Ordered as presented (breakage) in the video: 1. Butt Joint 60 lbs 2. Lamello 70 lbs 3. Domino 100 lbs 4a. Pocket Hole Inside 110 lbs 4b. Through Dowel Pins 110 lbs 4c. Dovetail 110 lbs 5. Pocket Hole Outside 170 lbs 6. Miter Joint 210 lbs 7. Box Joint 220 lbs 8. Miter with splines 270 lbs

@lolilol lolilol sorry for that bad translation. I think the chemical correct name is disodium silicate or natrium silicate. Basically any dehydrated silicic acid

@De Al what the hell is water glass ???

Howzit?

@Steve Perreira, link to that video when you finish it

Spoiler alert! :-)

With the dovetail I think it would hold best against consistent back and forth racking not just point load. What I mean is it wouldn't loosen up over time as easy.

Only extra thing id love to see tested is equal dovetail rather than asthecic dovetail. Having same thickness tails and pins is likely to be stronger than the asthetic skinny pins version.

Watching your results, one question would be how strong a true diamond (e.g., a drawer without the bottom) done with butt joints would be -- would it be weaker or stronger than the 60 lbs? Another thought (you did say a couple different ideas came to you) is that your pocket hold test needed to be done both ways -- with the pocket holes on the top of the support as well as the underside of the support. I can see how the stresses there might be different, since it's a kind of butt-joint with screws. As-done, it stressed the screws exactly in the "right" direction for maximum strength. Given your winner (see my other post about unconsidered alternative joint types), I would really really be interested in seeing the results of the angled miter spline (e.g., the "bowtie spline") and the angled dowel-miter joints. I'd be even more interested in an exposed-dowel angle miter -- one where the dowels penetrated inside the box to give them more angle on the corners (it would still be a somewhat decorative aspect of the work) e.g., the dowels were visible on the inside corner instead of fully contained in the wood. That plus a small angled-wood piece in the corner itself could make some interesting variations if the strength of the joint was highly important. The bowtie spline in particular would be less prone to failure given the way the splined miter failed. Whether it would weaken the joint in some other way is obviously a question.

i am way late on this and don’t know the technical terms but i’d love to see this with a dovetail joint with the tails and pins the same width (closer to the box joint but just with dovetail angles). also, a butt joint with screws

You also have to consider what the joint is for. A dovetail joint is designed to be strong in a particular direction - resisting pulling apart against the wedge of the dovetails. It's not as strong when being pulled in the other direction, and the wedge shape of the tails and pins may even make it easier to collapse in the diagonal force direction that you applied. If you were to retest with a 90° pulling force instead of a 45° pushing force, your results would definitely change because the mechanical advantage of the dovetail would actually play a factor.

@Duane Miller unfortunately You are absolutely wrong. In fact end-grain to end-grain glueing is indeed stronger. https://youtu.be/m7HxBa9WVis

This woman joints 😂11/10

its always nice seeing a woman who can appreciate math. stay away from the dark side

Yes. Not to mention the dovetail joinery is not meant to be glued together. It’s meant to be able to hold it self together with a shape alone. Counteracting a constant and predictable force.

@Daniel Hutton I have had (to many) years to learn it. I'm old, I lived the first 9 in Toronto Canada, and danish is so small a language, that we grow up with english on tv aso all the time. Besides that YT and 98% of everything I am nterested in is on english sites, and I actually prefere to do things as well as possible - without it slowing me down much. I'm "the guy" who apreciates being corrected, if done in a nice way to help. If it's to be a d*ck, I stab the person verbally, if I can.. :D About your not speaking german - our parents spoke danish at home, and had danish friends, and I didn't learn english before going out to play with others. But my a-whole dad forced me (not my sister - scape goat/golden child narcissist dad) to write "a diary" of my school day, and learn danish psalms by heart, so I haaate reading and writing - crappy parents might teach you things, but break things in you while doing it - so "f*ck speaking german :) ). I'm guessing your dad isn't german, or else you probably had picked it up. And how many times have you needed it - I guess about zero.. :)

Excellent video. Answered alot of my questions. The miter joint might be strong today but let it sit on a shelf for a year or two then try it. The box joint will be just as strong year after year.

Please do a drawer lock joint, the one made with one router bit, the drawer lock bit. I've gone solely to using this and would be interested where it falls. I would think it would probably come in 3rd, but just a guess. Thank you for the video, very helpful!

Miter joints may be stronger in this test, but unfortunately they're still more likely to come apart overtime than most others, just due to wood movement

Here is a bit of science behind the mitter, the 45 degree angle has larger contact surface between the 2 boards, also the angle in the joint is parallel to the ground so I think It handles the torque force way better. Im not an mechanic engineer so I cannot assure you that but its my observation.

As an engineer specifically in structures, the applied force and direction in relation to the joint have a huge impact on the results. The joint actually felt more force than the weight you put on top. This is called a moment arm between the joint and applied force. This is measured perpendicular from the joint and the applied force. I agree with you that more test would need performed as this is one case out of several cases and only measures the strength of these joints in a very specific instance. Still fun to watch and interesting.

@Mjolnirs Wrath everybody said I was stupid and it wouldn't make a difference when I took half inch wall thick quarters of PVC 12-in tubing and adhered it into the corner sections of a box and then demonstrated how much better the air flowing sound was after doing it. It's really interesting to observe the wave pattern behavior in a square shape versus a circle obviously the air movement will be far superior in the round enclosure after experimentation. Every right angle causes a standing wave and has restricted air movement

@Mjolnirs Wrath definitely

@Johnny Corn boxes are Piss poor Speaker Enclosures and cause Distortion, Spherical Enclosures are Far Superior due to internal and External distribution and Far less influence on Voice coil and diaphragm A more perfect piston movement

I think the people saying this lil experiment is flawed or not “valid” are incorrect. This just looking at one datapoint. Load in one direction with the joint at a certain angle. Completely valid for what it is. Could other ways of stressing this joint be helpful or better? Sure but that doesn’t mean this not useful information.

I build subwoofer boxes and some of them need to be very strong. what would be your recommendation for this particular application where the strength of the subwoofer can tear the box apart from the inside out if not sturdy enough. The higher power you go the stronger the box needs to be

The bevel cuts has more surface area than a but cuts. You are right about end grain soaking up the glue but the trick is to use slow setting type and too apply two coats of glue, let first coat soak in till almost tacky then refresh it, doing it on both ends, then clamp together. The other thing is the dovetail is directional stronger one way. The other thing I noticed was that you had both ends captured, you only needed to capture the bottom, then let the top slide onto weight board. The other thing is that that not the true weight that's on the joint. The weight is actually at a 45° relative to torque put onto the joint. Look up the definition of torque you know what I'm getting at.

My theory on the dove tail is that the pins were just too small. Your box joint beats it just by having more glue area. I think you could get a significant boost with a 50 50 ratio of pin to tail

Exactly!

My guess was that maybe the dovetails are not as tight as the box joint...

Was literally thinking the same thing.

@Kangal well, he did actuall mention that he made sure the same glue was used... 19:32

@Bryan Not for the dovetail. It was made outside, so it's not likely to be the same glue.

They had a machine made joint around the turn of the century (1900) that used round “dovetails” for drawer boxes

I would love to see this test done a second time with the same wood and joints, but this time testing the breakage in a pulling direction. As several already mentioned in the comments, different joints are strong in different aspects, and depending on what you're constructing you may need some joint over other. In physics, we call these different loads *compression* (what was tested in the video) and *tension* (if we pulled the ends apart). We also have *torsion* (by twisting the joint) and *shear loads* (by dislocating one board out from the plane of the ∟-shape), that would be interesting to look at. The differences in these strengths are actually quite important in fabrication. For example, if we were to construct a box (with no top or bottom) using only Miter joints we would now expect this box to be super strong from what we just learnt. But this is not necessarily the case.. If we try to crush this box (by for example by standing on its edge), only two of the box's joints will be under compression (the two joints on the side). The other two joints (the top and bottom joints) will actually be under tension. So if the Miter joint happen to be very weak under tension, then the box will break pretty easy, even though the Miter joints are super strong in compression.

You can use the word we all you want to, but it doesn’t change the fact that you obviously don’t know anything about structural engineering

@John Paulson Exactly, duh

All what you said is right, but please consider this is a YouTuber works, the main idea is to attract eyeballs 😂

Byyj

The joints tested are in bending. There is compression on the inside, and tension on the outside of the joint.

As a structural engineer that designs wood connections all the time, it would be really interesting to test the strength of something other than the glue. Some of those connections seemed quite strong if it weren’t for the “snap” of the glue bond failure. I’d love to see just how high you can go with things like truss plates, angles, and structural nails and screws. Obviously a carpenter isn’t making a cabinet to withstand an earthquake, but I think it would be fun either way.

Mmmm. mmmmh. mMaaybe I will!🤔strokes chin.

I would also be interesting to test these joints on different load cases. For example, pulling the opposite direction of the video, or straight pulling as well. There are no tests I know of, except calculations.

In Japan I guess cabinets are made to support earthquakes 😂

@mmm mmm So I shouldn't be gluing AND screwing my butt joints on say cornhole boards

@Homestake Models yup. not to mention the fact that joints are usually put together using glue. not using it would make the test even more pointless...

I'd love to see this test done in the sheer/torsion direction - 90 degrees from how you had it. And see how the joints stack up there. Some might be better in that orientation.

You should have tested a simple finger joint. It would have probable have been the strongest. It's been used for high strength shipping and ammo boxes since the 1800s. Its' all about the total cross grain glue area. I tested an almost identical 1/8" finger joint in 3/4 " yellow pine. I'm a fairly large guy at 220#. I tested the joints by setting them on the floor, apex up, and standing on the joint even Then I bounced on it. It would not fail.  A simple miter joint is also strong due to the increased glue area at 45 deg (thickness X 1.414).  All end grain (and 45 deg) joints can be made stronger by priming the joint with glue prior to glue up...kunk

You should team up with dusty lumber to test the next series of joints. I’d bet he has some damn strong joints

it'd be interesting to do a test on joints 1 year after they're glued, to see what kind of effect time has on the glue/joint integrity.

@sh0cktim3 I dont see it failing anyway since decent wood glue is stronger than the wood its holding together.

@Justin Smith I don't see the miter joint failing at all on a drawer if you add splines. The joint is so simple it shouldn't work so good, but apparently it does.

Ya, hopefully people don't start making drawers with miters because of this, lol. While this video was cool, the test was more or less irrelevant. The vector of the force was different than a push/pull force a drawer would receive. For a miter join, the glue would take all that repeated force over years which would inevitably lead to a failure. The dovetail, however, is distributing that force to wood-on-wood contact. Meaning, for the joint to fail the wood itself *must* break. You don't even need glue for a solid dovetail join. Fun test, fun video, but ultimately "wrong" and misleading.

@Dan Kay Grats on letting everyone know you are a pathetic loser.

Time is one thing, I would be more interested in repeated loading. I doubt that box joint would hold up well if you put 30 pounds on it 100 times.

Testing under a tensile load and testing fatigue strength to cyclical loading would probably have very different results and would be interesting to see

B4 watching the video, I’m betting on the dovetail, which I make hand cut all the time….. hmmmm, I was wrong…. Good video.

Great video! I hadn't learned this much about joints since watching Snoop Dog's TED talk.

I would be curious about 6 u would happen if you put a dowel or a nail through the finger joint . One that I like to use is a butt joint with screws into a dowel inserted into the edge near the end perpendicular to the grain.

Loved watching thee tests and the method you used. The dovetail could have been starved of glue. To many people make an ultra tight joint. No room for adhesive. I spent a good part of my life as a Cabinetmaker. And made hundreds of dovetail drawers via a dovetail jig I made in the shop. I found that I needed a certain amount of slop so that there could be proper glue joint allowance. Too tight and I squeezed out all of the glue.

It very much looked like it broke on the glue edges (which are long grain to long grain) - I think you're right.

@tom ruth Exactly.

I imagine the same is true for box joints

I'd like to note that the differences between the dovetail and box joints has a lot to do with surface area and the glue. Early in the video the glue butt joint performed much better than expected. The smaller cutouts on the box joint had significantly more surface area for glue. I'd like to see tests where either the base or the end of the dovetail are equal to the box joint. I think that would pose some interesting results.

Setting in a cabinet the load will be much different

Regardless of strength, I think contrasting splines in joinery is a great way to add character to what could be a simple piece.

Except you get to add character AND strength. I always enjoy form + function.

Miter had me stunned! Thank you for running the gauntlet! Also, stray option that might help: Drill into the narrow edges of the box-joint, and plug with wooden dowel (imagine if you were making a 'hinge' out of wood, dowel plugging through each 'tooth' of the box-joint) to prevent the two boards from tilting out of alignment; it should force the inner dowel to fail, first, which'd be difficult in that confined bore.

I would love to see the follow up video to this with more tests: • different sizes of dovetails/fingers • different wood glue uses • different woods and whether or not cross-hatching helps wood glue hold it tighter I liked and subbed!

I would like to see how equally sized dovetails fare, like how I was taught to make them. Less risk of just pulling the dovetails right off. But even then it’s of course going to depend on the direction of the force. In one direction it will be only about as good as a biscuit/domino/dowel joint.

Miter joint with splines IS the prettiest imo. followed by a miter w/o splines

As a completely non-woodworker I definitely guessed the splines and was pleased my guess was correct. My thought process was that the way your contraption was setup is that it emphasizes compression on the inside of the joint which translates to tension on the outside of the joint. So I assumed those splines would be best to resist that tension since they are full grain wood running the exact direction of the tension.

@Robert Hardy if the spline were cut in to proper depth (i.e. all the way through the joint) then it should be comparably strong for forces opening and closing the angle of the joint. If the spline was cut in very shallow then it would perform much better in closing the angle than opening. If I wanted to get really granular I could say that it should perform better with opening the angle if the applied force is properly compensated to apply the same torque relative to the joint hinging axis, and I would say this due to the fact that the spline depth perpendicular to the joint face tapers unfavorably toward the outside corner, causing the spline to want to pull out at the corner instead of actually providing the full axial strength. But on the inside corner it's the other way around where the spline has maximum length embedded and glued into the work piece, and thus maximum opportunity to provide axial strength without locally pulling out. In practice I'm not sure how significant this becomes.

Exactly, had he tested the expansion of the joint under the opposite load instead, then the joint would have failed earlier.

im 16 never done woodworking in my life randomly watching this. And instantly knew the splines would win because the wood is going the same direction as the force. Like its hard to tear a pice of wood by pulling on it or i n this case compresing. idk

Excellent analysis! This is the type of logical thinking I wish I'd see more of in woodworking. As Donny P said, most woodworkers seem to have very little understanding of these things.

well, this will teach me to read comments before I finish watching the video!

Awesome test and wonderful neutrality. I guessed it right! I figured the splines would essentially act as struts for a triangulated joint. Right, my pick a stronger joint would be: Box, with a dowel run longitudinally through the assembled joint. So visually it looks like a hinge pin. Just need a long drill bit! (I just made that joint up in my head.)

Nice job on that testing! This is good information to know. Here's a suggesting about a joint to try: Make a box joint, but dowel it so the dowel runs through all the fingers of the joint. That means only 1 dowel and you need to drill it perpendicular to both boards. The dowel will be the same length as the width of the boards. Does that make sense to you?

Great video! For some reason I suspected mitre joints to be rather strong, not simply because they have more surface area to hold glue, but because they convert the pressure on the joint to compressive force entirely eliminating torsional and shearing forces where the glue can best resist. but I never guessed they'd be THAT strong. There's one joint I presently go to more than any other; it's a locking mitre. For solid wood, I just use the router bit. For veneered plywood, I use the table saw, dividing the thickness into thirds, use the inside two thirds to create a locking dado, leaving the last third mitred. (Obviously, this is easiest using 3/4-in plywood.) It hides the plywood core completely leaving a finished corner inside and out, and I can orient the joint to oppose the direction of greater stress, and so far, they seem to hold an incredible amount of weight. I'd be excited now to see how well these test. Thank-you for this video.

I would think a locking mitre would win, and I was disappointed that it was not included in the test.. Otherwise it was an excellent video.

Great video, very interesting. I'm a retired carpenter and I briefly studied Japanese joinery about 40 years ago. They use incredibly intricate joinery that has to withstand earthquakes. I was buying Japanese shark tooth pull saws years before they became popular here in North America. We had one time use feather files for sharpening them. They also use slip joints so that during an earthquake the joints don't snap and break they move around.

The dovetails we used when I was making furniture, were more like your box joins in size and spacing, just dovetail shaped. Maybe the size and number made a difference. I think the big difference with this test is the amount of friction you can have versus tensile strength, maybe the ultimate joint would be the mitre with splines, but have the splines being evenly spaced and sized to the actual join wood, or at least increase the number of them. I have no idea really.

I've always thought of dovetails as more decorative. Box joints are stronger. I wasn't surprised. The strength of the miter joint surprised me though.

Dovetail is a fundamentally flawed joint type. Reguardless of the size or amount of em. All the pressure from the weight ends up on that small short "triangle" shape at the sides of each dovetail. So just as you saw, the wood will break on that triangle line leaving one side looking as if it was a box joint because that small wood section ends up as the weakest part of it making it much weaker than a normal box joint.

"...too thin." Remember how the glue only has to be just a bit stronger than the wood? Same holds for joint geometry. Look at the failure mechanism of the dovetail joint--the board failed in tension across the grain at a dovetail pocket. Why? Because dovetails are wedges. Wedges offer a mechanical advantage. It's why we use a wedge and maul, or a tapered axe to cut firewood. I'm not surprised at all that the box joint beats the dovetail, because it has the same loading through compression load transfer without the wedge effect. Still impressed with the miter joints. And lest anybody here try to introduce tapered tenons--just don't.

@John Brueggeman The joint is with respect to the types of wood used. The surface area depends on the porosity in the end grain and cut seams and the types of glue used. There's a large volume of physics and chemistry required to approach the limit of maximum stress:strain on a given surface area. The labor and time to produce the best joint often isn't worth the return on investment. If you want to build drawers that withstands a nuclear explosion then change the materials. A weld is always stronger. Mitered finger joints will always be the strongest. If you want stronger, then increase the number of joints per inch until you exceed the fiber strength of the wood used. Then you'll have failure in the wood, rather than the glue.

I don't know a ton about wood working, but the dovetail joints that I see are evenly sized. If you have much smaller joints on one than you do the other, it would stand to reason that there is a weakness in the smaller joints. So i agree with this comment.

Great video, thanks or simple easy comparison. I would like to see lock rabbet joint added to the list. I’ve heard they are stronger than dovetails which is not surprising given your test results. And they are really easy to make.

Fascinating video. I was not at all surprised with the miter/spline joint coming in first. I make these fairly regularly and are not only strong but give a nice modern look as well. Also to consider, although they wont live at 90 degrees, miters with steeper angles. Increasing the surface area of the connected materials and making incredibly strong joints.

I love the approach, this has been a fantastic ride. I am amazed by your findings and yes the lowly butt joint and his buddy the miter joint are far stronger than we need for most things. As you mentioned, I wonder if the advancement in our current glues has helped the “weak” joints be much stonger. One thing that is bothersome in my mind is that I don’t see dovetails used with stresses like this. Think of a drawer front. The dovetails are pulled on in line with the sides of the drawer. What I getting at is we have different types of joints for different applications. I really enjoy your presentation thanks for all you share with us.

Very interesting! I am a civil engineer and I would like to give a bit of info on the miter joint. Essentially, the force you are putting on, is put on the closest to orthogonal (the direction is closest to perpendicular) to the glued surface of all joints. With glue being best at pulling perpendicular to a surface, rather than having the shearing force of a less perpendicular joint, this is a great combination. Then lastly the miter joint has a greater gluing surface, allowing for an even higher pulling resistance. Its simple physics if you think about it, but it's not too obvious. In this test you basically only tested one direction of force. It might be interesting to test pulling force too, or a different pushing direction, I am almost certain the results will be quite different. With the right direction of force, the butt joint might even beat the miter joint.

@Aaron Stout I watched a glue comparison video in the past year or so that found End Grain glueups to actually be STRONGEER than Face Grain, which went against all previous recommendations. Perhaps the soaking of glue into the wood means the glue travels farther into the wood to provide more surface to adhere to? On the Miter joint, I think the physics part of it that BasTaart mentions is what is at play here and less about the end grain/face grain debate. While the board is trying to pull apart from the test, you have the inside portions of the joint pushing against each other acting as a small brace.

I also heard a convincing argument that end grain is a BETTER gluing surface, provided it gets enough glue. Since the glue bond is stronger than the wood itself, the breakage of the wood is the real issue, and wood splits a lot easier than it breaks. Therefore, my theory is that the miter is stronger because it eliminates the surface straight ALONG the grain, and converts it to something closer to end grain that can't "split"

An interesting thing is that the splines can be added to a miter joint after the fact. One part of the strength of the miter is that it is end grain to end grain, and wood glue generally works best that way - as it seeps into the pores, it effectively makes tons of tiny glue dowels in every pore of the wood.

Nice

Lots of great info and feedback here. As others have pointed out, a more thorough test should encompass different loading scenarios, for which some of these joints are better suited (dovetails under tension, for example). Other joints I'd like to see: Machine-cut dovetails. I think they'd approach the strength of the box joint with similarly sized pins. For that matter, try box joints with smaller pins to see if the additional glue surface helps. A miter joint with a spline parallel to the long direction of the joint, if that makes sense. Or, you could use a biscuit to do something similar. A rabbit joint, as used in the ends of drawers (poor man's dovetails). Keep up the great content.

Really interesting and broadly as expected, but I’d suggest the primary variable to be controlled for better understanding is the gluing, surface prep, glue penetration to joint and clamping forces. The timber variance cannot really be managed but I doubt it’s as significant so long as you have generally clean grain quarter sawn for all.

My ideas for a strong joints: -The 45° angle with thicker splines (similar to a box joint). Reason: It appeared as if the splines were actually the weak point. -Box joint but with a pin going through all of the pieces. The weak point of the box joint seemed to be the glue. So a pin should increase the strength by taking some of the load away. Another option would be to make the boxes narrower so the glued surface increases. That would of course combine well with the pin. If you want to be really fancy, you could try to reinforce that even more with some pocket hole screws. I think the possible strength of this is really just limited by the strength of the wood itself. -The spline thing but with deeper cuts so the splines actually go into the inside a bit. Another fancy way of doing this eould be to have bent splines so you are not dealing with pulling the grains apart.

My dad has been a finish carpenter for 40 years. I remember when he showed me how if you glue and clamp 2 pieces of wood and you went to break that piece of wood, it wouldn’t break on the glue seam. Wood glue is actually stronger than wood. Im assuming Mitre is strongest because you are glueing two identical pieces of wood/grain.

I think the idea of the dovetail being so superior is that as it begins to come apart or loosen up (say in a really old drawer that’s been opened and shut A LOT) it still functions whereas a miter, box, or pocket hole are basically shot the moment they start to loosen up

@Lisa T not very easy for someone who isn't a carpenter or doesn't have access to a workshop.

Ummm... sand and glue it again?

If you are still doing this.. try angling the outside splines in your mitre joint instead of all of them being parallel with your downward force. It could be as little as 10 degrees. Also, try some angled dowels as splines toward the inside of the joint. My theory is that the angles will transfer some of the downward force into other directions (namely into the wood itself) which would weaken the overall downward force applied to the joint. I also believe that there is an optimal degree of angle for maximum strength. Too high would be much less effective and would probably weaken the joint.

Also would be interesting to see how much the material used for the splines/dowels matters. It‘s likely that in softer/weaker woods, dowels and splines made of strong woods would have a greater impact on joint strength. I recently saw a gizmo for drilling dowels at opposite 45 degree angles (I think on 731 woodworks‘ channel?) which locks the joint together. Thought that was interesting. I‘ve seen many finish carpenters take that approach with moulding and brad nails, angling them opposite to lock it in, but hadn‘t seen it previously with dowels.

Thanks for this video, very useful info, presented in a clear and simple way. As others have mentioned, testing forces in other directions may give different results, but now that you've raised the question itself, and demonstrated how easy it is to test what we want to know, we can all check it for ourselves.

Such a well conceived and executed video. Fun, entertaining and informative. There are two types of forces happening to the joint in the test, the static force and the dynamic one as weights are added. I wonder if a hydraulic press and something measuring the force might be more accurate plus something measuring the angle of deflection at the joint. Very surprising result for sure.

I'd like to see a test for the opposite direction of pressure. Clamping boards to something upright and placing the weight on the outer edge to test joint integrity. I think a few of them would fare better and a few worse.

The strength of the miter joint is really surprinsing. A few thoughts on that: - Since your miter joint is 45 degree, and you placed it in a 45 degree angle, the strain is ideally angled, as the joint should "see" no to little shear stress. I wonder what happens, when you alter the force direction. - The surface area is around 40% greater than that of a simple butt joint. - The cutting surface is a mxiture of end grain and long grain. Could you do a test, where you presoak the endgrain in a mixture of water and glue, let it dry and then glue it? Super interesting video! I feel like such videos really bring reliable knowledge to the community!

I'm pretty sure it's not strong because of the angle. If you think about it the outside corner of the joint is being levered up with a lot of leverage, with the inside corner of the joint being the pivot. Seems pretty bad for the joint to me

Everyone looks at miter joints as less end grain and more side grain. I believe the benefit is actually the opposite. It's beneficial to have MORE end grain. By using a basic miter joint you have changed the test from a joinery test to an adhesive test. In a butt joint the side grain will shear because the glue is stronger than the lignin. In the case of miter as others have noted you are effectively putting the glue in a tensile loading situation. Almost anything you do to disrupt this glue line will have a negative impact. By installing the splines you have now adding two large surface area glue joints per spline(smaller the spline the better) that are in direct shear. They are not trying to split open the joint like the wedged dovetail.

The problem with using a simple miter joint in a project is that if you are off by a single degree and the joint does not make even contact with each other, the joint will be significantly weaker

@RaggedsEdge Not if all of the tests were repeated with the thicker wood, as I said

@Josh Bonney thicker wood would invalidate the test as an apples to apples comparison.

Funny and informative! As to science, from experience, now you have to replicate each of these 100 times, collate the data, run stats, write up your results, get everything peer reviewed, and publish in a reputable journal! Great video!

Just found your channel and what a great video! I would love to see this experiment repeated with the joint seated at the bottom of the testing rig so the weight pushes the sides of the joint apart instead of pushing them together (as was done here). Reading the comments, it sounds like there's some consensus that the dovetail joint may turn out to be much stronger in this situation, so it would be very cool to see this tested! I'm also curious if the miter joint is just as strong if the force on the joint spreads the sides apart instead of pushing the sides together.

I would like to see a miter with dowels

You defined my life as a woodworker: I like to make things stronger than necessary and more complicated than they need to be.

The simple miter makes sense in that you're increasing the gluing surface, although I am surprised it's nearly as strong as the box joint which has way more surface. I figured the miter would be maybe twice as strong as a butt joint. Plus, if you want to increase that even further (and add a little style), it's a simple matter to add splines. Might have to make it my go-to.

A great video to watch. And yes, the mitre join was far stronger than I ever expected. Two inconsistencies I felt made the testing inconsistent; First: The box join was cut 50/50 each side, where as the dovetail join was more 80/20, thus the 20% side failed earlier than expected. Just as different pocket hole joins are stronger than others, so too are dovetail joins. Second: The dowels and domino joins were using milder timber compared to the winning join, which used a more superior timber for the slots. If all joinery used white oak, it may have been a different outcome. I predicted the butt join to be weakest and the dovetail to be strongest, though as stated, I felt the dovetail got a raw deal on its joinery. I predicted the slot join to be second strongest. Not only did it win, but possibly the most aesthetic join of all, or at least on a par with a good dovetail join. It also highlights a simple but join with nails added is more than strong enough for any drawer. Thanks for going to all this trouble. It was great to watch.

Thank you for the interesting comparison you might wanna note that the test you've made might let you compare the torsion strength of these joints, and that the measure for the torque (NOT force or weight) equals the distance between the center of the mass (e.g. the weights) and the joint times the actual weight applied (units for this are ft.*lb.). So, referring to your say about "60 pounds is strong enough" - for a small drawer or box you might be right. but for bigger frames - you might wanna go for the stronger options Plus, I recommend to try a miter joint with pocket screws for even better torsion strength.

I love videos like this. Yeah there were a few things that could have been done better as mentioned in other comments, but in general, I learned something new. And that knowledge will come in handy when I go to do my own projects. Thank you for the informative video.

A lot of good suggestions in the comments. One thing I would add, it would be more beneficial to do multiple tests of each joint. It is entirely possible that one or more of the joints failed earlier than a typical example of that joint, and it is also possible that one or more were hero joints, holding on longer than a typical example of that joint. I know it is more work and cost to make and test multiples, but it would help to establish more reliable results.

Another point to consider is how the joint fails. Notice how some joints break instantly, while others begin to split, but are still together holding the weight. Also would like to see the result with impact weight.

@Bob Silverstein Not if *I* was singing, Bob.... the plant would die straight away. :)

@Mike Right. I’d even say that, between 3 and 100, you might not see much of a difference, but between 1 and 3 you could at least rule out a freak circumstance, which is why I think 3 is ideal. If 2 or 3 out of 3 perform the same, you probably can rely on the majority to be reproducible. But if you only do 1, you’ll never know if you got a lemon.

@sivacrom The big question is: If you build the same joint 10 or a 100 times, will there really be big variance between samples? Especially if you use exactly the same tools, same glue (and method of applying it), roughly same clamping force and so on …

@sivacrom also, I do remember experiments like the one you mentioned. Not surprising. You could even show that singing to a plant causes it to grow twice as fast, if you have an N of 1 :)

would love to see the same test but with soft wood (hard wood is expensive and because of that and a lack of woodworkers it's almost impossible to find hardwood and plywood in my country)

Another variation I use a lot is a simple miter with biscuits added for alignment. Maybe add that to the list next time. Very fast and easy to do, suspect very strong too.

Its pretty rare that a drawer or box is stressed that way. I would love to see these tests repeated as a pull test instead (think the pulling action on a drawer).

I think you may get differing results depending on the wood used as well. The stronger and harder the wood, the more surface area and friction are an advantage. Things like the dovetails would be good here because the wood would be less likely to break due to the thin sections. I think the reason the miter joint worked well had to do with the angle of the break. The surfaces between the two 45 degree cuts are completely horizontal, so the forces should balance. The break comes from the torque created by the off-center weight. This means that the glue was likely taking most of the load rather than the wood itself. Comparatively with a hard wood, the miter joint would be worse than the other options because once again, the glue is doing all the work, and while the strength of other joints would increase with a hard wood, the miter joint would just be relying on the same glue as this experiment.

As far as I can tell, the boxjoint (fingerjoint) was stronger than the dovetails, cause they were too delecate and thinn. If you’d made them more even in width or made more dovetails (5/4 or more instead of 4/3), like on the boxjoint it would have held more lbs.

Dovetail is a fundamentally flawed joint type. Reguardless of the size or amount of em. All the pressure from the weight ends up on that small short "triangle" shape at the sides of each dovetail. So just as you saw, the wood will break on that triangle line leaving one side looking as if it was a box joint because that small wood section ends up as the weakest part of it making it much weaker than a normal box joint.

Would have been interesting to see the box joint compared to one with more, narrower fingers, and even more glue surface area!

Similar to the dovetail being on the small side, I’d like to see how much you could increase the hold strength of the mitered spline joint if you used thicker splines and assuming straight grain perpendicular to the joint.

Simple miter kinda blew my mind :-0 The test were pretty much as expected. The issue with the dovetail vs box joint is that the dovetails didn’t have as much glued surface are as the box fingers, due to just a few narrow tails. => My vote for strongest, break-the-wood joint would be a dovetail with equal-dimension pins and tails and a steeper angle to them. Lots of glued surface area, and the mechanical interference between the pins and tails would make it much stronger than just glue alone.

Dowels were surprising. I knew the miter was strong but dang!! Dove tail I had second place. If the dowels were deeper, I wonder if it do better. Crazy results! Thanks for the time you put into this test. 👍

Credit where it's due - these videos are both informative and amusing - and also nicely put together - Good Work Sir! Good Work

One thing I'd add that I haven't seen mentioned yet: testing for max strength doesn't necessarily account for the effect that cyclic loading will have on a test joint — the goal with a drawer isn't to withstand a single incredibly forceful push/pull, it's to withstand pushes and pulls over the lifetime of the piece, as the materials age and as the piece undergoes varying environmental conditions. That's not to take anything away from this testing methodology. But rather, to point out that this test isn't going to give someone all the information they might need to select a joint design for a project. More specifically, I don't think it's reasonable to conclude from this test alone that dovetails are mostly for aesthetics. Beyond that, other people already mentioned the difference between static and dynamic loading, and I would emphasize that: it would be good to control for _how_ you apply the weight, to make sure that you're not (for instance) dropping the weight more when you're worried about a high stack of weights toppling onto your foot. Someone else has mentioned using a forcing screw, and I know Matthias Wandel already uses one for his experiments. Something like that would be a much more repeatable way to load the joint.

I love this guy. It was funny, informative, scientific, it had everything, even a lab coat. You sure know a lot of joint tricks. I would follow you anywhere sir!

Amazing results. It would be interesting to find out how diferent glue performs on miter joint.

Well the physics isn't quite right - but the consistency of your test makes up for it. If the boards were longer, wider, or thicker you'd have different results (physics) lol. Great test and very informative. Thanks.

So I'm a newbie - should I NOT be using pocket holes?

I'd like to see a mortise and wedged through-tenon setup (not dominoes) for the next go around. I suspect it would out-perform the dominoes and dowels, but it would be interesting to see the results. With that joint, the wood should break before the joint, if done correctly. That's been my experience with them anyway. Also, how do you NOT have a dovetail jig in that shop? Seriously. You literally have all this stuff nobody has ever heard of, but you have to outsource a dovetail? That alone may have blown my mind more than the test results. Anyway, really enjoyed this. Looking forward to round 2!!

A corner joint such as being tested here, is not the correct application for a through mortise and tenon. It would not be strong at all. The end grain of the one piece of wood would just blow out.

Very interesting and fun experiment. I wonder if a miter joint with dove tail splines (perhaps an experiment in itself) would be even stronger

That was a great experiment. I have to admit that I had the miter joint not lasting much longer than the butt joint, which I di have as the weakest. I also thought the dovetail with all of it's glue surface, and the cuts at angles would be stringer than the box joint. You learn something new everyday. Thanks for doing this!!

I almost always use a miter joint on drawers. Quick, easy looks great when done well and if you ad naills on the outside they are never seen and just add to the strength on the pull force. Great test I would like to see if it weakens or strengths with the nails. Plus why don't you do a pull test on drawer fronts with the joints? Keep up the great videos...Cheers

Great video, super interesting. I think that the strongest joint would be the box joint with a tweak. If you drill a hole through all the fingers and insert a big nail, it would hold 300lb.

I've found that while butt joints offer more than enough strength in a single instance, the repeated strain of opening and closing the drawer tended to cause failure over time... but this was still a valuable and interesting video, thanks as always for posting!

Pocket screws seem to do that over time also.

Indeed, impact strength is not the same as tensile strength!

Very interesting! I'd be curious what effect a typical biscuit might have, both on a butt joint and a miter configuration. I wouldn't expect much difference - maybe 10-20 pounds over the Lamello or plain miter. But more of us are probably going to have a biscuit joiner vs. a Domino or Lamello. I like them as an aid in alignment and would like to know what, if any, effect they have on strength. And like others mentioned, I think another dovetail test with more evenly sized tails and pins would be interesting. Maybe a few variations even, just to see how much affect the geometry has. Though it did look like the wood actually failed in the test - it looked like the wedge shapes split both sides of the joint along the grain. Great job and looking forward to a part 2 at some point.

Great test, would like to see a mortise and tenon joint test against the Domino joint. Yes I was very surprised too of the results but some joints are made to withstand pressure from a different direction. Love your videos keep up the great work 👍

The miter exposes the myth of end grain gluing. It is actually very strong because the glue adheres to the fibers of the wood. The fibers have the strongest tensile strength of wood compared to the lignin. You also get more surface area on the 45 cut. Wood glue is stronger than wood lignin, but weaker than wood fiber.

That's real interesting. Thanks. I quite like the splined mitre. I usually put them together with Mitre-Mate, for speed and ease; I think you call it CA glue in the States. Then I cut the splines, slots and glue them with a proper glue like epoxy, PU or the modern PVA alternatives :)

Great video, thank you for all the info. I do think that a dove tail joint would be the strongest if the tails were equally sized. May be you could include that in your next round of testing. Thanks again. P

Great video! I'm building a new camper soon and been experimenting with joining techniques and using thinner n thinner material to save weight and learnt than modern glue is amazing. Dovetail would of been my guess. Saved me a lot of time haha. I wrecken glue needs a fare amount of pressure to achieve full strength and you don't really clamp dovetails as much as other methods

A very entertaining and helpful video. I am now enamored with the miter + spline joint. I thought your testing was thoughtful and fair. I am sure someone else has already made the comment about the dovetail joint possibly having different results with different (equal) dimensions, but whatever. Splines... WOW! Who knew?! Thankful that you did this... as a woodworking hack, this is something I don't need to obsess over -- I will thank you from my wife in advance.

Very cool video, and very well done. I think what you're seeing here is that the surface area for glue is in large part dictating the strength of the joint. In many of the photos, you're seeing that the wood failed rather than the glue. Increase the amount of glue you can have, and give it the opportunity to work well (i.e. not directly in end grain due to absorption, though you can skim coat end grain and still have a strong joint because you sealed the pores). The box joint has more surface area for glue than the dovetail does. However, at some point there is a diminishing return. If you cut very, very narrow box joint which would substantially increase the surface area for the glue, you would be weakening the physical strength of the wood and its ability to remain intact against the tensile pressure being exerted by the lever and weight.

Dear Wendel, thanks for doing this test. It certainly revealed some surprises, particularly the dovetail joints. I built a bedroom suite 40+ years ago using veneered chipboard for the walls of the furniture modules. The only joint I could make easily was a mitre joint with glue. Despite decades of abuse, no sign of breakdown. I got it right way back then before your video {or computers or internet etc}. Cheers.

Dovetails are really strong on one plane and relatively weak on the opposite plane. This is pretty obvious why on visual inspection. Your test stresses both planes equally. It's really about how they're used. They are the king of drawers since all the force is applied in one plane in pulling the drawer out and very little side to side rocking force to worry about. Plus they look purty.

I am interested in the strength of wood attached with Drywall screws at right angles for comparison. Great video!

The splines in the miter and splines joint experience tensile stress (with a bit of torsion) along the grain, which is the strongest in wood. You pretty much have to break the splines by pulling them appart from both ends. What's more, they have a large surface area so the glue bond is strong, too. Make a 5 splines miter joint or more for extra strength!

Sir, the Mythbusters flashbacks I'm getting from this video make me feel ten years younger, and for that I thank you. I found the results extremely surprising as well, though I'm curious to see how no-glue Japanese woodworking joints would fair on this test.

An excellent video that triggered a storm of responses and professional opinions. Wow! IMO, your practical experiments taught us all a helluva lot ... grain, surface area, geometry, glue, the value of trial and error ... a thoughtful human effort. Thank you for your hard work!

In my thinking initially, the mitre was going to be second weakest... My thoughts on the dovetail joint though, if the tails were more evenly sized it may have been a lot stronger

I'm just research joining techniques for a speaker and amp cab I'm about to build. So newbie to joining beyond butts and miters screwed and glued. Is that not a joke of a dovetail joint? The slivers of just a few tails look weak af. I still expect a 50/50 split of tail and slot volume with as many tails as fingers in the box joint to be stronger than the box joint, or at least on par with it. Also, hydraulic presses with pressure sensors are not that uncommon. Staff at the lab I used to work at would all get a good chuckle at the methods used here, and a good cringe at the sell out coo-pon talk littering this low quality experiment.

Nice video! I’m wanting to build a simple box frame that can withstand force that would come from the side (meaning I’m trying to prevent the square from turning into a parallelogram). What joint is best for that kind of load?

24:21 was fascinating to me. To see how different people respond to a sense of danger. That's how I too would have responded. This test really tested shear strength of the joints, which in my view is pretty representative. But in reality that's not how these joints would bear their load. A better test is to test their tensile strength, that is, perpendicular to the joint or to pull away. This should very easy set up.