Nevada C-4A Painting Contractor Examination

Under NAC 624.220, what work does a Nevada C-4A Painting license authorize?

• AApplication of paints, varnishes, protective coatings, shellacs, stains and other pigment…
• BHanging commercial wallcovering and vinyl fabrics only
• CInstalling gypsum wallboard, metal studs and acoustical tile
• DTaping and finishing wallboard to create a permanent surface

What are the four basic components of architectural paint?

• ASand, cement, lime and water
• BPigment, binder (vehicle), solvent (thinner) and additives
• CResin, catalyst, hardener and glass flake only
• DOil, wax, bleach and grit

What does percent solids by volume tell a painter?

• AThe fraction of the wet film that remains as dry film after solvents leave
• BThe weight of pigment divided by the weight of the can
• CThe VOC content in grams per liter
• DThe flash point of the solvent

How are leftover latex (waterborne acrylic) tools and wet paint normally cleaned?

• AWith lacquer thinner only
• BWith denatured alcohol only
• CWith soap and water before the paint dries
• DWith muriatic acid

Which thinner is the usual field solvent for conventional alkyd (oil-based) enamel?

• AMineral spirits (paint thinner)
• BWater
• CDenatured alcohol
• DMuriatic acid

What is the correct solvent for thinning and cleaning shellac?

• ADenatured alcohol
• BWater
• CMineral spirits
• DXylene only

One U.S. gallon of a 100 percent solids coating, applied at 1 mil dry-film thickness with no loss, covers about how many square feet?

• A800 square feet
• B1,000 square feet
• C1,604 square feet
• D2,000 square feet

A coating is 50 percent solids by volume and the specification requires 4.0 mils DFT. What is the theoretical coverage per gallon with no loss?

• A100 square feet per gallon
• B201 square feet per gallon
• C401 square feet per gallon
• D802 square feet per gallon

A specification calls for 3.0 mils DFT. The coating is 60 percent solids by volume and is not thinned. What wet-film thickness must be applied?

• A1.8 mils WFT
• B3.0 mils WFT
• C5.0 mils WFT
• D8.0 mils WFT

Why must coverage be calculated from solids by volume rather than solids by weight?

• AWeight solids ignore the different densities of pigment and binder, so they do not predic…
• BWeight solids are always higher and therefore safer
• CPSI requires weight-solids math on closed-book exams
• DVolume solids apply only to powder coatings

What is the primary job of a primer on a paintable substrate?

• ATo replace surface cleaning
• BTo add gloss so the finish coat can be skipped
• CTo act as a vapor barrier on every exterior wall
• DTo promote adhesion, seal the surface and provide a uniform base for the finish coats

How does a zinc-rich primer protect carbon steel?

• AThe zinc particles provide sacrificial (cathodic) protection if the film is scratched
• BThe zinc dissolves rust so blasting is unnecessary
• CThe zinc raises the gloss of the finish enamel
• DThe zinc replaces the need for any topcoat outdoors

What is pot life on a two-component epoxy or polyurethane?

• AThe working time after the two parts are mixed, before the batch is too thick to apply
• BThe unopened shelf life in the warehouse
• CThe time from application until the film is dry to the touch
• DThe time the finish may remain in direct sun

Why is spar (marine) varnish specified on exterior wood instead of a conventional interior varnish?

• ASpar varnish is formulated with more flexible, UV-resistant resins for sun and moisture m…
• BSpar varnish is a water-only stain that never forms a film
• CSpar varnish is a cementitious masonry sealer
• DSpar varnish is an inorganic zinc primer

How does a penetrating stain differ from an opaque paint film on wood?

• AA penetrating stain colors the wood with little or no continuous film; paint builds an op…
• BStain always has higher volume solids than paint
• CStain can be applied only with an airless sprayer
• DPaint never requires a primer and stain always does

How does a solvent lacquer typically dry compared with a two-component epoxy?

• ALacquer dries mainly by solvent evaporation and can be redissolved by its own thinner; ep…
• BLacquer requires a 24-hour induction time and epoxy does not
• CBoth coatings dry only by oxidation with metallic driers
• DLacquer must be baked; epoxy always air-dries in 10 minutes

Five gallons of coating at 55 percent volume solids are thinned with 0.5 gallon of solvent. What is the new volume-solids content?

• A50 percent
• B55 percent
• C60 percent
• D45 percent

A coating is 40 percent solids by volume and will be applied at 2.0 mils DFT. Allow a 20 percent application loss. What is the practical coverage per gallon?

• A257 square feet per gallon
• B321 square feet per gallon
• C401 square feet per gallon
• D642 square feet per gallon

For an exterior polyurethane finish that will see sunlight, which resin type holds gloss and color better?

• AAliphatic polyurethane
• BAromatic polyurethane
• CUnmodified coal-tar epoxy
• DInterior nitrocellulose lacquer

A two-component epoxy data sheet lists a 15-minute induction (sweat-in) time. What should the painter do?

• AMix the two components thoroughly, then wait 15 minutes before spraying or rolling
• BAdd 15 percent extra converter and spray immediately
• CHeat the mixed pot to skip the wait
• DApply the first coat, then wait 15 minutes before mixing

What is the first requirement before any coating is applied?

• AThe finish color must be boxed
• BThe surface must be clean, dry and sound, free of oil, dirt, chalk and loose material
• CThe sprayer must be set to maximum pressure
• DA gloss enamel must be applied as a first coat

What does SSPC-SP 1, Solvent Cleaning, require?

• ARemoval of visible oil, grease, soil and other soluble contaminants before other cleaning…
• BWhite-metal abrasive blast with no staining allowed
• CPower-tool cleaning to a 1-mil profile
• DAcid etching of concrete only

Before recoating a weathered exterior, what must be done with peeling and loose paint?

• ARemove it and feather the remaining edges to a tight, smooth transition
• BApply a heavy gloss coat to glue the loose film down
• CCover it with plastic sheeting and paint over the plastic
• DWet the wall so the old film softens and stays in place

A previously enameled door is still glossy and slick. What preparation is required before a new coat?

• ASand or chemically degloss to dull the surface and provide mechanical tooth
• BWash only with clean water and paint immediately
• CApply a heavy finish coat so it hides the gloss
• DHeat the door with a torch until the old enamel melts

Dark, blotchy growth on a shaded exterior wall is identified as mildew. What is the correct preparation?

• ASeal it under a heavy coat of oil paint so it cannot breathe
• BSand it dry without wetting so spores stay in place
• CKill and remove the mildew with a mildewcide or bleach cleaner, rinse, and let the surfac…
• DIgnore it; primer will kill mildew

What is dew point in coating work?

• AThe air temperature at which moisture in the air condenses on a surface
• BThe boiling point of the paint solvent
• CThe temperature at which latex coalesces
• DThe flash point of mineral spirits

ASTM D3276 and common coating specifications require the surface to be at least how far above the dew-point temperature during preparation, application and cure?

• A5°F (3°C)
• B1°F (0.5°C)
• C20°F (11°C)
• DThe surface may be 5°F below dew point if the air is moving

SSPC-SP 2, Hand Tool Cleaning, uses which tools and removes what?

• ANon-powered scrapers, wire brushes and sandpaper to remove loose rust, loose mill scale a…
• BAbrasive blast to white metal
• COnly high-pressure water above 10,000 psi
• DOnly chemical strippers

SSPC-SP 3, Power Tool Cleaning, is best described as which method?

• APower wire brushes, sanders, grinders or needle guns used to remove loose rust, loose mil…
• BSolvent wipe only
• CWhite-metal blast with grit
• DAcid pickle in a shop tank

After SSPC-SP 6 / NACE 3 Commercial Blast Cleaning, how much staining is allowed on each unit area?

• ANo more than 33 percent staining; all visible oil, dirt, mill scale and rust are gone
• BNo staining of any kind
• CNo more than 5 percent staining
• DUp to 75 percent tightly adherent mill scale may remain

SSPC-SP 10 / NACE 2 Near-White Metal Blast Cleaning allows staining on no more than what portion of each unit area?

• A5 percent
• B10 percent
• C33 percent
• D50 percent

Which SSPC/NACE blast leaves a uniformly gray-white steel surface with no visible oil, rust, mill scale, paint or staining?

• ASSPC-SP 5 / NACE 1 White Metal
• BSSPC-SP 6 / NACE 3 Commercial
• CSSPC-SP 7 / NACE 4 Brush-Off
• DSSPC-SP 2 Hand Tool

What does featheredging accomplish at the break between remaining old paint and bare substrate?

• AIt tapers the old film so the new coats do not leave a visible ridge or weak edge
• BIt adds a decorative stripe at the color break
• CIt raises film build to hide peeling
• DIt replaces the need for primer on bare wood or metal

What is the standard sealer for resinous knots in pine or similar wood before finish paint?

• AA shellac-based (alcohol-borne) stain-blocking primer
• BA clear water rinse
• CA cementitious masonry filler
• DA zinc-rich steel primer

Cedar or redwood siding often brown-stains a new latex topcoat. What prevents tannin bleed?

• AA stain-blocking primer (oil-alkyd or shellac) made for tannin-rich woods
• BA second coat of the same open latex only
• CA zinc-rich primer
• DA high-pressure wash with no primer

Why should conventional alkyd enamel not be applied directly to new, unweathered galvanized steel?

• AThe alkaline zinc surface saponifies (soaps) the alkyd, destroying adhesion
• BGalvanizing is already a finish and may never be coated
• CAlkyd is too hard and will rust the zinc
• DGalvanized steel can only be coated with shellac

ASTM D4263, the plastic-sheet test for concrete moisture, is performed how?

• ATape an 18-inch by 18-inch polyethylene sheet on all four edges, wait 16 hours, and look…
• BHold a wet sponge on the slab for 60 seconds
• CMeasure only the air temperature above the slab
• DDrill a 6-inch core and weigh it

White, powdery salt on masonry (efflorescence) should be handled how before painting?

• ADry-brush or wash off the salts, stop the water source, let the wall dry, then coat
• BPaint immediately with gloss alkyd to trap the salts
• CCover the salts with heavy joint compound and enamel
• DApply shellac only; water stains on masonry do not need prep

Abrasive-blasted steel starts to show flash rust before the primer is applied. What is the correct action?

• ARe-clean to the specified standard; do not prime over loose flash rust
• BWipe the rust with oil so the primer sticks
• CApply a double-thick finish enamel and skip primer
• DWait for rain to wash the rust off

ASTM D3359 is used on a previously painted surface. What does that test measure?

• AAdhesion of the existing film by a tape test (cross-cut or X-cut)
• BChalk rating by photographic standard
• CDry-film thickness with a magnetic gauge
• DConcrete moisture with a plastic sheet

NAC 624.220 lists which application methods for C-4A painting?

• ABrush, spray or roller
• BTrowel and hawk only
• CThermal spray metallizing only
• DWallpaper paste brush only

What does keeping a wet edge prevent on a large wall?

• AAll fading for the life of the job
• BThe need to prime porous masonry
• COverspray on adjacent windows
• DLapping and picture-framing where a partially set film is recoated

Why are two thin coats usually better than one heavy coat of the same paint?

• AThin coats dry and cure more evenly, hide better in layers, and are less likely to sag or…
• BOne heavy coat always has higher volume solids
• CThin coats eliminate the need for primer
• DHeavy coats never need a recoat window

When the project specification and the coating manufacturer’s technical data sheet disagree on thinner or recoat time, what governs application?

• AFollow the specification if it is stricter; never exceed the manufacturer’s listed thinne…
• BAlways add extra thinner for faster spray
• CIgnore both and match the last job
• DUse gasoline as a universal reducer

On an interior wall, what is the usual sequence for a rolled finish coat?

• ACut in a wet border at edges, then roll the field into that wet edge
• BRoll the field first and cut in after the wall has dried overnight
• CSpray only the corners and never roll
• DApply primer and finish in one mixed pot