rjharper - I'm considering shop vac-ing my mash tun in my new brewery - but I am curious how do you keep the shop vac clean? do you suck up warm water after the mash? do you put a bag in the canister to capture the spent grain and then just dispose of the bag?
I dont use any bag, I remove the dust filter, and set it up for wet operation (usually have to flip the diverter from the hose) then I just suck away. Once I've emptied the tun, I usually add an inch or two of hot water, wipe everything down, then suck all that up too. After that the hose is clean, and I can just pour out the shop vac onto the compost heap, then hose it out clean.
After all that, its CIP with a little PBW.