A real-true sandblasting outfit is a sealed hood with a separate air supply. Like an astronaut hood with flexible air supply hose.
When I was doing a lot of sandblasting on an antique car frame, I hooked up a snorkle to EXHALE through, so the moist, warm air I was exhaling
went outside the hood, this just about eliminated the fogging on the inside of the hood's window.
I'd inhale through my nose, the hood had a filtered intake, and exhale through the snorkle. A bit awkward, but it worked, and I could see
what I was doing.
For smaller pieces, a sandblasting cabinet is wonderful.. keeps the dust, sand, dirt all inside the cabinet. You still have a hard time seeing the
object you are sandblasting, because of the sand and dust inside the cabinet. but you can get the job done.
If your sandblaster is a suction feed, then it is like a paint spray gun, the air pulls the sand from the supply of sand, often if the sand is damp, or
contaminated with dirt or flakes of rust because it was reused sand swept up and put back in the sand resevoir, the suction feed gets clogged.. it's
a real pain in the butt at times to clean out the clogged sand. Sometimes just putting a [gloved] finger over the nozzle of the hose will cause the air to
reverse and 'burp' the sand supply, and dislodge the clog. Sometimes you have to dump the sand and remove the clogging pieces.
ALWAYS pour the new or reused sand through a piece of window screen to catch the rust flakes, and other contaminants that will clog the
sand resevoir outlet port.. This is experience talking !!
A small piece of paper from the bags that the sand comes in can cause a
LOT of headaches !!
A pressure pot blaster has a sealed sand resevoir, with air pressure forcing the sand out of the resevoir, mixing it with the high pressure, high velocity
air in the blaster hose. As I mentioned before, getting the right mix of air pressure in the sand resevoir, and air pressure in the air/blaster hose and
nozzle is a bit tricky. A lot of trial and error is to be expected..
And to add to the 'trial and error', as the compressor gets 'behind' the demand for compressed air, the air supply volume and pressure drops, so your
'perfect mix' of sand and air changes..
And, when you compress moist air, the water tends to separate out, so you need to have a good water separator on the outlet of the air compressor, and
keep the compressor's air tank drained, so it doesn't collect water..
Water in the air supply causes air tools, sand blasters and painters all kinds of problems..