Selecting, Preparing and Maintaining Tools, Plant and Equipment
Matching the tool to the task
Good plastering depends on tools that are clean, correctly broken in and suited to the material. This domain tests tool knowledge, preparation and maintenance routines, and safe use of plant such as mixers, spray machines and hoists.
Core concepts to know
- Hand tools: trowels (finishing, laying, corner), hawk and board, floats (wood, plastic, sponge, steel), darbies and rules for ruling off, scratchers or comb hammers for keying, joint rules, and gauging trowels. Stainless trowels resist staining; carbon steel needs drying and oiling.
- Breaking in a trowel: a new steel trowel is dressed and worn in on abrasive material so it does not drag or chatter on finish coats.
- Mixing plant: paddle mixers and forced-action mixers; the drum and paddles must be clean so set material does not seed the new mix and cause fast set or lumps.
- Spray plant: hoses, nozzles, rotors and stators wear; a worn rotor/stator changes output and finish. Clean and flush after every use, especially with gypsum and polymer products.
- Preparation: clean tools before use, remove hardened plaster, check handles and trowel rivets, and inspect leads and plugs on power tools.
- Maintenance and storage: dry steel tools after washing, store trowels flat and protected, hang hoses, and service mixers and spray machines per the manufacturer's schedule.
Traps
Questions often test whether you clean a mixer between mixes (yes, always) or whether a worn spray rotor is acceptable (no, it affects output and finish). Another trap is using a wood float where a steel trowel finish is specified, or vice versa.
Worked rule of thumb
Before every pour or mix: is the tool clean, the right type for the coat, and undamaged? A dirty drum or a chipped trowel edge will show in the finished surface and cost more to fix than the two minutes of cleaning.