• Refill.  (Easy fix- yay!)

• Empty the powder, remove the orifice and inspect.
• The orifice should be at least 4x larger than the average particle size.
• Check out our Tank Orifice Selection Guide.
• Is moisture a problem? See block below.

• Look through the clear tank cover. Are clumps in the abrasive visible?
• Replace with fresh powder.
• Check that the air dryer is working properly.
• See block below about moisture contamination.

• Determine the type of gas that is connected to the system (Compressed Air, Nitrogen or Carbon Dioxide). Compressed air can cause moisture in the line.
• GAS WARNING! Never connect to pure Oxygen. It will cause an explosion.
• The compressed air line is the most common source of moisture. Look through the clear tank cover for obvious signs of moisture like holes or cracks in the abrasive leading down to the orifice. If not obvious, carefully remove the tank cover without disturbing the abrasive in the tank.
• If there are obvious clumps, cracks or holes in the abrasive; moisture is more than likely in your air line.
• Read our page on moisture issues and compare the information with your air supply and powder storage conditions.

• STORAGE NOTE: Abrasive must be stored in a cool, dry environment. No bags or bottles should be left open. Abrasive should not be left in the tank over the weekend or during downtime.

• Is a desiccant or a membrane dryer installed on the line? If a desiccant dryer in use, the desiccant may need to be replaced.
• DRYER NOTE: Our process requires a dew point of -25°F, but refrigerant dryers provide a dewpoint of +35°F. A refrigerant dryer alone is not sufficient, and your system requires an accompanying desiccant or membrane dryer.
• If a desiccant or a membrane dryer are NOT installed, it is time to do so.

• NOTE ABOUT THE MODULATOR: The modulator creates pulses of air by alternating between an open and closed position that allows free flow of air to the mixing chamber and a close position that stops the flow of air to the tank. As the modulator wears, the core no longer sits tightly against the polymer seat. If the core cannot sit tightly, the modulator cannot generate proper air pulses. The operator may get an initial flow of abrasive from a pressure pulse generated when the pinch valve opens; but after that, abrasive may only pull into the system through gravity.
• Does the modulator audibly hum when the footswitch is actuated? If not, or if it rattles noisily, the modulator should be checked and probably replaced.
• Most modulators need to be replaced after 5,000 hours of operation.

• Not all abrasive is designed for MicroBlasting. Industrial abrasives commonly have a greater percentage of fine and coarse particles, which impacts and interrupts a blaster’s performance.
• Consider switching to Comco abrasives. We use proprietary systems and tools to maintain the purity of all our abrasives, ensuring optimum performance.
• Learn more about the importance of quality abrasive.

• Verify that the power switch is on. The power light should be illuminated. If it is not illuminated but the switch appears to be in the on position; then the power switch may be defective. Contact our Technical Support Team 1-818-841-5500 or techsupport@comcoinc.com if you suspect that is so.
• Examine the power cord. Is it connected? Is it damaged? If it is connected and does not appear damaged; then call our Technical Support team at the number above.
• Check the fuse.

• If the needle on the gauge is pointing to 0, turn the regulator knob clockwise until it registers pressure.
• Set the regulator to desired blast pressure.

• Periodically desiccant may pass through the dryer and stick in the valve assembly. Remove the coil and body from the valve to check and clear trapped foreign particulate.
• If no foreign particulate appears to be trapped, check the valve to make sure the coil is not damaged. Replace if necessary.

• Remove the nozzle and look through it. You should see light shining through the hole on the tip. Keep in mind that you may see light through glass bead.
• If plugged, run a small wire through the nozzle hole to clear.
• Using Sodium Bicarbonate? Try soaking the nozzle in a mild acid, like vinegar, to clean. (Read our blog post on working with this abrasive.)
• If plugging continues despite changing out the nozzle; either the tank is releasing too much abrasive or the nozzle is too small to flow the type of abrasive you are using.
• Check out our Nozzle and Powder Brochure for a comprehensive list of sizes and options.

• Disconnect the abrasive line and check the fitting to see if it is clogged or crimped. Remove the clog or straighten the crimp.
• CLEAN: Sodium bicarbonate plates at the output fitting over time. Remove and soak the fitting in a mild acid, like vinegar. Dry the fitting completely before reinstalling. (Failure to dry completely will cause it to plate out again quickly.)
• REPLACE: Cutting abrasive will gradually wear away at this fitting until its walls collapse and close the opening. If cleaning did not solve the issue and/or the fitting appears thin; replace the output fitting.

• When the machine is on, the tank should be pressurized.
• If the tank is pressurized, then the problem is between the tank and the nozzle. (Read and follow directions in boxes above.)
• If the tank is NOT pressurized, the problem is between the regulator and the tank. (Read and follow directions in boxes below.)

• The modulator can become plugged with abrasive, prohibiting air from passing through.
• Remove the modulator and slide the core back and forth inside the body. If it does not slide easily, then the modulator is plugged and may require replacement.
• See the next FAQ and follow the instructions.
• Call our Technical Support Team at 1-818-841-5500 or techsupport@comcoinc.com to inquire about next steps.

 As the unit sits idle, does the pressure gradually creep up to line pressure, only to drop back down to the normal pressure once blasting begins?

• IF YES: there could be a problem with the diaphragm on the regulator. If the spring is not properly centered and air is leaking around it, pressure will increase to line pressure. Inspect the diaphragm and regulator assembly. Replace if necessary.
• IF NO: Contact our Technical Support Specialists at 1-818-841-5500 or techsupport@comcoinc.com.

• It is normal for the gauge to drop to 5-10 psi. For example, restriction in the line may cause a drop of 5-10 psi between idle and blasting states.
• If the drop is greater than 10 psi, then there may be insufficient air flow. Line pressure and volume may be too insufficient to support the current flow at the nozzle; and thus, pressure drops until it reaches equilibrium.
• Check the inlet air valve and regulator for a clog that could be restricting the air flow to the mixing chamber and nozzle.
• Check for leaks in the abrasive line going out of the nozzle.
• Check to make sure the nozzle has not been removed.
• If it has not been removed, check the nozzle size. The nozzle may be too large for the system.
• Check the inlet air supply to make sure it can deliver sufficient air volume. A 10 psi buffer should be maintained between blast pressure and supply pressure.
• Check the supply line from the compressor to the blaster. There could be a restriction, like a small diameter line, a partially open valve, etc.

• Inspect the check valve and filter assembly for a clog.
• Check for plating in the mixing chamber, the output fitting, hose and nozzle. Clean these areas, if needed, or replace those parts.
• Inspect the nozzle for clogs. Clean with a fine wire, if needed.

• A sharp bend in the hose just upstream from the handpiece will push all abrasive to the outside of the bend, wearing down the side that sees the most abrasive quickly.

• Due to their size, rectangular nozzles commonly wear faster than round nozzles. Once a wear characteristic starts to form in a nozzle, the characteristic will channel the abrasive through the location, accelerating the wear-rate.
• Two common wear patterns are the “football” and the “dogbone.”
• The football wear pattern occurs when the center of the rectangle wears faster than the edges. The center of the nozzle blows out quickly.
• The dogbone wear scenario occurs when the edges of the nozzle wear out faster than the center.