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Free Red Seal Painter and Decorator (404C) Practice Test
30 original questions with explanations. Pick an answer to check it instantly.
Question 1 · A – Performs common occupational skills
A painter is spraying a two-component polyurethane that contains isocyanates in an enclosed room. Which respiratory protection is most appropriate?
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Answer: C. A supplied-air respirator, as directed by the SDS and the employer's respiratory program
Isocyanates are strong respiratory sensitizers with poor warning properties, so the SDS commonly calls for supplied air during spraying. Dust masks and particulate-only filters do not protect against the vapours and mists, and a fan is not adequate ventilation.
Check it: RSOS task A-1 (performs safety-related functions); CCOHS Spray Painting
Question 2 · A – Performs common occupational skills
How should rags soaked with alkyd paint or linseed oil be handled at the end of the day?
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Answer: B. Lay them flat outdoors to dry, or put them in a sealed metal container filled with water
Drying oils give off heat as they oxidize, and a pile of rags can trap that heat until it ignites by spontaneous combustion. Spreading the rags out or sealing them under water in an approved metal container removes the risk.
Check it: RSOS task A-1 (performs safety-related functions); CCOHS Spray Painting
Question 3 · A – Performs common occupational skills
Before cleaning or changing the tip on an airless sprayer, what must the painter do first?
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Answer: B. Lock the gun trigger, turn off the pump and relieve the fluid pressure
Airless equipment holds fluid at very high pressure, and a release at the tip can inject paint through the skin. The safe sequence is to engage the trigger lock, shut off the pump and follow the pressure relief procedure before touching the tip.
Check it: RSOS task A-2 (uses and maintains tools and equipment); CCOHS Spray Painting
Question 4 · A – Performs common occupational skills
A room is 5 m long, 4 m wide and 2.5 m high. Ignoring openings, how much paint is needed for two coats on the walls if the paint covers 10 m²/L?
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Answer: C. 9 L
The perimeter is 2 × (5 + 4) = 18 m, and 18 m × 2.5 m = 45 m² of wall. Two coats is 90 m², and 90 m² ÷ 10 m²/L = 9 L. Real estimates also deduct openings and allow for surface porosity and waste.
Check it: RSOS task A-3 (performs routine trade practices)
Question 5 · A – Performs common occupational skills
A specification calls for 50 µm dry film thickness of a paint with 40% volume solids. What wet film thickness should the painter aim for?
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Answer: C. 125 µm
Wet film thickness equals dry film thickness divided by volume solids: 50 µm ÷ 0.40 = 125 µm. Checking the wet film with a notched gauge while applying is the easiest way to hit the specified dry film.
Check it: RSOS task A-4 (performs quality control assessments)
Question 6 · B – Prepares surfaces
A grey-black spot on an exterior wall is dabbed with diluted household bleach and lightens within a minute or two. What does this indicate?
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Answer: B. Mildew, which must be killed and washed off before painting
Mildew bleaches out quickly when touched with a dilute bleach solution, while ordinary dirt does not. Mildew must be cleaned off and the surface rinsed and dried, or it will grow through the new coating.
Check it: RSOS task B-6 (performs general surface preparation)
Question 7 · B – Prepares surfaces
Knots in new pine trim keep bleeding a yellow-brown stain through latex paint. What is the best fix?
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Answer: B. Spot-prime the knots with a shellac-based primer before painting
Knots contain resins that dissolve into waterborne coatings and discolour them. A shellac-based (or other stain-blocking) primer seals the resin in so the finish coats stay clean.
Check it: RSOS task B-7 (prepares wood surfaces)
Question 8 · B – Prepares surfaces
New cast-in-place concrete is to be painted. Why should the painter normally wait until it has cured, often about 28 days?
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Answer: C. Fresh concrete is wet and strongly alkaline, which can cause coating failure
Curing concrete releases moisture and has a high pH. Coating it too early can trap moisture, causing blistering, and alkalinity can saponify oil-based coatings. Check moisture and pH, and follow the coating manufacturer's limits.
Check it: RSOS task B-8 (prepares concrete and masonry surfaces)
Question 9 · B – Prepares surfaces
White powdery deposits keep appearing on a brick wall. What should be done before coating it?
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Answer: C. Remove the deposits and correct the moisture source that is carrying salts to the surface
These deposits are efflorescence: soluble salts carried to the surface by moving water. Coating over them traps the salts and moisture and leads to peeling, so they are brushed off and the water source is fixed first.
Check it: RSOS task B-8 (prepares concrete and masonry surfaces)
Question 10 · B – Prepares surfaces
Which surface preparation standard describes blast cleaning to near-white metal?
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Answer: A. SSPC-SP 10 / NACE No. 2
SSPC-SP 10 / NACE No. 2 is near-white blast cleaning, allowing only light staining on a small part of each area. SP 6 is commercial blast, SP 7 is brush-off blast, and SP 3 is power tool cleaning.
Check it: RSOS task B-9 (prepares metal surfaces); SSPC-SP 10 / NACE No. 2
Question 11 · B – Prepares surfaces
New hot-dip galvanized railings are to be painted. Which preparation is most suitable?
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Answer: B. Remove oils and passivation residues, then profile or etch before a compatible primer
New galvanizing is smooth and may carry oils or passivation treatments. It is cleaned, then lightly profiled or etched, and a primer rated for zinc is used. Alkyds can saponify on zinc and peel.
Check it: RSOS task B-9 (prepares metal surfaces)
Question 12 · B – Prepares surfaces
Why is a dedicated drywall primer used on new gypsum board before finish coats?
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Answer: A. It evens out the different porosity of the paper face and the joint compound
Joint compound and the paper face absorb paint differently, which shows as flashing and texture differences. A drywall primer equalizes porosity so the finish dries to a uniform sheen.
Check it: RSOS task B-10 (prepares plaster surfaces and drywall)
Question 13 · C – Prepares and applies residential, institutional and commercial paints, coatings and finishes
Which component of a paint forms the continuous film and binds the pigment to the surface?
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Answer: D. The binder (resin)
The binder, or resin, holds pigment particles together and makes the paint adhere. Solvents or water only carry the paint and evaporate, extender pigments add bulk, and colourants add colour.
Check it: RSOS task C-11 (prepares for application of paints and coatings)
Question 14 · C – Prepares and applies residential, institutional and commercial paints, coatings and finishes
Several 3.78 L cans of the same tinted colour will be used on one large wall. What should the painter do?
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Answer: B. Box the paint by mixing all the cans together in a larger pail
Small differences between cans can show on a large wall. Boxing, or intermixing all the cans in one container, gives a uniform colour across the whole surface.
Check it: RSOS task C-11 (prepares for application of paints and coatings)
Question 15 · C – Prepares and applies residential, institutional and commercial paints, coatings and finishes
How does a standard alkyd (oil-based) house paint cure?
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Answer: D. The solvent evaporates and the binder reacts with oxygen from the air
Alkyds dry by solvent evaporation followed by oxidation of the drying-oil-modified resin. Coalescence describes latex, a hardener describes two-component coatings, and redissolving describes lacquers.
Check it: RSOS task C-11 (prepares for application of paints and coatings)
Question 16 · C – Prepares and applies residential, institutional and commercial paints, coatings and finishes
What is the main purpose of keeping a wet edge while rolling a wall?
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Answer: B. To prevent lap marks where fresh paint overlaps paint that has started to dry
Rolling into paint that is still wet blends each section into the last. Rolling over paint that has begun to set leaves a visible lap of extra thickness and sheen.
Check it: RSOS task C-12 (applies paints and coatings)
Question 17 · C – Prepares and applies residential, institutional and commercial paints, coatings and finishes
When spraying with an airless gun, which technique gives the most even coat?
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Answer: A. Keep the gun square to the surface at a constant distance and overlap passes by about half
Arcing the gun changes the distance and angle, giving thin ends and a heavy middle. A square, steady pass with about 50% overlap, triggering at the start and end of each stroke, builds a uniform film.
Check it: RSOS task C-12 (applies paints and coatings)
Question 18 · C – Prepares and applies residential, institutional and commercial paints, coatings and finishes
In a decorative glaze finish, what is the main purpose of the glaze medium?
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Answer: D. To make the coloured layer translucent and keep it workable long enough to manipulate
Glaze medium extends open time and makes the colour translucent, so tools such as rags, sponges or combs can create patterns that let the base coat show through.
Check it: RSOS task C-13 (applies decorative/specialty finishes)
Question 19 · C – Prepares and applies residential, institutional and commercial paints, coatings and finishes
In Venetian plaster work, how is the characteristic polished sheen produced?
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Answer: A. By compressing and burnishing the final thin coat with a steel trowel
Venetian plaster is applied in thin coats with a steel trowel, and the last coat is burnished by trowelling with pressure as it sets. This compresses the surface and creates the polished, marble-like look.
Check it: RSOS task C-13 (applies decorative/specialty finishes)
Question 20 · D – Prepares and applies wall coverings
Before hanging the first strip of wallpaper on a wall, what should the paperhanger establish?
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Answer: A. A true plumb line, not the room corner, to align the first strip
Corners, ceilings and trim are rarely perfectly plumb or level. Hanging the first strip to a laser or plumb-bob line keeps the pattern vertical across the wall.
Check it: RSOS task D-14 (prepares for application of wall coverings)
Question 21 · D – Prepares and applies wall coverings
What does 'booking' a pasted wallpaper strip mean?
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Answer: C. Folding the pasted side onto itself and letting it rest before hanging
Booking means folding the strip pasted side to pasted side and letting it rest. This lets the paper expand and relax evenly so it does not bubble or shrink at the seams on the wall.
Check it: RSOS task D-15 (applies wall coverings)
Question 22 · E – Prepares and applies wood finishes
Which wood usually needs a paste grain filler for a glass-smooth clear finish?
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Answer: A. Red oak
Red oak is an open-grain wood with large pores that show through a thin clear coat. Maple, cherry and birch are closed-grain woods that rarely need a grain filler.
Check it: RSOS task E-16 (prepares for wood finishing applications)
Question 23 · E – Prepares and applies wood finishes
A nitrocellulose lacquer film turns milky white when sprayed on a hot, humid day. What is this defect called?
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Answer: A. Blushing
Fast-evaporating lacquer solvents cool the surface and moisture from the air condenses in the film, causing a white haze called blushing. A slower thinner or retarder and better conditions help prevent it.
Check it: RSOS task E-17 (finishes wood surfaces)
Question 24 · F – Prepares and applies industrial paints and coatings
Ambient conditions are checked before coating steel. What is the common minimum gap between the steel surface temperature and the dew point?
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Answer: D. At least 3 °C above the dew point
If the steel is at or near the dew point, moisture condenses on it and causes poor adhesion and flash rusting. A margin of at least 3 °C above dew point is the common rule, unless the product data sheet says otherwise.
Check it: RSOS task F-18 (prepares for application of industrial paints and coatings)
Question 25 · F – Prepares and applies industrial paints and coatings
Which tool is commonly used to measure the anchor profile left by abrasive blasting on steel?
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Answer: D. Replica tape read with a spring micrometer
Replica tape is burnished onto the blasted surface to take an impression of the peaks and valleys, then measured with a spring micrometer. A wet film comb measures wet paint, a psychrometer measures humidity, and a holiday detector finds pinholes.
Check it: RSOS task F-18 (prepares for application of industrial paints and coatings); ASTM D4417
Question 26 · F – Prepares and applies industrial paints and coatings
What does 'pot life' mean on the data sheet for a two-component epoxy?
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Answer: D. The time the mixed coating stays usable before it becomes too thick to apply
Once the base and hardener are mixed, the reaction begins and the material thickens. Pot life is how long it stays usable. The wait after mixing is induction time, and the time between coats is the recoat window.
Check it: RSOS task F-18 (prepares for application of industrial paints and coatings)
Question 27 · F – Prepares and applies industrial paints and coatings
Why does a coating crew apply a stripe coat by brush to welds, edges and bolts before the full coat?
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Answer: A. These areas are hard to coat evenly, and the stripe coat gives them extra film build
Paint pulls away from sharp edges and is hard to build on welds and bolts, so these are where corrosion starts. A brushed stripe coat works the coating in and adds film thickness where it is most needed.
Check it: RSOS task F-19 (applies industrial paints and coatings)
Question 28 · F – Prepares and applies industrial paints and coatings
What type of protection does an organic or inorganic zinc-rich primer give to blast-cleaned steel?
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Answer: B. Galvanic (cathodic) protection, as the zinc corrodes in place of the steel
Zinc is more active than steel, so in a zinc-rich primer the zinc sacrifices itself to protect the steel at damage points. That is galvanic or cathodic protection, which needs a clean, well-profiled surface for electrical contact.
Check it: RSOS task F-19 (applies industrial paints and coatings)
Question 29 · F – Prepares and applies industrial paints and coatings
A 2-component epoxy topcoat on an outdoor structure has turned chalky after a summer. What is the most likely reason?
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Answer: C. Epoxies break down under UV light and chalk unless a UV-resistant topcoat is used
Most epoxies have poor ultraviolet resistance and chalk in sunlight, even though they protect well. That is why exterior systems often finish with an aliphatic polyurethane topcoat over the epoxy.
Check it: RSOS task F-19 (applies industrial paints and coatings)
Question 30 · F – Prepares and applies industrial paints and coatings
After a thick epoxy tank lining cures, the inspector wants to find pinholes through to the steel. Which test is used?
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Answer: D. Holiday (spark) testing at a voltage set for the film thickness
A holiday detector finds pinholes and discontinuities that reach the substrate. High-voltage spark testing is used on thick linings, with the voltage set to suit the film thickness so the coating is not damaged.
Check it: RSOS task F-19 (applies industrial paints and coatings); NACE SP0188
These are VoltExam questions written for the Red Seal Painter and Decorator Interprovincial Exam, not official exam questions. Each shows the rule or standard to check it against. New to this exam? Read the Red Seal Painter and Decorator (404C) guide.
Last checked against Red Seal Program (with provincial and territorial apprenticeship authorities) on .
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Official sources
- Red Seal – Painter and Decorator trade page ↗
- Red Seal – Painter and Decorator exam information (breakdown) ↗
- Red Seal – Painter and Decorator examination weightings ↗
- Red Seal – Red Seal Occupational Standard: Painter and Decorator ↗
- Red Seal – Overview of the Red Seal Examination ↗
- Skilled Trades Ontario – Painter and Decorator, Commercial and Residential ↗
- Skilled Trades Ontario – Painter and Decorator, Commercial and Residential (404C) trade report ↗
- CCOHS – Spray painting ↗
Sources checked November 3, 2026. VoltExam is independent and not affiliated with Red Seal Program (with provincial and territorial apprenticeship authorities). Rules change: confirm details with the official source before your exam.