Glue Myths Video

[roger wiegand]

One of the things that I learned working as a scientist is that when the data from your experiment contradict what you see happening in the real world, 99.9% of the time you have a problem with your experiment.

Having repaired perhaps 100 mitered picture frames over the decades where 100% of them had failed at the near end-grain miter joint while having only seen long grain joints fail in situations where the glue was seriously degraded by extreme age or by flood damage, I have to say I'm skeptical. I'm not a material science guy, so I'm not going to critique the testing methodology, but the outcome reeks of an artifact of the specific methodology employed.

I for one am not about to glue two 2x10's together end to end and then stand on the piece as planking on a scaffold.

[Frank Pratt]

One of the things that I learned working as a scientist is that when the data from your experiment contradict what you see happening in the real world, 99.9% of the time you have a problem with your experiment.

Having repaired perhaps 100 mitered picture frames over the decades where 100% of them had failed at the near end-grain miter joint while having only seen long grain joints fail in situations where the glue was seriously degraded by extreme age or by flood damage, I have to say I'm skeptical. I'm not a material science guy, so I'm not going to critique the testing methodology, but the outcome reeks of an artifact of the specific methodology employed.

I for one am not about to glue two 2x10's together end to end and then stand on the piece as planking on a scaffold.

And the way he states the results serve to confirm his conclusion & confuse the issue. The bottom line is that an end grain to end grain glue joint is still far weaker than a solid piece, whereas a long grain to long grain joint is stronger than the surrounding wood.

He has not proven or shown anything that is not common knowledge. He just presented it differently. But the reaction to his findings do show that most people need a bit of education in this area.

[Andrew Hughes]

And the way he states the results serve to confirm his conclusion & confuse the issue. The bottom line is that an end grain to end grain glue joint is still far weaker than a solid piece, whereas a long grain to long grain joint is stronger than the surrounding wood.

He has not proven or shown anything that is not common knowledge. He just presented it differently. But the reaction to his findings do show that most people need a bit of education in this area.

Thats really well said Frank.

[Mark Bolton]

In my experience, most furniture glue joints fail over time due to repeated expansion - contraction. The edge/end joints he shows will certainly fail this way. I have made countless picture frames with mitered 45 degree corners. Even before time for expansion contraction, drop it on the floor and the joint will separate at the glue line...hence the reason for splining joints. There are many reasons for end grain scarf joints and mortised face frame corners beyond endgrain joint strength. Most involve resistance to expansion/contraction shear forces.

And Jerry for the win!! Well said.

[Keegan Shields]

Oh wait, some guy on YouTube has discovered one neat trick for gluing end grain... This is how you drive clicks and views.

I think the unfortunate reality is that life is pretty boring and instances where people disprove conventional wisdom is exceedingly rare. And those big events are usually accompanied by a technology innovation (like a new type of glue for instance).

Does it happen? Yes! Just not nearly as much as YouTube videos or the internet would have you believe.

[Jim Dwight]

I think it is myth that there is any relevant information in that video.

Side grain to side grain failed in the wood, not at the joint. No surprise, we know wood is weaker across the grain. Doesn't really tell us the glue joint of side grain to side grain is weak.

End grain to side grain was strong but it won't stay that way. We all know wood moves across the grain, very little along the grain. So the end grain portion will move and fail the joint as humidity changes. So it is still a weak joint, it will just take a little time to fail.

End grain to end grain failed at the glue line. So the joint was the weakest portion of the piece. If we knew that wood moved uniformly across both pieces with humidity changes then it might stay together but I suspect it will not move uniformly and this joint will fall apart.

The myth the creator of the video is creating is that the reason we don't glue to end grain is weakness of the glue joint initially. That is not the case. We do not glue to end grain because of wood movement with humidity changes. The wood movement will fail the end grain joint.

If you still think end grain joints are a good idea think about why trim manufacturers finger joint paint grade trim. They would not waste the wood and do all the extra work if they could just glue end grain to end grain and get a decent joint.

If you can't already tell, I think the video is just nonsense. Nothing useful to be gained from it. Don't glue to end grain if you can possibly avoid it. You will regret it if you do.

[Mark Bolton]

What we will see next is a video trying to disprove picture framing a band around an end grain cutting board because the end grain picture frame will hold back the massive expansion and contraction of the field.

[Edwin Santos]

I have made countless picture frames with mitered 45 degree corners. Even before time for expansion contraction, drop it on the floor and the joint will separate at the glue line...hence the reason for splining joints.

Do you think there is a difference between a glue joint's resistance to shock (like your drop test, or a mallet pounding) versus progressively applied force (like the video author is using, or say mass/gravity over time, or expansion/contraction)?

The subject of a Domino joint's resistance to shock load came up in another recent thread so it was on my mind.

Perhaps a particular glue joint or a particular glue will respond well to one kind of load and not the other.
I don't believe I've ever seen anyone test the particular issue I'm describing.

[Frank Pratt]

What we will see next is a video trying to disprove picture framing a band around an end grain cutting board because the end grain picture frame will hold back the massive expansion and contraction of the field.

I would not be in the least bit surprised if someone posted a link in this thread to just such 'proof'

As far as the video this thread is regarding, he has good methodology and video quality, but he's just demonstrated what most anyone that's worked with wood for a few years already knows. He just presented it in a manner that would, shall we say, generate clicks. Not a statement of his intent, just the optics of it.

[Edwin Santos]

What we will see next is a video trying to disprove picture framing a band around an end grain cutting board because the end grain picture frame will hold back the massive expansion and contraction of the field.

Mark, here's a funny story for you.
Once at an arts fair, I encountered a table where a woodworker was selling cutting boards and cheese boards just like the picture.
I squared up my shoulders and walked up to him like a gunslinger and challenged his work over the obvious expansion/contraction shortcomings.
He proceeds to tell me the exposed end grain was 1/8" veneer sliced on a large bandsaw, run through a wide belt sander, glued up over two pieces of baltic birch, and then wrapped with the mitered frame. Then he winks and asks me if I want to buy a high priced Baltic Birch cutting board.

I hung my head, laid the fiddle at his feet and walked out of the octagon.

[Mark Bolton]

I hung my head, laid the fiddle at his feet and walked out of the octagon.

Ive seen the same several times however, a drum with a head beaten so much its in tatters, you still see the solid wood execution almost daily if you check in on any of the "sale" sites. It even happens here at the shop occasionally with people stopping in to show off their latest creation. I use to try to give some input, now I just say "wow, thats beautiful" and they simply must learn the hard way.

Not that I make cutting boards but in my world pulling a "con" on someone thinking they are getting a solid end grain cutting board wouldnt fly. The minute they were made aware of "plywood" it would be set back down.

But all the power to anyone who rationalizes however they choose to part their customer from their funds.

[Edwin Santos]

Not that I make cutting boards but in my world pulling a "con" on someone thinking they are getting a solid end grain cutting board wouldnt fly. The minute they were made aware of "plywood" it would be set back down.

But all the power to anyone who rationalizes however they choose to part their customer from their funds.

Well you pretty much summed up the entire post WWII commercial furniture industry.
I'm not arguing with you. At the time I thought it was clever woodworking and it didn't occur to me that his creativity might be unethical to some.

[Mark Bolton]

Well you pretty much summed up the entire post WWII commercial furniture industry.
I'm not arguing with you. At the time I thought it was clever woodworking and it didn't occur to me that his creativity might be unethical to some.

I dont disagree. No one in this day and age "needs" a full thickness end grain cutting board. No one is butchering whole or quartered animals with a 5lb cleaver and needs the forgiveness of the end grain. So the veneer is a far better capitalization of resources for an esthetic board. Makes total sense. I suppose in hind sight it all comes down to a price point. True end grain board is $xxx.xx, faux is $xx.xx. Is what it is.

Im not a purist. I could care less as long as the customer is happy and its not crap that is fatally flawed from the get go. And now, who cares about that... hopefully the fatally flawed get sued or fold up with returns/complaints. I guess thats the post war law of the land you speak of.

[andrew whicker]

Millions upon Millions of face frames use edge to side grain on glue up.

[johnny means]

Millions upon Millions of face frames use edge to side grain on glue up.

Of course, it helps that the entire face frame assembly is glued to another object.