CSLB Painting (C-33) Trade Practice Test

Câu hỏi luyện tập mẫu

Một vài câu hỏi thực tế từ ngân hàng miễn phí này, kèm giải thích đầy đủ. Dùng công cụ luyện tập ở trên cho toàn bộ.

1. 1. Surface Preparation

   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

   Đáp án: b

   Giải thích: 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.

2. 2. Products & Materials

   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

   Đáp án: c

   Giải thích: 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.

3. 3. Planning & Estimating

   A job requires 18 gallons of paint at $45 per gallon. What is the material cost for the paint?

   • a.$810
   • b.$630
   • c.$450
   • d.$900

   Đáp án: a

   Giải thích: Material cost equals quantity times unit price: 18 gallons x $45 = $810. A complete estimate also adds sundries such as tape, brushes, rollers, and masking. Marking up materials appropriately is part of pricing the job.

4. 4. Surface Preparation

   A brown ring has appeared on a ceiling under a bathroom. The plumber has repaired the supply line. What is the correct coating sequence?

   • a.Dry the drywall, spot-prime the stain, then coat the ceiling
   • b.Apply three coats of ceiling flat directly over the stain
   • c.Prime the ring with a waterborne drywall sealer, then coat
   • d.Sand the stain out of the drywall paper and coat it out

   Đáp án: a

   Giải thích: Water-carried tannin and rust stains dissolve into waterborne films, so they are sealed with a stain-blocking primer once the substrate is genuinely dry. Piling on flat coats simply feeds the stain more water to travel in. A drywall sealer equalizes porosity but does not block a water stain. Sanding through drywall paper damages the board and does not remove the stain from the gypsum.

5. 5. Surface Preparation

   A painter cleans a greasy garage wall with a strong detergent solution before priming. What step decides whether the primer sticks?

   • a.Letting the detergent dry on the wall to keep working overnight
   • b.Rinsing thoroughly so no detergent residue is left behind
   • c.Applying the primer while the wall is still slightly damp
   • d.Adding more detergent to the second pass to be certain

   Đáp án: b

   Giải thích: Detergent residue is itself a bond breaker, so the clean is only finished when the surface has been rinsed and allowed to dry. Letting the solution dry deposits exactly the residue that has to come off. Priming a damp wall traps water under the film. Increasing concentration without rinsing makes the residue worse.

6. 6. Products & Materials

   Five gallons of latex paint were left in an unheated truck through a hard freeze. What should the painter check for?

   • a.A skin on the surface that indicates the paint has cured in the can
   • b.Separation of colorant into a layer that stirring will not fix
   • c.A drop in viscosity that requires adding thickener before use
   • d.Coagulated lumps and stringiness that will not stir out

   Đáp án: d

   Giải thích: Freezing can break a latex emulsion permanently, leaving grit and lumps that no amount of mixing will disperse, and that material must be discarded. Skinning is an oxidizing-alkyd behavior, not a freeze indicator. Pigment settling is normal and stirs back in. Freeze damage usually thickens or curdles the paint rather than thinning it.

7. 7. Products & Materials

   Why do exterior coatings for a California hillside home often specify a mildewcide even when the climate is dry?

   • a.Shaded, irrigated walls stay damp enough for growth
   • b.Mildewcide also protects the coating from ultraviolet degradation
   • c.Mildewcide is required by state law on all exterior coatings
   • d.Mildewcide replaces the need to wash the surface before repainting

   Đáp án: a

   Giải thích: Microclimate matters more than regional climate: north walls, dense landscaping, and sprinkler overspray keep surfaces wet enough for growth even in a dry area. Mildewcide is a biocide and does not screen ultraviolet light. No statute mandates mildewcide in every exterior coating. Existing growth still has to be killed and washed off before painting.

8. 8. Application

   A vacant apartment ceiling is being sprayed and back-rolled. Why is the back-roll worth the extra labor on a smooth ceiling?

   • a.It doubles the applied film thickness on the ceiling
   • b.It removes the need for a second coat in every case
   • c.It evens the film so the ceiling reads uniform
   • d.It allows a lower-quality paint to be substituted

   Đáp án: c

   Giải thích: Ceilings are viewed under raking light from windows, and back-rolling levels the sprayed film so the pass pattern does not show. Back-rolling redistributes material rather than doubling it. Coat count is set by hide and specification, not by the roller. Technique does not compensate for a paint with inadequate hide.

9. 9. Planning & Estimating

   A job has 340 linear feet of baseboard that averages 6 inches in height. What area does that represent?

   • a.340 square feet
   • b.170 square feet
   • c.2,040 square feet
   • d.85 square feet

   Đáp án: b

   Giải thích: Six inches is half a foot, so 340 x 0.5 = 170 square feet. The 340 figure treats every linear foot as a square foot. The 2,040 figure multiplies by 6 without converting inches to feet. The 85 figure divides by four instead of two.

10. 10. Safety

    A painter takes his dusty coveralls home and his spouse shakes them out before washing. What hazard does that create?

    • a.A fire hazard, because coating residue can self-heat in a dryer
    • b.A respiratory hazard limited to the worker who wore the clothing
    • c.Take-home lead exposure, which is why contaminated clothing is handled and laundered under employer control
    • d.No hazard, provided the clothing is washed separately from other laundry

    Đáp án: c

    Giải thích: Lead dust carried home on clothing has poisoned children and spouses, so the standard requires the employer to provide, handle, and launder contaminated clothing rather than sending it home. Spontaneous combustion is an oil-rag hazard, not a lead one. The exposure specifically reaches people who were not on the jobsite. Separating the wash does not stop dust released during handling.

    Nguồn: Cal/OSHA Title 8 §1532.1