My Sandblaster is Surging

[BJ42LX]

I have a blast cabinet from Eastwood. I removed the sand, cleaned the window and vacuumed it out pretty good (media was dirty).

I replaced the sand with some black aluminum oxide from Harbor Freight. Now the sand is surging coming out of the nozzle. Pressure is constant at 80 psi, but the sand goes: woosh, woosh, woosh, etc.

What causes this?

 

[Sancho]

Plugged or obstructed nozzle?

 

[lametec]

The media is probably "sticking". Try giving the cabinet a shake. If the media immediately comes out, you found the problem.