Step 3: Fabricate door bracket / install pistons
Next I had to fabricate a bracket to connect the pistons above the door to the actual door. I welded up a bracket out of some steel flat bar from Home Depot and attached it to the back of the door with a spacer block. I could have really used some more advanced tools at this point, but I had to work with what I had at the time. You can fabricate this bracket from sheet metal, steel bar, wood, or whatever you can find.
With the two brackets fabricated and installed, I mounted the two 16" pistons above the door, side by side. Air supplied to the back of the pistons would open the doors, and air supplied to the front of the pistons would close the doors, as seen below. I rigged up the valve temporarily to test everything out.