On Sunday, March 1, 2015 at 3:20:13 PM UTC-6, Ignoramus32591 wrote:
I have a 48" sandblast cabinet that I only recently put to use (long
story).

This cabinet has a blower and a filter bag.

It is full of fairly fine sandblasting sand.

My question is, if I run the blower while sandblasting, will that
blower pick up only dirt (such as blown away rust, paint etc), or will
I also experience loss of sand itself?

Does that blower pick up sand?

thanks

I'm assuming the blower actually produces a vacuum, not pressure? If set up correctly it will maintain negative pressure in the cabinet. Any dust it pulls out will be too fine to be useful in cleaning. However, it will be very bad for you if it's in your breathing air.
Mine is a cheap HF cabinet, but it has a mesh filter over the air inlet in the back of the cabinet. On the other end is a hole for a vacuum hose. I use a shop vac with a good filter. Before it gets to the vac, the hose runs into a closed bucket half full of water. The inlet hoe from the cabinet ends up underwater, and the out hose is in the top of the bucket, running to the vac. The vac is always started before the blasting, and the exhausted air bubbles through the water before going through the vac filter and then out into the air. I also have the vac exhaust as far away from me as possible. When I am ready to open the cabinet, I let the vac run a few minutes before I crack the seal.