I am starting a new project and intend to use more joinery techniques. I am going to make a chair, and I was hoping to create some mortise and tenon joints for the chair that I am making. I do not have access to a router at this time.
How do I create mortise and tenon joints by hand?
Chisel to create the mortise -- you can save a huge amount of work by drilling out most of the waste. Saw the tenon to slightly over the final size (saw outside the markup lines), then fine tune with plane and chisel (shoulder plane will avoid the need to chisel).
There is always a traditional hand-tool solution. It may or may not be more work, and often that depends on how many you need to make.
Note that dowels, loose tenons, lap joints or other joinery options may also be worth consideration. M&T is elegant but not every joint needs elegance.
The old way to cut a mortise purely by chisel is the following:
You need a mortising chisel which is a chisel of the width of the mortise with the sides narrower than the blade, and a mallet.
The chisel is held straight up and driven into the wood near one end of the mortise with the flat of the blade facing the near end.
The blade is then walked away from the end and another blow struck. A chip should fly out.
This continues until reaching the other end of the mortise where the chisel is turned around and the blade is driven exactly true to the end
The blade is then walked back again towards the first end. Ideally this pass should cut the depth of mortise exactly to what is needed. Obviously it takes a great deal of skill so that each blow sends the blade to the correct depth and no further.
When the original end is reached the blade turned around a second and final time, cutting the first end exactly true.
Notes:
A mortise is always cut across the grain
The chisel should never be applied to the sides of the mortise, only from end to end
The previous answers are well written and describe the process well. I can only add my personal experience to this which, of course, may vary from one person to the next.
I find that both the "bash it out with a mortise chisel" and the "drill it out and clean up the edges" methods work about equally well and are both a lot of work. Not that work is a bad thing; but the process will take some time. Using a mortise chisel had the benefit for me of ensuring that the walls of my mortise were parallel.
As to the tenon, I found it tricky to get the sides and shoulders perfect using only a chisel and ended up buying a shoulder plane. In fact, I bought this one [from Lee Valley.] This made it much easier to get the tenon sides and shoulders to fit well. For some reason, these shoulder planes are always expensive; I was unable to find one on Ebay, or any of the online tool dealers that was both in good condition and less than $100 USD. So I just bought a new one and the one from Lee Valley is very nice to use. Most importantly, it is easy to adjust.
