Nozzle size: 5/6 1/2 inch
Air / Grit mixture The grit valve is to be set at a lean feed. Too much grit in the air flow results in low production and less profile. Start with the grit valve closed, open gently until you get the proper effect and leave it there. The grit coming out of the nozzle should look like a blue haze and not like a black cloud.
Distance to surface: Optimum distance between nozzle and surface is around 30cm (12 inch).
Nozzle direction: Avoid blasting perpendicular (90 degrees) to the surface. An angle of 75-80 degrees gives the best performance
 
Nozzle pressure: Air Pressure at the nozzle should be between 80 and 100 psi, the closer to 100 psi, the better the performance.
Remember, to achieve high nozzle pressure:
  • Nozzle size to be in relation to the capacity of the compressor (see diagram) Note that at continuous working the compressor should not run at more than 5% of the capacity.
  • The air hose between compressor and blasting unit to be of as large diameter as possible and as short as possible.