Virtually all my projects got a hand rubbed finish that didn't require any spraying. Still, about anybody with a shop will occasionally need to spray something, even if it's from a spray can of paint.
Long ago, Northern Hydraulic (now Northern Tools) had a store in our town and I bought some take-off (used) blowers. They had a
5/8hp motor and were dual stage centrifugal blowers presumably from some big copier machines. I had to locate run capacitors for the motors, but outside of that, I had some pretty cool toys to play with.I built a plywood box, complete with castors, and installed the blower inside. On the outflow port of the blower, I installed the biggest air filter I could find from a semi truck, then continued on with a 4" flex hose. This gave me a pretty decent supply of some finely filtered air. On the blower's intake side was just a plain old Filtrete furnace filter.
When spraying something small, I'd use a 55 gallon trash can liner with the corner cut out and the 4" hose inserted and tied off with black plastic tape. There would be adequate airflow to partially hold the bag open, and this was supplemented by a couple hoops of metal I made from an electrician's conduit snake. The ends of the cut off pieces of the snake were stuck into little holes I drilled in the workbench to keep them secure and upright.
The result was a barrel-shaped, flat bottomed bag with an outward airflow of dust-free air. I could put the part inside and spray the heck out of it. In fact, I later learned I could hold the piece in front of the bag opening, with the clean air blowing past it, and hit it with the air hose to knock off any residual dust or debris before spraying. Taking things down was simple- I'd just remove the two metal hoops, fold up the bag and roll the blower-in-a-box back to its corner.