Red Seal Painter and Decorator industrial paints and coatings practice questions.

Five free practice questions on industrial paints and coatings: block F of the Red Seal 404C Painter and Decorator exam, about 29 of its 130 questions. They are in the exam's format: four options, one correct answer. Answer each one before opening the explanation. No account, no email.

01The questions

1. Recall · Prepares industrial paints and coatings

   Why is an alkyd not applied directly over a zinc-rich primer?

   1. The alkyd stops the zinc from protecting the steel.
   2. The alkyd's solvent softens and lifts the zinc primer.
   3. The alkaline zinc breaks down the alkyd's oil binder.
   4. The alkyd dries too hard to flex with the zinc.
   Show the answer

   C. Correct. The zinc surface is alkaline and attacks the drying-oil binder of an alkyd (saponification), so the alkyd loses adhesion and peels. A topcoat compatible with zinc is used instead.

   Why not the others

   A. The reason is the topcoat's own failure: the alkaline zinc surface breaks down the alkyd's oil binder (saponification) and the alkyd peels.

   B. Lifting is a solvent problem between incompatible coats, but it is not why alkyds are kept off zinc. The zinc surface is alkaline and breaks down the alkyd's oil binder, so it peels.

   D. Hardness is not the issue. Zinc is alkaline, and alkalis break down an alkyd's oil binder, so the alkyd saponifies and peels.

   Source: Red Seal Occupational Standard, sub-task F-18.01

2. Procedural · Applies industrial paints and coatings with spray equipment

   The specification for a steel truss calls for a stripe coat on all welds and edges before each spray coat, carried 25 mm onto the steel on each side of the weld or edge. The welds and edges total 180 m. What area does one stripe coat cover?

   1. 90.0 m²
   2. 4.5 m²
   3. 45.0 m²
   4. 9.0 m²
   Show the answer

   D. Correct. The band is 25 mm on each side, 50 mm (0.050 m) wide in all, so one stripe coat covers 180 m × 0.050 m = 9.0 m². The stripe coat's material is worked out from that area; it adds film where coating pulls thin at edges and welds.

   Why not the others

   A. 90.0 m² reads 25 mm as 0.25 m on each side: 180 × 0.50 = 90. 25 mm is 0.025 m, so the band is 0.050 m wide and covers 180 × 0.050 = 9.0 m².

   B. 4.5 m² counts the 25 mm on one side only: 180 × 0.025 = 4.5. The band runs 25 mm on each side, so it is 50 mm wide: 180 × 0.050 = 9.0 m².

   C. 45.0 m² reads 25 mm as 0.25 m and counts one side only: 180 × 0.25 = 45. 25 mm is 0.025 m, and both sides together make 0.050 m: 180 × 0.050 = 9.0 m².

   Source: Red Seal Occupational Standard, sub-task F-19.02

3. Procedural · Installs fibre-reinforced plastics (FRP)

   Where is the MEKP for an FRP lining job kept on site?

   1. Apart from resins, solvents and combustibles.
   2. Beside the resin, so the two always stay together.
   3. In the solvent cabinet with the thinners.
   4. Premixed into the resin, ready for use.
   Show the answer

   A. Correct. MEKP is a strong oxidizer and a fire and explosion hazard, so it is stored apart from the resin, solvents and anything combustible, as incompatible products are.

   Why not the others

   B. Keeping the catalyst with the resin puts an oxidizer beside a flammable liquid it reacts with. MEKP is stored apart from resins, solvents and combustibles.

   C. A flammables cabinet holds solvents, which an oxidizer like MEKP must be kept away from. It is stored apart from resins, solvents and combustibles.

   D. Catalyzed resin starts to cure in the pail and cannot be stored. MEKP is added only when a batch is mixed, and kept apart from resins, solvents and combustibles.

   Source: Red Seal Occupational Standard, sub-task F-18.02

4. Procedural · Applies industrial paints and coatings with hand tools

   Notch gauge readings on an epoxy being rolled onto a wastewater channel wall are below the wet film the data sheet gives for the specified dry film. What does the painter do?

   1. Make it up by rolling the next coat heavier.
   2. Thin the coating so it spreads farther per pass.
   3. Let it cure, then confirm with a dry film gauge first.
   4. Roll on more coating while the film is still wet.
   Show the answer

   D. Correct. Wet film checks are made during application so a thin film can be corrected at once: more coating goes on the area while it is still wet and blends in, and the area is gauged again. Waiting for cure turns an easy correction into a repair.

   Why not the others

   A. Each coat in a system has its own specified thickness, and the next coat may be a different product. Building it up to hide a thin coat leaves this coat out of specification and can put the next one over its maximum.

   B. Thinning lowers the volume solids, so the same wet film leaves even less dry film. The correction is more coating while the film is wet, not more thinner.

   C. The wet readings already show the film is light. Waiting for cure means the shortfall must be fixed later with another application, instead of now while the film is wet and the extra coating blends in.

   Source: Red Seal Occupational Standard, sub-task F-19.01

5. Recall · Prepares industrial paints and coatings

   Coal tar epoxy has been specified for steel at a pumping station. Which drawback does the crew have to plan around?

   1. It cures only by drawing moisture from humid air.
   2. It grows brittle and can delaminate between coats.
   3. It loses its water resistance after long contact with water.
   4. It cannot be built to a high film thickness in one coat.
   Show the answer

   B. Correct. Coal tar epoxy builds high and resists water well, but it becomes brittle with age and tends to delaminate between coats, so the data sheet's recoat limits are kept closely.

   Why not the others

   A. Curing from moisture in the air describes a moisture-cured urethane. Coal tar epoxy is a two-component epoxy that cures by reaction; its drawbacks are brittleness with age and poor intercoat adhesion.

   C. Resisting water in buried and immersion service is what coal tar epoxy is chosen for. Its drawbacks are that it turns brittle with age and tends to delaminate between coats.

   D. High build is one of coal tar epoxy's strengths. Its drawbacks are that it turns brittle with age and tends to delaminate between coats.

   Source: Red Seal Occupational Standard, sub-task F-18.01

02Answer key

03What block F covers

Industrial coating systems: mixing two-component epoxies and urethanes, induction time, pot life and material temperature, thinners and accelerators as the data sheet allows, flash points, ventilation and grounding, fibre-reinforced plastics and their catalyst, wet and dry film thickness and volume solids, recoat windows, amine blush, dew point readings, airless spray safety, and inspecting the film by gauge and holiday test.

The Red Seal Occupational Standard names this block “Prepares and applies industrial paints and coatings”. It carries 22.3% of the exam, about 29 of the 130 questions, split across two tasks. The share column is each task's weight within the block, as the standard publishes it.

04What the questions turn on

Pot life is chemistry, not a thinning problem

A two-component mix thickening late in its pot life is the cure reaction running its course. Solvent does not stop it, so the last of it is set aside and a fresh kit mixed. Cold kits are warmed until the material itself reaches the data sheet's minimum before mixing.

Wet film times volume solids gives dry film

Only the solids stay once the solvent leaves, so DFT is WFT times volume solids, and thinning lowers the solids in the wet film. A dry film gauge on steel reads the whole system, so each coat's build is found by subtraction.

Respect the recoat window and the weather

Past the maximum recoat time the cured coat is abraded before the next goes on. An oily film on an amine-cured epoxy after a cold, damp night is amine blush, tested for and removed before recoating.

High pressure and solvent vapour are the hazards

The tip guard stays on an airless gun because the jet can inject coating through the skin. The pump is grounded and metal pails bonded to it, since static from fast-moving coating can ignite solvent vapour.

05The other blocks

The 404C exam has six blocks. Each has its own page of free questions:

The 404C Painter and Decorator practice exam page describes the full question bank. How these questions are written and checked: how our questions are made. Found a mistake? Tell us and we will fix it.