After cutting the pieces, sanding them down, and painting them with polyurethane, I attached the sides to the base with three screws each (use a 1/8 drill inch bit to drill pilot holes for all screws), then attached the top and installed the two shelves, being careful to keep everything square. Here I test fit the front trim and back on the main assembly, and check to see how the LED lights look. Turns out the lights are more directional than I expected, I'm going to need to make a mount to angle them towards the center of the enclosure floor.
There are many ways to go about providing ventilation. I like these two inch plastic drains. A two inch hole saw cuts the initial hole, which then needs to be widened a bit with a Dremel to perfectly fit the slightly tapered drain. After test fitting the drains to ensure a perfect fit, apply a couple coats of polyurethane to seal the freshly exposed wood. The drains sit one inch deep, so they need to be trimmed to sit flush with the 3/4 inch plywood. Once the drains are trimmed and the holes cut, I cover the drains with two layers of hardware cloth and hammer them into place. At this point they are pretty secure, but we are talking about the master escape artists known as snakes, so to be absolutely sure they cannot be pushed out I fix them in place with a couple half inch #6 wood screws. Drill a couple 7/64 inch pilot holes right at the edge of the drains flange to install the screws. Be careful not to drill the pilot holes too deep here, a bit of masking tape wrapped around the drill bit helps gauge a proper depth.
After installing the vents is was time to sort out the wiring for the lights and heat tape. I lined up the back and drew out the slot for the heat tape wires, the holes for the thermostat probes, and the the holes for the lights wires. The heating elements I assembled the same as always, cut the head off of a small extension cord, attach heat tape connectors to the cord with a bit of solder, connect the connectors to the heat tape, and seal it up with electrical tape. The heat tape has to go in as the back is installed, here it is temporarily held in place with masking tape. It will be thoroughly tacked down with silicon when I install the linoleum floor. Note that the wire leads are different lengths to allow the wire to be run out near the corner, to keep the slot for the wire as small as possible. Once the back was installed I installed the front trim, being careful to maintain a 6-1/2 inch gap for the glass doors all the way across all three enclosures.
With the unit assembled, the next step was to install the linoleum floor. First I tack down the heat tape with silicon, making sure to apply plenty of silicon around the wiring for the tape. Then I tack the linoleum to the heat tape and floor with silicon, and weigh it all down until the silicon sets. Keeping the connectors and wire leads for the heat tape inside the enclosure, under the linoleum floor, does mean there are bumps under the floor in the back right corner. I did consider routing slots for the connectors and wire leads so the linoleum floor would sit perfectly flat, but decided not to bother with it.
Once the silicon holding the floor cured, I set about the somewhat tedious process of sealing all the interior seams with silicon, installing the lights at the same time. You can see the mount I made for the light from a bit of scrap plywood, it angles the light towards the center of the enclosure floor. I ran a bead of silicon along the front top edge of the enclosure and pressed the mount into it, then ran another bead of silicon over the mount and pressed the light into it. I then ran a bead of silicon from the light, around the corner, and all the way to the hole for the lights wire, and pressed the wire into the silicon. I filled in the hole for the lights wire the rest of the way, and continued the bead of silicon along every interior seam, smoothing it out with my fingertip as I went along. The final order of business was to install the glass track. A fairly straightforward job, just cut the track to size, roughen the mating surfaces up a bit with sandpaper, apply a bead of Liquid Nails glue, and clamp the track in place until the glue is set.
The completed enclosure in its place. Looks pretty nice really, though you can definitely see some sloppy cuts on the front trim. I think I'll get myself that table saw for Christmas, lol. I'm waiting, impatiently, for a week or so to be sure the silicon and glue is completely cured before moving animals in. Thanks for looking!