Sandblasters are use to clean metal, glass, woods and plastics. Sandblasters operate on a pressure system or a siphon system. The troubleshooting process is similar regardless of the type of system. The input to a sandblaster is high-pressure air from a compressor, and an abrasive such as silicon carbide. Output is a mixture of the air and abrasive. There are very few pieces to malfunction in a sandblasting system. Aside from obvious things such as no compressed air, the majority of your problems will deal with moisture in the lines or tanks, and/or valve adjustments.
Test your air gun to ensure that you have high-pressure air available, eliminating the possibility of a faulty gauge. Confirm that the air compressor output pressure gauge indicates adequate pressure available when the compressor runs. No air generally means a faulty compressor.
Activate the sandblaster gun and verify that you can see and feel the abrasive coming out of the nozzle. If you can, your sandblaster is working. Unexpected changes like this are not unusual. Clogged abrasive lines will often free themselves if they are moved or bumped. If you can feel the air but are not getting abrasive though the gun, you either have an empty abrasive tank or plugged up feed lines. In the case of a pressure blaster, the mixing valve on the pressure tank may be defective or obstructing the abrasive feed.
Inspect the area you are blasting. If you appear to have adequate air and abrasive material, but are getting a reduced blasting effect, change your nozzle. The nozzle will wear over time and as the orifice enlarges, the blast pattern will get larger and less effective. This is a gradual failure and sometimes it is overlooked. Enlarged nozzles will also cause your blaster to use more abrasive.
Drain condensation build-up in the compressor tank weekly as a minimum, more often in high humidity areas. This is the most important preventive maintenance you can do. The drain is located at the bottom of the tank. Use a small crescent wrench to remove the drain. Nothing creates more problems for sandblasting than moisture in the air lines or in the abrasive.
Do your troubleshooting in an orderly fashion and maintain a maintenance log which should be kept with the equipment.
Do not look into a sandblaster nozzle while the air compressor is connected to the system. Wear a respirator while troubleshooting a sandblaster when it is outside the cabinet.