Sandblasting Logistics

Spent the better part of my short workday blasting our very rusty dump body.
When blasting I'm making fairly good progess taking a surface with about
1/8" of flaky rust to white metal, but it takes a lot of blasting media. I'm
using crushed limestone, which is softer than traditional silica sand but is
almost silica free and I have a lot on hand. Blasting with a 5/16" Boride
water injection nozzle ( with a minimum amount of water) and a 185 CFM
compressor at about 120 PSI. The sandblasting pot has a Thompson type
metering valve and takes about 250 pounds of crushed limestone each filling.
I was a little surprised when I wrapped up to find I had used 1500 pounds of
crushed limestone, and the job is not done yet. I've been dragging 50 lb
bags out of a container and to the blasting pot, I think I'll try loading
them on a pallet tomorrow. I can see now why the big sandblasting outfits
use those huge pressure pots.