Finishing and Safety
Finishing and Safety
This domain tests surface preparation, finish application, and the safety rules that apply in a cabinet shop. Exam items cover sanding sequence, stain and topcoat compatibility, spray practices, PPE, ventilation, machine guarding, and housekeeping.
Finishing sequence
- Sand progressively, for example 120, 150, then 180 grit, removing dust between grits. Do not skip coarse scratches; the finish will reveal them.
- Raise grain on water-based finishes with a damp wipe and light sanding. Test stain on scrap of the same species and plywood face.
- Seal, stain, and topcoat according to the product system. Solvent and water-based products have different recoat times and compatibility.
- Spray in a ventilated booth with explosion-proof equipment where required. Wear the respirator specified for the coating, not a dust mask.
Safety rules
- Guard exposed blades and bits; use push sticks and featherboards. Keep gloves away from rotating tools.
- Store solvents away from ignition sources. Oily rags can self-heat; place them in a closed metal container.
- Use lockout/tagout for servicing. Keep aisles clear and extension cords out of walkways.
- Check SDS for hazards and first aid before opening an unfamiliar product.
Worked example
A cabinet door has planer tear-out and a glue spot. Start at 120 grit to remove the tear-out, then 150 and 180. Sanding only with 220 will polish the glue spot and leave a dip; the stain will blotch. The reasoning: coarse grit removes the defect, while each finer grit removes the previous scratch pattern. A finish is only as flat as the surface beneath it.
Traps
- Wearing a dust mask while spraying solvent lacquer.
- Sanding through veneer at an edge.
- Mixing water-based and solvent-based products without checking compatibility.
- Leaving finish-soaked rags in an open bin.