Beginnings

To keep the booth light, I used a very thin hardwood plywood sheeting. Also shown are the legs that will keep the booth about two feet above the floor (allowing me to paint without having to be on my knees!).

Cutout

Using my Skil Saw, I cut along the length of the rectangle I drew on the top panel for the downdraft filter. I was careful to leave the corners intact so that the curve of the blade didn't extend the cut further than I wanted it.

Corner Cut

I used a small saw to cut the corners out to drop out the center panel.

Filter Box

To make the sides of the filter boxes, I used strips I'd made of some 1x12, and cut a rabbet with multiple passes on the table saw, moving the fence over with each pass. This rabbet, once assembled into a box, is where the filter will rest, ensuring that the vacuum doesn't suck it up into the box.

Depth Setting

I used the thickness of the filter to set the depth of the rabbet. This would ensure that there isn't a lot of slop in the filter box.

Rabbet Cut

Here is the final pass on the table saw.

Baby Loves Rabbets

Here are the sides of one of the filter boxes. The rabbets are a little rough after being cut with the table saw, but a sharp chisel took care of that little problem.

Gluing

I used the filters to make sure that the boxes were more or less square ("close enough" is just fine for this work). The ends were glued on, and finish nails made sure they didn't go anywhere.

Finished Box

With the center section, that I'd cut out previously, used as a lid for the filter boxes and glued/tacked in place, I have a finished filter box. And look, the filter fits!

Paint

To make sure that powder comes off the panels easily, so that I don't make a mess of myself when moving it, I used a gloss green paint I'd picked up for $5 a gallon at Home Depot. If you're not picky about the color, Home Depot's paint department's mistakes/no-shows is a great, cheap source of paint.

Assembled

To make sure that this booth doesn't take up much space, I built it to be collapsible. The three side panels are held together with hinges, and the top panel simply sits on top of the three sides (yes, it's kind of "house of cards", but until I have a better way of attaching the top without making it permanent, this will have to do).

Opening

Here is a frontal view, minus the filters and filter boxes.

Filtered

The rear filter box is in place. The plan for this is to push air down through the top filter (giving clean, particulate-free air going downward), and then pulling that air to the back filter so that any overspray will then be filtered through the rear and not get all over the garage. That's the theory, anyway.

Boxed In

The rear view of the booth, showing the rear filter box in place. The booth legs act as guides for the sides of the box, and a small piece spanning the distance between the legs keeps the box located vertically. A spring attached to each side of the box ensures good contact with the booth.