Introduction: Wooden Zipper
First off, this is a piece of art and conversation piece. It is not a functional zipper. It will make a nice wall hanging and definitely catch people’s attention.
This Instructable shows you how to make a wooden zipper from a tree branch. We will be making the second one shown above from a desert willow branch.
Credit for the idea goes to Robert Gwalchmai who’s incredible work inspired me.
Tree branch, 10 to 20 inches long, 2 to 4 inches round, with a slight curve to it - must be dry!
Various hardwoods for the teeth and zipper pull, preferably in contrasting colors
Wood glue, CA glue, wood screws
Small pieces of plywood
Bandsaw, table saw, sander, drill
All dimensions I mention are for general guidance only; everything depends on the size of your tree branch and how much detail you want to present.
Step 1: Preparing the Tree Branch
Start with the tree branch and remove the bark and any loose pieces. Cut the ends straight and parallel to each other.
Mount two rectangular pieces of plywood on the ends of the branch by using screws. The plywood pieces should be a little larger than the branch diameter. They will serve as guides while slicing the branch lengthwise on the bandsaw.
Step 2: Slicing the Branch
Mark the centerline of the branch on both plywood ends. The curved part of the branch needs to point upwards as shown in the pictures.
With double-sided tape or hot glue mount the branch/plywood ends on a carrier board so you can safely run it through the bandsaw. Do not make this cut on a table saw, it is unsafe and dangerous!
Use the band saw to cut the branch in half along the centerline. A wider blade (3/8” or 1/2”) will give you a straighter cut.
You will have two beautiful book-matched faces for your wooden zipper.
Sand the two pieces to get their surfaces cleaned up.
Step 3: Mounting the Zipper
At this time, depending on the curve in your branch, you can decide to make a typical half open zipper, or a ‘broken’ zipper that is coming apart in the middle, see the example pictures. I'm going for an opened zipper.
For this the bottom part of the two pieces need to be joined. The easiest way is to mount the two halves on a plywood backer board that is not visible from the front. As shown above I have cut out a recess in both branch pieces to glue/screw in the backer board. The backer board is shaped to follow the curvature of the zipper in order to hide it as much as possible. I left a gap between the two pieces to accommodate the zipper teeth.
You could also use a biscuit joiner to join the two pieces. A third way is to cut a groove along the inside edges of the two boards and join them with a spline. A close-up picture of that approach on a different zipper is shown in the last picture of this step.
You have now completed what is called the 'tape' of a zipper. Mine ended up being 14 inches long and 7.5 inches wide at the top, with a 1/2 inch wide gap at the bottom.
Step 4: Making Teeth
Prepare the teeth from a contrasting wood strip that is a bit longer than the zipper pieces. The length/width dimensions for the teeth are flexible but depend on your branch and the gap you left between the two zipper pieces. A good guide is a length to width ratio between 2 to 1 and 3 to 1. The teeth should be at least 1/4 inch thick. I my case the gap between the zipper pieces is 1/2 inch wide, so I made the teeth 1-1/8 inches long, 1/2 inch wide, and 1/2 inch thick. I started out with a strip of walnut that is dimensioned 1-1/8" by 1/2" and 17" long.
Take the wood strip and cut a rabbet as shown along the strip. The rabbet allows the teeth to hang over the edge of the boards along the zipper. Then cut off 1/2" pieces to make the zipper teeth. I used blue tape to prevent chip-out when cutting the teeth, it worked well!
Glue the teeth to the zipper boards and space them one tooth apart, alternating on each side, just like in a real zipper.
Step 5: Making the Pull
Now we’ll make the slider and the pull tab. Again, use contrasting wood species for a more distinct look. Check out the pdf files for the shape of the slider, the bridge, and the pull tab. I am presenting two designs, but feel free to design your own. Enlarge or shrink the designs for your project.
For the slider you need a wood strip (I used maple) that is a little wider than the teeth at the closed zipper part. The slider will straddle the opposing teeth. Cut a wide groove in the center of the wood strip. The groove should be wide and deep enough to fit over the teeth. Be careful when you make these cuts on the router table or table saw. After cutting the groove shape the slider by cutting with a scroll saw or by sanding or carving. The Fusion 360 models show the construction of the zipper slider and pull tab assembly.
I made the bridge from a small piece of cherry, and the pull tab from a strip of oak.
Glue the slider, pull tab, and bridge on your wooden zipper. Everything is glued together, there are no moving parts as it would be to fragile.
Step 6: Finish and Show Off!
Clean up any glue, do a light sanding, round edges as desired, and varnish your wooden zipper. Attach a hook or wire on the backside to hang and display your zipper on a wall.