Adjustments Guide: ZERO ® 4-Gallon Tumble-Basket Blast Cabinet

Watch how to make adjustments to Clemco's ZERO brand 4-Gallon Tumble-Basket Blast Cabinet. Blast batches of parts up to 35 lbs with this suction cabinet that provides consistent parts coverage, easily switches between different media, and is far more efficient than manual blasting. Clemco is the world's largest manufacturer of air-powered abrasive blasting equipment, including abrasive blast machines, blast cabinets, blast rooms, safety equipment and blasting accessories.

Welcome to the Adjustments Guide for Clemco’s ZERO Brand 4-Gallon Tumble-Basket Blast Cabinet


This video is the second of a three-part series. It outlines how to adjust the controls of the 4-Gallon Tumble-Basket Blast Cabinet, while Videos 1 and 3 outline how to set up and operate the cabinet. This video covers:

    • Adjusting the Controls During Blasting

Note that this video is not a replacement for reading the 4-Gallon Tumble-Basket Blast Cabinet Operations Manual, which should be read in full by anyone who uses the cabinet. Failure to comply with the instructions in the operations manual can result in severe injury or even death.

Adjusting Gauges and Components: ZERO 4-Gallon Tumble-Basket Blast Cabinet

Adjusting the Controls During Blasting

Setting the Air-Inlet Damper

  • The air-inlet damper is located on the top of the cabinet and must be set to create negative pressure inside the cabinet. The label on the damper shows the settings in degrees. The initial setting should align the handle to 30 degrees.
  • Loosen the lock nuts and position the damper.
  • When correctly positioned, tighten the lock nuts to maintain the setting.

Adjusting Blast Pressure with the Pilot Regulator

  • The pilot regulator enables an operator to adjust blasting pressure while blasting. It is located on the top, front edge of the cabinet. It conveys the pressure to the main regulator on the inlet plumbing. When blasting begins, the main regulator opens to the same pressure noted on the pilot regulator.
  • The maximum recommended pressure is 80 psi. Lower pressure may be used for delicate parts. Higher pressure may cause dust or media to escape from the cabinet.
  • To adjust pressure, unlock the knob by pulling it out and turn it clockwise to increase pressure or counterclockwise to decrease pressure. Pressure usually drops from closed-line pressure when blasting starts.
  • After the operating pressure is set, push the knob in to lock it to maintain the setting.

Adjusting the Air Jet

  • Make sure the air jet is properly adjusted with 3-1/2 to 4 threads exposed past the lock nut.
  • If it is not correctly adjusted, use the optional air-jet adjustment tool to correct the setting.

Adjusting the Media-Air Mixture

  • If the air exiting a nozzle pulses or if media does not flow smoothly from it, the metering valve for the corresponding nozzle requires adjusting. To adjust it, first loosen the locking nut and adjust the metering screw until the holes closest to the locking nut are closed off and the holes farthest from the nut are fully open.
  • If pulsation occurs, either media is damp or not enough air is entering the media stream. While blasting, loosen the locking nut on the metering valve and slowly turn the adjusting screw out (counterclockwise when viewed from the top) until the media flows smoothly. Tighten the locking nut to maintain the setting.
  • If media flow is too light, decrease air in the mixture by turning the metering screw in (clockwise when viewed from the top), which covers more of the holes so less air enters the media hose. Tighten the locking nut finger-tight to maintain the setting.

Adjusting Blast Gun Alignment

  • Load parts into the basket, close the door, and then turn the timer ON to rotate the basket until the parts lay in the section of the basket in which they will be blasted. The basket may only need to rotate one-half to one-fourth a revolution, or even less, in order for the parts to reach this position.
  • Open the window and check the alignment of the guns by eye or insert the optional laser alignment tool into a blast gun nozzle and point the laser beam toward the parts to be blasted.
  • If the guns do not point toward the center of the batch of parts, loosen their gun bodies or slotted brackets as required to point the nozzles toward the center of the batch, but at different parts within the batch.
  • If the optional laser alignment tool was used, remove it from the blast gun nozzle and tighten the hold-down brackets to maintain the settings.
  • Close the window and make sure the door is securely latched.

Adjusting the Dust Collector’s Pulse Pressure

  • Adjust the pulse pressure using the pressure regulator mounted on the pulse reservoir.
  • To adjust the pressure, unlock the knob by pulling it out and turn it clockwise to increase pressure, or counterclockwise to decrease pressure. After pressure is set, push the knob in to lock it and maintain the setting.
  • Adjust the pulse pressure regulator to 60 psi. However, only pulse a filter cartridge that has been properly seasoned. Pulsing an unseasoned cartridge can cause premature cartridge failure or decrease the efficiency of the dust collector.
  • As the filter cartridge cakes with dust and pulsing does not adequately clean the cartridge, increase the pulse pressure by 5 psi increments until the maximum of 90 psi is reached. As dust cakes on the cartridge, the differential pressure (the pressure drop between the clean and dirty side of the filter cartridge) increases.
  • Using an optional pressure-differential gauge to measure the pressure is an effective way to tell if the cartridge is heavily caked.
  • If the maximum pulse pressure of 90 psi is reached and the differential pressure stays above 4 inches WC, replace the cartridge.

Adjusting the Pulse-Control Panel & Timer

  • The pulse-timer is powered ON with the exhauster.
  • To season a filter cartridge with no pulse, use the regulator to reduce the pulse pressure to zero.
  • The timer is factory set at 20 seconds OFF and a fraction of a second ON. Every 20 seconds, the cartridge is pulsed.
  • When the maximum pulse pressure of 90 psi is reached and pulsing does not lower differential pressure below the changeover pressure of 4 inches WC, the filter cartridge should be replaced and the pressure set to 60 psi.

Adjusting the Reclaimer Static Pressure

  • Static pressure requirements vary with size, weight, and type of media.
  • Adjust static pressure by opening or closing the outlet damper, which is located above the reclaimer on the underside of the top of the power module.
  • If the damper is not opened far enough, the reclaimer will not remove fines, resulting in dusty media and poor visibility, or it will not convey media, causing media buildup in the hose between the cabinet hopper and the reclaimer.
  • If the damper is opened too far, it may cause carryover (usable media carried into the dust collector), which leads to excessive media consumption.
  • Open only as far as necessary to obtain a balance of maximum dust removal without media carryover.
  • An optional manometer is useful for adjusting and monitoring static pressure.
  • When pulsing no longer maintains the necessary static pressure, readjust the damper.

Correct operation of Clemco’s ZERO brand 4-Gallon Tumble-Basket Blast Cabinet is necessary to protect blast operators and others in the vicinity of the cabinet from blasting and inhalation hazards that can cause severe injury or even death. The purpose of this video series is to familiarize viewers with how to set up and then begin operating the 4-Gallon Tumble-Basket Blast Cabinet. However, this video is not a replacement for reading the cabinet’s operations manual, which should be read in full by anyone who uses this machine.