My kotatsu heater took about 2 weeks to arrive and came nicely wrapped in a Japanese newspaper. It came with all the things I needed – the heater, a cord with on/off switch, and mounting screws. Now that that is all set and done it’s time to hit Home Depot to pick up the supplies needed to put it all together.
Depending on the power (wattage) of your kotatsu heater they give you a recommended table size that the heater can heat. This table will be 32″ W x 32″ L and roughly 18″ H. In metric this is ~ 81cm x 81cm x 46cm but for some reason Home Depot doesn’t believe in metric.
Take a good look at the picture above to make sure you understand what it is that you are trying to build. It’ll come in handy when you are picking up supplies to know which part is supposed to fit where. Basically, it’s a simple square table without the table top but instead, there are extra cross pieces on the inside. Not attaching a table top takes away some strength and stability, but the cross pieces help with that. However, the real reason they are there is of course to mount the heater.
I only had a rough idea of what I needed to buy so I had to make two trips, but this should be everything you need…
Wood – frame
1″ x 3″ x 10 feet (outside frame) – $10.20
2″ x 2″ x 8 feet (legs) – $8.80
1″ x 2″ x 10 feet (inside frame) – $8.25
I bought an extra piece of 1″ x 3″ just in case, and it came in handy. I’m no expert on wood types but I chose fir because they had it in the right dimensions and it was cheap. Sometimes decisions are that easy to make.
Wood – table top
4 feet x 4 feet Sureply board (table top) – $9.95
This decision was tougher. Anyways, I found this plyboard meant for flooring beneath carpets that worked out well. It was cheap, light, had a nice wood surface, and thin. I wanted thin because I didn’t want my working surface any higher than it had to be, but I couldn’t just cut the legs short otherwise it would be cramped underneath.
4 x stainless steel 1/4″ carriage bolts (4″ length) – $2.76 total
4 x 1/4″ locking washers – $0.52 total
4 x 1/4″ wing nuts – 1.96 total
bunch of screws – I had these around
small piece of 1/8″ hardboard – $1.98
This goes between the top of the heater and the blanket so that they never touch directly, for safety. You only need 30cm x 30cm but I had to buy 3′ x 3′ and cut to size. Heat-resistant foam board would be best.
sandpaper – $3.68
You’ll need this if you are planning on painting/staining your table, but it’s probably a good idea to smooth out rough patches anyways.
foam brush, wood stain, wood putty – $12.75
Optional – I wanted to stain the wood to a dark brown.
blanket/duvet – $12.99
Great if you have one lying around. I didn’t so I went to Ikea and picked up the thinnest cheapest double/queen size duvet I could find. 86″ x 86″ is an almost perfect fit.
Total bill: ~$90