Introduction: DIY Leftover Wood Chair

About: Love for LEDs, woodworking and miniature scale amusement rides.

Here at home, there is a room that we use to store the things that I will define as “a sample of the content you can see in those accumulator tv shows”. There's no way! Once in a while we organize and clean this “hut”, but it gets dirty and messy in the blink of an eye.

I mean, not anymore from now on, because recently I set up a workbench and a combined L-shaped desk to occupy a good part of the floor area of the room. However, at the end of this project, several material remains were left over. Some beams, planks and wooden boards of different sizes and pieces were going to become “accumulation materials”. Unless I could use them to create something from scratch, in a short time!

And so was born the incredible “Leftover Chair”, a chair made in less than two days with very accessible materials and tools.

In this Instructable, I'll teach you step by step on how to assemble your “Leftover Chair”.

With that being said, let's get to work!



- Wooden beam (for the legs of the chair, mine measures 5.5 x 5.5 x 150 cm);

- Wooden plank (for the seat and backrest of the chair, mine measures 1.7 x 30 x 90 cm);

- Wooden board (for feet and seat and backrest supports, mine have different dimensions, but in total I used 330 centimeters);

- Screws;

- Wood glue;

- Varnish (optional, for now I will not varnish my chair, as I will do this when I can varnish my bench and table).


- Circular saw;

- Drill (a battery drill, with a screwdriver, like mine, will be very useful);

- Drill kit;

- Pencil;

- Measuring tape;

- Clamps (optional, will make work much easier if you are building the chair by yourself);

- Chisel (optional, will help you when making the recesses in the wood);

- Paint brush (optional, will help you spread the glue).

Step 1: A Quick Project Overview

Before I started building, I took some time to set up a project on my computer, this way I could go to the execution with some direction of what to do.

The idea of the “Leftover Chair” is to use two wooden beams as the main support that connects the feet of the chair to its seat. The feet are formed by a kind of square "C", as well as the seat support, and it has a charming inclination to slightly break the straight lines of the wood and match the inclination of the chair legs. For the backrest, we will use a combination of angles that will finalize the design of the furniture.

It was designed using the same language as the furniture that was already built on the room, keeping straight lines and simple construction planes.

The schematics to all the pieces are attached in the PDF down below. Feel free to download the material, it will be useful to help you during the execution of the chair.

Step 2: Chopping All the Pieces

I feel more comfortable cutting all the pieces as a first step when building any furniture. So let's get to it!

Chop the beam and cut the ends at an angle, according to the inclination of the legs.

Pay attention to the symmetrical parts, as the seat fittings are mirrored on one of the axes.

Note that any rough material need to be sanded prior to making the cuts. In my project I used different types of wood and some of them were not sanded, but I kept it this way, as I was not concerned with the different appearance between the parts. This difference in textures gave a charm to the final product.

For cutting the angles of the leg beam, I built this jig that consists of two steel angles and two pices of wood scraps screwed together. The angle on one of the wood guides matches the angle of the cut we need to perform, so it will always be the same, no matter how many pieces we need to replicate.

Step 3: Creating the Lap Joints

I will dedicate this step to talk exclusively about cutting the recesses. They are the main part of our project, since the chair will be supported by the encounters between faces and edges of the woods.

The easiest and most effective way to create the lap joints using the hand saw is, in my opinion, using the back-and-forth method.

Attach the saw guides to the wood and secure the wood to a firm surface.

Set the saw blade depth to match the thickness of your board, this way it can rest seamlessly on the lap we're creating.

Holding the saw firmly, make the first cut close to the guide positioned on the wood. Then, turn the saw back and move it to the side, aligning the blade with the next piece of wood to be cut.

Repeat the process until the entire recess is created.

My tip here is that you cut all similar parts at the same time, so you don't lose any setup made to the machines between the processes.

Step 4: Test Fitting Everything

After separating the wood in each piece, we will check if all the fittings are solid and if they match together.

As we used the circular saw to open the recesses, we may need to sand the faces where the saw teeth have left marks. You can use a chisel to make the faces smooth, it will make the task easier and the final result will be even better.

Step 5: Gluing and Screwing the Fittings

After we made the cuts, it's time to assemble the fittings.

Arrange all the parts on a surface to keep track of which parts have already been assembled and which have not.

Glue all the faces that will touch, but don't overdo it. The tip to create a good joint between glue and wood is to apply a thin and very uniform layer of glue.

Secure the pieces in the final position using a clamp and check the angles to make sure they are in sync with the schematics.

Drill a pilot hole for each screw and then screw the pieces together.

Follow your drawings so you don't miss the position of each piece.

Step 6: Gluing and Screwing the Backrest Support

Now that we have built the “legs” of the chair, let's glue and screw the supports that will hold the backrest.

This join will be simple, since we didn't opened a recess in the beam. Let's glue and screw face to face.

Align the faces and glue them. Hold them with a clamp and drill the pilot holes. Screw the parts together right after.

Pay attention to the positions of the parts, as they are the easiest to be confused in the project.

Step 7: Putting the Halves Together

The time has come to give dimension to the chair. We will join the two halves with three pieces of wood.

Start with the boards that connect the feet and the seat supports, respectively. Drill the pilot holes and align the pieces in the square.

Glue the faces and screw.

To give more stability to the chair, we will place a lock in the middle of the legs. Measure the midpoint of the length of the legs and mark. Fit the beam to the center of the mark and check to make sure everything is well aligned.

Drill the pilot holes. Detach the part and spread glue to the faces. Refit the parts and screw.

Done! Our base is structured.

Step 8: Screwing the Seat and Backrest

There is little left to do!

We will align the seat with the base of the chair, using a distance of 2.5 cm between the edges of the seat and the outer edges of the seat support. Make the 2.5 cm mark on the bottom of the seat. Then, place the seat on top of the chair, aligning the lines to the seat support. Screw the seat onto the bracket.

Note: I joined the wooden plank to the support so that the screw is visible at the top of the chair. It was a functional choice, as the board is too small to hide the screws under the seat. There are some more sophisticated ways of making the junction, but I appealed to practicality, because of the occasion.

To fix the backrest, we followed the same process, with one difference: the side guides of the backrest will be 3 centimeters (instead of 2.5 cm) away from the support. We mark the part and then align the markings to the support. Screw everything.

You may have noticed that my backrest is a little longer than what I described on the project instructions document. I made the backrest longer because my wooden board was longer than I planned, so I thought I didn't needed to chop it off afterall.

Step 9: Done!

We're done, now just enjoy it! As I said at the beginning of Instructable, I chose not to varnish my chair for now. You can give your final touch to the chair from here, since you have already learned the basics.

Use your imagination!

Scraps Speed Challenge

Participated in the
Scraps Speed Challenge