It’s been two weeks since my last post, but I actually have a good reason for not posting sooner. If you have ever made mortise and Tenon joints, you know they can be hard to get perfect using power tools. The most common tool used to make tenons is the table saw. You cut your boards to length set up a stop block, and then guide the board through the cut using a miter gauge. This method has a draw back though, your miter gauge must be perfectly square to the miter slot, and it can have now slop as it travels through the slot. If your set-up doesn’t meet both these requirements the checks won’t end up in the same plane, and thus one side of your joint will have a gap. If the gap is small then it’s usually not a big issues, because very rarely are both sides of a M&T joint visible.
As you would expect I first made the tenons for my end tables using the method i’m familiar with, but they had some small gaps. My end tables have several joints where both sides are visible so they need to be perfect. After a minor freak out, I started researching how to fix the issue. It took almost a week, but I found a method that i will use from now on to make tenons. The method is a derivative of the method used by Garrett Hack in this video series.
Step 1: Joint one edge(yellow) of a board, and then use that as reference face to cross-cut both ends(green) of the board. This is very easy and super accurate with a cross-cut sled. Mark the length of your tenons for future reference. If you have a marking gauge, use it, because it’s the most accurate tool for the job, and it will help prevent tearout later on.
Step 2: Using a miter gauge and a dado stack, remove the bulk of the material from both faces of the tenon. Stay shy of your line a 1/32″ or so.
Step 3: this is where the magic happens, set your miter gauge aside, and adjust your rip fence to cut right to the line. It will take a little getting use to, but you are going to reference the cut using only the end of the board(green). Since the same face is being used as a reference to cut both shoulders it’s all but impossible for them to not be co-planer. Warning a kickback risk does exist with this type of cut, so I recommend using push pads while making the cut.
Step 4: With both faces sized, cut the edges to proper depth. Again staying 1/32″ or so shy of your line.
Step 5: Clean up the waste along the edges using a chisel and a mallet.