Ace the Red Seal Drywall & Plasterer Exam 2025 – Let's Nail It & Shine Bright!

The putty knife is the tool commonly used for applying joint compound in drywall finishing. Its design features a flat, flexible blade that allows for smooth and even spreading of the compound over joints and seams in drywall. The flexibility of the blade enables the user to control the thickness of the application and the ease of maneuvering around corners and edges, which is essential for achieving a professional finish.

In contrast, while a utility knife is effective for cutting drywall or trimming tape, it is not suited for applying joint compound. An angle grinder is primarily used for cutting or grinding materials and is not applicable in this context. A carpenter’s square is a measuring tool, often used for ensuring right angles and layouts, and does not play a role in the actual application of joint compound. Thus, the putty knife is the ideal choice for this task.