[Steve Hamilton]

Berndt
A few things to check
Blasting material needs to be very dry.
Air supply also needs to be free of moisture.
The blasting material has to be able to flow , if it clumps due to moisture or too fine like a powder it will not work.

Mine works good until the material level gets down to the bottom 1/4 then I need to shake it.
Setting the valves for air and material flow can be tricky. You need to have enough air pressure to the top of the pot to keep the material flowing. The valve on the vertical pipe controls that.
The valve on the bottom of the tank controls material flow, to much material flow makes a big restriction to the air stream.

How I set mine up
Fill to top with material
Turn material valve off
Turn on main air supply
Slowly turn material valve on just til you get a good material stream
Lastly adjust pot top pressure to keep material flowing.

Good luck
Steve