Here is one of the glued-together boxes. It's pretty representative of the way the three assembled boxes all look.

The cookie sheets inside the box are just there for an intuitive size reference. The boxes are 24" wide by 18" deep at the top, and 18" high. They're 28" wide by 22" deep at the bottom, so they nest reasonably well.

The corners are a little interesting. You see, the front and top are clear plexi, but to save cost, weight and assembly difficulty the backs and sides are corrugated white plastic, like they make "for sale by owner" signs out of. I took advantage of this to do score-and-bend corners.

The acrylic-acrylic joint is done aquarium-style, as are all the other joints between sides and top. The rest use a little overlap with the corrugated plastic.

I had started last night on the sleeves for the fourth box, which I figured I would experiment with on a not-installed acrylic sheet to save awkwardness. The clear plastic tarping Home Depot sells isn't very easy to see through, I note.

Home Depot's smallest 4 mil tarp was still pretty big, so I decided to try and make a bunch of different sleeves for comparison. The fastest way to make them is by heat-sealing the edges together with a soldering iron, but I suspect that the glued seams will be sturdier and more reliable. To attach the sleeve to the acrylic sheet I glued down the sleeve, and then put a circular ring of tarp over the whole joint to hold everything together.

Now there's the question of the seal with the work surface. By the way I've fabricated the boxes all of the long edges on the bottoms of the boxes are factory-cut edges and very straight --- only the cornders did I cut myself. The score-and-crease corner construction gives the boxes a little flex, so I believe that they can just be set down on a flat surface and naturally seal adequately (once all the corner panels are trimmed). Should that not be the case, we can weather-strip or tape the bottom edges. It should be noted, however, that one word for "pressurized box that seals well with the surface it's on" is "hovercraft."

The only other thing I've built is the hose splitter. That little vac moves quite a bit of air --- even though the splitter is still leaky (nothing some glue and tape can't fix) it comes out with satisfying velocity and pressure at the ends of each of the four smaller hoses.

Yes, those are garden hoses. I figure we'll want to draw some water through those before use to clear out any dust that might be in them. Likewise, the boxes will want a thorough washing.