Outdoor sandblasting

Check your local regs, Ig.
I understand that blasting outside of a cabinet is now a no-no in some jurisdictions.
--Winston

Check your local regulations. Lot's of places prohibit open blasting now.
If you are OK the easy solution is an outdoor blasting booth. Basically take one of the easy up type canopies and get the side curtains for it. Also get a tarp that will cover the ground and come up inside the canopy enough that you can secure it with snaps or similar. The tent and tarp let you reuse the blast media by keeping it cleaner. Just sweep it up and re-use it. I picked up a cyclone unit and run the media through it to remove dust and crap lighter than the media.
Get a good sized blaster with a large fill opening.
For blast media Black Beauty (ground up mill slag) seems to work well and it's not that expensive if you buy it in pallet quantities.

Silica dust IS bad for the heallth. So wear the proper mask. Doesnt need to be a full faced one, just a dust mask of good quality.
Gunner
One bleeding-heart type asked me in a recent interview if I did not agree that "violence begets violence." I told him that it is my earnest endeavor to see that it does. I would like very much to ensure - and in some cases I have - that any man who offers violence to his fellow citizen begets a whole lot more in return than he can enjoy.
- Jeff Cooper

Black Beauty is a grit made from coal slag. It contains less than 1% silica but does have some trace elements that are not innocuous. Garnet is a good blasting medium if you can reclaim it, too expensive otherwise. If your employees have to use respirators, you need to set up a respirator fit testing program and meet some other OSHA requirements. Your workers comp premiums may go up substantially if you are blasting. Also, blasting with a 10 HP compressor will require some waiting periods as the tank refills.

Something to be aware of is that blasting warps sheet metal, sometimes severely. I have had success sometimes and trashed good parts other times.
BobH

Good idea on the booth, we can easily weld a frame from various steel tubing we have laying around. Thanks. As often happens, I had a kick-ass blasting pot a year ago, but I sold it.
The stuff below was bought for $100.
I now wish that I kept the blasting pot.
i

Just don't blast anything with lead paint on it. If caught, you'd get your house and yard cordoned off by the EPA while a very expensive lead abatement team removed every last speck.
(If that happens to anyone here, I recommend taking the 8 hour EPA Lead Abatement class and doing the abatement yourself, saving probably $10-20k.)
And check local regs. I believe that outdoor sandblasting in many areas is required to be done wet now, to reduce the silica movement.
Supplied air helmets with N100 intake filters are the most common, but I don't consider them low-cost.
-- The business of America is not business. Neither is it war. The business of America is justice and securing the blessings of liberty. -- George F. Will

I will hang on to the skid steer. First, we need to do a lot of landscaping, and second, we will need it for the snow in winter.
i

Nobody's mentioning the other half of the equation: You need a real paint spray booth to get a good finish on the desks. They aren't cheap, and they attract just as many Official Types as the sandblasting will.
They need a local Building Permit to erect it in your shop area, and a Fire Permit (because most paints burn) and a fire extinguishing system of some sort.
And for the best finish you need a Fully Enclosed booth like you shoot cars and trucks in, where the air coming in gets the bugs and dust filtered out first, then you filter it again to catch the paint overspray before it goes out. Go find an auction for a Body Shop.
Good news, you can get three or four desks in there at a shot - Work toward the exhaust fan, and cover the ones that haven't been painted yet with tarps.
You can't use an open-face style paint booth and be doing any sort of sanding, blasting or assembly work in the vicinity until it's fully dry - you make dust anywhere in the area and it WILL get sucked right into the booth and smack onto the freshly painted desk surface...
Make sure you treat the air properly before using it to paint with - First a really good Coalescing Filter to get all the oil out, then a refrigerated air drier, then an accumulator tank. Right at the booth you send it through another coalescing micron filter and a desiccant dryer just ahead of the gun whip.
All the hoses and hard lines are New (not bought surplus or reused pipe) and dedicated to Painting Air Only - Pick an unusual color of hose that NEVER gets borrowed for use elsewhere in the shop, like Gray or White, and use a different series of air quick couplers on the paint guns that will NOT interchange with the rest of the building.
And take it out of the employees pay if you find a White painting hose being used on untreated air. You have to cut it up and trash the offending (potentially oiled) hose, or you'll get Oil Hickies in the finish and ruin a paint job or three.
-->--

Blasting comes in handy some days.
If the SS has a high flow pump, start hunting for one of the snowblower attachments for it. They beat a blade/bucket hands down for snow removal.

I'm not seeing the OP, so I'll just add some comments here.
Sandblasting is good for removing rust (on heavy gage steel) but not for paint removal.. and blasting sheetmetal will often result in badly warped panels.
Getting the sand out of the drawer slides will be problematic, otherwise the drawers will operate like an old cheap desk.
Sanding and primering scratches will be more cost effective and eliminate the problems associated with sandblasting. The original factory finish will have the best adhesion that can be attained, so there's no point in a costly process to remove it, and it saves a lot of prep work that is required for bare metal.
Applying some of the newer water-based finishes will require some research and practice, but could probably be done safely in an improvised, enclosed/isolated clean area with adequate ventilation and filtered intake air.