When air comes out of the compressor, it is hot.  As such, air retains
more moisture.  My suggestion is to have 25' to 50' of tubing between
the compressor and the moisture collecting system.  This way, you get
more of the moisture out of the air, prolonging the life of air tools
and making blasting easier.  We installed a coil of copper tubing
between the compressor and the moisture collector.  This works
extremely well.

On another note, glass dust is very dangerous to breathe.  Even with an
exhaust system, you may find that a fine mist of glass dust will linger
in the air after you open the cabinet and dust off the parts.  To avoid
permanent damage to your lungs, I suggest wearing a dust mask when
spraying abrasives, both during and after the blasting process.

Bob Yorburg