Sorry, I think the only conclusion you can come to here is that a 2x2's tensile strength under these conditions can withstand about 500-600lb. In all five tests, it was the *wood* that failed, and the variances in lb necessary to cause failure can likely be explained by variations in the wood grain etc.. The glue joints were both intact, and the screws weren't broken and didn't pull out of the wood. It doesn't appear that you have found the actual strength of either the glue or the screws in these tests. Further investigation would be required. :)
+jakkarth I did consider that to be a possibility, and you might actually be right. I suspect someone will also point out that this is just one stress angle, and that pulling the boards apart lengthwise (shearing them) might have a different result as well. I'll probably revisit this test in a few months and try to account for these variables.
+jakkarth The wood broke around the points the screws were inserted. On the glue joints the wood broke somewhere other than the joint. This proves the glue is stronger, and more reliable method of bonding.
You are the only one making sense. Basic mechanics course tells us this. You now only measuring the strength of the wood. (Or whats left of it after weakening it with a screwhole)
Way late, but I don't think that's necessarily true. This won't tell us if glues or screws are stronger, but it will tell us if screws or glue provide a more stable bond. The point about weakening it with screw holes is significant, because that's one thing that happens when you use screws that doesn't happen when you use glue. Aside from the holes themselves, screws also provides discrete points of stress for the wood, whereas the bond from the glue is more evenly spread over the surface of the wood. The fact that 2 screws failed much quicker than 4 screws tells us that the latter is probably more significant.
I think we would have a better test if you could find a way to glue, screw, and both where you can have a hook on each side try to pull them apart.. That way there is no way for the wood its self to fail before the joining object fails.. Like may be putting to I bolts into a 2 4x4's and gluing them together and pulling on it like that.. Would have to find a way to make it where the bolts doing get pulled out before the glue or screws fail.. BTW I love your videos..
Then you would be testing pullout strength of the bolt or attachment point. That is why this is hard to measure. The pullout strength may be lower than the shear strength.
I was thinking that as well, however, the glued boards did not break at the glue joints, but rather it was the wood that failed. So unless adding screws to the glued joint would cause it to be weaker, it would likely be another wood failure. So the numbers should be close to the same. It would make no sense that a glued and screwed joint would be stronger than the glue alone joint that did not fail.
But the strength of the joint depends on area? E.g., a small glued area vs a small area joined by a screw because then you're dealing with a small surface area vs a connector going into the wood?
This is one of those tests where I went into it thinking for sure a certain outcome would happen, and then after the first test thought it was going to go exactly the opposite. Only to find out in the end my first guess was correct. I love when that happens! It keeps the test fun and keeps me guessing.
Not a good control. The wood for the control is only 1/2 the thickness of the glue and screw pieces. Beam strrength is the square of the depth. Your glue and screw pieces should have greater strength due to the greater depth in the load path. Many other tests have shown that in a good glue joint where the pieces have close fit, the glue line is stronger than the surrounding wood. In such glue joints the wood fails in a place other than the glue joint. I rarely use screw joints, sometimes for positioning along with glue. Fine Woodworking and others have tested various wood glues. Yellow PVA glue normally is the strongest, beating out epoxy.
Glue is almost always superior to screws. You just have to ensure you get a good amount of long-grain-to-long-grain surface area bonded, although I saw some tests where end grain glue joints still resulted in wood failing before glue. Modern glues are probably just that much stronger than old hide glues and such. Screws are good for providing clamping force for glue ups, and combining the two provides excellent strength.
I can already hear all of the whiners who will say this test doesn't prove anything but that the glue is stronger than the wood,. While that's true, it **does** prove the ultimate point being made here. Glue IS stronger than the wood, and therefore proving its just as good as screws, if not better. Bravo. Great video! Keep them coming good sir!
That's the reason Stratavari stopped using screws on his violins. They looked bad and kept exploding onstage. He finally went to rabbit glue, which I feel sorry for.
I think which is stronger is the wrong question to ask. It's pretty obvious glue is stronger (more surface area, etc.). The real reason to use either glue or screws is whether you want a permanent or a repairable/changeable bond. Let's say you're building a cabinet with set shelves. For the cabinet itself, glue makes sense, because it's stronger. But if a shelf breaks or sags over time, you're gonna have a really bad time replacing it, if it's glued in. If it has screws, it's an easy job. If you need absolute strength, and know you'll never change it, and you're making it strong enough that it'll never need repair, glue away. In any other case, screws are faster and easier. Both have their advantages.
When you revealed that the screwed wood failed along the screw lines, my immediate suggestion was to try predrilling the holes. With less compression (potentially creating micro-fractures) the threads may be able to keep the wood locked together without causing a weak point.
Since the joint held what was found was more values for wood failure, NOT the joint failure values. For that the actual joint failure is needed. All we know is that 1. the joint is stronger than wood AND 2. Joint failure is higher than wood failure values (which you found with the experiment). Great and useful stuff nevertheless so the conclusions are valid, just not numerically so.
What about an end grain to long grain joint? And at what increasingly smaller length a long grain long grain joint becomes weaker than a same length screwed joint, That would be interesting to see!
One thing I am wondering is if it wouldn't be better (and I have absolutely no idea how you would test this) to see what it takes to pull the two pieces of wood apart? Would that not figure the holding power of either glue, screws, or glue and screws?
Great video! Anything that requires steel cables and the risk of catastrophic failure is fun to watch. ;) I like the test and would like to see more. My only critique is along the same lines as some others in talking about testing the shear force required to break the joint. It seem like a shear test would be more representative of the type of stresses edge joints (like the ones in the video) would face. Most edge joints I make when woodworking are panel glue ups for things like tabletops and carcass sides. The greatest potential for damage these parts would face come from a force applied perpendicular to the plane of the surface, like a kid jumping on top of a table or someone kicking the side of a carcass. A simple way to test this would be to pinch one side of the glued up (or screwed together) panel in some type of jaw setup. Maybe two flat steel plates that can be clamped together or tightened with some threaded rod, with the edge of the two steel plates (the jaws) aligned perfectly with the glue joint. Then make another identical setup that can pinch the panel on the other side of the glue/screw joint and apply some type of pulling or pushing force to only that jaw. You could probably just weld the end of an eyebolt to the bottom jaw, hook the come-along and force meter to it, and watch the destruction. But again, enjoyed the video and can't wait to see more! Thanks!
Very surprising. Thanks for the definitive tests. Very well done, with the force lever and gopros and force meter n whatnot..you really do live up to your name :-)
the force should be applied on the glued surface, and not on the back of the wood. Also, what type of glue and screw was used? Curing time? Type of wood? The test should have better if you used 2 equal opposing forces, band on 3 points (force-glue-force-glue-force).. then you are demonstrating the ripping of glue against the wood or glue itself.
MIKE What I would have liked 2 more tests Glue & screws to justify their use at all---AND to use 3/16 bolts and very thick washers [ Actually sq plates that have holes drilled in them. it is no doubt that the screw threads shred the wood as the wood yields.
Decent tests. Agree that the glue didn't fail, the wood did. I would be curious to see more tests, though. You had glue spread along the entire common faces between two pieces of wood, so using only two or four screws seems inadequate -- why wouldn't you maximize the use of screws? How many screws does it take to improve strength? Can you position them to NOT create "fault lines" in the grain? Also, every test of this sort I have seen is always done using PINE -- what happens when you use cedar? Spruce? Birch? Maple? Oak? OSB? MDF? Keep going! :)
You made a good test there but joint strength is highly dependent on the type of material , specially on wood there is so much different configurations, anyway i really thought that with glue the shear forces were just going to peel the surface and fail much sooner really impressed ! :D
I don't think it was fair for the control board and test boards to have different geometry. Should have done a contropl 2x2, then glued/screwed a 2x2 with a lap joint or similar.
Yea you need to do a shear test I think to really prove you hypothesis correct or wrong on this as well as trying a leverage test by that I mean you make an L shape representing a corner and test in pulling up and pushing down and see what happens in those tests as well but good video to start with though and can't wait to see you revisit this
+Shawn Chamberlin Yes sir! I am going to try to do that in a future video. That's going to require some better safety measures though, because we will be talking 1000+ lbs of force at that point.
I like this new series... a lot!! Seems like you'd need to find a way to fix the back piece to something so it would never move and then only apply the pulling force to the front piece somehow. Not sure how you'd do that. Again... I really like this show concept... please keep them going!!
Should have used a 2x4 as the control, and cut the test subjects in half and then secured them together. Glue failed where the joint ended because the board broke.
This is why I like the method of gluing and using brad nails to hold the pieces together till the glue dries. I rather use that method that screws. Screws break, and they create weak points for failure.
Here's two issues I have with these type of videos (yes there are other videos). 1) Both joints are essentially equal. No, they didn't break at the same point. They each went beyond what you would use them for though. If a 2x2 breaks at 600 lbs., you just wouldn't use it in a situation beyond 300, maybe 400 lbs. I'd guess 250-350 lbs for jointed material. 2) You really should test actual projects constructed with each method. Under real world use I bet you'd find both joints are equally good. After this you can go Mythbusters on the projects and test their absolute limits. This limit would most likely never be encountered in the real world.
I'm not an expert, but isn't there a significant difference in the sturdiness of the joint, depending on the direction of the force? like the difference between a perpendicular force and a parallel force? idk i'm drunk, just a thought.
If you made a pulley-system, you'd be able to apply force to the joints from much safer distances. Also, your approach seems just fine, you just need to test the strength at different angles. Same procedure, just more data and pulley for added safety! (Wherever you attatched the rope in the other end, just replace it with a carabiner and run the rope through that) That might be one way to do this safely
Wow, often I wondered about glue vs screws. Thank you for sharing this information. Comment: we came to hear what you have to say, not listen to music. The background music is distracting, absolutely adding nothing to the video, in fact it is annoying, some of us have hearing difficulty thus in order to understand you we must fight the music. Truly, why UA-camrs think they must include background music, baffles me?
I don't like the design of this test because the glue joint is purposefully made the strongest point so the wood is breaking but not at the glue joint this test needs to be made where the weakest point is clearly AT the glue joint that way WHEN it breaks you can properly compare it to when the screwed one breaks
the problem with glue is that it can be expensive is usually messy and takes forever to dry whereas with a screw you just tap a little hole then twist it in and you're done
You reconfirmed what has been known for at least 100 years. Good glue is stronger than the wood it is attaching. Screws are almost always weaker as they have less surface area and tend to weaken the wood due to either removal of material (pilot holes if used) or of splitting (often the case when pilot holes are not used). And you made every statistician cringe when you said you like to use two samples to draw conclusions. 😂
Structural engineer here - this is painful to watch. I had to stop at about 3 minutes when I realized he's not even testing the actual strength of the glue. Your control wood has a completely different cross section than the first glued member. It's apples to oranges, and you're testing bending moment, not the shear strength of the glue. He probably doesn't even have a proper screw pattern. Some situations glue is better, some screwed is better. But per the same area, glue is much stronger.
Dave Mastriano structural engineer my ass. It's clear and a known fact a glue bond is stronger than the wood itself, when screwed wood will fracture more easily from screw to screw, creating a weak link in the structure. Either go into the field and get some experience or back to school.
For alle people whondering what those strange American units mean: 500 pounds is ~ 2.2kN which equals the gravitational force of 220kg. 1000 punds is ~4.45kN which is 445kg.
So the Glue is stronger than the wood? No! Your wood only (control) test was the one that lasted the longest. So either the general quality of the wood pieces you used don't line up well against each other. More or less making this test pointless. Or it's better to use just one big peace of wood whenever possible and not use either glue or screws.
I'm johhny on da spot dawg. I don't generally give the time of day to morons (thats you bro), but you think the test is invalid cause the solid wood is stronger than the joined wood. That's fucked up bro. Of course it is. That coffee mug you super glewd back together stronger after the glue or before the glue? damn dude you dumb.
Actually my problem is he clearly isn't using peaces of wood that he checked for quality. For the record wood glue is actually stronger than wood. If you have ever seen something made of wood break that has wood glue it never breaks where the glue is as long as they used the glue right. In every case in the video it was the wood that failed. The only reason one lasted longer than the other was due to the wood itself. That means his test is invalid. It's invalid because he is trying to determine whether wood glue is stronger or screws are stronger. We didn't learn that from his test we learned that his ability to chose consistent wood sucks. By the way wood glue is not the same as whatever crap you use to fix your mugs. Not to mention you are comparing a person who works with this stuff for a living to a random person trying to fix an item on their own likely using whatever glue they have lying around. Not all glue is the same. Of course you would know that if you ever did this kind of work. Which you clearly haven't since you managed to miss entirely what I was saying and think I'm an idiot for saying it. I get it your just looking to get a rise out of someone and laugh at it. The thing is I'm not pissed in the least. In fact I'm laughing at you trying to debate something you clearly have no actual knowledge of. So keep it coming.
Sorry, I think the only conclusion you can come to here is that a 2x2's tensile strength under these conditions can withstand about 500-600lb. In all five tests, it was the *wood* that failed, and the variances in lb necessary to cause failure can likely be explained by variations in the wood grain etc.. The glue joints were both intact, and the screws weren't broken and didn't pull out of the wood. It doesn't appear that you have found the actual strength of either the glue or the screws in these tests. Further investigation would be required. :)
+jakkarth I did consider that to be a possibility, and you might actually be right. I suspect someone will also point out that this is just one stress angle, and that pulling the boards apart lengthwise (shearing them) might have a different result as well. I'll probably revisit this test in a few months and try to account for these variables.
+jakkarth The wood broke around the points the screws were inserted. On the glue joints the wood broke somewhere other than the joint. This proves the glue is stronger, and more reliable method of bonding.
+TheGeekPub Hmm, sheer strength would probably be a scary test. I can imagine that it would take a LOT more to break. Good test!
You are the only one making sense. Basic mechanics course tells us this. You now only measuring the strength of the wood. (Or whats left of it after weakening it with a screwhole)
Way late, but I don't think that's necessarily true. This won't tell us if glues or screws are stronger, but it will tell us if screws or glue provide a more stable bond. The point about weakening it with screw holes is significant, because that's one thing that happens when you use screws that doesn't happen when you use glue. Aside from the holes themselves, screws also provides discrete points of stress for the wood, whereas the bond from the glue is more evenly spread over the surface of the wood. The fact that 2 screws failed much quicker than 4 screws tells us that the latter is probably more significant.
I think we would have a better test if you could find a way to glue, screw, and both where you can have a hook on each side try to pull them apart.. That way there is no way for the wood its self to fail before the joining object fails.. Like may be putting to I bolts into a 2 4x4's and gluing them together and pulling on it like that.. Would have to find a way to make it where the bolts doing get pulled out before the glue or screws fail.. BTW I love your videos..
Then you would be testing pullout strength of the bolt or attachment point. That is why this is hard to measure. The pullout strength may be lower than the shear strength.
You should have tried it with both glue and screws to see what would have happened.
Nice, would've been cool to see a board glued 'n' screwed.
+Modern Builds When I revisit this in the future, I'll do that. I also plan to duct tape one. ;--)
Right on!
just guessing but I bet it will be similar to a plain old screwed board.
I was thinking that as well, however, the glued boards did not break at the glue joints, but rather it was the wood that failed. So unless adding screws to the glued joint would cause it to be weaker, it would likely be another wood failure. So the numbers should be close to the same. It would make no sense that a glued and screwed joint would be stronger than the glue alone joint that did not fail.
But the strength of the joint depends on area? E.g., a small glued area vs a small area joined by a screw because then you're dealing with a small surface area vs a connector going into the wood?
Awesome test! Looks like a fun time 💕🤙
Nice! I think you should have tried it with and I-Beam glued and bolted to the wood! Joking.
This is one of those tests where I went into it thinking for sure a certain outcome would happen, and then after the first test thought it was going to go exactly the opposite. Only to find out in the end my first guess was correct. I love when that happens! It keeps the test fun and keeps me guessing.
+TheGeekPub Glue would not hold in the long term though.
Hello
Not a good control. The wood for the control is only 1/2 the thickness of the glue and screw pieces. Beam strrength is the square of the depth. Your glue and screw pieces should have greater strength due to the greater depth in the load path.
Many other tests have shown that in a good glue joint where the pieces have close fit, the glue line is stronger than the surrounding wood. In such glue joints the wood fails in a place other than the glue joint.
I rarely use screw joints, sometimes for positioning along with glue.
Fine Woodworking and others have tested various wood glues. Yellow PVA glue normally is the strongest, beating out epoxy.
+LV_Woodturner Interesting. I'll try to take your comments into consideration when I revisit this test in a few episodes.
Glue is almost always superior to screws. You just have to ensure you get a good amount of long-grain-to-long-grain surface area bonded, although I saw some tests where end grain glue joints still resulted in wood failing before glue. Modern glues are probably just that much stronger than old hide glues and such. Screws are good for providing clamping force for glue ups, and combining the two provides excellent strength.
I can already hear all of the whiners who will say this test doesn't prove anything but that the glue is stronger than the wood,. While that's true, it **does** prove the ultimate point being made here. Glue IS stronger than the wood, and therefore proving its just as good as screws, if not better. Bravo. Great video! Keep them coming good sir!
That's the reason Stratavari stopped using screws on his violins. They looked bad and kept exploding onstage. He finally went to rabbit glue, which I feel sorry for.
I think which is stronger is the wrong question to ask. It's pretty obvious glue is stronger (more surface area, etc.). The real reason to use either glue or screws is whether you want a permanent or a repairable/changeable bond.
Let's say you're building a cabinet with set shelves. For the cabinet itself, glue makes sense, because it's stronger. But if a shelf breaks or sags over time, you're gonna have a really bad time replacing it, if it's glued in. If it has screws, it's an easy job.
If you need absolute strength, and know you'll never change it, and you're making it strong enough that it'll never need repair, glue away. In any other case, screws are faster and easier. Both have their advantages.
When you revealed that the screwed wood failed along the screw lines, my immediate suggestion was to try predrilling the holes. With less compression (potentially creating micro-fractures) the threads may be able to keep the wood locked together without causing a weak point.
How about glue and screws combined?
Great video Mike!
Since the joint held what was found was more values for wood failure, NOT the joint failure values. For that the actual joint failure is needed.
All we know is that 1. the joint is stronger than wood AND 2. Joint failure is higher than wood failure values (which you found with the experiment).
Great and useful stuff nevertheless so the conclusions are valid, just not numerically so.
What about an end grain to long grain joint? And at what increasingly smaller length a long grain long grain joint becomes weaker than a same length screwed joint, That would be interesting to see!
+Dave from Lancashire I like it!
One thing I am wondering is if it wouldn't be better (and I have absolutely no idea how you would test this) to see what it takes to pull the two pieces of wood apart? Would that not figure the holding power of either glue, screws, or glue and screws?
+Erik Cordell Yes sir. I plan to try just that in a future video.
Mike, fascinating experiment! And interesting results! Great video 💛😎
Great video! Anything that requires steel cables and the risk of catastrophic failure is fun to watch. ;) I like the test and would like to see more.
My only critique is along the same lines as some others in talking about testing the shear force required to break the joint. It seem like a shear test would be more representative of the type of stresses edge joints (like the ones in the video) would face. Most edge joints I make when woodworking are panel glue ups for things like tabletops and carcass sides. The greatest potential for damage these parts would face come from a force applied perpendicular to the plane of the surface, like a kid jumping on top of a table or someone kicking the side of a carcass.
A simple way to test this would be to pinch one side of the glued up (or screwed together) panel in some type of jaw setup. Maybe two flat steel plates that can be clamped together or tightened with some threaded rod, with the edge of the two steel plates (the jaws) aligned perfectly with the glue joint. Then make another identical setup that can pinch the panel on the other side of the glue/screw joint and apply some type of pulling or pushing force to only that jaw. You could probably just weld the end of an eyebolt to the bottom jaw, hook the come-along and force meter to it, and watch the destruction.
But again, enjoyed the video and can't wait to see more! Thanks!
+Nathan Connelly Thanks for the feedback. I'm already working on ideas to incorporate these tests in a future video!
Very surprising. Thanks for the definitive tests. Very well done, with the force lever and gopros and force meter n whatnot..you really do live up to your name :-)
great video coverage. You could have showed the go pro shots instead of saying the timeline.
wow that yard is amazing I want a yard like that
How did you choose your master shot camera placement? Look for the one spot we couldn't see anything because you kept blocking the view?
the force should be applied on the glued surface, and not on the back of the wood. Also, what type of glue and screw was used? Curing time? Type of wood? The test should have better if you used 2 equal opposing forces, band on 3 points (force-glue-force-glue-force).. then you are demonstrating the ripping of glue against the wood or glue itself.
great watch
MIKE What I would have liked 2 more tests Glue & screws to justify their use at all---AND to use 3/16 bolts and very thick washers [ Actually sq plates that have holes drilled in them. it is no doubt that the screw threads shred the wood as the wood yields.
great test! just what i was looking for to teach my construction students about glue vs. just screws.
+ke4mcl Thanks! Hope they enjoyed it!
Lots to ponder. Thanks
Decent tests. Agree that the glue didn't fail, the wood did. I would be curious to see more tests, though. You had glue spread along the entire common faces between two pieces of wood, so using only two or four screws seems inadequate -- why wouldn't you maximize the use of screws? How many screws does it take to improve strength? Can you position them to NOT create "fault lines" in the grain? Also, every test of this sort I have seen is always done using PINE -- what happens when you use cedar? Spruce? Birch? Maple? Oak? OSB? MDF? Keep going! :)
+Duncan McRae I like the way you think!
Great video ! I think you should test with wood in T shape, with both glue and screws, because the results might be different...
You made a good test there but joint strength is highly dependent on the type of material , specially on wood there is so much different configurations, anyway i really thought that with glue the shear forces were just going to peel the surface and fail much sooner really impressed ! :D
Could you test a sample with glue and wood screws?
Interesting. I would have expected more of the screws.
I don't think it was fair for the control board and test boards to have different geometry. Should have done a contropl 2x2, then glued/screwed a 2x2 with a lap joint or similar.
Yea you need to do a shear test I think to really prove you hypothesis correct or wrong on this as well as trying a leverage test by that I mean you make an L shape representing a corner and test in pulling up and pushing down and see what happens in those tests as well but good video to start with though and can't wait to see you revisit this
+Shawn Chamberlin Yes sir! I am going to try to do that in a future video. That's going to require some better safety measures though, because we will be talking 1000+ lbs of force at that point.
I like this new series... a lot!!
Seems like you'd need to find a way to fix the back piece to something so it would never move and then only apply the pulling force to the front piece somehow. Not sure how you'd do that.
Again... I really like this show concept... please keep them going!!
+Awesome Wood Things Yes sir. I am already seeing a revisit of this test happening in a few episodes. ;-)
Should have used a 2x4 as the control, and cut the test subjects in half and then secured them together. Glue failed where the joint ended because the board broke.
What kind of glue did you use?
This is why I like the method of gluing and using brad nails to hold the pieces together till the glue dries. I rather use that method that screws. Screws break, and they create weak points for failure.
Here's two issues I have with these type of videos (yes there are other videos).
1) Both joints are essentially equal. No, they didn't break at the same point. They each went beyond what you would use them for though. If a 2x2 breaks at 600 lbs., you just wouldn't use it in a situation beyond 300, maybe 400 lbs. I'd guess 250-350 lbs for jointed material.
2) You really should test actual projects constructed with each method. Under real world use I bet you'd find both joints are equally good. After this you can go Mythbusters on the projects and test their absolute limits. This limit would most likely never be encountered in the real world.
So how about glue plus screws plus duct tape wrapped around it?
I'm not an expert, but isn't there a significant difference in the sturdiness of the joint, depending on the direction of the force? like the difference between a perpendicular force and a parallel force? idk i'm drunk, just a thought.
You're right and I have thought about a follow to this video, but I can't think of a way to do it safely.
If you made a pulley-system, you'd be able to apply force to the joints from much safer distances. Also, your approach seems just fine, you just need to test the strength at different angles. Same procedure, just more data and pulley for added safety! (Wherever you attatched the rope in the other end, just replace it with a carabiner and run the rope through that)
That might be one way to do this safely
did you break the grain the same way?
Wow, often I wondered about glue vs screws. Thank you for sharing this information.
Comment: we came to hear what you have to say, not listen to music. The background music is distracting, absolutely adding nothing to the video, in fact it is annoying, some of us have hearing difficulty thus in order to understand you we must fight the music. Truly, why UA-camrs think they must include background music, baffles me?
I expected that but what wood glue did you use I'm guessing title bond 2
+DIY Tutorials And More Titebond II
very Good test...
I don't like the design of this test because the glue joint is purposefully made the strongest point so the wood is breaking but not at the glue joint this test needs to be made where the weakest point is clearly AT the glue joint that way WHEN it breaks you can properly compare it to when the screwed one breaks
nice video!
the problem with glue is that it can be expensive is usually messy and takes forever to dry whereas with a screw you just tap a little hole then twist it in and you're done
It would be great to see at what force the glue actually breaks, maybe you could tear that with thicker pieces of wood.
Test*
You reconfirmed what has been known for at least 100 years. Good glue is stronger than the wood it is attaching. Screws are almost always weaker as they have less surface area and tend to weaken the wood due to either removal of material (pilot holes if used) or of splitting (often the case when pilot holes are not used). And you made every statistician cringe when you said you like to use two samples to draw conclusions. 😂
Your not screwed...your glued. You can use that line btw.
Structural engineer here - this is painful to watch. I had to stop at about 3 minutes when I realized he's not even testing the actual strength of the glue. Your control wood has a completely different cross section than the first glued member. It's apples to oranges, and you're testing bending moment, not the shear strength of the glue. He probably doesn't even have a proper screw pattern. Some situations glue is better, some screwed is better. But per the same area, glue is much stronger.
Dave Mastriano structural engineer my ass. It's clear and a known fact a glue bond is stronger than the wood itself, when screwed wood will fracture more easily from screw to screw, creating a weak link in the structure. Either go into the field and get some experience or back to school.
wow I thought the screws where going to win
+Jose Duran I did too at first!
try glue and screws
BowRow's Vids invinsible xD
never thought wood glue is so strong
this is a fail. the wood breaks where the glue or screws dont even hold, my english is not the best..
+elowenhamn Svenska This is not true. The wood broke on the screw samples at their insertion points.
Min 2.35, 4.44 watch it slow motion.. the wood broke not the joint
i won't be screwing any boards that i glue. This test proved there is no need.
glue it screw it and Brad nail it :-)
each tree is different.
For alle people whondering what those strange American units mean:
500 pounds is ~ 2.2kN which equals the gravitational force of 220kg.
1000 punds is ~4.45kN which is 445kg.
So the Glue is stronger than the wood?
No!
Your wood only (control) test was the one that lasted the longest.
So either the general quality of the wood pieces you used don't line up well against each other. More or less making this test pointless.
Or it's better to use just one big peace of wood whenever possible and not use either glue or screws.
And a moron "Cometh" from the woods!
That was fast for a video over a year old.
Nice argument by the way. Your comment is a real thinker. ;)
I'm johhny on da spot dawg. I don't generally give the time of day to morons (thats you bro), but you think the test is invalid cause the solid wood is stronger than the joined wood. That's fucked up bro. Of course it is. That coffee mug you super glewd back together stronger after the glue or before the glue? damn dude you dumb.
Actually my problem is he clearly isn't using peaces of wood that he checked for quality.
For the record wood glue is actually stronger than wood. If you have ever seen something made of wood break that has wood glue it never breaks where the glue is as long as they used the glue right.
In every case in the video it was the wood that failed. The only reason one lasted longer than the other was due to the wood itself. That means his test is invalid. It's invalid because he is trying to determine whether wood glue is stronger or screws are stronger. We didn't learn that from his test we learned that his ability to chose consistent wood sucks.
By the way wood glue is not the same as whatever crap you use to fix your mugs. Not to mention you are comparing a person who works with this stuff for a living to a random person trying to fix an item on their own likely using whatever glue they have lying around.
Not all glue is the same. Of course you would know that if you ever did this kind of work. Which you clearly haven't since you managed to miss entirely what I was saying and think I'm an idiot for saying it.
I get it your just looking to get a rise out of someone and laugh at it. The thing is I'm not pissed in the least. In fact I'm laughing at you trying to debate something you clearly have no actual knowledge of. So keep it coming.