a lutherie trick: it's better to have slightly rough surfaces in the contact/glue area, especially with woods that are difficult to joint (due to their high oil content). It does not hurt to make small "scratches" in the areas before joining, especially on processed boards (mdf, plywood, etc)

I used to feel so uncool for making my half lap joints on my table saw because it was easy. Now I can feel quite smug and confident!

I appreciate that you hit on the gripe I have about all of these "OMG STRONGEST JOINT" videos, going back to Matthias' seminal video. Use a joint that's strong enough, meets the aesthetics of what you're making, and will last the desired lifespan of the part. I see no problem with some pocket screws and plywood for workbench drawers, but I wouldn't use it for (hopefully) heirloom furniture. There's no one size fits all joinery and that's part of the fun ;)

One of the main advantages of morris and tenon joinery was before glue was commonly used. A mortise and tenon can be pegged and will be quite strong with no glue at all. Try that with the other joints.

Mortise and Tenon joints were considered the "strongest" for a reason - they last. Lap-joints certainly are stronger but in general they will fail earlier as they are fully reliant (in most configurations) on the strength of the glue. So when seasonal changes in temperature and humidity slowly degrade the glue the Lap-join will just fall apart. Where as the Mortise will still hold together decently even without any glue. Mortise is also stronger against loads in other directions. But the joints that are nearly always the weakest are the butt- and miter-joint. They are just inherently weaker as they do not have a mechanical locking nor a lot of surface nor continuous grain. Of course to everything there are exceptions. If you have something like say a house-frame then one of the best ways to connect a horizontal top-plate to the vertical struts is just ... laying it flat on top - a butt joint. For the loads it will have to withstand this is just the strongest it can get.

This video is as solid as a combo half-lap/bridal/mortise and tenon joint with 3 hickory dowels. Well done! Looking forward to seeing more of your new garage shop.

You can have taller hair in the new shop! My joint test was to build a workbench with tool storage, put hundreds of pounds of tools in it and load it into a container. The container went by truck, rail, ship, barge and truck from NC to Hawaii. Then 5 years later, to CO. In between, I used it as a workbench. Wedged M&T joints are fine 20 years later.

A "chocolate teapot" actually makes perfect sense. It is a thing intended to hold hot liquid, made out of a material that melts very easily.

"because no one knows how much effort we put into anything, it's the ultimate joint" 😂

Thanks for this. I'm building my library and setting up my shop and tooling now. Looking forward to learning joinery, and it sounds like I'll be doing half laps for my face frames.

I recently read something about gluing end grain that is claimed to make it much stronger. The issue with gluing the end grain is that the end grain behaves like a glue sponge and wicks the glue down into the wood and away from the joint, with the result is that critical thin glue layer might not be continuous across the entire joint surface, resulting in a weak joint. The solution offered was to let the end grain soak up as much glue as it wants, and then apply additional glue! To do this, slather glue to the piece with end grain and allow it to sit for 5-10 minutes (but not so long that it starts to dry and set). Then apply additional glue and clamp the joint. This should saturate the end grain with glue so the additional glue stays in the joint space rather than being wicked down into the end grain. I would be very curious if you have heard of this, if you have tried it, and, of course, if it actually makes the joint any stronger.

I think its misleading to say that the bridle and half lap are stronger than the mortise and tenon. They are stronger for a force coming from that specific direction, but a mortise and tenon would do better resisting forces from other directions. Joints are held together by glue strength and mechanical interference and the way you are testing these joints puts the half lap and bridle in the best situation, where they have both the advantage of large glue surface area and mechanical interference. If you were put a force in the opposite direction (pressing down of the levered parted of the joint instead of up) you would lose the mechanical interference and just rely on the glue strength. In fact in the six possible directions (up, down, left, right, towards, away) the half lap only has mechanical interference in two directions (up and towards), a bridle has mechanical interference in three directions (up, towards and away) and a mortise and tenon has mechanical interference in 5 (up, down, towards, away and left). If you put a dowel in your mortise and tenon it has mechanical interference in all six directions. This is why it is a joint you can use even without glue and why it is so popular for pieces of furniture which will experience forces from several different directions. Obviously the bridle and half lap have their place and they will likely stand up fine in a piece of furniture, but you shouldn't think of them as a 1-to-1 improvement over a mortise and tenon.

The new shop is looking great. I especially like the wood roll up door. Looking forward to the next installment.

A while ago i started using half-lap joints in typical 2x4 construction and it's amazing just how much stronger things became. Even without glue (just screws) everything is way more rigid since in something like a T shape (and to an extent a regular 90) the end of one board is kept from splitting by the board it's cut into. I use a radial arm saw with a small dado stack in it since boards are often too big to be safely shaped on a table saw.

Not sure if it's a new camera, lens filter, or the lights in the new shop but this video is on a new level

A nice test of the common flat joints. Since I make a lot of boxes, I'm looking forward to your upright joint tests. Though I will say that since I'm not making wooden strongboxes, I still mostly use the easier to construct splined half-lap upright joints for the corners. Yes, I'm sure finger joints (which I think are ugly) and dovetail joints (way cool, but with high skill & time requirements) are stronger, the modest half-lap, reinforced with structural AND decorative splines, is strong enough for my use. It's also easy to cut rabbets along the top and bottom edges of the side pieces for the inserted lid and bottom. richard -- “Everything that needs to be said has already been said. But since no one was listening, everything must be said again.” - André Gide

Hey Scott! It was cool meeting you in person last week in Toronto at the Festool event. Another great video. I just tried making a half lap joint last week for the first time, but it’s great to see its strength quantified in relation to other common joints. Looking forward to the next video!

I have a Festool Domino, one definitevely don't NEED it, but it makes your life so much easier. I believe it worth it's price.

The advantage of the half lap over the tenon is that you clamp the two sides of the joint together. You don't have that in a tenon joint, so the contact of each surface of it isn't tight.

Soooo... Bridle Joint, about twice as difficult to get that glue down in the crack (without a special jig), and just barely stronger than Half Lap. Got it! 😆 And you can EASILY make a Half Lap on any CNC even. So a fancy table saw is not even needed. 😆

Never had good luck with a lap joint. I definitely like the spline and will use it. Thank you for testing.

The traditional tenon width is 4/10. And like with dovetails the single best reason to use it is the ability to forego glue. Heck, if you work with varying degrees of green, like stick chairs, you don't even have to peg the joints.

As always, thanks for the video. I need to go through and watch all of your sled/jig videos. Appreciate your time sir.

Grwat video! I just made some flat panel quarter-sawn oak cabinet diors using bridle joints, and I'm pretty sure they will last longer than the house they're going to be installed in. 😁

Reason you were getting crazy numbers on the box joint was due to the jack being so close to the joint. Double the distance from the jack to the joint, and will break at 1/2 the force. It's like using a torque wrench, longer the handle, the easier it is to turn.

My experience restoring furniture, particularly chairs where the joints are put at challenge, is that the main joint used is mortice and tenon and the most common failure is glue related, then tenon related and very few was mortice failures. This makes me think that if you want something that lasts a long time mortice and tenon is the way to go and to make a tenon ticker then the canon 1/3 is a wise practice. I found some pegged or wedged tenon joints without any glue older then a century in perfect shape, I doubt that any joint that relies on glue can last so long as with time the glue cristalizes and becomes brittle so can not cope with the seasonal movements of the wood. If the goal is to build something that is very strong but does not have to last a long time then rely on glue is a sound practice so in this case tests like this one can help, while I doubt that can help if we build something that is made to last a long time, an example is the miter joint if used in a frame, the wood expanding and contracting due to seasonal changes will constantly change the angle from the perfect 45° we build and a glue failure will happen.

Missed your videos Scott, glad to have you back!

Thanks for these awesome videos. I’m trying to build a fairly basic shelf, except I need it to fit inside of a closet with a small door, so I need to be able to assemble (and hopefully disassemble it when needed) easily inside the closet. Also, I have limited tools, I do have a miter saw, a circular power saw, some chisels that I’m terrible at using. I’m considering getting a router, as they are fairly affordable and don’t take up much storage space, not sure what bits I’d need (and bits seem pricey). I’m trying to avoid buying a table saw, as I don’t have the space for it, and do as few cuts as possible, so I’ll be getting pre-cut 2x4s for the legs (I think) and pre-cut shelves (48x15.75). Since I want it to be easy to assemble and disassemble, I’m trying to avoid screws and angle brackets as much as I can. I’ve been researching wood joints. Thinking something like a half lap or dovetail to prevent the frame that would hold the shelf from sliding in or out of the legs. Also considering trying to do dadoes in the main legs for the shelves to go into, but I’d still need something to make the whole thing stay together, and to stop the shelves from sliding out. Or maybe just a mortise & tenon with some soft of a peg, to stop it from sliding out for the long way part of the frame, and maybe halved lap joint for the short way to hold it all together. Hopefully this makes sense, any suggestions for joints and tools needed?

In most cases the mortis and tendon is the strongest joint if you apply tension in all directions and also it is a concealed joint as to say not exposing itself this is essential in fine cabinetry

Thanks for mentioning Stewart!

Thank you for the (series of) excellent joinery videos. I loved it and I especially liked that you showed homemade jig options for each method. One small point I would like explained further… when you are splining a miter joint isn’t almost all the added strength added to resist “closing the book” vs “opening it”? I would love to see a testing series based on the real world failures of frames. Dropping against a corner, etc Thanks for the awesome videos !

Forgive me if this was pointed out, but keep in mind the distance from the joint where the jack presses changes the leverage it gains. As long as it is consistent, the measured break results should be relatively true. But I noticed in the teaser clip of a different joint, that the jack was about 1/2 closer to the joint. This result will not be true, relative to the others. I hope that makes sense… Love the video, though!

Thanks Scott! Excellent video. Nice to know easy can be just as good, if not better than, fancy.

Scot...Great to see a fellow CDN 🇨🇦🇨🇦🇨🇦 woodworker online...grand You Tube videos!! Have learned a lot...& you saved me from diving into a Domino kit!! Is there a link to David "Presutti's" Miter sled build?

Thank you Borat

I do love a good joint.

Chocolate teapots can actually be really helpful in certain situations

Congratulations on the new workshop!

I've always liked the look of a half-lap with a dowel through it.

I would definitely love to see some tests on differently proportioned mortise and tenon joints at some point, I can't really find any testing online.

Not all joints are equal, but "by how much" is tricky to tell. The tests I see treat the joint as a monolithic structure. In fact, it is composed of many micro-elements. So when the splined miter is tested in a mode (compression, or pushing the two ends together; vs. tension, pulling the two ends apart), you have to examine the elements. External compression of a joint creates both compression and tension in the wood; likewise, tension test of a joint also creates both tension and compression elements in the wood, but the locations are different (of course). The role of the spline changes depending on whether the wood at the spline is in tension or compression. A spline doesn't help much when it's in compression; but when in tension, the spline can enlarge the stress area, allowing more stress before failure. The joint is not uniform in its strength direction, and most testing only operates in a single direction, which makes simple conclusions very difficult.

Educational and entertaining! Thank you for honoring others who give us test results as well as your own testing, which is credible and invaluable.

3:55 The miter was 2.4 times stronger than the butt. Most of this difference could be explained by the miter joint being 41% longer (=sqrt 2) than a butt joint. Beam bending strength increases with the cube of the beam height. 1.41^3 = 2.7 I suppose the difference could be in the end-edge grain difference and whether the outside corner buckled.

I wish you showed the breaking in more detail. You have two fundamentally different types of failure: The glue, or somewhere that's not the joined surface. Your first miter joint was interesting in that it opened up gradually as you increased the force, rather than breaking suddenly. Your lap joint broke elsewhere, meaning the glue was the strongest part. The bridle joint improved the strength because you had grain going in two directions at right angles, like plywood. This makes it more difficult to pull the fibers apart in one of the legs. Also, note that you can make a lap joint that looks like a miter, on one side.

Traditional cabinet joinery does not need glue. For example, a corner lap is a glue joint, whereas a mortice and tenon is self-supporting. The Japanese are masters at wood joinery designs.

Great video. Thanks. I would have liked your conclusion on the experiment. Perhaps, strength vs. effort?

The mortise and tenon is the Holy Grail because of its difficulty, not because of its strength. I don't even bother with them. Time management is king for my shop.

I love the look of the bridle and half lap but the mortise and tenon has another longevity benefit that might not ever actually matter, but m&t holds together on the ends when other joints might pull away from humidity. that's because the m&t has that enclosed wood framing. It could split but that would require force that would also pull the other joints away too.

HE RETURNS! Make more videos please Scott!

The major difference between butt joints and miters is that end grain allows much greater surface area due to the channels naturally present to accept glue in the end grain, as opposed to the negligible spaces in the surface of the flat of the board.

Tis all about application. If you are making picture frames, then a glued mitre will work just fine as long as there are no weight/stress issues associated with the overall project. As I used to tell students you can keep trying differing joints for different situations and details, but do be aware that you don't need an elephant gun to shoot a mouse. Tis all about application.

Simple explanation regarding half-lap: glue, when fully dried, is stronger than the wood it's holding together. This is why plywood exists...

Great job Scott! Interesting results. I know a preponderance of woodworkers focus on joint strength, but is that because we are only seeing the amateur woodworker side on YT? What about the professional woodworker perspective? The TIME == $$ perspective. Do I really need my drawer joints to support 500 lbs of force? What about a utility curve perspective? Time/effort vs strength or another way to say it would be how fast/cheap can I make the joint that's good enough for the purpose? Looking forward the 2nd part video! (the new shop looks great!)

Nice! I always love watching these woodworking joint testing videos. Also, nice new shop!

Excellent job! And a pantorouter shot!

nice test jig! except it would be better to put the bottle jack outside of the scale to joint pathway, so that the effects of you pumping on the jack handle do not interfere with the measurement.

A whole lap does exist. Just slap those two boards together without any cutting. :)

I only subscribed for the glasses. Please bring them back 👓

Hell Scott.. I thought I was the only silly goose in a woodworking shop..

The strength of a simple miter joint is good enough for anything, and it looks decent, and if you want to make it look fancy there is such a variety of ways you can do that with spines. I don't think there's any reason to bother with fancy dovetailing and the skill that you have to develop for that when you can do something that looks almost as cool and is as strong.

The other guy's miter splines also went full depth on the miter; yours were limited to a bit over half by your table saw blade.

This was a lovely video. Your beauty shots of all your joints are fantastic. Some nice tips and tricks sprinkled in.

A thing to keep in mind when comparing with traditional joinery convention, is the tools used to make those joints. Miter joint is far more difficult to make with traditional tools than a mortose tenon joint. Even for a lap joint, the surfaces must be smoothed perfectly for the glue to hold up, which is harder to achieve with traditional tools. A mortise tenon joint, relies more on mechanical strenght.

Nice job Scott

Being old, 68, I started in late 1960s. Glues were nowhere near as strong and the only machines we had were lathes. Tenons and mortices had to be strong without glue, maybe with a peg, and the glue was not as strong as the wood. Now, the wood fails before the wood

No one has answered to my satisfaction just how strong a joint has to be and for what application. I wouldn't want a butt joint for a bed frame, but it would be just fine for a picture frame. A cabinet made with pocket holes and glue is a modern technique that seems to offer the potential for centuries of utility.

I like your miter spline jig. I have an idea to make it more versatile. It appears that it is made for only one width of mitered wood pieces. Why not make one of the angled pieces to slide horizontally to accommodate various widths. Mill a horizontal slot in one of the 45° pieces and add some tee-nuts to the sled. Attach the movable piece to the sled with bolts with knows. To use it, place the workpiece in the jig, move the movable piece to the desired opening and tighten the movable piece.

Thank you very much. That was a very thorough test and most illuminating.

9:56 Ohhhh NOOOOOO! NO WAY!... I heard those "encouraging" and "thoughtful" words once before, many years ago!... 12 to 18 hours before I woke up in the woods next to a briefcase full of cash three states away from home wearing the front-half of a two-person Unicorn costume... Thank god I had an entire paramedic-flight bag stuffed full of Funions and Pepsi!.. It was a long and awkward walk. BUT, at least it was raining really hard the entire time to take my mind off of the missing finger!

Welcome back!

Very good video Scott. One question, I noticed your joints broke a lot on the actual wood, then the question is: do you think if you use harder wood the joints would be stronger? Maybe another video, hopefully...

Thanks for testing - it's great to see some unexpected results, but mortise in MT joint usually does not goes so close to the end of the board - there should be some "meat" left for joint to hold on.

you forgot to test the hand tool only mortise and tenon - the strongest of all!

Very nice show, dialog content and delivery great.

Your back!!!!!

If more glue is the way to get a stronger joint then clearly the best thing to do is to get rid of the wood completely and make everything out of glue and rename our profession to Glueworking.

This is a glue strength test showing results based on surface area, more surface area more strength. Assemble all these joints using wooden dowel or wedges etc that would be a better way to show joint strength. These results would be different using different glue types.

If you're not painting the cabinets (in which case you'd be looking at a lot of painted endgrain whenever you opened a door), and if the client isn't averse to some endgrain in their door joinery, the bridle makes for a highly attractive joint. I know I sent hundreds of such doors (meaning thousands of such joints) out into the world, where they would last a few centuries in the unlikely event they don't get scrapped in about ten years time, which is about as long as kitchens survive before the next remodel, in the U.S at least. Sort of sad to think about it like that. Then there's the thousands of handcut dovetails in the drawers… _Fine Woodworking_ magazine did this test a few years ago (I think they may do it periodically), and I recall the bridle proved to be the strongest. I did a more informal test on my bridle joints: I glued together a rail and stile, stood the stile upright on the floor, and then made a seat of the rail by putting virtually all my weight on the distal end. When the joint didn't budge it was good enough for me.

youtube just randomly suggested you to me, and it was a great reccomendation, you are so interesting to watch and talented, the first video was the flipping coffee table haha

Great sense of humor

I believe that the strength of the half lap and bridle joints comes from the fact that you are clamping the glued surfaces directly together. The mortice and tenon for example does not- no way to close an imperfect fit.

Most joinery is not stressed in either closing, or opening fashion, but rather sheering... for which the spline and mortise and tenon are strongest at the grain direction, and are a really good choice. The half lap is best because it relies on the glue more than the wood for strength, and the glue is by far, stronger than wood itself.

Thanks!

An important point: the solidity of an assembly depend of the proportions: so, if you try with a thicker miter, or if you have a thicker tenon it will be stronger. As you see, the sides of the mortises are 2/3 and tenon is 1/3. The miter you used was perhaps only 1/5 or less. Even, that's widely strong enough to build a furniture.

Ive noticed that most of these strength tests don't usually include mortise and tennon, half lap or bridal joints with two through dowels as well. That I'd really like to see.

6:58 - maybe i didn't get the joke but a chocolate teapot is a good analogy for something that fails under its intended use. Anyway, all the testing is very much appreciated and unlike so many youtube testers you seem to actually reach for some semblance of a statistical sample.

That is quite the eye opening video! Thanks for posting this very useful info.

Wonderful video, congrats on the new shop!!

maybe you should test those joineries to their intended orientation of strength or load-bearing characteristics or how it is designed to hold or oppose load and tension. Surely all of those will fail if the force applied is on the opposite side or not the intended directional orientation of the joinery design. And maybe clarify the most suitable uses of each joinery as additional info bits :D

Been watching the progress on Instagram. Super excited to watch this

I'm curious: when is strength a factor? Certainly making a box, certainly not when making a cabinet door frame. Perhaps match the joint type to strength?

The reason you use 1/3rd is simple...leverage. The longer the tenon, the more leverage you give to turning forces.

I may add that the reason why the mortice and tenon is regarded as the strongest is because it is when the wood is thick enough. The strength of half laps comes from glue, the strength of mortice and tenon comes from the wood. On thinner pieces of wood, the strength of the glue on half laps surpasses the endurance of the rather thin slice of wood around in a tenon. If you take pieces of wood three times the thickness the glue surface in a half lap is the same, but the tenon (and mortice sides) triple their thickness. If you imagine making a frames for barn with 8 by 8s or 10 by 10s, those tenons can withstand literal tons. For regular furniture-sized project since the development of glue there are stronger joints than M&T, but if you go big it's still king.

Ultimate strength isn't usually the main goal of a joint... longevity, beauty and other characteristics are more important, usually... If ultimate strength were the goal, we'd make joints as in a wood aircraft fuselage and wings, quarter round glued internal corner braces, and plywood plates nailed and glued over intersecting butt joints...

How about the most maligned joint the pocket screw? For case work more than strong enough and quick and easy. I was a little surprised by the strength differences. Thank You

A nice addition would be cross dowelling the bridle and lap joints like a draw bore mortice and tenon

A glued assembly has to be made so that the glued parts are working in shear stress, and not in traction. Glue isn't effective while stressed in traction mode. Probably explains why the miter joints were bad

Thanks

To compare to the lapped joints, you should have made a 'through' morose and tenon, whereby the mortice extends right through the piece of wood and the tenon is as long as the depth of the mortice. This would be more comparable. A short, stubby tenon joint is less strong..

I noticed that in some cases, the WOOD broke, not the joint, meaning the joint was stronger than the timber.