400 questions
Before repainting a previously painted, chalky exterior stucco wall, what is the FIRST thing a painter should do to ensure adhesion?
- a.Apply two finish coats without priming
- b.Wash the surface to remove chalk, dirt, and loose material✓
- c.Sand the stucco smooth with 220-grit paper
- d.Spray a heavy fog coat of the finish color
Chalk and surface contamination prevent a new coating from bonding. Washing (often with a pressure washer or detergent solution) removes the chalky residue and dirt so the primer or paint can adhere. Painting over an unwashed chalky surface commonly leads to peeling.
What is the primary purpose of caulking gaps around window trim before painting?
- a.To add color contrast to the trim
- b.To increase the paint's gloss level
- c.To seal the joint against water and air✓
- d.To speed up drying of the topcoat
Caulk seals the joint between dissimilar materials such as trim and siding, keeping water and air out and preventing paint from cracking at the gap. A properly tooled caulk bead also gives a clean, continuous paint line. Paintable acrylic-latex caulk is typically used before priming or painting.
When patching a small nail hole in interior drywall, which sequence is correct?
- a.Fill with spackle, let dry, sand smooth, then spot-prime✓
- b.Prime the hole, then fill with spackle and leave unsanded
- c.Paint the hole first, then fill with caulk
- d.Sand the wall, then apply finish coat directly into the hole
Lightweight spackle is pressed into the hole, allowed to dry, then sanded flush with the surface. Spot-priming the patch seals the porous filler so the finish coat dries to a uniform sheen. Skipping the primer often causes 'flashing,' where the patch shows through as a dull spot.
Under the EPA Renovation, Repair and Painting (RRP) Rule, work that disturbs painted surfaces in housing built before which year generally triggers lead-safe requirements?
- a.1998
- b.1978✓
- c.1985
- d.1960
The RRP Rule applies to housing and child-occupied facilities built before 1978, the year lead-based paint was banned for residential use in the U.S. Firms disturbing more than the de minimis area of paint in these buildings must be certified and use lead-safe work practices. This protects occupants, especially children, from lead dust.EPA RRP Rule
Which work practice is REQUIRED by the EPA RRP Rule when disturbing lead-based paint in a pre-1978 home?
- a.Dry-sanding to keep the dust airborne
- b.Using an open-flame torch on the paint
- c.Containment, HEPA vacuuming, and wet cleanup✓
- d.Sweeping debris into the yard afterward
Lead-safe practices require containing the area with plastic sheeting, minimizing dust, and cleaning with HEPA vacuums and wet wiping. Open-flame burning and uncontrolled dry sanding are prohibited because they generate hazardous lead dust or fumes. A cleaning verification step confirms the area is safe before reoccupancy.EPA RRP Rule
What causes efflorescence, the white crystalline deposit sometimes seen on masonry and concrete?
- a.Excess paint sheen reacting with direct sunlight
- b.Water carrying soluble salts to the surface✓
- c.Sanding dust left behind on the wall
- d.Overheating of latex paint while curing
Efflorescence is water-soluble salt that migrates through masonry as moisture moves to the surface and evaporates. Painting over it traps salt and moisture, causing the coating to peel. The deposit must be removed (dry brushing or a masonry cleaner) and the moisture source addressed before coating.
Before painting new bare wood trim, why is sanding in the direction of the grain important?
- a.It smooths fibers without cross-grain scratches✓
- b.It removes the need for any primer coat
- c.It increases the moisture content of the bare wood
- d.It darkens the natural color of the wood
Sanding with the grain levels raised fibers and creates a smooth surface without visible cross-grain scratch marks that telegraph through paint. Sanding across the grain leaves scratches that become obvious under a gloss finish. A dust-free, smooth surface improves both appearance and adhesion.
How should mildew on an exterior surface be treated BEFORE repainting?
- a.Paint directly over it with two full finish coats
- b.Sand it off dry and leave the residue
- c.Clean it off with a cleaning solution, then rinse✓
- d.Cover it with a bead of clear caulk
Mildew is a living fungus; painting over it lets it grow through the new coating. It must be killed and washed off, often using a diluted bleach solution or a commercial mildew cleaner, followed by a thorough rinse. Using a mildew-resistant coating helps prevent regrowth in damp areas.
What tool or method best confirms whether a concrete slab is dry enough to coat?
- a.A visual glance at the surface color and tone
- b.A calcium chloride or plastic-sheet test✓
- c.Touching the slab with a bare hand
- d.Smelling the surface for dampness
Concrete can look dry on the surface while retaining moisture that causes coating failure. A calcium chloride test measures moisture vapor emission rate, and a taped plastic-sheet test reveals trapped moisture as condensation. Coating a slab that is too wet leads to blistering and delamination.
Why should glossy or previously enamel-painted surfaces be 'de-glossed' before recoating?
- a.A dull, abraded surface bonds better✓
- b.It adds gloss to the finish coat
- c.It removes the need to clean first
- d.It changes the substrate color
Sanding or using a liquid deglosser scuffs a slick, glossy surface so the new coat can grip it mechanically. Painting over an untreated high-gloss surface often results in poor adhesion and peeling. Cleaning to remove contaminants is still required in addition to deglossing.
Bare ferrous (iron/steel) metal should be primed with what type of primer to prevent corrosion?
- a.A drywall sealer
- b.A masonry block filler
- c.A rust-inhibitive metal primer✓
- d.A latex wood primer only
Ferrous metals rust when exposed to moisture and oxygen, so a rust-inhibitive (corrosion-resistant) primer is used to protect the steel and provide adhesion for the topcoat. Block fillers and drywall sealers are formulated for masonry and gypsum, not metal. Surface rust should be removed before priming.
What is the purpose of a primer/sealer on new, unpainted drywall?
- a.To make the wall surface glossy and hard
- b.To equalize porosity for a uniform finish✓
- c.To replace the need for taping the joints
- d.To add a stipple texture to the finish
New drywall has paper facing and joint compound with different absorption rates; without a sealer the finish coat flashes and shows joints. A drywall primer/sealer (PVA primer) evens out porosity so the topcoat dries to a uniform sheen. It also improves adhesion of the finish coat.
Loose, flaking paint on old siding should be handled how before recoating?
- a.Painted over at once to lock it down
- b.Left in place because it improves adhesion
- c.Covered with a heavy bead of caulk
- d.Scraped to a sound edge, then feathered✓
New paint is only as sound as the surface beneath it, so loose and flaking paint must be scraped off to firmly bonded material. Edges are then sanded (feathered) to blend the transition. On pre-1978 homes this work must follow lead-safe practices.
Why is it poor practice to paint over a wall contaminated with grease or oil?
- a.It makes the paint dry far too fast
- b.The contaminant blocks adhesion, so paint peels✓
- c.It permanently changes the paint's final color
- d.It increases the film thickness required
Grease and oil act as a bond-breaker, so paint cannot adhere and may crawl into 'fisheyes' or peel. Surfaces such as kitchen walls should be degreased with a suitable cleaner and rinsed before priming. Clean, dry, dull, and sound is the standard rule for a paint-ready surface.
New galvanized (zinc-coated) steel often needs what preparation before painting to avoid adhesion failure?
- a.Coating it immediately while still oily
- b.Applying a masonry block filler first
- c.Cleaning off oils, then a galvanized primer✓
- d.Sanding it all the way down to the bare steel
Fresh galvanized surfaces carry oils and a smooth zinc layer that ordinary paint will not grip, so oil-based paints may peel. The surface should be cleaned of oils and coated with a primer formulated for galvanized metal. Some specifications allow the metal to weather before painting.
When patching a larger hole in drywall, why is joint compound often applied in multiple thin coats rather than one thick coat?
- a.Thin coats dry evenly and crack less✓
- b.Thin coats change the wall color
- c.One thick coat is always stronger
- d.Thin coats remove the need to sand
Thick applications of joint compound shrink, crack, and take much longer to dry. Building up the repair in thin, progressively wider coats produces a flat, crack-free patch that feathers into the surrounding wall. Each coat is allowed to dry and is sanded or wiped before the next.
What is the main reason to remove dust after sanding and before painting?
- a.Dust improves paint flow
- b.Dust left on the surface prevents proper adhesion and creates a gritty finish✓
- c.Dust changes the sheen of the paint can
- d.It is only an aesthetic preference with no effect on adhesion
Sanding dust acts as a contaminant that keeps paint from bonding and leaves a rough, gritty film. Wiping with a tack cloth, vacuuming, or damp-wiping removes the dust for a clean bond and smooth finish. This step is part of preparing a clean, sound surface.
Knots and sap streaks in bare softwood can bleed through paint unless they are sealed with what?
- a.A thin coat of clean water
- b.Only the finish paint, applied twice
- c.A stain-blocking or shellac primer✓
- d.A coat of clear paintable caulk
Resin and tannins in knots and sap can bleed through ordinary paint, leaving yellow-brown stains. A stain-blocking primer, often shellac- or oil-based, seals the knot so it does not discolor the finish. Spot-priming the knots before the full prime coat is common practice.
Why should exterior wood be checked for moisture content before painting?
- a.Dry wood cannot be painted at all
- b.Wet wood traps moisture and blisters✓
- c.Moisture makes the paint cure harder
- d.Wet wood improves paint penetration
Excess moisture in wood pushes outward as it dries and lifts the paint film, causing blisters and peeling. Wood should generally be below roughly 15% moisture content before painting. A moisture meter provides a reliable reading before coating.
What is 'feathering' when preparing a spot repair on a painted surface?
- a.Sanding the repair edges smooth✓
- b.Adding feathers to the wall texture
- c.Applying a thick ridge of paint at the edge
- d.Removing all paint from the entire wall
Feathering sands or tapers the edge of a patched or scraped area so there is no visible ridge between old and new material. A feathered edge lets the primer and finish blend seamlessly. Without feathering, the repair outline telegraphs through the finish coat.
When dry-cutting or grinding concrete during prep generates dust, what airborne hazard is of concern under Cal/OSHA?
- a.Lead only
- b.Asbestos only
- c.Respirable crystalline silica✓
- d.Carbon monoxide
Cutting, grinding, or abrading concrete and masonry releases respirable crystalline silica, which can cause silicosis. Cal/OSHA requires engineering controls such as water suppression or vacuum dust collection and, when needed, respiratory protection. This applies to prep work as well as demolition.Cal/OSHA Title 8
Before applying an elastomeric coating to a stucco crack, what prep step is typically needed?
- a.Wetting the crack with a strong solvent wash
- b.Cleaning and filling the crack when dry✓
- c.Applying a gloss enamel sealer coat first
- d.Sanding the entire wall to bare masonry
Elastomeric coatings bridge hairline cracks but the substrate must first be clean, sound, and dry, with larger cracks filled or reinforced. Loose material and contaminants would cause the thick coating to fail. Proper prep lets the elastomeric film stretch over the crack without delaminating.
Why is it important that a masonry surface be fully cured before painting with most coatings?
- a.Fresh masonry is alkaline and attacks paint✓
- b.Cured masonry cannot hold paint at all well
- c.Fresh masonry is too smooth to paint
- d.Curing changes the color of the paint
New concrete and masonry are strongly alkaline while curing, and this alkalinity can break down oil-based coatings, a reaction called saponification. Allowing the masonry to cure (often about 28 days) and/or using an alkali-resistant primer prevents coating failure. Testing surface pH can confirm readiness.
A previously painted surface shows widespread peeling down to bare wood. What does this MOST likely indicate?
- a.The previous paint was too expensive
- b.The surface was cleaned too thoroughly
- c.A prep or moisture problem underneath✓
- d.The paint color chosen was too light
Peeling to bare substrate points to an adhesion failure, usually from painting over a dirty, glossy, damp, or unprimed surface, or from underlying moisture. Correcting the cause and properly preparing and priming the wood is required before recoating. Simply repainting without addressing the cause repeats the failure.
What is the correct order of the basic surface-prep steps for a typical repaint?
- a.Prime, clean, scrape, and then sand
- b.Clean, scrape, sand/patch, then prime✓
- c.Sand, prime, clean, and then scrape
- d.Prime, sand, clean, and then scrape
A logical prep sequence is to clean the surface, remove loose and failing paint, sand and patch defects, and then prime bare areas. Cleaning first prevents grinding contaminants into the surface, and priming last seals the prepared substrate. Following this order produces a sound base for the finish coats.
What is the main advantage of latex (water-based) paint over traditional oil-based (alkyd) paint?
- a.It always lasts longer on any surface
- b.It never needs a primer underneath
- c.Faster drying, water cleanup, and low odor✓
- d.It cannot be tinted to a color
Latex paints dry quickly, clean up with water, have lower odor, and generally lower VOCs than solvent-based alkyds. They also stay flexible and resist yellowing, making them common for most interior and exterior work. Oil-based paints still offer benefits such as leveling and stain-blocking in certain applications.
In California, VOC (volatile organic compound) limits for architectural coatings are primarily regulated to accomplish what?
- a.Reduce smog-forming emissions and protect air quality✓
- b.Increase the gloss of paint
- c.Lower the cost of paint
- d.Speed up paint drying regardless of air quality
VOCs contribute to ground-level ozone (smog), so California, through CARB and local air districts, limits the VOC content of architectural coatings. Painters must select compliant low-VOC products in regulated categories. These rules affect which coatings and thinners can legally be used.CARB
Which sheen is generally the MOST washable and durable, making it common for kitchens, bathrooms, and trim?
- a.Flat
- b.Semi-gloss or gloss✓
- c.Ultra-flat only
- d.Primer
Higher-sheen finishes such as semi-gloss and gloss have a tighter, harder film that resists moisture and scrubbing, so they are used where cleaning and durability matter. Flat finishes hide surface imperfections but are harder to clean. Sheen selection balances washability against how much it reveals surface flaws.
A paint has a spread rate of 350 square feet per gallon. How many gallons are needed for one coat on 1,400 square feet of wall?
- a.4 gallons✓
- b.2 gallons
- c.8 gallons
- d.6 gallons
Gallons equal area divided by spread rate: 1,400 sq ft / 350 sq ft per gallon = 4 gallons for one coat. Always round up to whole containers when purchasing. For two coats you would double the amount to 8 gallons.
A wall measures 2,100 square feet and the coating covers 300 square feet per gallon. How many gallons are needed for TWO coats?
- a.7 gallons
- b.3.5 gallons
- c.10 gallons
- d.14 gallons✓
One coat needs 2,100 / 300 = 7 gallons. Two coats require 7 x 2 = 14 gallons. Rounding up ensures enough paint to finish both coats without running short.
Why does a rough or porous surface (like bare masonry) reduce a paint's effective spread rate compared to the label value?
- a.Rough surfaces repel paint entirely
- b.Texture and absorption soak up more paint✓
- c.Porous surfaces make paint cover more
- d.The label value accounts for all textures
Manufacturers' spread rates assume a smooth, sealed surface, but rough and porous substrates have more actual area and absorb paint, lowering coverage. Estimators reduce the assumed coverage for textured or unsealed surfaces. Priming a porous surface first reduces topcoat absorption.
What is an epoxy coating typically chosen for?
- a.Delicate interior ceilings and trim only
- b.Adding a flat, chalky look to wood
- c.Hard, chemical-resistant concrete floors✓
- d.Reducing the durability of metal
Two-component epoxies cure to a hard, dense film with excellent adhesion and resistance to chemicals, moisture, and abrasion. They are common on concrete floors, tanks, and industrial equipment. They require careful mixing and have a limited pot life once catalyzed.
What does '100% acrylic' latex paint offer compared to a vinyl-acrylic (PVA) latex?
- a.Better exterior durability, adhesion, and flexibility✓
- b.Lower cost with no performance difference
- c.It can only be used as a primer
- d.It cannot be used outdoors
The acrylic binder in 100% acrylic paint provides superior adhesion, flexibility, color retention, and weather resistance, making it a strong choice for exteriors. Vinyl-acrylic (PVA) formulas are more economical and common for interior use. The binder quality is a key driver of paint performance.
What is the function of the 'binder' (resin) in paint?
- a.To thin the paint out for spraying
- b.To bind pigment and bond the film✓
- c.To provide the color and nothing more
- d.To evaporate away during drying
The binder is the film-forming resin that locks pigment particles together and adheres the coating to the substrate. Higher-quality binders yield better adhesion, durability, and washability. Pigment provides color and hide, solvent carries the material, and additives modify properties.
Which thinner/solvent is generally correct for cleaning up oil-based (alkyd) paint?
- a.Water
- b.Vinegar
- c.Mineral spirits or paint thinner✓
- d.Household bleach
Oil-based coatings are solvent-borne and are thinned and cleaned up with mineral spirits or paint thinner, not water. Latex paints, by contrast, clean up with soap and water. Using the wrong solvent can ruin the film or fail to clean the tools; solvent rags must be disposed of safely.
A block filler is used on masonry primarily to do what?
- a.Fill pores and voids for a smooth base✓
- b.Add gloss to the final finish coating
- c.Waterproof exterior wood siding boards
- d.Replace the need for a topcoat
Concrete masonry units are porous with open voids, and a high-build block filler fills those pores to create a uniform, smooth surface. This reduces topcoat consumption and improves appearance and moisture resistance. It is applied before the primer or finish coats on block walls.
When selecting a coating for a surface exposed to constant direct sunlight, which property is especially important?
- a.Low material cost above all else
- b.UV resistance and color retention✓
- c.The fastest possible drying time
- d.The lowest possible film build
Ultraviolet light degrades binders and pigments, so exterior coatings in full sun should have good UV resistance and fade-resistant pigments. 100% acrylic exterior paints are commonly specified for this reason. Matching the coating to the exposure is a core part of product selection.
A primer's main job is to do what?
- a.Provide the final color and gloss level
- b.Replace the need for surface prep
- c.Add a stipple texture to the wall
- d.Seal the surface and promote adhesion✓
Primers seal porous or stained surfaces, block stains, and create a bond between the substrate and the topcoat. Using the correct primer for the substrate (wood, drywall, metal, masonry) improves adhesion and finish uniformity. The primer is not usually the final decorative layer.
If a coating is applied at 4 mils wet and the paint is 50% solids by volume, what is the approximate dry film thickness?
- a.4 mils
- b.2 mils✓
- c.8 mils
- d.1 mil
Dry film thickness equals wet film thickness times the percent solids by volume: 4 mils x 0.50 = 2 mils dry. The solvent portion evaporates, leaving only the solids as the dry film. Knowing solids content lets a painter target the specified dry mil thickness.
What is the purpose of adding a small, manufacturer-recommended amount of the correct thinner to paint for spraying?
- a.To lower viscosity so it atomizes properly✓
- b.To raise the VOC limit allowed by law
- c.To make the paint dry more slowly
- d.To change the color of the paint
Thinning to the manufacturer's recommendation lowers viscosity so the material atomizes and sprays evenly, reducing clogging and improving finish. Over-thinning causes runs and reduced film build, and any thinning must stay within VOC limits. Always follow the product data sheet for the correct solvent and amount.
Which coating type is commonly used to bridge and waterproof hairline cracks on exterior stucco?
- a.Flat interior latex
- b.Shellac primer
- c.Elastomeric coating✓
- d.Lacquer
Elastomeric coatings form a thick, flexible film that stretches to bridge and seal hairline cracks in stucco and masonry while resisting water intrusion. They are much higher-build than ordinary paint. Proper surface prep and film thickness are essential for them to perform.
Why should you avoid mixing incompatible coatings, such as applying a strong solvent-based lacquer over fresh latex?
- a.It always improves adhesion between coats
- b.The solvent can lift or wrinkle the old film✓
- c.It safely reduces the total drying time
- d.It has no effect on either coating
Aggressive solvents in some topcoats can soften and lift an incompatible underlying film, causing wrinkling or delamination. Painters check compatibility and recoat windows on the product data sheets before combining systems. When in doubt, a test area or a compatible primer prevents failures.
One gallon of paint is stated to cover 400 sq ft at the recommended film thickness. If you apply it too thin to stretch coverage to 500 sq ft, what is the likely result?
- a.Thin film, so poor hide and early failure✓
- b.Improved durability from a thinner film
- c.Higher gloss and better protection
- d.No change, because coverage is unlimited
Spreading paint beyond its rated coverage reduces the dry film thickness below spec, hurting hide, washability, and weather protection. The coating may fail prematurely. Applying at the manufacturer's recommended spread rate ensures the intended performance.
What information does a product's Technical/Product Data Sheet typically provide that guides application?
- a.Only the price per gallon of the product
- b.Only the available color options and sizes
- c.Spread rate, film thickness, recoat times✓
- d.The painter's state license number only
A product data sheet lists coverage, wet/dry film thickness, drying and recoat times, thinning and cleanup solvents, and surface preparation requirements. Following it ensures the coating performs as designed. Ignoring the data sheet is a common cause of application failures.
Which statement about VOC content and drying is generally TRUE?
- a.Lower-VOC paints cannot be used indoors
- b.Low-VOC coatings cut emissions and odor✓
- c.High-VOC paints are always required by law
- d.VOC content is unrelated to air rules
Low-VOC and zero-VOC coatings emit fewer smog-forming and odorous compounds and are frequently required by California air-quality rules. They are widely used for interior work where occupant comfort and code compliance matter. Painters must verify a product meets the applicable VOC limit for its category.
A ceiling area is 600 sq ft and the paint covers 400 sq ft per gallon. Rounding up to whole gallons, how many gallons should you buy for one coat?
- a.2 gallons✓
- b.1 gallon
- c.3 gallons
- d.4 gallons
600 / 400 = 1.5 gallons for one coat, and you round up to whole containers, so 2 gallons. Buying partial gallons is not practical, and having enough avoids stopping mid-job. Any leftover can be kept for touch-ups.
What is the main difference between a stain and a paint?
- a.Stain has more pigment and hides completely
- b.Stain penetrates and shows the wood grain✓
- c.They are the same product, labeled differently
- d.Paint can only be used on metal surfaces
Stains are formulated with less binder and pigment so they soak into and highlight the wood grain rather than forming a thick opaque film. Paint builds a continuous, opaque film on the surface that hides the substrate. Semi-transparent and solid-color stains fall on a spectrum between the two.
Which roller nap length is best suited for a smooth surface such as new drywall or a fine finish?
- a.1 inch nap
- b.A short nap (about 1/4 inch)✓
- c.1-1/4 inch nap
- d.No nap is ever used on drywall
Short-nap rollers (around 1/4 inch) hold less paint and lay down a smooth, fine finish suited to smooth walls, doors, and trim. Longer naps are for textured or rough surfaces because they reach into the profile. Matching nap length to surface texture controls stipple and coverage.
For a heavily textured surface such as rough stucco, which roller nap is most appropriate?
- a.A 1/4 inch short nap
- b.A 3/16 inch mohair fine nap
- c.A long nap, 3/4 to 1-1/4 inch✓
- d.A smooth foam roller
Long-nap rollers reach into the deep texture of rough stucco or masonry so paint fills the profile and covers evenly. A short nap would skip over low spots and leave voids. The rougher the surface, the longer the nap needed.
What is the difference between an airless sprayer and an HVLP sprayer?
- a.Airless uses fluid pressure, HVLP uses air✓
- b.They are identical in every practical respect
- c.HVLP is only used on exterior masonry
- d.Airless cannot spray latex paint at all
Airless sprayers pump paint at very high pressure through a tip to atomize it, giving fast, high-production coverage on large areas. HVLP uses a high volume of low-pressure air to atomize gently, producing a fine finish with less overspray, ideal for cabinets and trim. Each suits different production and finish needs.