I received a few PMs asking about the use of the solenoid valve to control the air to the gun.
All you need to find is a 110V coil, normally closed, solenoid valve with 1/2" NPT ports. These can be found on Ebay easily, brand new, in the 20-40 dollar range, and that is by far the cheapest way that you are likely to find one. Brand new retail, these things can cost more than three times that amount. Avoid the temptation to buy a used solenoid valve, most that you are likely to find have been used in industrial settings and have led a hard life. Any savings will be eradicated, if you wind up having to buy a rebuild kit for the valve.
I wanted to put a regulator right up front on the blast cabinet so that I can adjust the blast pressure easily to accommodate the different types of blast media I might try, down the road. Many types of organic blast media (walnut shells, etc) are said to work better at lower pressures. On my old cabinet, the regulator was on the wall behind the unit, and, not knowing any better, I always had it pretty much maxed out, and never, ever adjusted it.
On this project I found an old piece of 1/4" Aluminum scrap and just bored a hole in it and put a bend in it, to mount the regulator to the cart which holds the blast cabinet.
These Parker regulators I really like, because they are easy to "panel" mount this way and they are easy to adjust and lock the setting by pushing down the knob. These regulators are industrial quality and also are easy to find on Ebay for about the same money (and sometimes, less) than one would pay for a chinese no-name regulator.
The easiest way to get a foot pedal switch up and running, is to get a Clipper / Linemaster foot switch with the "no fuss" plug already on it. (yup - Ebay) You plug the switch's plug into an outlet, and then whatever item you want to control with the foot switch, into the back of the plug (the picture below should help make sense of that):
Just wire up a 110V cord to the solenoid, with a plug on the end, and plug that in to the footswitch plug, and go!
Of course, you can also just buy a "bare" linemaster footswitch and wire it all up. I just liked this one, because it was one less thing to have to do...
In the pic below, the lower black hose is air coming in from the supply line. The upper black hose is after the solenoid valve, going up to the gun inside the cabinet.
Hope this helps,