Introduction: Scrap Wood Balancing Rocks - Tumi Ishi

About: I am an engineer by trade and a creator at heart.

Most woodworking projects produce scraps and off cuts. Sometimes these can be quite small and only useful for the fire pit. But there is new hope for these forlorn little pieces of wood, turn them into endless hours of stacking balancing fun!

Tumi ishi is a Japanese game of stacking wood rocks. The goal is to make a tower as tall as possible, simple in concept but it becomes trickier with every block added.

Alternatively, wood rocks can be used to decorate your home in new and fun ways. The size of the rocks depends on the scrap pieces used.


Wood Rocks are fun and easy to make with minimal tools. I have made them with two different sets of tools but there are other ways to make these. The easiest method is a powered sander such as a disk sander or belt sander. An alternate method is with a vice and wood plane. A hand saw can be used to help create the initial shapes and sand paper is also helpful when the vice is not able to hold the wood well. No matter what way is used to make the rocks, personal protective equipment is a must. The only other thing needed is scraps of wood such as off cuts, scraps, checked wood or other bizarre pieces; the rocks are not picky.

Possible Tools-

Power Sander


Wood Plane

Hand Saw


Sand Paper

Stain- If desired

Finish- I used danish oil


Wood- Scraps are great

Step 1: The Birth of a Rock

Now for the fun part, making rocks! The process I describe here will work with what ever method you have available. The first step is to see if the chunk of wood has any key features (i.e. weird angles, bevels, broken off piece etc). If it does, that can be the ground work for the shape of the rock. If the piece of wood is a bit big or square a hand saw can be used to make a non square cut to save time on removing material. If you are using a hand plane, the saw can be used to start the shape of the end grain.

The next step is to start removing material. I find it easier to remove material from a side, then immediately remove from the opposite side rather than working around the rock in a circular pattern. The pictures show a piece being progressively shaped as described. A key feature I focused on as I shaped a rock is to avoid ever having two parallel sides. We are trying to simulate nature.

Finally, it is just a wood rock from scraps. There is no right or wrong answer. If you like how it looks great, if not keep working at it. Worst case the fire pit finally gets the scrap.

Step 2: Finish and Enjoy!

Now you have a selection of wood rocks. Add the finish of choice and enjoy!

Scraps Speed Challenge

Second Prize in the
Scraps Speed Challenge