Complete this tutorial and you’ll have a great start to making a shelf of kickassery. Puzzle Cut Shelves are only half-way done without the crafted log that supports them. The Shelf Support Log is the Watson to the Puzzle Cut’s Holmes.
Because the puzzle cut shelf or other slat shelves are a solid piece of wood, this Shelf Support Log is critical to the structural integrity of the table. This tutorial will show you how to craft a log for this very specific and important purpose.
The shelf log starts out like any other spindle. First, you need to measure the length of each log. With my legs fastened tight, I’m going to use a customized tape measure to get each length by measuring from the inside of one hole to the inside of the adjacent hole. The tape measure is pretty simple, I just attached a 5” stick to the bottom of it. When I get my measurement, I butt the stick into the back of the hole and extend the end of the tape into the adjacent hole. Then I add 5” to the measurement I get. I’m going to label each set of holes and I’ll make note of those labels when I write down the measurements.
Before I cut the logs to length, I need to think about the diameter needed. I’m going to be carving 2” diameter spindles into these logs and I want to flatten the log almost an inch into on side. So I want to make sure I use logs that are about 3” in diameter. Cut the logs to length per the measurements you just took. Be sure to label the log with the appropriate label so that you assemble them in the right place.
I suggest finding logs with wiggle, knots or other neat shapely action for the front of the table and straight logs for the back of the table. If the table is going to be viewed from all angles, and not against a wall, then go ahead and use shapely logs on both sets of legs. This will give the puzzle cut shelf opportunity to have a lot more character.
Next we’ll take our logs to the joiner to flatten one side. This can be a dangerous task since I have to remove the fence and the guard in order to complete this step. Use a clamp to hold the log as you pass it over the blade and keep you hands as far away as possible. I also recommend wearing gloves and eye protection. Flatten one side of each log until you have about 2 ¼” of thickness left. If your log has curves or knots, position the log so that those shapes are parallel to the jointer. This will guarantee that the flattened side shows off all those beautiful curves the log has to offer!
Carving the tenon is the most technical part of this. I’ll go ahead and give a quick overview of how I carve tenons, but if you want a more detailed tutorial, click on this link!
To carve the tenon, use your pattern (with a 2” hole) to trace a circle at each end of the log. Make sure the circle just ever so slightly overlaps the flattened edge. Lock the log in your lathe and use a draw-knife to carve the tenon.
Once you’ve peeled it down to your circle, use a random orbital sander with 60-80 grit sand paper to smooth out the shape. Push the pattern onto the tenon periodically to show you where you need to continue sanding. Do this until the pattern can be pushed about 2-3” up the tenon.
After both tenons are complete, peel the bark and sand the rest of the log EXCEPT the flattened side. Don’t sand the flattened side and do not round the edges of the flattened side. If you sand it, it won’t be perfectly flat anymore and that’s a bad thing.
Back at the assembly bench, loosen the legs so that you can spread them far enough to get the logs into place. Before inserting the logs, spread wood glue in the holes using a brush. Insert the logs, spin them so the flat side is facing the bottom of the table top and press everything together as best you can by hand.
Flip the table over so it’s right side up. Slightly tighten the bolts holding the table top to the legs. Span a square across the two flattened logs and turn them so that the square sits flat on the flattened side of the log.
Drive your bolts through the legs, into the flattened logs. Make sure the log doesn’t twist as the bolt pulls it all together nice and tight. If the log does twist, it’s going to take some real hand and arm strength to twist it back so it’s much easier to just go slow when driving the bolt.
Once all four of your bolts are in and everything is nice and tight, go ahead and finish tightening the bolts holding the table top on.
Click on the video below to view – How-To Carve a Tenon
That’s it, you’re done! You’re ready for the shelf! To learn how to make the puzzle cut shelf, click on this link right now!
Thanks so much for reading this tutorial! If you have any questions or comments please feel free to leave them here and I’ll personally respond to each one!
Scott Shaeffer, Owner/Operator