The Paul Sellers Mortise & Tenon Technique

Posted 21 August 2017

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Paul has developed his own system for cutting mortise and tenon joints using a conventional hand router plane to create perfectly sized mortise and tenons that are accurately aligned. This system will revolutionise the way you think about mortise and tenon joinery.

Notice of Republication
After reviewing the original version of this presentation, we decided to re-film this method to ensure clarity and to make sure it was a definitive example of this technique.

124 Comments

  4. I use a similar setup. I plane a board down to whatever offset I want the mortise to be from my reference face. I glue that board to a scrap of plywood and this is the part that clamps in the vise. I have several of these for different offsets. I find that I only need to mark the ends of my mortise since the guide gives me a consistent offset and the chisel determines the width of the mortise.

    I like how you leave a bit of material on the ind of the tenon to support the router. I’ll have to give that a try.

    2. I think I’ll even make the tenon longer initially to plane the whole surface of it with the router plane fully supported, and then cut off the supporting material and the tenon to length. I find the extremes of the tenon difficult to plane..
      Or maybe I should add a wooden sole to mine, as Paul did.
      Mic

      1. Or you can keep the middle part and start from the edge and towards the shoulder of the tenon.

        I usually set my router plane to the final depth and instead of adjusting the depth I place couple of pieces thick paper. After each cut I remove one paper and slowly cut more down until there’s no more paper (spacer) left between my router plane sole and the wood…

    3. That’s helpful Mike. I set about to use Paul’s jig, only to realize it only works if both pieces are of the same dimension. I’ll try making a few of the jigs as you describe. At any rate, Paul’s recent revision of his mortising method, whereby the same chopping technique is supplemented with a mortise slightly wider than the chisel—and then cleaned up with the jig—has really improved my mortises.

  5. I have never thought of keeping the bit at the end of the tenon as an outrigger to keep the router at the right depth, then using the tenon saw to remove the “outrigger”. The key is to not change the setting of the router you used as the marking gauge when you layout the mortise. If you were doing a bunch of rails then one short gauge block would be helpful when pairing the mortise sides because otherwise you would have trouble pairing due to the fact the chisel handle would get in the way of holding the back of the chisel flush with the rail surface. That joint was so tight! A couple of drawbore holes and who needs glue?

    Brilliant Paul!

    1. I was thinking the jig is great for the middle, but doesn’t do much at the extremes. Since the real boards would be longer, and would get in the way of the chisel, it would be best to have a short board with a tenon as a jig. In that case, the board could be half an inch or an inch wider, to provide support for the end walls of the mortise.

    2. Draw bore method relies on getting the tenon OUT of the moritise after marking the drawbore hole location. Not sure this joint will ever separate, tight as it is. Just a straight thru dowel good enough for insurance.

  10. Such a great video brimming with helpful tips to watch for. One of my favorite things to hear is Paul describing grain direction and adjusting his approach (quite literally) to work with the stock at hand. One question: at 19:48 when Paul checks the mortise wall thickness equals the tenon shoulder thickness, then flips the part, wouldn’t he want to match the opposite shoulder against the other mortise just in case? I understand he used the router as a marking gauge that guarantees equality but for a beginner who might remove extra material while cleaning up it might be helpful to make it foolproof.

  12. My goodness. That is extraordinary. Paul, you are the most effective teacher of woodworking via the internet that I have seen. You have transformed me from a doubtful to a confident learner of woodworking. And using hand tools as well. To me you are the Saint Paul of woodworking. Thank you again!

  18. Paul,
    When you made the tenon I thought it was the actual rail for your project. Then you cut it down to use it as a guide. As a result, half your work was unnecessary. Also, wouldn’t it be quicker to saw the tenon cheeks then smoothed the cheeks by using the guide lying flat at the end of the tenon to support the outer end of the router?

    1. Hello Terrance, often the rail will be too long to use a guide. Otherwise it obstructs the chisel. As far as using the guide at the end to support the router, I’m not sure I understand how the guide and tenon are being oriented and held in place when routing. Do have a go and get back to us to let is know how it works.

  22. Hi Paul and Team, I’ve just finished marking 20 mortises ready for chopping tomorrow. Came in from my workshop and put my I pad on, just what I needed.
    Thank you for a great idea.

  23. Well done, Paul. I’ve a suggestion: instead of leaving the ‘outrigger on the tenon, couldn’t you have used the other piece of timber (the one you used for the mortise) as the outrigger to bridge and support the end of the red router plane?
    I have seen a video on YouTube (treebangham) where the other piece was used but both pieces were clamped to the top of the workbench. This worked very smoothly and efficiently. Again well done Paul

    1. It’s tempting 🙂 but it’s better to dry fit first. As you drive them together you’ll feel if it needs to be loose or not. I wasn’t by Paul when he drove them together, but I had a feeling that the wood will split.

  29. Any one ever read Modern Practical Stair building and hand railing by one George Ellis written all most one hundred years ago when craftsmanship was at its pinnacle.
    This technique is described therein in relation to making wreathed or twisted stair strings
    .
    Nice to see it put into practice on the mortise and tenon joint.
    Incidentally Ellis’s other two works, Modern practical Carpentry and Modern Practical joinery are an absolute gold mine of information on all aspects of constructive carpentry (much of which is now obsolete) and joinery.
    I see many parallels between these two great craftsmen.
    Many thanks for all you teach and keep alive.

  31. Now we know the MAGIC of using a tenon exactly 1/3 the thickness of the lumber.

    Tenons of about 1/3 seem very common, what I assumed was a general “Rule of Thumb.” Yet, this shows that exactly 1/3 works out incredibly handy.

    THANKS, Paul, for refining the technique and sharing it with us!

    1. I think it doesn’t have to be exactly 1/3, this technique should work with any tenons where both pieces of stock are the same thickness or to be more accurate where one side is intended to end up flush between tenon and mortice piece, as you only use the template from one side.

  32. Paul, I enjoyed the tutorial video as usual.
    Might I suggest a slight variation that I think you will agree with.
    In the beginning make the piece on which you will be cutting the tenon a little longer, by the amount that you desire to support the router plane on the end of the stock.
    Make your saw cuts as you did, but the second cut will be at the piece end.
    You will make the entire tenon at that time and cut the support piece off to complete the tenoned piece.

    Thanks for all your hard work and sharing of your expertise.

    JIM

  33. To overcome the problem of the chisel handle getting in the way, I suppose you would have to cut tenons on all the rails absolutely equal to the one on the guide. Which means making sure that the router blade depth doesn’t alter.
    But what happens if you have a tenon with four shoulders? Do you mark the width of the tenon on the side of the guide, and transfer the marks to the mortice piece? Though now I think about it, I suppose you could mark the ends of the mortice by just laying the tenon piece flat across the mortice piece and making knife marks directly before clamping the pieces in the vice.
    A great video, like all your videos, Paul. A propos of which: I hate to be greedy, but will there be any more Q&As?

    1. Hello Denis,
      It is the length of the rail that would get in the way of the guide, not the length of the tenon.
      As you mention, there are not many changes when the tenon has shoulders on all sides.
      Are you referring to the YouTube Q&A’s? If so, they won’t be returning in the same format, but we will be answering common questions.
      All the best, Phil

  39. Thank you Paul,
    Very exciting! And timely, I am about to build a coffee table with 8 mortise and tenons and my first one was kind of rough, this is exactly what I need so excited to give it a go!!!
    Regards, Michael Price

  44. I happen to be in the midst of a bed project. The head and foot boards have numerous mortise and tenon joints. I a reasonable at cutting the mortises with a chisel but not a 100% and the surfaces tend to be rough. I tried Paul’s method to sweeten up the sides and guarantee that the sides of the mortise are square to the surface. Worked like a charm. I will try it from the beginning next time. Thanks

  45. There is so much to be seen and appreciated in your videos. I feel it’s wise to watch every second, pause for thought, and come back to earlier videos every so often. I’m still watching (and advising others) the workbench series, and still seeing new elements, new movements, new details.

    Your help is much, much valued here, Paul.

  47. Hi Paul,
    That technique is just great, as an aside I wondered if you have covered sharpening hand router cutters? if not would you? if you have is their a video link I and maybe some others would appreciate, thank you for all your instruction it’s awesome,
    Blessings, Andrew.

  50. Thanks Paul,

    Your ingenuity is a gift to everyone that loves woodworking. With this method I should be able to make some great joints every time.. After retiring from being a production carpenter for over 45 years, I’m now able to turn my attention back to the joys of using and gathering hand tools. You’ve already inspired me to complete the bench project.
    My next tool needs to be a hand router.

    Cheers and carry on!

    Ken T.

  52. As you may or may not remember Mr Sellers when I attended your 2 day course at the end of last year I struggled to control my hands when working with wood (well anything really). This for me was almost the one single thing that made me think that I’d never be able to carry out work to an acceptable standard of accuracy. This video and the technique that you have demonstrated has genuinely lifted my spirits. Thank you for everything. I can now start to believe again that I can continue working with wood and can now produce pieces that I hope others will enjoy as much as I enjoyed making them.

  54. Great technique for creating mortise and tenon joints. The hand tool users of the Guild of Oregon Woodworkers are learning a lot from your videos and blog. I hope to share what I’ve learned with my fellow woodworkers.

  55. This is a great video, but the beginning woodworker needs to know one thing. The tenon that Paul created was a sacrificial tenon. Anything longer than the one shown and the handle of the chisel would be on the guide, throwing it off.

    By making the sacrificial tenon, you would be able to even do offset tenons.

    Other than that, it is a great looking mortise.

  58. When Paul showed us mortises in his month long class, there were some variations that I’ll mention in case they help someone. Mortises are quite often not centered. Look at the rocking chair, for example, or at the aprons on many tables. Thus, we only used a guide from *one* side. You could try to make two guides with the second used only to pare the far side of the mortise, but it really isn’t necessary. Moreover, if you are handplaning your material rather than using machines, you only have one reliable reference surface, and you will place your guide block on that side. This gives you everything you need, works for handplaned material, and works for off-center mortises. If you are doing a through tenon, you rotate the work and the mortise jig, staying referenced on the reference face, to chop the opposite side. The beauty of this is that you will end up with lined-up mortise faces, which is needed for clean, neat through tenons. Just take care with your gauge lines on both surfaces: accurate, and sharp gauge pins. Again, if you work from only one side, you only pare down one face. Don’t worry about the other.

    As another comment, Paul emphasized to us that routers are precise, but slow, and encouraged us to develop our ability to get as close as possible with just the saw, chisel, and layout gauge lines. Splitting tenons, when the grain is favorable, is the fastest. Paring like in this video is the next fastest and can deal with most grain conditions. The slowest is sawing, but it can be used in any grain. I don’t see any need for the outrigger he showed here for normal sized tenons. We never used one once in the class. The router plane is quite capable of reaching that far out, especially with the added base and, if it can’t reach quite that far, just flatten as far as you can with the router and you can clean up the rest with a #4 (since the plane mouth own’t need to reach all the way to the shoulder) or even a chisel, riding off of the flattened portion that the router could reach. Maybe for through tenons you’d be super careful.

    Be advised that, if you are practicing with construction lumber (2×4), that stuff is pretty junky, at least in the US. The tree growth is so fast that you often have hard rings spaced by wide, soft, spongy rapid growth. When you try to pare across the tenon, the wood can break out in big hunks between the hard rings and when you chop the mortise, the ends of the mortises will likely be torn. Try some oak or some real pine from a reputable lumber lard, properly grown and dried.

    I must say, this is the first of Paul’s videos in which he used a technique he would have chided us over in class, in particular eyeballing a square to a nick rather than taking the extra second to put your knife in the nick and then bring the square up to it, perhaps with due consideration of which is the waste side. And knifing the full width rather than just the mortise? That would be a chargeable offense. I don’t think Paul wants us to copy that early part of the video…he was just trying to get as fast as possible to the mortise itself.

    1. Thank you for filling in some blanks with your comment! I still wonder (in the case of an off center mortise) why paring down the ‘far’ side of the mortise isn’t necessary. Is it because it’s not a show side? I’d think it would affect the fit if it was ragged. Thanks.

  59. My mortising skill are OK, but not at the level I want. After seeing the video I went to the shop and tried it. I used some clear pine and the results were really good. It seems that one part of it is to size the tenon to match the chisel. My good 1/2” chisel is actually 33/64” and setting the depth of the 71 based on that and the wood thickness made it work without any adjustment of tenon or mortise. Even if the mortise was not better this system would result in a big gain in speed. But, the mortise was better, the very first time. I had just finished a project for a family member that used a lot of mortises and I was wondering how to improve them. Now I know how.

    Thanks to Paul and the WWMC team.

    -Eric

  62. Not to spoil the party, but am I the only one who noticed the tenon piece is slightly twisted in the mortise piece? I like the outrigger trick–making it slightly longer than the desired tenon, as someone suggested, then cutting off the extra.

    2. Hi Chris & Charles,
      After reviewing that section of the video, we did feel that this wasn’t a prime example. The camera close-up does seem to show up a little gap at the shoulder. Paul has demonstrated this technique many times without this issue. We have now re-filmed and re-published this. Thank you for bringing this to our attention. I hope this clarifies it.
      Best, Phil

  64. Brilliant method! Thank you for sharing this, and all of your knowledge, Paul.
    It’s so tight, does this need any glue? If you were to use some glue, wouldn’t it come out as soon as you try to put the tenon in the mortise hole?

    Thanks, regards.

  65. I have been curious about one particular detail whenever Paul cuts a mortise. Why does he use a narrower chisel to clean out the chips instead of the paint can opener tool he blogged about some time ago? I adopted the paint can opener tool method as soon as I read about it and it works wonders! No damaging the ends of the mortises or squashing fingers.

    Excellent lesson as always! Cheers!

  66. Wow! Utterly fantastic idea! I just tried this technique and it worked like a dream. I also like the fact that I’m making a “test” tenon before I commit to the real thing. That’s where I’ve messed up in the past, doing them by hand. I used to do the tenon on the radial arm saw but noq, it’s all hand work.
    Thanks Paul!

  67. Thanks so much, Paul – as usual you have the very solution to my problem! As a newbie, I was finding that all my practise M&T were not lining up side to side, I always had a tiny skew in the vertical. Was just trying to figure out a system for providing a good vertical reference, when lo and behold, you give us such a nice present. I know that you hear this a lot, but you are awesome.

  68. You never know when the information you’ve absorbed will come in handy. Yesterday, I was salvaging an old panel door. The original latch was one of those deep mortise jobs (4 inches or more.) I needed to fill the cavity with a fresh block of wood, glued in place. The original mortise had been done by hand and was, for my purposes, quite rough and inconsistent in size. After some head scratching, Paul’s mortise and tenon technique occurred to me. The rest is just in the doing. It was a perfect fit on the first try. Paul Sellers is with me every time I’m in my shop. And always will be. What a wonderful legacy.

  69. Paul, I’m sure others have said it many times before, but you’re a remarkable combination of craftsman and instructor, and I envy anyone who has had the chance to work with you in person.

    I’m a woodworking newbie, just getting my personal workshop started, and one of the things I think I’ve been learning from your videos is how to achieve precise results without obsessing over them. Building the precision — and error tolerances — into the technique lets you focus on getting the work done efficiently. I *really* need to make time to apply what I’m learning.

  71. Making both sides of the “tenon” on the gauge block was not necessary, but if the mortice were asymmetrical, then the two sides of the block could be different. If there is an offset in the two faces, that could also be worked into the block. Need to get another full sized router.

  72. I posted a technical question in the tools and techniques secrion of the forum… I probably should have posted it herr, instead.

    Technical Question: is Paul doing math and eyeball to set the hand router depth, or wome other magic that I cannot see?

    For example, let’s say (just for illustration…) that the boards are exactly 1 inch deep, and the mortise/ tenon is planned to be 1/2 inch thick. This would give, minus the 1/32nd ‘space’, a hand router depth of 1/2 mortise divided by 2 to give a 1/4 inch router depth minus 1/32nd to equal setting the router depth at 7/32nds deep needed for marking in leiu of a mortise gauge.

    This is all well and good and easy math; however, the video does not give that explanation, and Paul does not allude to how he gets the depth of the static hand router.

    Am I missing something? Or is it an example of the innate measuring eye of Mr. Sellers 🙂

  73. A question that I have when I watch the video is if there’s a way to do this without two router planes. As someone who doesn’t even have one, I’d like to get away with only purchasing one of them. I’m leaning towards the veritas which has a depth stop. Instead of setting a second router, do you think it would be possible to just set the depth stop of one router? Where I haven’t used a router yet, I’m not sure if this would work or not, but it seems like it would if the stop if a definite point.

  75. And just when I was thinking a poor man’s router would do I accepted I need to buy a decent hand router. But why stop at one when two will do! I guess you could use a poor man’s router to sneak up on the finished tenon cut…. thanks again

    1. He’s saying that the width between the marking gauge or router lines with this method needs to be slightly wider than the chisel but it isn’t critical as long as it’s slightly wider so anything in the 1mm – 3mm range over the chisel width will work fine. You would normally let the width of your chisel set the width of the mortise and fit the tenon to that, but this system uses the jig he makes to set the final mortise width and tenon thickness. It all has to match because the same router setting is used on both sides of the tenon as well as both sides of the mortise hole and for the jig. I don’t think he really explained how he got the router setting to begin with. I’ve used this method and I center the chisel as best I can for the tenon and make a couple of pencil marks. Then I set the router to the mark on one side and try that setting on the other side to see how close I am and make minor adjustments from there. You could just as easily set a mortise gauge and make some short marks, then set the router to those marks. It’s a great method – super accurate!

        1. It would be if you didn’t pare down both sides of the mortise using the jig as a guide. The jig is what insures that the mortise is exactly centered and that’s also why the your marks need to be a little wider than the chisel. If the chisel is as wide or wider than the marks, when you move the jig to the opposite side there will be no material there to pare and the centering as well as the width of the mortise won’t match the tenon.

  79. If I understand this method correctly, then I don’t really need to buy a mortise/combo marking gauge or a tenon saw, correct? I could save my money for a quality router plane like the Veritas or LN, and a quality dovetail saw? Instead of buying more, lesser quality tools?

    1. You will run out of depth to mark larger tenons, just my personal opinion also, but I would shop around and probably be able to find a saw router and gauge for the price or the veritas tool. I typically only use one cutter in each of my full size routers – people complain about the ever rising price of router planes, then shop for ones complete in the box with price tags and fences and depth stops included. You can find a great router without the fence or extra cutter or box for under 100$

    1. Doing it with a bench chisel that is the most likely chisel that beginners will get first avoids the ‘I can’t chop a mortise unless I also have a set of mortise chisels’ mental block that some people may get. There is quite a good youtube video that was done showing the mortise being chopped behind glass (both with a mortise chisel and a bench chisel).
      https://www.youtube.com/watch?v=q_NXq7_TILA

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