust collector

When applying passivation use what

Brush, sponge, cloth, touch-n-prep pen, spray or immersion

Epoxy primers and polyurethane are generally what

Catalyzed

Warning what paint removal method isn't authorized for advanced composites

Chemical paint removal

Passivation

Chromate conversion coating (alodine)

Advanced Composites

Classified as "non metallic" structure, susceptible to damage, plastic media blasting is the preferred method of paint removal for advanced composites

Blasting booth theory of operation

Clean dry compressed air mixed with clean dry media

Pre blast preparation

Clean surface, compatible solvent, cotton rag, wipe surface, dry completely, prevents media from clamping up and becoming contaminated, prevents possible damage to the blasting unit, control leaks, masking, areas of direct impingement require id plates,

Surface prep

Clean using solvent then water break test

Orange peel

Coating material too cold, using wrong air cap or fluid nozzle, stroking too far from surface, overspray, insufficient air pressure

Primer

Corrosion protection to the metal surface and an adherent for the topcoat

Adjust fluid needle adjustment screw clockwise to do what

Decrease flow

Adjust spray pattern adjustment screw clockwise to do what?

Decrease width of paint

Runs or sags

Dirty air cap and fluid tip, not releasing the trigger, stroking too close, coating material cold, gun not at 90 degrees, coating applied to heavy

What causes pinhole cavities or "solvent pop"

Dirty surface, oils and solvents trapped

Peeling

Does not adhere, can be lifted off in sheets, Greene oil or water on the surface

random orbital sander

Dual action sander start on the surface stop when off the surface, keep sander as flush against the surface as possible, HEPA vacuum attaches to sander for dust collection

Dry abrasive blasting

Excellent and rapid paint removal method, must be approved by SPD, remove paint only down to the primer on advanced composites

Keep surface wet until when alodine does what and how long does it usually take?

Film forms it takes 1-5 minutes

Spray gun cleaning unit types and what they do

Filtration- reutilizes the solvent until soiled replace solvent and periodically change filter

Startup/Shutdown

Follow manufacturers procedures and facility/ local procedures

What is Alodine form 1, 2 and 3

Form 1 is liquid concrete, form 2- powder, form 3 pre mixed liquid, mix form 1 and 2 to get 3 instructions in T.O 1-1-8

Solvent wipe down

Gets all nasty stuff off part

The grades of abrasive mats

Grade B fine used for primer removal, Grade C medium for topcoat removal

Mechanical paint remover

Hand held abrasive, abrasive cloth, abrasive paper, aluminum oxide or silicon carbide

Removal preperations types

Hand-held abrasives, motor driven abrasives, chemical paint strippers

Pre/post blast preparation

Hoses, valves, vibrating screen, dust collector, cabinet/booth check the barrel under dust collector, check media level, check breathing air, drain moisture separator, inspect magnetic separator, respirator/ helmet adjustments

Position aircraft tools or component where?

In a covered facility

Adjust fluid needle adjustment screw counterclockwise to do what

Increase flow

Adjust spray pattern adjustment screw counter clockwise to do what

Increase width of pattern

HVLP low pressure design results in

Less paint overspray, less paint waste, safer for the user, safer for the environment, better finished paint job

Vehicle

Liquid portion of the coating consisting of volatiles and nonvolatiles

Spray pattern adjustment screw

Located at rear of spray head assembly

Caution what particles, dust, and powder are extremely flammable

Magnesium

Blasting cabinet

Major components: cabinet/glove box, blast/ reclaimed assembly, dust collector

Protect special areas with what?

Masking tape, plastic, paper, aircraft cover

Viscosity

Measures liquids resistance to flow with a viscometer

Gravity feed

Most common type of spray gun used in the field for painting small to medium sized parts

Streaks

Not overlapping, air pressure to high, not maintaining 90 degrees

Blast direction

Only at object being blasted

Pressure feed

Paint is fed to the gun by a pressurized tank also called pressure pot used for large volume painting

Crazing, mudcracking, and checking

Painting over hard glossy coat, too much catalyst, too much heat when Force dried, insufficient drying times between coats

Heavy center

Pattern too small, low atomizing pressure, fluid pressure too high, air nozzle too large for fluid used

Nonvolatile

Pigments and resins form actual film on the surface

Why open a container slowly

Pressure

Topcoat

Provides excellent gloss (from flat to high gloss finishes) superior toughness and outdoor durability as well as good chemical resistance

Fluid tip does what

Pushes coating material out

Chemical paint removal

Quick and easy but very hazardous, strict epa enviormental regulations, check weapon specific t.o before use

distilled

Recycles the solvent and separates out the waste does not require solvent disposal

Post-blast clean-up

Remove masking, remove/sand remaining paint, thouroughly vacuum-up remaining media, alternate remove media with low pressure air under 30 psi or water wash

Pitting or cupping

Resembles fish eyes, poor surface prep, corrosion left on surface, moisture in airlines, trapped solvents from improper portions, Greese and oil left on surface

Blistering

Resembles water blisters, oil or grease on the surface, moisture in the airlines, or incorrect thinner

Tack ragging

Resined rag picks up dust

What must you do with all absorbent materials after using alodine before discarding?

Rinse with water

Pneumatic drill

Secure attachments using drill chuck, start and stop off the surface to prevent damage, apply least amount of pressure possible just enough to remove the coating

Mechanical compatibility

Select the right tool for the job

Fluid needle

Should come as a matched set with the fluid tip because they're the same diameter when trigger is pulled the needle moves back and releases fluid

Fisheyes

Small crater like depressions, silicon or other contaminants cause this

Plastic media blasting

Small jagged particles cut from plastic stock, type v acrylic plastic commonly used

Volatile

Solvents and dilutents lost through evaporation

Suction feed

Suction fed HVLP guns utilize pressurized paint cups 20 psi or lower to assist in delivering the paint to the spray nozzle

What are the 3 types of HVLP guns

Suction, gravity, pressure

Motor driven abrasives

Surface conditioning discs, aluminum oxide bonded to nylon mesh discs, attaches to a sanding arbor used with a pneumatic drill or die grinder

Adhesion

Surface must be roughed and clean for paint to stick

Air cap features

The air cap has wing ports that push out air and face the direction of travel

Do not allow solution to come in contact with what?

Thinners, acetones or other combustible materials

Due to sparking what surfaces should be blasted first

Titanium and steel

Blasting booth blasting parameters

Type of media, nozzle pressure, stand-off distance, angle of impingement, dwell time

Fluid cup holds how much paint (gravity fed and suction fed)

Typically holds 1 quart

Booth ppe

Tyvek or cotton overalls, leather shoulder cover, leather and disposable nitrile gloves, steel toed boots, ear plugs, blasting helmet with supplied air

Sandpaper finish

Unsatisfactory primer, insufficient scuffing, dry spray, overspray, spray too far away, excessive dirt in spray area, improperly cleaned paint lines (pressure pot)

Motor driven abrasives top coat removal

Use 120 grit

material compatibility

Use like metals during corrosion/coating removal abrasive and substrate (surface) must be compatible with each other

Wire wheel

Used with pneumatic drill

Abrasive flap wheel

Used with pneumatic drill or die grinder

Coating

Usually consists of a primer and topcoat