When using a blasting cabinet, dust is created by the material you are blasting off of the part, as well as from the abrasive breaking down from impact. This will form a dust cloud in the cabinet and make it difficult to see. The heavier abrasive particles fall back to the bottom of the cabinet to be picked up and shot through the gun again. The lighter dust particles are best removed from the cabinet by some type of dust collection system. Blasting dust is hard on electric motors and can quickly ruin a shop vacuum. I built a water filter as a pre-filter to collect the majority of dust before it can reach my shop vacuum.
I used a 2 gallon plastic bucket and an assortment of PVC pipe to make my filter. I call my creation the “blasting cabinet dust separatorinator”.
The design is a pipe inside of a pipe. The outer pipe is 2”, while the inner pipe is 1 ¼”. The vacuum draws air through the outer pipe creating a low pressure area inside the bucket. This causes dust from the cabinet to be drawn down the inner pipe where it bubbles out under the water in the bucket. This traps the dust in the water.
I cut a piece of plywood to fit the top of the lid. I cut a 2 3/8” hole through the plywood with a hole saw. Next I ran a 2” threaded coupling through the plywood and lid assembly.
I ran some screws through the underside of the lid to make the assembly more stable.
This picture shows the air intake nozzle that is inside the bucket. It is made from a 2” to 1 ½” reducer. There is also a 1 ½” to 1 ¼” reducing bushing that is reamed so the 1 ¼” pipe will pass all the way through. The air holes are 3/8”.
This picture shows the assembled lid with 2” threaded coupling and air intake nozzle.
This picture shows a vacuum port where a vacuum hose is connected. It is a 1 ¼” to 1” threaded bushing. I removed the threads with a rotary file to make a good fit for the vacuum cleaner hose.
This picture shows the completed assembly.
Because I used a 2 gallon bucket, there was enough turbulence that the vacuum was picking up too much water. I added a splash shield made from a 4” pipe cap to reduce water pickup. There are also small drain holes in the bottom of the splash shield. Another option would be to use a 5 gallon bucket so that the air intake is farther from the water.
This picture shows the vacuum hooked to the “T” and the cabinet attached to the top of the unit.
Here is everything ready for use.
