Module 2: Assessment Quiz
Module: U10M2 - Cabinet Operation and Technique
Duration: 20-30 minutes
Passing Score: 70%
What is the recommended standoff distance for general-purpose blasting in a suction-feed cabinet?
Explanation: A 6-8 inch standoff distance provides optimal media velocity and pattern width for most cabinet blasting applications. Too close causes excessive wear and narrow pattern; too far reduces impact energy.
Before operating a blast cabinet, what must be verified first?
Explanation: Dust collection must be verified before any blasting operation. Operating without functional dust collection exposes the operator to hazardous airborne particulates and reduces visibility inside the cabinet.
What causes a blast cabinet to lose blasting pressure gradually during operation?
Explanation: Nozzle wear enlarges the orifice, which reduces air velocity and pressure at the work surface. Ceramic or tungsten carbide nozzles last longer than steel. Check nozzle size with a go/no-go gauge regularly.
What is the optimal blasting angle for maximum material removal?
Explanation: A 45-degree angle optimizes the cutting action of abrasive particles, maximizing material removal rate. A 90-degree angle is better for peening and surface compression.
How often should blast cabinet gloves be inspected for wear?
Explanation: Cabinet gloves are a primary containment barrier. A pinhole or tear allows abrasive dust to escape and contact the operator's hands. Inspect before every use and replace immediately if any damage is found.
What type of nozzle material provides the longest service life in a blast cabinet?
Explanation: Tungsten carbide nozzles last 500-800 hours versus 20-40 hours for steel and 300-500 hours for ceramic. The higher initial cost is offset by dramatically longer service life.
What does a "dead zone" in a blast cabinet refer to?
Explanation: Dead zones are areas in the cabinet floor where spent media and debris accumulate instead of being drawn into the recirculation system. Regular cleaning of dead zones prevents contamination and media mixing.
What is the purpose of the foot pedal on a blast cabinet?
Explanation: The foot pedal provides dead-man control of media flow. Blasting stops immediately when the pedal is released, giving the operator precise control and an instant safety shutoff.
When should you change the media in a blast cabinet?
Explanation: Media breaks down with use — particles fracture into smaller, less effective fragments. When blasting time increases noticeably or dust production rises, the media charge needs replacement. Most media lasts 5-30 cycles depending on type.
What is the correct procedure if the viewing window becomes difficult to see through during blasting?
Explanation: Poor visibility indicates either dust collector malfunction or a worn/frosted viewing window. Never blast blind or open the cabinet during operation. Stop, diagnose the issue, and correct before resuming.
What pressure range is typical for suction-feed blast cabinets used in makerspaces?
Explanation: Suction-feed cabinets typically operate at 40-80 PSI. This range provides effective blasting while keeping air consumption within the capacity of most shop compressors (5-10 HP).
What travel speed should you maintain when blasting a flat surface for uniform coverage?
Explanation: A consistent 1-3 inches per second with 50% overlap between passes ensures uniform coverage. Holding the nozzle stationary creates hot spots and over-blasting; moving too fast gives incomplete coverage.