“If you do not expect it, you will not find the unexpected, for it is hard to find and difficult.”
…Heraclitus 500 B.C.
This woodworking online episode is part of the Let’s Build Series
Woodworking Tips and Techniques:
1.) Creating a wedged tenon joint.
We continue with Part 6 of our arts and crafts wood project, how to make a jewelry box with Koa wood veneerdrill bit, . We begin our joinery process by finding the center on the wooden box lid. To do this we use a straight edge of a combination square to mark diagonally across the corners of the lid. Once the center is located we line it up to the center of the brad point bit at the drill press. To secure the lid of the jewelry box for the boring we adjust the hold down clamps and sliding stop blocks of the drill press table. This makes for a safe, reliable, and accurate method of drilling. The drill bit we have chosen is slightly larger than the tenon of the handle because the tenon will be expanding inside of the mortise.
We are making a wedged tenon joint. The mortise and tenon will be very tight once the wedge is set in place and pressed to fit. At the workbench we set the jewelry box handle in the woodworking vice and proceed to bore a 1/16″ hole through the tenon to where the tip of the wedge will be pressed. Next, we saw into the center of the tenon with a thin kerfed japanese saw. Our cut is made across the grain and down to the hole we just bored.
Now, we make the wedge. We could cut a wedge on the band saw however, we are working quickly today due to the 103 degree desert heat. In this case we pick up a leftover piece of Koa veneer and flip on the switch of the disc sander. Within a few seconds we have created a wedge that will work perfectly for our joinery. We then cut the wedge to length and focus on taping around both sides of the mortise with green tape. This will protect the Koa wood from getting excess glue.
We are using cyanoacrylate glue as the adhesive for our wooden joint since we are working quickly. We spread the super glue at its location on the lid and also on the tenon. The bottom of the handle and saw kerf also receive a dab of glue. Now we place the tenon into the mortise and carefully set the tip of the wedge into the tenon’s kerf.
The next step is an important procedure in this process. We place the assembly of the lid, handle, and wedge into the workbench vise and once lined up we slowly crank the handle of the vise to press-fit the wedge into place. This locks the mortise and tenon and creates a very secure joint.
Some woodworkers may be inclined to tap the wedge home with a mallet. This may work some of the time however, it can create problems as well. Keep in mind that when hammering the wedge there is vibration taking place that can lead to misalignment of the joinery. Vibration can lead to cracking of the wood as well. However, we line up the joinery in the vice and then securely squeeze the wedge into the tenon for a pressed fit. .
Notice in the video that a spray accelerator was used to set the cyanoacrylate glue on the lid’s bottom. This further helped to speed up the process so that the exposed joint could be sanded and prepared for the finish.
We choose to use a Watco natural danish oil for our finish. We apply multiple coats of the oil to bring out the beautiful chatoyance of the premium curly Koa. Note: (Be sure to safely dispose of oily rags to prevent fires.)
We have completed the Koa wood veneered jewelry box utilizing a variety of woodworking tools that include the band saw, vacuum press, table saw, jointer, open drum sander, drill press, wood lathe, and the disc sander.
Our accuracy and skill level for this woodworking project has been improved by the use of various table saw sleds. We have used the cross cut sled, dedicated miter sled, and the flat board miter sled. We have also applied a few woodworking tips for this wood project. These tips include the use of tape to hinge our miter joints when gluing the joints. We also used blue and green tape to protect the wood from the excess glue. Furthermore, we used paper shims against the stop block of the cross cut sled to achieve pin point accuracy when fitting wooden components of the jewelry box.