With all of the leg mortises completed and the knee blocks cut, attached and shaped, the next task at hand was to cut the tenons on the aprons of the Queen Anne Side Table.
I milled all of the stock for the aprons, top rail and drawer front in a single session at the jointer and planer. This assured that all of the apron stock would be identical in thickness. When cutting the pieces to size, I saved the offcuts to use for test pieces when cutting the tenons. The first step in machining the tenons was to make the shoulder cuts. This was done using the miter gage at the table saw. The tenons are to be 1/4″ thick from 3/4″ stock. So, the key here was to set the blade height just lower than 1/4″. This left a thin web to trim when fine tuning the tenon thickness and avoided cutting too deep into the tenons. In the pictures (click for larger view) you can see all of the aprons with the shoulder cuts completed.
With the shoulder cuts completed, it was time to cut the cheeks of the tenons. It took a bit longer to do this than I had anticipated – not because I had any issues in doing so but rather, I decided to make a new tenoning jig for the table saw in order to complete the task. A couple of years ago I made a tenon jig that used the miter slot as a reference point. It had a movable carriage on top that allowed for the workpiece to be moved closer to and farther away from the saw blade in order to vary the width of the tenon. This sounds like a workable premise for the jig however, in operation the carriage had too much play and did not always lock down parallel with the blade. The result was tenons of unequal thickness. This time I decided to take advantage of the accuracy of the Biesemeyer Fence on my table saw. The new jig rides on the fence body and has both a cam clamp and a quick release clamp to keep the work secure as it is moved through the blade. It was definitely worth the trouble to build this jig – it worked flawlessly and I had all of the tenon cheeks cut in minutes!
In the picture you can see my “micro adjuster” for the tenon thickness. As I mentioned earlier, I used cutoffs from the stock for my test tenons. After the initial setup, I cut a test tenon and tried it in a mortise – it was just a bit too thin. To micro adjust the tenon thickness, I clamped a block to the fence with two thicknesses of paper between it and the fence. Then I loosened the fence, removed the paper, butted the fence against the block and locked it down. After cutting both tenon cheeks in the new positon, the result was a tenon about 1/64″ thicker than before and a perfect thickness for some final fitting later.
Because of the height of the table aprons, solid tenons would be problematic for dealing with future wood movement in the table. The best approach here was to split the tenons into multiple smaller tenons to allow the aprons to move with future changes in humidity without cracking. I did this by measuring the tenon locations directly from the leg mortises and cutting the tenon shoulders on the table saw with the miter gage. In the picture you can see the divided tenons. This left a step of removing the waste adjacent to the tenons on the aprons. I did this by cutting close to the shoulders with a Japanese Dozuki saw for the outer pieces and a coping saw for the pieces in between the tenons.
The cuts with the Dozuki and coping saw left rough areas in need of some minor cleanup. This was accomplished by paring with a sharp chisel to yield clean tenon shoulders. With the tenons cut to size I needed to round their corners to fit the router-cut mortises. After some quick work rounding the tenon corners with a file, I was ready for a trial fit for the aprons. As expected, there was still a bit more fine tuning to be done as each tenon was fit to its respective mortise. The best tool for this job is the shoulder plane. With this tool I was able to sneak up on a perfect fit for the width of the each tenon by carefully shaving the cheeks of the tenons until they slid perfectly into their respective mortises. For the dry fit, the shoulder plane also excelled at shaving the tenon shoulders perfectly square so that the aprons fit tightly against the leg posts and the table carcass was square.
In this picture of the dry fit it looks as if there is a major color variation between the back and side aprons and the rest of the table – in reality these came from another board and they are a bit darker however, not nearly as much as it appears in the picture. I may try to get the other parts into the sunlight for a tanning session to give them a bit more color to see if I can even things out. Hopefully, I won’t have to wait until July for that opportunity…
As always, if you have any comments or questions, please leave them here using the comments link at the end of the post, or email me at firstname.lastname@example.org.