Mark (TheCraftsmansPath.com) on September 25th, 2007

Recently there has been a lot of buzz in the woodworking community about the new Festool Domino joinery system. If you have not yet seen this system, it’s kind of like a Biscuit Joiner on steroids. However, different from the small circular blade on a Biscuit Joiner that cuts a football-shaped groove, the Domino cuts a rounded mortise with a router-like bit. The unique aspect of the Domino is that the bit both plunges into the work and also oscillates from side to side creating a very clean and precise mortise. Just like a Biscuit Joiner, the Domino is used to mortise both work pieces that are to be joined. The Domino joint is completed the by gluing loose tenon stock (specifically designed and supplied for the system) into the mortises.

This system has a lot of advantages. Some of the major ones are:

  • Joinery, layout and execution are fast and straightforward – just mark the center of the mortise on each work piece and cut
  • Work pieces can be cut to exact lengths – there is no need to add extra length to account for the tenons on the ends of pieces
  • The mortises need no additional work, they are very clean and the loose tenons fit snugly into the mortises
  • The joints made with the loose tenon stock are much stronger than those made with biscuits. In fact, loose tenons create a joint that is arguably as strong as any traditional mortise and tenon joint
  • Making multiple mortise and tenon joints where required for strength is as simple as laying out and cutting another mortise in each work piece
  • Unlike with biscuits, there’s no evidence that loose tenons will telegraph their shape to the surface of a work piece (this sometimes happens because biscuits swell when the get moist with glue – if the surface above them is sanded or smoothed prior to them drying out, a depression in the shape of a biscuit will often show up above the joint on the surface of the work piece)

So, with all of these advantages, why would you use anything else? This seems like the holy-grail of joinery! Well, if you have the means to purchase the Festool Domino, I would say: go for it! It looks to be an extremely well-engineered tool that excels at what it does. I may even add one to my shop in the future. However, if you are looking for loose tenon joinery on a budget, you should realize that there are alternatives. In fact, I have been doing loose tenon joinery for years using a basic plunge router and a simple jig.

Loose Tenon Joints on a Budget: The Router Jig

I often use loose tenon joinery in the construction of furniture projects. The system that I use involves a basic plunge router, an edge guide for the router, an upcut spiral mortising bit and a shop made jig. Because most woodworkers already have a plunge router and some scraps around the workshop to make a jig, this technique can be accomplished very economically. Better yet, all of the advantages of loose tenon joinery listed earlier are also realized when using this system.

Loose_Tenon_Jig.JPG

The jig that I use for cutting mortises with the router is a relatively simple affair. It is adapted from a jig in the book: Router Magic by Bill Hylton. As shown in the picture, the jig is basically two pieces joined at a ninety degrees. The horizontal base component is for the router to ride on and the vertical riser component allows the jig to be clamped to the workbench. The work piece is secured to the jig with a toggle clamp that is mounted on a component that is attached with basic hardware through slots to allow for variable sized work pieces.

Jig_Top.JPG

The only other components of the jig are lateral stops on the top that limit the travel of the router. These stops have a slot down the middle to ride over a piece of 1/4″ dowel for alignment. In the picture you can see the stops and a center line that is is scribed on the horizontal base for aligning the workpiece to be mortised.

Using the Router Jig: Marking and Alignment

The router jig is simple to use. Once I know the location and size of the mortise to be cut, I can mark the work pieces. In this example, I have two pieces acting as a Rail and Stile in a frame, though the same ideas apply to other kinds of work pieces.
Stile.JPG

I mark the Stile by striking a line indicating the center of the mortise and I align that point with the center line on the jig. Then, I can mark the corresponding Rail by marking its center from that point while aligning the edges of the two pieces.

Rail.JPGYou’ll also notice that on the Stile I’ve marked the extents of the mortise. This is only necessary on the first mortise. Once the stops have been set, only the center line of subsequent mortises will need to be marked. This feature makes the jig very efficient to use to cut batches of the same sized mortise.

Using the Router Jig: Position the Bit and Set the Stops

Before you can cut a mortise with the jig you need to set the location of the router bit and then set the stops.

Router_in_Position.JPG

To position the bit, I put the edge guide on the router and position it to ride against the back of the jig. Using the edge guide adjustment I position the bit roughly in the center of the thickness of work piece – it does not need to be exact, as long as I keep the same side of the Rail and Stile against the jig, the joint will be aligned when completed.

Mortise_Limit.JPGTo set the stops I align the edge of the bit with the marks on the work piece that indicate the extent of the mortise. On each side I slide the stops against the edge guide bars and tighten the hardware to secure the stops. A this point, I’m ready to cut a mortise.

Using the Router Jig: Cutting the Mortise

Cutting the mortise is straightforward. I set the depth stop on the router to about 1/16″ more than the desired mortise depth (this extra space is to allow for a glue reservoir) .

Router_Mortise.JPGI begin with the router against the stop closest to me. I cut the mortise by taking passes at a depth of about 1/4″. I continue making passes until I have reached the final depth. The advantage to using an upcut spiral bit on the router for this operation is that it is designed to plunge directly into the work piece and it also pulls the chips up and out of the mortise keeping the bit cooler as it runs. This results in a very clean mortise with precise edges and smooth walls.

Of course, this routing operation is the same for the Rails as it is for Stiles except for the orientation of the work piece. As I mentioned previously, once things are set it is as simple as aligning the centerlines, clamping the work piece and routing away. No further measuring is necessary!

Loose Tenon Stock

Loose_Tenons.JPGI usually make the loose tenon stock from scraps of the project that I’m building. I first cut some stock to the desired width of the tenon. The stock is then planed down to the diameter of the mortising bit. I usually use 1/4″ thick tenons for general joinery (in 3/4″ thick stock) and 1/2″ thick tenons for heavy duty applications – the only limit is which router bits you have on hand. At this point the tenon stock has square edges but the router cut mortises will have round edges. To remedy this, I simply pass all of the edges of the tenon stock over the router table with a round over bit installed (1/8″ round over for 1/4″ tenon stock and 1/4″ round over for 1/2″ tenon stock).

Chamfered_Tenon.JPGThis may seem like a lot of work but it is actually very quick to do. I usually make a batch of tenon stock all at once in long sections so that individual tenons can easily be cut off to the desired length. Any remaining tenon stock can be used for future projects. Once the loose tenons are cut to size, I usually sand a quick chamfer on the edges so that they enter the mortises without issue.

The Completed Loose Tenon Joint

Completed_Mortise_and_Loose_Tenon.JPGOnce the matching mortises are cut into the two work pieces, the loose tenon is inserted and the pieces are dry-fitted. If all is well, I can spread some glue into the mortises and on the tenon and clamp the joint until dry. Because there is such a close fit of the tenon and the mortise with this method of joinery, not a lot of glue is necessary. I’ve noticed that if I’m careful I get very little glue squeeze-out. So, any cleanup is minor.

Assembled_Loose_Tenon_Joint.JPGAs long as I am diligent about referencing the appropriate sides of the work pieces against the jig, I have very little sanding or scraping to do to level the completed joint. The photo shows the results.

As you can see, this simple system has many of the advantages of the Festool Domino. The one thing that it lacks is portability. The Domino has the advantage of being able to be taken directly to the work pieces, whereas with this system the work piece must be taken to the jig. However, for the investment of a few hours time to make a simple jig, I think that this system performs very well.

As always, please contact me at thecraftsmanspath@gmail.com with questions and also please leave comments here using the comments link at the end of the posts.

**UPDATE**

Stile_1.JPG

In the comments, there were a couple of questions regarding the routing of the rail with the jig. So, here’s a picture of a routed rail in position in the jig.

As you can see the jig component with the toggle clamp is rotated to be in a vertical position. The clamp bar is attached via a couple of additional T-nuts in the jig to accommodate this (they were hidden from view in the original pictures). Hopefully this clears things up.

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36 Responses to “Loose Tenon Joinery: A budget alternative to the Festool Domino”

  1. Great write up. Makes the Festool not so tempting.

  2. Betsy,

    Thanks for the nice comment.

    I think that the Festool line of tools is terrific. However, I would hate to have someone feel that they have to hold back their woodworking for lack of a specific new tool. There are many ways that we can get the job done – from hand tools to power.

    Having said all of that, I would love to have the Domino in my shop. I think that it would make the process of Mortise and Loose Tenon joints even more efficient.

    –Mark

  3. Mike from Cincinnati
    October 10th, 2007 at 7:51 pm

    Your way of mimicking the domino is pretty cool. I will look at doing this for my next project. I have a question about how you position the rail on the jig. I see how the stile sits nice for the router to cut but I can not figure out how the rail would be held down to router it. Do you have a picture of a rail hooked up to the jig.

    thanks

    Regards,

    Mike

  4. Mike,

    Thanks for the comments and for visiting the blog. Please continue to stop by.

    Sorry for the confusion, I did not take a picture of the rail in the jig while routing the mortise in it. However, the operation is simple. For the rail (or any mortise that needs to be cut in the end of a workpiece) the bar with the toggle clamps is moved into a vertical position. There is another T-nut directly below the one on the left of the jig so to move the clamp bar I just unscrew it from the right side rotate it down and secure it in a vertical position with the other T-nut. Then just clamp and route the mortise in the end of the piece. I hope this makes it clear. If not, let me know and I’ll post another picture with a rail in position.

    Thanks again.

    –Mark

  5. Nice write up. I don’t find the Domino tempting as a very expensive “one trick pony”. I’ve thought about using a trim router with a jig since I don’t like using a router table for a blind cut. You’ve given me the motivation.

  6. Gary,

    Thanks for stopping by and for the comment.

    Yes, as you say, I guess the Domino is a bit of a “one trick pony”. It certainly does its intended job well, but it is not within reach for everyone.

    The method that I describe is simple and inexpensive. If you were to want to do traditional tenons with this method, you could as well by simply rounding the tenons to fit the router-cut mortises. I’ve done both but, for the reasons described, the loose tenons are nice.

    I’m glad to have inspired you to give it a shot. Let me know if you have questions on the construction or operation of the jig.

    –Mark

  7. Mark, I like your idea and would enjoy seeing a picture of how you adjust the jig to route a rail. Thanks!

  8. Joe from IL and and Mike from Cincinnati,

    Please see the update at the end of the post regarding the position of a rail in the jig. I hope that this clears things up for you.

    –Mark

  9. Clear, concise and practical. It’s so easy it’s almost like chocolate- Sinful!
    Thanks for the guidance

    Bob

  10. Bob,

    Thanks for stopping by the web site. I hope that the technique can help you in your woodworking. Let me know how it goes!

    –Mark

  11. Mark,

    Just discovered your blog. I think I will spend a few more hours reading all the great material you have here!

    One thing I have always wondered is the Domino hype. Other than efficiency, I am not sure what one gets with the Domino. I am also not sure you get out of loose tenon joinery that you don’t get with regular mortise and tenon. TO me, it seems like the processing of making m-t is not that much more difficult.

    Would you please share your thoughts?

    Thanks

  12. R Wood,

    Thanks for stopping by the site.

    With regard to the Domino, I think that the thing that it gives is flexibility – you can bring a fairly portable tool to the work rather than bringing the work to the tool. To me this flexibility is its biggest asset.

    As far as loose tenon joinery vs. traditional mortise and tenon: the advantages to loose tenons are that you can cut very precise mortises in both work pieces and then simply fit an accurately sized tenon to that mortise. The strength is essentially equivalent to a standard mortise and tenon. If you standardize the tenon sizes you can mill up tenon stock ahead of time and have it on hand. Then a loose tenon only has a single machine setup.

    Having said all of this, I still use a mix of loose tenon and traditional mortise and tenon joinery in my work.

    Please continue to visit by the site and let me know if you have other questions.

    –Mark

  13. Your explanation and ideas are great. Thank you.

    One small point: in the photo showing the setup for mortising the rail end, it appears unlikely that the sliding clamp has marginal adjustment range to align the mortise center with the line. As shown, it is not aligned. For a vise at the left end of a bench, it might be better to drill the mounting holes for the clamp board on the right-hand side of the center line, allowing for wider rails.

  14. Mark,
    I stumbled upon your website and found a friend! I, too, am in the midst of making a Hal Taylor version of the Maloof Rocker. However, you’re more in the “midst” than am I since I haven’t even purchased the wood yet. I’m still in the “making jigs and purchasing tools” phase of pre-production. I would like to compare notes with you on the phone, if that would be alright. I find that often trying to type my questions is more labor intensive than I would like. Please let me know if I can call and on what number. My cell phone number is XXX-XXX-XXXX. I live in Dallas, Tx. Please take a look at my website. I’m more of a bowl turner then a furniture builder but have been inspired by Sam’s passing to make at least one heirloom to pass on to my progeny.
    Ray

  15. Ray,

    Thanks for stopping by the site.

    Quite a coincidence! I too do some turning. It’s quite the addiction. I’d be happy to have a conversation with you. I’ll send you a separate e-mail with phone info (I removed your number from the comment posted on the site because I did not think it was good for it to be public).

    I also looked at your web site. You do some very nice segmented work. Oh and the Cowboy Hat is exceptional!

    –Mark

  16. Mark,

    I am a johnny-come-lately but thanks for the info. I was drooling over the Festool but could not justify. You explanation will get me off square one.

    Thanks

  17. Terry,

    Glad the info helped you!

    –Mark

  18. I was thinking of buying one of these, but was unsure. After reading this, I think I am going to make the leap and purchase – love the site!

  19. Mark:

    I am in the process of doing my research on building some dining room chairs. I already have the Festool Domino. As you no doubt know, most dining room chair designs have compound angles. The side rail for the seat I am modeling my chair on splays outward toward the front by 8 degrees and is lower at the back where the rear leg is by 2 degrees. The Festool Domino is fine with angle joints, but not so user friendly with compound angles. I may be able to get to where I need to be using wedges to put the workpiece in the right position, but I was wondering whether you have tried to use your jig for compound angles, and if so, how you did it. From what I have seen, the FMT jig appears to be fully capable of handling compound angles but that is at least another $500-$600 by the time the dust settles. Any thoughts?

    Bill Neild

  20. Hi Bill,

    Thanks for visiting the site and for your comment.

    I’ve never used the jig for a compound angle mortise. However, with a bit of modification, I think it could be used.

    I would think that if a flat piece of plywood/MDF were added to the font face \and attached with a piano hinge, then the jig could be used for compound mortises. Obviously, you would also meed to incorporate a way to hold that surface at the appropriate angle as well as the piece to be mortised. I think it could definitely work with some forethought.

    If you give this a try, let me know and send me a picture of your modifications. Sorry that the Domino did not work for this…maybe Festool should take this as a cue and incorporate this kind of capability into their very expensive tool!

    –Mark

  21. I saw your jig for loose tenon joinery. I liked the concept. However, I’m curious how to do really long pieces. I recently did a dining table. The aprons were 75 inches long. How could you use your jig on a piece that long? I cut tenons for this with my router where they intersect the legs. Worked okay, but a lot of work. Any ideas?

  22. Roy,

    Thanks for your comment. My best suggestion for cutting the mortises on longer pieces would be to mount the piece to the jig as normal and run the router in along a vertical path. This setup would not be not as stable as the horizontal setup but with light passes it could work.

    The other way that would work well is to build up a horizontal router table that holds the router with the bit in a horizontal fashion and you ride the piece on a table feeding it into the bit in small increments.

    –Mark

  23. Any experience withe Dowelmax?
    At $310 it”s not cheap” but does an excellent job and the locations of the mortises are reproducible on both the Stiles and Rails.

    John

  24. John, no experience with Dowelmax. That’s quite a steep price. I would think that you could fashion a very accurate doweling jig similar to Dowelmax with some drill bushings and wood. I just can’t see spending that kind of money on something that can easily be made in the shop.

    –Mark

  25. Hi, I love this post! It is a great concept which I must try soon. I have been looking at the festool as a joint purchase with my Dad, but will definitely give this a go first!

    Thanks again for a great and detailed post, now I’m off to look at the rest of your site!

    Garry (Scotland)

  26. I saw this jessem mortiss mill and price are really good. It looks also a good quality tools. Jessem also create very nice doweling jig that I think its comparable or better than DowelMax in terms of quality, ease of use and price.

    http://www.jessemdirect.com/Po...../08200.htm

  27. Mark, thanks for the review of the Festool. I also researched the domino tool, and found it to be a bit pricy. I have decided to go with the Mortise Pal for $209. Great tool…good price. Very versitle and user friendly. Cheers…Stewart

  28. Thanks, Mark.

    I had been considering making a jig to use router template guides, but had not gotten all the details worked out. This looks a lot simpler, so I think I will give it a try.

    I’m just, at the age of 70, trying to upgrade from crude woodwork to higher class work and getting tools and jigs sorted out. I’ve been using the Kreg pocket screw system but, good as that is, I sometimes get slight misalignment or (worse) screw tips pointing out through the face or even cracked wood (and yes, I am using the fine hardwood screws). Hence my interest in the loose tenon idea.

    Seems as if this might be a good way to join cabinet tops to sides, when using solid lumber. Maybe the mortice in the top would be a bit shallow, what do you think?

  29. Mark, Thank you for detailing this bench mortising jig concept so well, and I also wanted to thank Francis for her comments…
    David

  30. Thank you for the article on festool alternative. I have a tabletop with mitered apron (flush-top) to make. I was planning in reinforcing and aligning the miter with buiscuits. I wonder if the jig can be adapted to work at 45 degrees, and if the extra effort is worth, given that there is not much more depth than what is allowed by the thickness of the boards.
    thank you in advance

  31. Thank you so much for this. I have been looking for a way around not buying an expensive Domino and this jig is such a great idea.

    best
    Gary

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