After completing the DIY course at CMU, I was invited to TA the class the following year. The class size increased from 40 students to 60, so we needed an additional heat box for an assignment involving industrial clay. Here’s (most) of a how-to. I sort of neglected to include how I put on the hinges, but that’s pretty straightforward.
You’ll need the following:
- 4′ x 8′ sheet of plywood (about 0.5″ thick)
- Wood glue
- Panel nails
- Aluminum foil tape (optional)
- Insulation (foil-sided is ideal)
- Aluminum or steel bar (optional for door-prop)
- Wood screws (optional for door-prop)
- Clamp light
- Light bulb
- Sharpie or pencil
- Cordless drill
- Drill bits
- Dremel sanding drum
- Dremel router bit
- 24″ bar clamp (optional)
- Tape measure or ruler
The first thing to do is to cut all the panels to the correct size.
- Left & right sides: 18″ x 18″
- Top & bottom: 29.5″ x 18″
- Front & back: 19.25″ x 29.5″
These dimensions worked for my 19/32″ thick plywood sheets. Based on how things are put together, the back and front panels need to be adjusted in the height dimension (19.25″).
I don’t have a table saw at my place, so what I did instead to cut really straight lines is to clamp my straight edge to the plywood for cutting with a circular saw.
Use the thickness of the Sharpie o your advantage! It tends to be pretty close to the thickness of circular saw blades, so line up those teeth with the cut line.
Apparently finding a length and dividing by two is above my pay grade. These two sheets were supposed to be the same length, cut from one sheet of plywood.
Well, after fixing the length of the sheets, I tacked down all the nails along the edges a 1/2″ in from the edge of the plywood sheets and tried to get them evenly spaced with at most 5″ between the nails.
Apply glue to the edges that are supposed to be joined…
All edges glued and nailed together. The plywood was just slightly more bowed, so I opted to use a bar clamp to keep to edges tightened down while the glue dried.
The back was put on pretty similarly: evenly spaced nails, glued faces.
I’ve somehow managed to survive without a compass to draw circles, so I just used my calipers to measure the size of hole to cut (2″ for my lamp) and scribed it to the center of the top of the box.
If I had a 2″ hole saw, I probably would have used that here, but instead I just drilled a while bunch of holes to I could cut through them all with the routing bit on my Dremel.
After cleaning up the hole with the sanding drum, I added 1/4″ chamfer on the underside to accommodate the taper of the lamp bell.
I sort of just forgot about documenting the last couple parts (putting in the insulation, foil, hinges, and handle), so… here’s a picture of the final product:
Oh… and here’s a closer picture of the door-prop:
If you’re interested in putting the same door-prop on yours, I’ve uploaded the STLs to a Thingiverse “Thing.”
As a final note, a 60W light bulb works fine, but an 80W would be better if there’s a lot of clay or if the door needs to be opened and closed really often.