Home > Parenting, Woodworking > Kotatsu build, happy birthday Callie!

Kotatsu build, happy birthday Callie!

Who of you out there knows what a kotatsu is? I had never heard of them before my then 14-year-old daughter asked me to build her one. I had just started woodworking and I was immediately asked to build something way beyond my skill level. I told her that is she paid for the materials and was willing to wait a while, I would build one for her. On Saturday she turned 15 and for her birthday I built her one. It took 2 full days in the shop but I was able to pull it off. She couldn’t have been more pleased with the result!

Design Phase

First off a caveat for those of you looking for inspiration and/or plans for your kotatsu. I simplified the bracing because we are not going to add the traditional low-wattage heater underneath the table.  So for all practical purposes this could be considered a small coffee table or a side table on steroids. What it really is, is a design that I came up with based on my daughter’s vision of what she wanted. The project started with a conversation with my client and jotting down the design criteria.

Kotatsu Request

We came up with the basic table height and size and then she added her wish that the legs be arched. At the time I had not yet purchased the bandsaw AND I figured I’d make the legs out of 2″x 2″ stock so this complicated things but I too thought it would be a nice touch. I thought maybe I could make the entire project from a sheet of plywood but I had no plans. Time to hit the Net for inspiration.


A long time ago in a galaxy far, far away …..

I worked for an environmental firm drafting land use maps, report graphics and court exhibits using AutoCAD and GIS software. By today’s standards the tools and computers were primitive but I am no stranger to the concepts. It was all 2D modeling because we really didn’t have the horsepower to render 3D all that effectively like we do today. Fast forward to today and everyone seems to be using SketchUp to draw up their woodworking plans. I needed to catch up so I went through the tutorials (not all of them) to get started and began by drawing up my conference room at work. Now I’m not going to lie, learning new software, any software, takes a commitment of time. I consider myself an IT professional and I spend days at this stuff. Like any new challenge, you just have to hang tough and have fun with it. I had a hard time finding ANY kotatsu plans much less ones in the size and design required by my daughter. I decided to draw my own design up in SketchUp and so I did. It took me about 2 days because the first day I was struggling with the software but I was learning. The second day I was able to solidify the design and show it to Callie for her approval. For those of you who don’t have children I’ll interpret our conversation.

Me: “Callie, I have something to show you. I’ve designed your kotatsu and I wanted to show it to you to see if you like it”
Callie: “Oh it’s pretty”
Me: “Do you like it?”
Callie: “We spent a whole year using SketchUp at school.”
Me: “It doesn’t have curved legs but they are tapered, it simplifies things.”
Callie giving the thumbs up sign: “It’s all good.”
Me: “Does that mean you’re OK with this design?”
Callie: “It’s all good.”
Me: “So that’s a yes?”

So what she really meant to say was, “I’m thrilled with the design, thank-you for spending all that time designing my kotatsu. I love it and I appreciate you. Will you be able to build it for me?” But conversations with children rarely go off like a parent would have imagined it.

Callie's Kotatsu - SketchUP

If I get a chance to clean up the drawing, I’ll post it to the Google 3D Warehouse. I actually needed another session to fix all the things I wanted to fix. The table I built was an inch taller than the model plus I purchased 1×8 stock instead of 1×6 so that changed things slightly also. Before I post it I’d want to correct everything and make sure the model reflected the table I actually built.

Saturday’s Build

I woke up early and while awake in bed, began to worry about the details of the day’s build. I had no idea how long it would take me but I knew that I didn’t want to spend weeks on it either. So how was I going to join the apron? I bet I considered every technology possible and I really had no problem doing whatever was easiest and within my skill level. I finally decided that I would cut simple dovetails instead of mitering the corners. I didn’t want to fail and it would take longer but I needed the experience and I though it would also hold up the best. Better get up and get started.

I began by cutting the pieces a bit oversized using my miter saw.

Kotatsu Cut Stock

I couldn’t make myself go through with the original idea of using all plywood because the stuff I find at the home center is just awful. I planned to use poplar but when I got to the store, they didn’t have all of the dimensions I was looking for and then I noticed the “select” pine was well stocked and slightly less expensive. I decided to go that route.

After rough cutting the apron, I jointed the edges using my hand plane and laid out the simplest of dovetails.

Kotatsu Apron - Dovetails

Need I reiterate, I am a beginner so I was very pleased the joints were even serviceable. I used my bandsaw to cut out what I could and chiseled out the rest. I also used a coping saw on the tails (note: I meant the pins).

On to the center braces. Again going round with how to do this, I settled on a center lap joint and screwed edges. I was shocked how simple it was to make the lap joint on my bandsaw. Pleasingly shocked that is.

Kotatsu Apron and Braces

With the frame well underway, I figured that I had better get the table top glued up. I knew that I didn’t have near enough clamps but I thought I had 6 that would work. Turns out only 2 of them were the right size so I was severely limited with my options. I improvised use of my tail vise and the 2- 48″ F-clamps and took my best shot. Notice I put waxed paper on my table so at least I didn’t glue my top to my bench (DOH!).

Kotatsu Panel Glue-up

By this time, Susan and Callie had returned from their “go see a movie with just me and Mom on my birthday” time and Callie surveyed the progress. I hadn’t taken a break all day when my youngest brought me water, sandwich and an apple but by now it was late afternoon when Callie very sweetly served me tea.

Tea Time Kotatsu Build

I finished up Saturday by cutting the 8 tapered pieces that would form the legs. I thought it was pretty clever cutting two leg halves out of each length of board and of course, much easier than cutting each piece in an arc.

Kotatsu Leg Half

I didn’t get them prepped but I did give myself a preview and jointed one of the pieces to see how it was going to go. I planed off the bandsaw marks and relieved the edges with my LA spokeshave and block plane.

Sunday’s Build

I figured it would take over an hour to finish the leg pieces but I was surprised how quickly things went, once I got in a rhythm. I wasn’t hurrying but I did think about how productive a “real woodworker” would probably be and tried to stay on track.

Kotatsu Frame Built

With the leg pieces completed it was time to attach them to the apron. I glued and screwed cross members and the legs using counter bores which I would later plug. I gave some thought to the screw placement on the legs and having already bored the cross members, I arranged them vertically to match. I also setup a stop block on my drill press to make sure that I bored each piece consistently. Here is where I would have normally screwed up but I must be learning because I knew to pay attention. There are 4 right facing and 4 left facing pieces; if I had bored them all the same I would have messed up big time. So I did the 4 with the stop block on the left, then measured again setting it up on the right side of the fence for the other 4 pieces. It’s not rock science but in the fog of war, one can make a lot of mistakes until you gain some experience and begin to think more clearly.

With legs attached I now needed to fabricate some feet. I was concerned all along that these legs needed to be structurally joined even though the table was going to be pretty small and not very tall. So I came up with the idea of adding decorative feet. I begin by marking directly onto a piece of 3/4″ 1×3 stock and having at it on the bandsaw. The prototype piece ended up being a tad too small but the concept was good so cut a second piece slightly oversized and took it to my belt sander. Once I was happy with it, I tried it on all the leg sets and found it to be acceptable on each. I then used it as a template to mark the other 3 pieces.

Kotatsu Leg Detail

I’m going to skip over the part about how one of the legs ended up being too tall but I obviously had to correct it so that I could mount the foot piece. A rasp, block plane and flush cut saw were involved with varying degrees of success and catastrophe.

With the base mostly complete, I now moved on to flattening the top. The good news, 3 of the 4 panels were pretty good. The bad news, the one panel meant flattening 2 joints and this didn’t go as well as I would have hoped. Looking back at it, the wood was basically flat sewn which caused problems for me. I ended up with a fair amount of (Gulp!) tear out.  My bevel up smoothing plane was probably not the best choice for this job. I’m thinking a high angle smoother would have been a better plane for this task?? Perhaps a more talented use of the plane I own??  I had to get the sucker flat so soldier on I did.

Prepping the Top

After flattening the top I had Susan help me at the table saw. Using 4-1×8 panels made the width 29 1/4″ so I made two cuts on my new table saw to square the top. These are my 2nd and 3rd cuts with the saw respectively and the first to actually be used in service.

I needed to complete work on the top but a thunder-storm rolled in about this time and Susan suggested I wait until it passed to use any power tools. I relieved the edges on the bottom of the table using my spokeshave and block plane. I also cut and glued plugs for the screw holes and by this time the storm had passed by enough for me to pull out the router. I used the laminate router with a chamfer bit to cut a 1/2″ bevel on the top edge of the top. I have a limited number of router profiles and of those I had I thought the angled relief would match the leg tapers nicely.

Dowels and a Beveled Top

I ended Sunday’s build session by cutting the plugs flush and frustrating myself with this task once again. I admit I was tired by this time and it had been a long time since I last did this task. I remember that I had a lot of trouble then (saw bench build). I couldn’t remember what I finally decided worked so history repeated itself. The flush cut saw isn’t a good one and it marked my pieces. Use of the chisel resulted in the cheap poplar plug material actually tearing. I also managed to mare the legs while paring out the plugs with the chisels. What seemed to work for me and what I will do the next time I try this is to be much more accurate cutting the plugs, leaving only a small amount of plug raised above the panel then I can go straight to the block plane and plane it flush. Assuming I’ve consistently bored the stock on the drill press it should be easy to come up with the appropriate length and cut them all precisely. At least this is my plan for next time.

So I did it! I designed and built my first piece of furniture. Two full days in the shop and in the whole many more things went right than went wrong. It felt good to finally be building something, after putting all that time and money into the shop. Most of all it felt good to be the Step-Dad that makes his daughter proud of him. Happy 15th birthday my darling Callie!

Callie's Kotatsu

You have been reading an excerpt from the shop journal of the Turtlecovebrewer.

Categories: Parenting, Woodworking Tags:
  1. Eric
    August 6, 2013 at 3:12 pm

    Hi Art,

    Checking in with the blog. Table turned out great – I remember you talking about this some time ago. Seems like your prowess as a woodworker has progressed quickly! Best – Eric

    • August 6, 2013 at 3:46 pm

      It is a journey to be sure but I’m having fun while on the road 🙂

    • August 6, 2013 at 6:34 pm

      Thanks Eric, I look forward to brewing with you soon.

  2. November 21, 2016 at 4:54 pm

    Thank you so much for your blog about building kotatsu! I realized it can be pretty hard to buy a kotatsu outside of japan, so building one yourself might be the only option!

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