Backenzahn - a Small Side Table, Stool, or Plant Stand

Here is a quick and simple weekend project for a small side table, stool, or plant stand; to be used inside or outside. I'll walk you through an easy build for an outside side table or stool using Douglas fir; and show you two more refined builds from cedar wood you would be proud to show off in your home.

The design is called the 'Backenzahn', the German word for molar tooth. The look surely resembles one. The original BACKENZAHN™ was designed in 1996 by the German architect Philipp Mainzer.

The title image was rendered in Fusion 360.

Supplies

6" by 6" by 8' cedar, cypress, fir, or pine timber

Polyurethane construction glue, or PVA wood glue

Bandsaw, sliding miter saw, hand saw

Table saw or router

Step 1: Design

The design is really simple to make. Cut four 20" long pieces off the six by six timber on the miter saw. If you use a handsaw try to make the cuts as square as possible.

Look at the cut faces to determine the center and curvature of the tree rings. Arrange the four pieces so that the top faces create a pleasant pattern with regard to the tree rings. Remember that this will be the top, i.e. most visible part of your stool or table. Then mark (with tape) the outside edge of each piece.

The dimensions for the Backenzahn are shown in the attached pdf drawing. The dimensions are flexible, so tweak them to meet your needs.

Step 2: Cutting Dados for the Joints

Clean up the two inside faces on each leg with a joiner or planer for a better glue joint in the next step. I skipped this for my outside table/stand shown here. Cut a 3/4" by 1" dado on the two inside faces of each piece as shown. Use a table saw or router to cut the dados. Either cut the dado all the way along the piece as shown, or - preferably - stop the dado cut about 1 inch from the top face to hide the joint. Be sure to cut the dados on the inside faces.

Step 3: Cutting the Legs

Draw a pencil line on an outside face of each piece as shown in the pictures and the drawing. The bottom feet are a 2.5" square. Check again that your top wood-grain/tree-ring pattern is as you intended. With a bandsaw cut along the pencil line to create a taper. Then redraw the second line on the cut face, and cut along this line. You now have one tapered leg. Repeat for the remaining three pieces.

Step 4: Assembly

Prepare four 3/4" by 2" by 8" long pieces of wood to make loose (floating) tenons for joining the four legs together. I made the tenons from the cut-offs from the prior step. Test-fit the tenons in the dado grooves on the four legs and adjust the width as necessary. Mask the legs with painters tape to keep any glue squeeze-out off the legs. Then join the four legs with the tenons in place. I recommend polyurethane construction glue which will perform better than wood glue on the rough surfaces. Apply the glue to the 5.5" by 6" faces, the dados, and the tenons. Check for proper alignment and clamp until the glue sets. I glued and clamped all four legs/tenons at once. The construction adhesive gives you about 1/2 hour working time to make adjustments. The pictures show how I clamped everything together. Yes, I use a lot of clamps! Clean off the glue squeeze-out with mineral spirits before it dries.

Step 5: Finishing

It may require a bit of work to level the top surface with a sander. A belt sander will work best if you have one. Check, and if necessary trim the legs so the table/stool doesn't wobble. In the pictures I left the outside faces rough-cut just like they came from the lumberyard.

If you want a more polished look for an inside table/stool you should sand and/or plane all faces. You should do that before you make the tapered cuts on each individual leg. Planing the surface will also allow you to make a better glue joint and use wood glue instead of construction adhesive.

Take a look at the two Backenzähne I made from cedar, shown in the introduction. They feature a stopped dado for the loose tenon joint that does not show on the top face.

My exterior Douglas fir Backenzahn is finished with Messmer's U.V.Plus natural wood finish.

For the interior cedar Backenzähne I used satin water-based polyurethane.