Loose Tenon Joinery for Chairs

Loose tenons are easier than traditional mortise and tenon joinery, and they are a more robust and authentic solution than dowels or biscuits. October 26, 2011

Is anyone making chairs with the Domino? I did one last week as a test. It was pretty darn fast and those things are tight. I put two 6mm in each joint, some side by side, and some in a row. I know itís better than the dowels that are sort of holding billions of chairs together. I think itís not quite as good as if I machined tenons on the rails.

My question is, is it good enough for custom chairs that are intended to last a long time? I could probably lower the price because I could make them faster. Itís sort of hard to justify the cost of the tool when I already use the multi router though.

Forum Responses
(Furniture Making Forum)
From contributor F:
I don't have the Domino but I do have a slot mortiser and use a fair amount of loose tenon construction. I'd think you'd be hard pressed to destroy a good loose tenon joint. As for price justification it's simple, how much time will the Domino save you over your current method? How much is your time worth?

From contributor C:
I have used the Domino for a headboard, and some other furniture. I would say if your work is supposed to be heirloom quality, no, I wouldn't use just the Domino.

From contributor D:
That reminds me that FWW ran an article in the mid 80ís called "Make a chair with biscuits" or something like that. Being young and dumb, I did just that with my next set. Those were the only chairs I ever made that broke, and it didn't take long. I've used loose tenons cut on a multi-router ever since without problems. If you are representing your work as heirloom quality, then I recommend that you use methods that are proven to perform in service. There are other ways to cut costs. As a last thought - if you showed your clients both the traditional and Domino joints, which one would they choose? Keep in mind that they are talking to you because they have already rejected factory made.

From contributor M:
I've done a couple of sets of chairs using the Domino to cut mortises. For the most part, I cut tenons on the tablesaw. They fit in those slots too!

From the original questioner:
I don't use loose tenons on chairs, but I use them on plenty of other things. They are usually larger though - typically 3/8" thick x 1 1/2-2" wide. I trust those. The dominos are just so small - but when ganged up they seem to make a strong joint. Would it be crazy to pin them?

From contributor S:
Contributor D has it right. A true "heirloom quality" chair does not have biscuits, dowels or dominos. They have traditional mortise and tenon joinery. Biscuits, dowels and dominos have their place in woodworking and it is not in chairs. The last thing I would want for one of my clients to experience is the sensation of freefalling to the floor as the chair beneath him gives way because I chose to use a joinery method that was quick instead of strong. If your reputation means anything to you, don't try to win the race of who can build the most furniture in the shortest amount of time. Instead, do your absolute best and finish the race of champion woodworkers.

From contributor D:
To clarify: I have used loose tenons cut with a multi-router to make thousands of chairs. No problems. That system allows me to size the joint appropriately and control the fit much better than traditional tenons, and faster, too. In my opinion the mortise and tenon joints in a chair are only half the equation - the corner blocks are just as important and merit careful thought and fabrication.

The Dominos look a little small to me, but I suppose that doubling them up has the potential to provide sufficient strength. I doubt that cutting bunches of Domino joints on chair parts is faster or more accurate than a multi-router. Properly set up, it can cut a lot of joints in a day. The air clamps are essential to speedy cutting - does the Domino help you position your work piece in any way? If not then it will be very slow.

If you are going to be making chairs professionally, then cutting joints accurately and fast is essential. The multi-router is, in my experience, unsurpassed. We jigged up our CNC machine to cut all the parts and joints for our chairs, but it did not decrease the build time compared to the multi-router and shaper jigs, and it was difficult to achieve comparable accuracy.

From the original questioner:
I'm generally on the same page as Contributor D. I believe the multi router is the fastest, most accurate way to do almost anything, and you do have control over the size of the joint. I haven't thought about the logistics of dealing with dozens of parts as with a set of chairs and how you deal with that and the domino. It does help to have the parts clamped down to the bench. Maybe jig up a board with the pneumatic clamps or just a Destaco.

One thing I really like about the Domino is the ability to reference the first mortise and all others with the index pins. For example, I did this little bench the other day. The legs had half a dozen mortises each and I didn't have to make so much as a pencil line to do it. I couldn't have done that on the multi router. I had all the joinery done in about 20 minutes. I think I'll make a few chairs with it and try them out with the abuse of my house and kids and some not so small people.

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