Painter & Decorator (Red Seal)

Performs common occupational skills

Oily rags used to wipe up a drying-oil wood finish are left crumpled in a pile overnight. What is the main hazard?

1. The rags will stain the floor to keep the finished work sound
2. The rags will dry out and become brittle as part of doing the job correctly
3. Spontaneous combustion as the drying oil oxidizes and generates heat
4. The colour of the finish will fade, not a matter of drying or oil

Drying oils such as linseed cure by oxidation, a reaction that releases heat. When oil-soaked rags are bunched up, the heat cannot escape and can build until the rags ignite without any flame source. Staining, brittleness, and fading are minor cosmetic concerns by comparison. Used oily rags must be spread to dry or stored in a sealed metal container to prevent a fire.

RSOS 2022 | A-1.02 Maintains safe work environment

Prepares surfaces

When using an electric heat gun to soften old paint for removal, what is the chief hazard a painter must control?

1. The paint becoming glossy for a durable, professional finish
2. The gun running out of paint for the substrate and coating in use
3. Scorching the wood or igniting debris because of the high heat
4. The colour of the paint changing according to the product data sheet

A heat gun produces enough heat to char wood and ignite dust or loosened paint, so the operator must keep the gun moving and clear of combustibles. Gloss change, paint supply, and colour are irrelevant to the safety of the method. Heat is also unsuitable on suspected lead paint because it can release fumes, so the hazard and substrate must be assessed first.

RSOS 2022 | B-6.01 Removes existing paints and coatings

Prepares and applies residential, institutional and commercial paints, coatings and finishes

An airless sprayer leaves tails, the fingerlike heavy lines at the edges of the spray pattern. What is the most likely cause and fix?

1. Too much thinner, so add solids to protect the quality of the result
2. The wall is too cold, so heat the room for a durable, professional finish
3. The hose is too short, so add hose for the substrate and coating in use
4. Insufficient pressure or a worn tip, so raise pressure or replace the tip

Tails appear when the fluid is not fully atomized, usually from pressure set too low or a worn spray tip that no longer breaks the paint into a clean fan. Adding solids, heating the room, or lengthening the hose do not atomize the paint. Raising pressure to the lowest setting that gives a full pattern, or fitting a new tip, removes the tails.

RSOS 2022 | C-12.04 Applies residential, institutional and commercial paints and coatings with spray equipment