I’m a sucker for cutting tenons. Maybe because it provides me with a great excuse to swing an axe. Maybe because once I get into the groove, I feel a great sense of accomplishment when I’m able to cut and clean up a tenon swiftly. Cutting a tenon — by hand — is a great skill to learn and practice, and I want to make the argument that it can be done by hand rather quickly, too. After cutting tenon after tenon, I got to the point of being able to do the bulk of the work with a saw and axe. I skipped the chisel altogether at some point. Here’s my process for cutting tenons by hand, perhaps my favorite “grunt work” of timber framing. Actually, I like it so much I wish I had an excuse to cut some right now…
How to Cut a Tenon By Hand
Let’s assume your tenon is already laid out. If you are fortunate that there is not a lot of extra length beyond the end of the tenon, you can spare yourself a full end cut through your lovely 8×8 (or whatever dimensions you may be working with). If you have more than an extra inch or so beyond the tenon, you’ll probably want to go ahead and chop that end off with your saw of choice. (Speaking of saw choices, I have mostly switched between a common Stanley SharpTooth and a Japanese pull saw. I actually prefer a SharpTooth in a lot of cases, especially if it’s perfectly straight. But I digress.)
Go ahead and cut your shoulder, right on the line, and make sure you make a clean, level cut. Be sure you have no rising hump in the middle of the timber, which seems to be a common problem. A good way to check is to flip your (western) saw upside down, and slide it down the kerf. See if it rocks in the middle. If it does, saw a few more strokes and knock it out. Don’t be afraid.
Next you’ll want to make a few more kerfs, and depending on the length of tenon, you may need more or less. Try not to have more than 2″ of material between kerfs. 3″ is probably pushing it. Remember, use the absolute full length of that saw! There is nothing worse than making more strokes than you have to — using the full blade will ensure that the job is quicker, and you’ll be less tired by the end of it.
About to waste some wood
Once you’ve got your kerfs cut, it’s time for the best part — wasting the wood. Here’s where my favorite tool comes in — the axe. I use a Gransfors Hunters Axe, but use what you’ve got, as long as it’s appropriate… and sharp. Actually, you might choose to roll the timber 90 degrees at this point, but you’ll save energy if you can learn how to swing horizontally.
Pop loose the chunks of wood. With enough practice, you’ll be able to approach the tenon line very closely without going over. A few swings should free up the majority of the wood. It’s all about practice, as with most things.
Shaving the tenon, using the axe like a wide chisel
At this point, some people may choose to switch over to a chisel, but I encourage you to try cleaning up the tenon entirely with an axe. Practice the technique of pushing the axe like a chisel, with your dominant hand choked up on the handle, and your other hand pushing on the poll. Little chopping motions are very effective, too. If your timber has decent grain, you can easily get to the line without ever using a chisel. Again, your axe must be critically sharp for this method to be effective.
Why do I like using an axe so much? I suppose it’s because you can alternate between small chopping motions and shaving rapidly and effectively. Sometimes I find that I actually have more control, as opposed to striking a chisel with a mallet, which is not always my favorite motion.
You may, or may not want a slick to clean up, but you’ll definitely want a plane to really flatten out the tenon. It’s perfectly okay (if not preferable) that the thickness of the tenon slightly less than the thickness at the edges.
How to Check The Thickness of Your Tenon
Once you are satisfied, flip your timber and repeat the process. You should never move a timber more than you have to, so try to be sure that you are pretty satisfied with the first half! With both sides cleaned up, you can check the fit of your tenon by making a “tenon checker” with two framing squares and a pair of stair gauges. Set the width to two inches (or whatever width your tenon is), and slide the checker over the tenon. This is a great method and it will immediately highlight where you may have high spots.
A tenon checker is extremely useful for checking your tenon thickness
This description, I hope, will give you some inspiration for learning how to cut timber frame joinery with nothing but hand tools.
Ultimately, the fun is finding the tools you really like, and getting practice in how to most effectively use them.