I've done alot of sandblasting with an ALC 70lb pressure pot and numerous others. Best thing we ever did was run a 3/4" line from the compressor to the blaster. Also, remove the deadman valve, typically unless it is a high dollar (thousands) unit, the deadman makes more of a mess than it does help.
Also learn to regulate the sand with the valve that is on the outlet side of the Pot. When you get a sound that is nearly a whistle, you are ready to blast.
Remember, a nice "white" blast is the best way to prep metal for Paint/Powdercoat.