how about simple scarf joint? popular among on boatbuilders
@matthiaswandel
Ай бұрын
takes up twice as much length, and more complicated to clamp
@briantaylor9266
Ай бұрын
@@matthiaswandel I'm agreeing with you here. There is certainly the practical aspect of the difficulty of producing a scarf joint in the home shop. Also, in a production environment a scarf joint 'wastes' more material compared to a finger joint. But the engineering aspects may give a scarf joint improved performance. With a point load (as in your test set-up) more of the joint is further away from the point load, where the moment and shear are reduced. But that particular rabbit hole is getting a bit far removed from your original question of the strength of finger joints.
@denada4242
Ай бұрын
@@matthiaswandel true, is the strenght same or comparable?
@custos3249
Ай бұрын
@@briantaylor9266 If material waste is that much of a concern, just do a buttjoint. But really, waste is only guaranteed at the ends of a boards. With sufficient board length, each cut provides both positive and negative sides, i.e. no waste beyond the kerf. Regardless, people suggesting a scarf joint aren't expecting 15 to 5 degree angles. There's clearly a happy middle ground that balances strength to feasible cut angle. Personally, I'm more interested in seeing a combination scarf+V joint.
@DSWoodworkUSA
Ай бұрын
@@briantaylor9266 I feel less stupid when learning that their are such sophisticated fellas such as you and @matthiaswandel out there.
@Peter_Enis
Ай бұрын
Intuition told me the finger joints should be stronger.........the data proved me wrong....love it!!
@billj5645
Ай бұрын
Most people say don't bother trying to glue end grain to end grain, the joint with straight fingers has half of the total area of the wood that is actually end grain to end grain. If you disregard that the maximum strength of the straight fingers is 50% of the total strength of the wood.
@plusmanikantanr
Ай бұрын
I wonder how much dove-tails and wedged joints are compared to finger/V joints. Are mortise and tenon so difficult to make with modern power tools ?
@Lizlodude
Ай бұрын
That's one of my favorite things about these random material test videos. I don't do a lot of woodworking so I don't have a good intuition on the strength of different joints and woods, so just having an idea of how they behave is super useful.
@samTollefson
Ай бұрын
I recall from my boat-building days many, many years ago, we used 8-to-1 scarf joints on plywood glued with epoxy. This was supposed to give the wood close to non-jointed strength. Although this may not be practical for what you are doing, it is a great way to get 16' lengths of plywood.
@Srulio
Ай бұрын
Wow, I also comment before reading other comments. The 1:8 ratio is widely recommend for scarfing plywood.
@samTollefson
Ай бұрын
@@Srulio My comment was the second comment, and I read it.
@ShawnsWorkshop
Ай бұрын
Great video. This is the kind of interesting and useful content that makes KZitem worth watching.
@Kizmox
Ай бұрын
I used to work in building wooden aircraft. We used 1:15 ... 1:20 single sided scarf joints to join both birch plywood and pine. Joint was first primed with raw SP106 epoxy followed by thickened (fumed silica) SP106 as actual gap filler.
@evanbarnes9984
Ай бұрын
Wild! What aircraft were you making from wood?
@Kizmox
Ай бұрын
@@evanbarnes9984 Atol amphibian
@Kizmox
Ай бұрын
@@evanbarnes9984 Atol amphibian
@rydekk-4644
28 күн бұрын
Holy smokes, I forgot about you. Watched your content all those years ago, back when you only had like 50k subs. Glad to see you're still doing well.
@philipwittamore
Ай бұрын
My daydream about using finger joints just got a reality check! Thanks for the taking the time to think it through
@sdspivey
Ай бұрын
As I get older, my finger joints pop more and more.
@amconsole
Ай бұрын
The joint, even with end grain pores cut at a suboptimal for bonding strength angle, did perform very well relative to solid wood, retaining near 50% of strength of a solid piece. This is plenty strong if dimensioned right.
@Elnufo
Ай бұрын
In einem alten (1956) Buch über Flugmodellbau wird auch das verlängern von Vierkantleisten aus Kiefer und Balsaholz behandelt, Dort steht, man schrägt beide Enden einseitig an (also nicht V förmig) und verleimt es zu einer längeren Leiste. Die Länge der Schäftung ist dabei die 10fache Materialstärke. Habe ich immer so gemacht und hatte nie einen Bruch.
@pgtips4240
Ай бұрын
Yes this makes perfect sense to me because both parts of the stock ha e equal thicknesses and no weak (thin) parts. The longer length of the joint halves will cause the joint to flex more before it fails.
@moninum
Ай бұрын
Und wie spannt man die Leisten ohne dass sie verrutschen?
@queazocotal
Ай бұрын
Worth noting that the permenant bending you saw after a minute or twos load happens at around a third of the breaking strain, if applied for years. This limits the practical load limit in many cases to well into the glued joint region.
@matthiaswandel
Ай бұрын
but I have seen old glue joints become unglued over time too.
@whocantexplain
Ай бұрын
It would be interesting to see some of these tests scaled up (or down) in size a bit as well if only to see the relation between size and strength in each joint. Basically it’d be cool to see the workpiece/joint size vs strength curve on a graph. Great video series!
@simonhopkins3867
Ай бұрын
Your test gear is the star of the show for me. So much better than trying to catch a car jack. 😂
@briantaylor9266
Ай бұрын
I've been following this series with interest. For finger jointed lumber like mouldings and such sold in the building centres the results are directly applicable. But it occurs to me that for panels made up of several finger jointed strips, unless the finger joints line up the panel as a unit will fare better. It might be an interesting statistical exercise to make an estimate of the panel strength compared to individual strip strength.
@MCsCreations
Ай бұрын
Fantastic testing, Matthias! Thanks! 😃 Stay safe there with your family! 🖖😊
@billide1463
Ай бұрын
Very impressive performance of the vee joint, all the same. Great test, as always. Thanks. senior from Ajax
@thomask4836
Ай бұрын
Matt, In the beginning of the video I was wondering about 10 degrees so thanks for reading my mind and answering my question before the end of the video!. Take Care, Virtual Step Dad
@iotaje1
Ай бұрын
With all those glue failures I'm wondering if spraying a little water on the hardwood right before gluing would help the glue penetrate deeper into the wood.
@gregfeneis609
17 күн бұрын
I appreciate all this research. Thanks for sticking with it
@gregmislick1117
Ай бұрын
When building the old stick and cloth airplanes, any scarf joint was recommended to be 30:1 meaning 30x the thickness in terms of length. So your 20mm thick spar would have a 60mm long scarf at whatever angle that turned out to be.
@quebrachoquebracho7432
Ай бұрын
20 x 30 = 600 !!! (not 60)
@DracoOmnia
25 күн бұрын
Pretty sure you did the math here wrong, and I don't think his sticks were 600mm long...
@amconsole
Ай бұрын
Most seasoned woodworkers just go by "longgrain to longgrain is the strongest" rule without ever testing it. Now that people outside material testing labs have access to affordable loadcells and can rig up a testbench to get somewhat repeatable results, there's more and more videos that put this belief to the test and as it turns out, with modern glues, the end grain to end grain joint is actually stronger than sidegrain to sidegrain for equal glue area, as the glue is stronger than lignin holding adjacent fibres together. As demonstrated and explained by excellent series of videos by Partick Sullivan called Glue Myths. However, apart from absolute strength You also have to consider mode of failure and glue area, as well as wood movement that weakens the joint over time. For a joint like this though, You can get both the strength of an end to end butt joint and the gradual failure of a longgrain joint if You add a scarf part to it. The total area of end to end pores would be the same, but the total glue are would increase and also include some longgrain contact that would fail without abrupt separation.
@imqqmi
Ай бұрын
It would seem that the glue makes the fibers of the wood more brittle. I wonder if there's glue that matches the elasticity of wood more and might give similar strength as non glued?
@matthiaswandel
Ай бұрын
interesting theory. maybe like welding steel that is too hard. I just figured the grain discontinuity was the culprit.
@Alexander84129
Ай бұрын
Maybe the same chemical that prevents the glue from curing also mildly dissolves the lignin upon application.
@plusmanikantanr
Ай бұрын
If a wood piece is very knotty does that affect the strength of the entire piece or only around the knot ? Do you cut off and re-joint those sections? Is it better to use biscuits for jointing two load-bearing sections ?
@larrymyers6749
Ай бұрын
Mmm.... maybe polyurethane construction adhesive.
@earld1403
Ай бұрын
@@matthiaswandel Would love to see a set of tests using resorcinol glue (typically used in adhering the plies of exterior and marine grades of plywood)
@niels_m_h
Ай бұрын
Bu in practice, you would rarely ever use a single board jointed to another to extend the length, they're almost always used in laminated pieces with multiple offset pieces assembled to a single board. I'm not sure if your current testing apparatus can supply enough force for it, but a test of commercial glued laminated boards versus same measure of single-piece boards might be interesting. Another possibility could be OSB vs plywood vs glued laminated shelf stock.
@matthiaswandel
Ай бұрын
bit of you just want to lengthen a board, that’s way over complicated.
@Nathanm7977
Ай бұрын
another great video. Always love them because you teach and share knowledge.
@wiseoldfool
Ай бұрын
Yesterday a Wes Hamstra video, today Matthias. It makes rainy days worthwhile!
@MatchaMakesThings
Ай бұрын
Thank you. I really appreciate the knowledge you share
@user-oy4lk7fd9w
Ай бұрын
god bless metal and god bless welding is all can think when i see this...
@JonnyDIY
27 күн бұрын
Awesome thanks for sharing Matthias 💕👏👍 so it seems it is a viable joint to use
@amconsole
Ай бұрын
Matthias, could You also redo the same test with a simple butt joint (end to end) for control on how end pore orientation affects strength of glue adhesion and then adjust the result relative to glue area. I expect the result to be surprising to most woodworkers that have been taught all their career that long grain to long grain gives the strongest joint.
@weldabar
Ай бұрын
These tests are always fascinating. I've always wondered how some of those Japanese scarf joints would fare. But nobody's got time to make a batch of those.
@Bloodray19
Ай бұрын
It's not that I dislike your scientific testing videos, I enjoy them quite a lot, but I really miss the old videos where you actually built stuff. It was so refreshing to see the video where your wife built that bookshelf with you. Wish you'd do stuff like that more often, reminded me of old times. Grew up watching your videos, and you're the main reason I got really interested in woodworking.
@dondywondy
Ай бұрын
I'd like to see a "peg joint" test, where one end has a protruding peg (a couple inches?) and the other side has a drilled hole for the peg. Since there is some of the original solid wood, and a lot of surface area for glue, I think that would be a strong joint. Or maybe the strength would be only as good as the peg part. Might need a conical part at the bottom of the peg and a matching tapered hole for more strength and glue area. Only one way to find out. (Can't think of a quick and easy way to make the cone and tapered hole though.) Or maybe using just a dowel and drilled pieces on each side would be easier and probably nearly as strong. Hope I get to see if I'm right! If I didn't have to build some kind of pressure tester I might try it myself!
@billj5645
Ай бұрын
That looks like a lot of fun and everything you said sounds right on. As a structural engineer I'll say that I thought the long V joint would develop more strength. It appears to be limited by glue strength meaning you could try making it even longer. Also I wonder if epoxy would do better as an adhesive. Your comment about the straight fingers should be correct also- having half of the wood fingers in what amounts to end grain to end grain should limit the strength of that joint to about half of the total strength. Even if you had a good finger joint bit this could still be a problem because there is still a good percentage of end grain involved. I was surprised that the straight fingers came as close to the V joint as they did, the straight fingers do have a lot of glue surface area to help them.
@doug9176
Ай бұрын
You could use the pantorouter for tabled, tensioned scarf joints. Only fairly narrow stock and clean up with a chisel, but it should work.
@ronboe6325
Ай бұрын
While in air frame school we were taught that a scarf joint with a 1:12 slope (minimum) with planed smooth surface and plywood glued over the joint seam (one on each end) to be an approved repair. Other trades that had to splice wood for strength also mentioned the 1:12 slope (this seems to spread the stresses out long enough to approach solid wood. Naturally this uses a lot of wood so for many folks they avoid (as in furniture making). And it ain't easy to do well. If memory serves Resorcinol glue was used.
@billj5645
Ай бұрын
1:12 is about 5 degrees vs. the 15 degrees in the video so should give a lot more glue surface.
@amconsole
Ай бұрын
It's a trade off of material waste vs strength. At 15 degrees, the glue area is substantially smaller, still retaining nearly 50% of strength of a solid piece, which considering how much deflection the solid piece experienced before breaking, would be more than enough for any practical application.
@virtualfather
Ай бұрын
Thank you for sharing your testing data
@kenchilton
Ай бұрын
A lot of those failures look like adhesion failures. You also showed that the type of glue used was significant to the results. I wonder if a construction adhesive like PL-8X would work on your V joints, even at lower angles. I have used construction adhesives and tried taking them apart after realizing there was a mistake only to end up destroying the wood in the attempt.
@hartshut
Ай бұрын
Please do a video on how much weight an empty ice cream cone can support before it collapses.
@schechnera
Ай бұрын
Data! Love it.
@georgedavall9449
Ай бұрын
The level of ingenuity and creativity this Man possesses is on a GOAT level, seriously!
@AllenBrosowsky
Ай бұрын
It appears that you are on your way down a rabbit hole with this various joint strength testing. Well, if you do proceed that way, I am curious to see where it goes. There is a possibility I might need to do some joints like this in the near future.
@doug9176
Ай бұрын
I'd like to see you test different scarf joints (tabled, tensioned and stopped) at different ratios, 4:1 to 20:1 for instance. Perhaps a bit trickier to set up but it would be interesting to see the results.
@patrick-quora
Ай бұрын
the problem is you're using too inflexible glues. wood fibers can flex a pretty large amount, but once you put ordinary glue on it, it becomes too inflexible and thus will crack either the hardened glue or the wood around the hardened glue.
@JamesKelly89
Ай бұрын
Enter: Construction adhesive.
@zolotiyeruki
Ай бұрын
For what it's worth, in the airplane world, if you need to join two pieces end to end, the standard is a scarf joint with a 15:1 ratio of wood thickness to length of joint. IOW, if you're joining two 1"-wide pieces, the scarf joint has to be 15" long.
@Alexander84129
Ай бұрын
Is titebond 3 really stronger than titebond 2? I use 2 because it’s cheaper unless it’s in a wet location.
@matthiaswandel
Ай бұрын
titebond 2 as far as I can tell is just yellow glue
@Vozka666
15 күн бұрын
Hi Matthias, out of this topic, it would be nice if you try strength of wood with holes inside. Usually people use it for boards to make them lighter, f.e. for beds in caravan they drill lot of holes 5cm or bigger and it is still strong enough. But it will be interesting to measure bow much strength it looses by drilling those holes... Thank you
@matthiaswandel
12 күн бұрын
There would have to be a specific pattern of holes that everyone uses for it to be of much use to people.
@thedevilinthecircuit1414
Ай бұрын
Fascinating stuff as always! I'm wondering if you'll achieve different results on the V joints if you apply glue to both pieces and allow them to remain unjoined for several minutes...then apply a little more glue and join/clamp. The reason is end grain can pull glue out of the joint, leaving a starved glue joint. The extra step of allowing some 'soak time' may improve the bond.
@troysmoker
27 күн бұрын
It'd be really cool to cut a V then turn the wood 90° and cut another V. It would constrain movement in all 3 axis as well
@oldoldpilgrim7898
Ай бұрын
Matthias, I saw your thumbnail and compared the color of your gig to my shirt. Did you realize your signature color is safety green?
@Wuuz
Ай бұрын
V + turn 90degree and sawblade slit in middle for gluing in flat piece to brace it?
@B.M.0.
Ай бұрын
Ultimate strength would be the side by side wedge cut but one peak is deeper than the other so you don't get the perforation effect you got from the finger joints
@rootvalue
Ай бұрын
Thank you for the captions! ❤
@pkoparanov
Ай бұрын
Благодаря , много хубави видиота и научавам доста от Вас!
@maciejtrybilo
Ай бұрын
A 1:10 thickened epoxy glued scarf joint used in boatbuilding may not be practical in most woodworking. I'd still love to see a test of that as the common claim is that such a joint is close to the strength of a solid plank.
@kevinforward3249
Ай бұрын
I seem to recall that Norm Abram seldom used clamps when gluing and relied heavily on his brad nailer. Could you test this approach if you have not in the past. PSReally enjoy all of your woodworking videos
@matthiaswandel
Ай бұрын
not interested. I want to test the glue
@kevinforward3249
Ай бұрын
I mean to suggest that you test Brad nailing a s a clamping strategy for gluing
@berzerka1000
Ай бұрын
Typically you would design the member for deflection as well as strength. It would nice to see an stress-strain curve on these test.
@kenniesdead
Ай бұрын
to add to the visuals you put "place cards" atop the samples so when they break the cards would go flying
@fredio54
Ай бұрын
I love your testing, but I don't love the lack of epoxy. Epoxy basically never fails, the wood fibres always do. Do an episode on just that doing all the various tests again and showing it versus the lesser glues.
@scottnelle
Ай бұрын
Have you ever used your strength testing setup to test the old trick of rubbing a bit of glue across the end grain and letting it sit for about 10 minutes (with tite-bond 2, anyway) to soak in before adding more glue and clamping up an end-to-end or butt joint? People swear it works, and I'd be curious to see what the numbers say!
@steveggca
Ай бұрын
So the moral of the story is finger joints for low to no stress applications only
@FWtravels
Ай бұрын
But they use finger joints on the flanges of wood I-Beams 🤔
@steveggca
Ай бұрын
@@FWtravels as it happens the second storey of my house is supported by finger jointed I beams and rated for the 2" layer of concrete for hydronic heating. As they only span 12 feet and are very Much over rated I think that falls into low stress
@lint2023
Ай бұрын
or for cosmetic reasons
@johngaltline9933
Ай бұрын
@@FWtravels Would make for an interesting test. In an I beam, the load is pulling the board apart from each end, rather than bending along the joint. It may vary by manufacturer, but the one's I've seen use some sort of really tough epoxy rather than glue as well.
@Manigo1743
Ай бұрын
Or for cases where you would try to pull the wood apart instead of bending it, like in a box or a drawer.
@krenwregget7667
Ай бұрын
I love when you break stuff for science.
@DracoOmnia
25 күн бұрын
I have to wonder about a half lap joint test now, and whether increasing the joint size would increase strength. Also scarf joints from boats but they can be a pain to glue up. Pin nails? Or perhaps a small alignment dowel?
@ajbent1
Ай бұрын
I'd be curious how different diameter and length of dowels would fare as a method for extending boards
@matthiaswandel
Ай бұрын
weaker than the finger joint, I'm quite sure. For the same reasons the finger joint is not that strong.
@rolfbjorn9937
Ай бұрын
@@matthiaswandel A Round dowel of hardwood embedded say 2 inches on either side would potentially lead to less stress concentration, especially combined with some PL 8x or a non brittle 5 to 15 min epoxy
@plusmanikantanr
Ай бұрын
@@rolfbjorn9937 Does round vs square dowels make any difference? Which one lines up evenly with the grains?
@johngaltline9933
Ай бұрын
Would be curious on the various joints, with a bamboo skewer pin through them.
@LukeTheJoker
Ай бұрын
I think you need to retest the finger joints as you have changed a variable with that spreader on the testing rig. Otherwise enjoying this series.
@srmofoable
Ай бұрын
I'd be interested to see if a simple fastener in the joint would help, especially in the joints that had glue failure
@DustySplinters
Ай бұрын
So basically... Use of the V joint ir finger joint is best for decorative non load bearing conditions.
@amconsole
Ай бұрын
That depends on Your criteria for joint strength as % of a solid piece. The V joint performed very well, reaching nearly 50% of the strength of a solid piece.
@ordelian7795
Ай бұрын
The 'W' shaped cut your considered at the end would not have any increase in glue surface to just a single 'V' shape since you're just flipping the tip of the 'V' over.
@matthiaswandel
Ай бұрын
but I could get more width for the same depth, or use a lower angle
@madtitan9639
Ай бұрын
Very interesting! The shallower the V, the more it's end grain, and the steeper V more side grain, so, next test: Do you really have to go twice as long to get twice the strength? Would a more flexible glue perform better - something that flexes about the same as the wood?
@buttonjack2653
Ай бұрын
Glued diagonal cut works fine too
@andrewjones2505
Ай бұрын
I’ve used scarf joints before. I read that they are common in aircraft manufacturing. They use a ratio of 1:6. If the stick is 1” wide, the joint needs to be 6 inches long. This is easy to cut on the table saw. Can you investigate the strength of this joint?
@evanking6329
Ай бұрын
As for glue, try pl premium… go to the technical doc and they state the glue’s strength. I made a glue-lam column with pl, it was the only glue that offered stated strengths… nice video
@matthiaswandel
Ай бұрын
my experience is it’s weaker than wood glues
@evanking6329
Ай бұрын
@@matthiaswandel 👍
@onjofilms
Ай бұрын
Your videos make me want to be a metal worker.
@rolfbjorn9937
Ай бұрын
Thanks for the further testing! If I may bet my 2 cents and grains of salt, I'm convinced that half lap joints and scarf joints are both superior and look better. A simple enough fixture (couple stop blocs and some screws/cyano ) to glue multiple scarf joints can be made to offset the "difficult" glue up. I say "difficult" because the alternative is weak joinery with sharp visible joint lines that imitates cheap mass made boards, therefore mostly pointless to me, especially given a similar time investment for either methods anyway.
@matthiaswandel
Ай бұрын
what makes you think a half lap will do better than the finger joint, which in itself didn’t do great?
@victorhopper6774
Ай бұрын
@@matthiaswandel for post uses instead of beam the box joint might be better but those pressures get insane real quick.
@billj5645
Ай бұрын
Half lap would give you about half the strength max. because you only have half the material going continuous through the joint. And if you bend it the wrong direction it will have 1/4 the strength.
@victorhopper6774
Ай бұрын
@@billj5645 not used much except for tensil positioning
@rolfbjorn9937
Ай бұрын
@@billj5645 I disagree, the glue will replace lignin and the fibers are mostly intact for over 85% of the thicknress and are in the same "plane" we should have nearly identical strength and weaknesses as the original board. Fingers and box joints create localised stress points where a half lap has only a thin glue line interrupting the original woodgrain orientation. Figure a 2.00" x4.00" board (actual) with a 6.00" long x 2.00" wide joint.
@andro7x
Ай бұрын
What about only 1 finger?
@matthiaswandel
Ай бұрын
that would be weaker.
@kaapporaivio
Ай бұрын
Very interesting watch, like all the strength testing videos! A thought: at some point, could it work to make a pure analysis video that tried to draw general conclusions/rules of thumb based on your extensive testing? That kind of [trustworthy] information is very hard to come by!
@welshman100
Ай бұрын
Would be interested on how west systems epoxy would hold up under your scrutiny.
@rondoanderson
Ай бұрын
Now I kind of want to see what would happen with a v joint that spans the entire length of the wood. Totally pointless to test, but I'm curious anyway.
@Thisissomeone12432
Ай бұрын
What effect did difference in surface contact area for the glue have?
@sdavidleigh6642
Ай бұрын
keep going you are terrific.
@pgtips4240
Ай бұрын
Matthias I am not sure what the conclusion of this experiment was? There were two main variables here, the glue strengrh and the mechanics of the joint design. The problem with the v joint from a mechanical point of view is the thin end of the female v will fail first causing the rest to fail. I think the v joint performed better than the finger joints because of the longer crossover of thicker material. I think the strengrh therefore would increase as both the overall length of the joint was increased while having a design with the thickest material on both components. A thin part of a component will fail quickly reducing the overall load capacity of the piece. A v joint is therefore not the most optimal joint for strength although I agree that it is simple enough to make and still very strong. What this experiment has shown to me is that the mechanical properties of the glue are inconsistent with the properties of the wood itself and that results in the thinner parts of a join failing first especially when the joint has short overlap. In other words if the glue offered the same properties as the wood the results in theory should be the same for the solid pieces of wood as it was for the joined pieces. Wood joined at the cellular level is mechanically superior to synthetic glues.
@matthiaswandel
Ай бұрын
watch the conclusion of the video.
@CaseyConnor
Ай бұрын
Hey Matthiad - have you ever experimented with "wood welding"? Not sure there is anything actually useful there, but might be fun/interesting?
@matthiaswandel
Ай бұрын
in that case, a longer piece of wood would be much easier. practicality is a major consideration.
@CaseyConnor
Ай бұрын
@@matthiaswandel Sorry, i just meant in general, not necessarily related to this video. Regardless, practicality is still a consideration. :-) I just think it's a neat subject and I'm sure you'd have an interesting take.
@ebrewste
Ай бұрын
That very deep v joint seems like it could be done on a band saw
@awesomearizona-dino
Ай бұрын
Half laps with a dowel in the joint ?? we appreciate your efforts.
@JasonEllingsworth
Ай бұрын
have you compared tightbond 3 to tightbond 2? I believe 2 is supposed to be stronger, though it is less resistant to water. Since we are not in the habit of putting our wood joinery in water, tightbond 2 would be the proper glue to test with.
@sion023
Ай бұрын
Fascinating, what is the skarf angle on those fancy unaffordable fingerjoint cutter blocks you showed in the previous video?
@matthiaswandel
Ай бұрын
don’t know. you research it.
@axelSixtySix
Ай бұрын
Boatbuilders use the long scarf joint and they believe it's the best, especially for hulls. It should be easier to make by the way. What about long curing time epoxy ?
@rallen7660
Ай бұрын
Does your test stand record deflection at detected break? I know you've done *a lot* of break tests of both soft and hard woods, but have you collated the data to show which woods are better for flexible or stiff applications? The amount of deflection/breaking force/wood species would be an interesting graph to see!
@matthiaswandel
Ай бұрын
harder woods are stiffer, I think I did record that in my wood tests back in 2021
@Infrared73
Ай бұрын
I’m curious how some of those traditional Japanese joints might test.
@matthiaswandel
Ай бұрын
badly. too much wood is cut away. generally, screws beat Japanese joi ts easily.
@amconsole
Ай бұрын
Decorative joinery vs structural.
@MarkBaldridge
16 күн бұрын
What about a 15:1 scarf joint as used in wooden aircraft construction? It’s generally deemed to be as strong as a solid member.
@matthiaswandel
12 күн бұрын
do tell how to cut one of those on the end of a board. Also, an awful lot of length is lost.
@MarkBaldridge
10 күн бұрын
@@matthiaswandelI agree a lot of length is lost. I’ve seen them cut a few ways. For a member of moderate height, it could be clamped to a table saw sled. For very wide members, a slanted router jig could be constructed. Wooden boats and aircraft both use scarf joints. Albeit, the slope on boats isn’t required to be 15:1. Even plywood is scarfed on boats.
@Dobbiner
Ай бұрын
Stopped scarf joints are annoying to cut but easy to clamp. I would be curious to see what technique/jig you would come up with to make scarfs easier to cut. Finishing the stop cut by hand isn't too bad.
@matthiaswandel
Ай бұрын
my solution is the v joint.
@tAbes314
Ай бұрын
Very interesting video! Did you notice any effect on the break point based on the loading condition? I noticed halfway though that the load was cyclic, this could induce the time dependancy on stress/deformation
@thebigswede1736
Ай бұрын
Hi Matthias. Would it be feasible to do some testing of breaking strength vs. Glue line thickness(clamping pressure)?
@mtheory3
Ай бұрын
I hope you test a scarf joint too. I want to see how much stronger it is than a V-joint and if the extra effoet is worth the time
@matthiaswandel
Ай бұрын
the v joint is actually easier
@mtheory3
Ай бұрын
@matthiaswandel Deinitely. That was a clever way you cut it in the video. Supposedly, the scarf joint should be even stronger, but I'm hoping you'll test it in another video
@amconsole
Ай бұрын
My prediction is that it would not be any stronger when adjusted for glue area.
@jamesp2127
Ай бұрын
Good stuff man
@TLS7719
7 күн бұрын
Have you considered or tested what the optimal clamping pressure, heat humidity, or drytime would affect the strength of a glue joint?
@bennythey
Ай бұрын
I'm sure u know what I mean... We're in Germany got 1 old glue names Knochenleim. I remember that it was the strongest of the last 30 years but nobody use it anymore. Maybe you tested this one.
@matthiaswandel
Ай бұрын
perhaps it was the strongest for 30 years long ago.
@EugeneFir
26 күн бұрын
Have you made a wood joint video comparing an old bottle of glue against a new bottle of glue? (link?)
@paulsmyers203
Ай бұрын
The one piece of information I didn't catch is how long you let the glue dry on these. Speaking of, did you do a video on glue drying time frame?
@matthiaswandel
Ай бұрын
24 hours or more
@alexandrugajin763
Ай бұрын
I am curious how epoxy would hold as a glue, or CA. The thing is, the 5,20 min etc. curing epoxy is not that strong, i mean the glue itself is, but the bonding to other materials is not that great. Compared to other types of epoxy wich take more than 24 hours to cure, and even more to totaly cure. Problem with that epoxy and wood is that wood tends to suck all the glue and leave the joint dry. So to make sure the joint is left with planty of glue you can mix the glue with fine wood dust from the sander, or something wich i found makes a really strong glue mixed with epoxy is soot from my wood burner. There are also glues made from animal skin, from fish. It would be intresting to see these ancient glues compared to modern glue. Anyway, for most aplications, constructions, furniture, wood glue, altough is not that strong, is strong enough, and if you compare the cost, with other glues, such as epoxy. Wood glue is still the best glue for wood. But i think your goal is to make a joint wich is as strong as the wood itself. And i think you can only achive that with epoxy. But then you have another problem, because the wood fibers are flexible, and then that kind of a joint would not be, it will tend to break right near the joint, and therefore weakening the piece, meaning a very strong joint is actually not good. Is fun to watch these experiments, but i think you should really watch the making of wood bows, more specific the modern wood laminated bows, bowmakers seem to me to be the masters of glueing wood. And you would see there that even the slighest imprefection in a joint would weaken it by alot, is not always about the glue, is more of how you aply it, making sure you leave zero bubles out, etc.
@ckra2001
Ай бұрын
Interesting! When buying "Leimbinder" they use multiple Vs for joining pieces. What about adding a dowel to the v-joints?
@dpmeyer4867
11 күн бұрын
thanks
@plusmanikantanr
Ай бұрын
Don't Japanese woodworkers use strange Z-shaped and inter-locked joints held together with hammered in through-pegs that tighten and lock the joints ? How do those compare in strength and easy-to-make process ?
@matthiaswandel
Ай бұрын
too much wood take a way. a glued or screwed joint will hold much better
@DEADB33F
Ай бұрын
That's mainly because back in the day they didn't have glue, screws, bolts, etc. Nowadays people only continue to use those kind of joints for the aesthetic, not because they're particularly strong.
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