End Grain Glue Joints Are Weaker, Right?

[mdbuntyn]

Someone shared this on another forum, & I thought that I should share it here

 

[Echd]

Now that's interesting. Very cool to see something we always took as a fact be shown as categorically incorrect.

I expect to see scads of less rigorous and more "trendy" youtube personalities attempt to replicate this en masse soon. I certainly don't see any disqualifying or compromising features of his test.

 

[Graywolf]

Interesting,that certainly debunks some dogma

 

[Martin Roper]

This reminds me of an old Firesign Theatre album:

 

[llucas]

Thanks for sharing.
Stuff like this reminds me to keep an open mind and value critical thinking even more than I already do.
Sometimes critical thinking seems to be losing the battle with "I don't care what you say. I know what I know!"

 

[tvrgeek]

This reminds me of an old Firesign Theatre album:

View attachment 204139

Out of the smog and into the fog he walked into a sandstone building. " Ouch my nose"

Glad I never worried about it.

 

[Willemjm]

Great video.

I think although the end grain to end grain test showed the strongest, or needed the most force to fail, it was a glue joint failure rather than a wood failure next to the joint.

I occasionally have pocket screw joints, side to end grain on face frames fail and the failure is always approximately 90% glue failure with the remaining 10% of the joint actually ripping the cellulose fibers apart. This happens when cabinets are abused in the field, or dropped during shipping. Sometimes we have pocket screw joints of a piece with dimensional errors and we take the piece apart to salvage some wood or fit it in the scrap bin. Breaking those apart do not necessarily agree with the above test.

Would be interesting if his tests can be repeated with more samples and perhaps different wood species. Some lumber species do not absorb end grain glue as much as others.

One thing is for certain, the wood glues available today are far superior those those used in the old days.

 

[bob vaughan]

His tests were clearly true under the sample size and conditions of his tests, but in real world applications, conventional wisdom prevails. On an end grain joint such as a miter, the pieces joined will have far more leverage due to the normal length of stock. His points will hold true if you're gluing up something like a little Soma block puzzle, but not a cabinet face frame.

 

[Rwe2156]

I did not watch it b/c I know from 40 years experience and testing it myself that it does fail and it’s always a glue joint failure. I’m sure his test is valid, even still, try it red oak and see what happens.

Plus, common sense tells me …… Why aren’t cabinets built that way? Why do so many apparently uenlightened people spline miter joints?

And why aren’t 30‘ beams made by simply butt gluing a bunch of boards?

Funny, we still have all those finger jointing machines making mouldings……

 

[Graywolf]

I did not watch it b/c I know from 40 years experience and testing it myself that it does fail and it’s always a glue joint failure. I’m sure his test is valid, even still, try it red oak and see what happens.

Plus, common sense tells me …… Why aren’t cabinets built that way? Why do so many apparently uenlightened people spline miter joints?

And why aren’t 30‘ beams made by simply butt gluing a bunch of boards?

Funny, we still have all those finger jointing machines making mouldings……

And you left out all those fancy scarf joints found in post and beam structures.

 

[mdbuntyn]

I did not watch it b/c I know from 40 years experience and testing it myself that it does fail and it’s always a glue joint failure. I’m sure his test is valid, even still, try it red oak and see what happens.

Watch the video

 

[Gotcha6]

I have to wonder what - if any - impact surface texture and preparation plays on this. I would think if his hypothesis about how end grain glue acts is correct that sanding dust would clog the pores of the grain to the point of disallowing a good penetration of the glue. Just a thought..........
Nonetheless, still an interesting video to watch but it needs to be watched in its entirety for maximum understanding.
Thanks.

 

[tarheelz]

A couple years ago I was able to reconcile "joint strength" and "glue strength" and "end grain/side grain" debates in my head by concluding, "If you use proven techniques you don't need to worry about this stuff." That quieted the voices in my head.

End grain to end grain is strong enough to never fail with good glue and good prep. Is it even stronger than side grain to side grain? I don't need to know.

 

[Matt Furjanic]

That made a believer out of me. Thank you for sharing that…