Last winter when I was taking down our Christmas tree, I decided to save the trunk just in case I came up with something to make out of it. I trimmed off all the branches and stuck the bare trunk in the corner of my garage. It sat there drying out for almost eight months waiting for me to come up with a good project for it.
I eventually decided to try to turn it into a didgeridoo. This ended up being a fun, challenging project, and I was happy with the results. Here are the details.
Step 1: Acquire a Used Tree
For everyone else, check around your neighborhood after Christmas. Really, any type of appropriately-sized tree or large tree branch should work for this project. I believe this particular tree was a noble fir.
You can see this actual tree in action in the background of the intro pictures in this instructable.
Step 2: Remove All the Branches
I used pruning shears for most of the smaller limbs, and a hand saw for some of the bigger ones.
Step 3: Let It Dry Out Completely
Over the period of eight months while this was just sitting there, I was tempted to throw it out many times. But I've learned to hold on to neat stuff like this.
Step 4: Remove Branch Nubs and Strip Bark
This saw also worked well to carefully shave off the outer layer of bark, along with much of the remaining bark underneath.
I used clamps to secure the trunk to my work table while I was sawing.
Step 5: Sand Until Smooth
I used 80 grit sand paper on my palm sander to remove any remaining bark and smooth out the blemishes left by the reciprocating saw.
Step 6: Draw a Line
Step 7: Bore Out the Center a Few Inches Deep
I began with a 3/4-inch bit, and ended with a 1 1/2-inch bit. The idea was to bore out the center as straight as possible, while keeping the sidewalls around about 1/2-inch or so.
For sections of trunk that were more straight, I was able to make deeper bores. For areas that were twisted or curved, shorter sections had to be bored out and cut off.
I began with my normal drill, but soon switched over to a high-torque, low-speed drill. This worked much better.
Step 8: Cut Off Bored-out Section
Step 9: Bore, Cut, Repeat
I lined up all the pieces in order in preparation for reassembly.
Step 10: Glue It All Back Together
I used clamps or weights where I could to ensure a good bond.
When gluing, it's important to put an even layer of glue on both surfaces to be joined. The glue immediately grabs the wood and begins seeping into the tiny pores, preparing for a good bond. Plus, if you let the two pieces sit for a couple minutes, the glue will start to get tacky. When the two pieces are joined together, the two sides of tacky glue will grab onto each other and create a really solid, fast bond. This is an especially useful technique when clamping is not feasible, which was the case with the upper half of the trunk.
Step 11: Sand the Joints
Step 12: Widen the Openings
I fixed this by widening the mouth-end opening of the didge using a rotary rasp attached to my drill. I fluted out the bottom end as well, just for good measure.
Step 13: Finish Sand and Stain/lacquer As Desired
I gave the entire didge a few final sandings with progressively higher grits, and then gave it three light coats of spray lacquer and a light sanding to finish it off.