Blasting Described

Blasting in its simplest form involves a blast gun held by an operator who inserts his arms through armports in the front of the cabinet with work admitted through the same armports or through side work loading doors. Worktables are provided on the interior of the cabinets.

Manual units are used for extremely simple, low production work. Pressure Blast has enormously extended the state of the blast finishing art through the development of seemingly endless variety of automated units custom designed to individual specifications.

Instead of equipment requiring the operator to hold the workpiece in one hand and manipulate a blast gun in the other, a variety of work handling devices have been designed. Special fixtures, either stationary or rotating, hold workpieces for exposure to blasting. Fixtures may be manually loaded and unloaded or interfaced with other production processes.

Automated wet blast units are offered with cold or hot water rinsing systems, recirculating or nonrecirculating, air blowoffs and drying ovens.Dry blast units are fitted with blowoffs or vacuum cleaning capabilities. Single guns or multi-gun clusters may be fixed into position, caused to rotate or stroke in any plane. In short, Pressure Blast-developed techniques for automation have lifted dry blasting out of the foundry and wet blasting out of the tool room and created two extremely versatile production finishing methods.

Choice of Blast Systems

Wet and dry Pressure Blast units are available with two types of operation. Suction/siphon or Pressure/pump.


Involves the delivery of wet abrasive slurry or dry abrasive into the blast gun at relatively low velocity.

  • In the case of wet blasting, the suction is created by the passage of compressed air through a venturi in the blast gun.

  • In dry blast equipment, abrasive feeds into a mixing chamber, by gravity, is picked up by compressed air and carried to the blast gun.

  • In both systems, upon introduction of the abrasive slurry or dry abrasive into the blast gun, the media is met by compressed air which then expels it through the gun nozzle to impinge upon the workpiece. This is called the Pressure Blast regular velocity system.


  • This method of abrasive delivery involves the pressurization of the media in a pressure tank or pump which then introduces abrasive into the blast gun under pressure and velocity. Here, as in the regular velocity system, it meets with the compressed air and is shot from the gun and impinged against the workpiece. This is called the Pressure Blast high velocity system.

  • Abrasive velocity utilizing the high velocity principle is twice that of the regular velocity system and two to three times that developed by the regular velocity system. In terms of effective work finishing speeds. Additionally, the higher velocity system must always be employed when blasting is to take place at a highly restricted area such as a deep hole.