Interesting video that may change your mind
#11
  
Long grain to long grain glue ups are much stronger than end grain to end grain glue ups. Right?






Well, maybe not!
"Mongo only pawn in game of life."        Mongo
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#12
  Re: Interesting video that may change your mind by clovishound (Long grain to long g...)
Sidegrain glueups are stronger than the wood is in that direction, and endgrain glueups are much weaker than the wood is in that direction along the grain. That's what leads to traditional joints.

People periodically notice that glued endgrain does hold, but the expectation of greater wood strength in that direction, and the question of bond survival with moisture cycling make me wonder whether it matters.
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#13
  Re: Interesting video that may change your mind by clovishound (Long grain to long g...)
I enjoyed the video. The controlled test was done and explained so it is very easy to follow and understand. I had also been taught that end grain glue joints were weaker so this is my "learn something new every day". (As in; "Be a damned poor day if you didn't") Something I did learn somewhere along the way was that I don't really need tenons or dowels on cabinet doors. My cope and stick cutters provide more than enough glue surface for their intended use. That's basically end grain to edge grain with a little edge to edge in the cove. The doors may break a little easier than with tenons/dowels but neither actually breaks on the joint. This is surprisingly apparent with MDF. Next time you're running stile and rail bits, run a couple scraps of 3/4" and glue and clamp for 20 min.s or so. I challenge you to break the joint apart!
Sign at N.E. Vocational School Cabinetmaking Shop 1976, "Free knowledge given daily... Bring your own container"
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#14
  Re: Interesting video that may change your mind by clovishound (Long grain to long g...)
How old were the joints and how much changes had they gone through in humidity conditions? My point is that don't throw away everything you've learned about end grain and glue-------yet. Not until the test of time is part of the experiment.

Splits in wood don't happen overnight even when wood movement is ignored. 

Simon
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#15
  Re: RE: Interesting video that may change your mind by Handplanesandmore (How old were the joi...)
(09-10-2021, 12:41 AM)Handplanesandmore Wrote: How old were the joints and how much changes had they gone through in humidity conditions? My point is that don't throw away everything you've learned about end grain and glue-------yet. Not until the test of time is part of the experiment.

Splits in wood don't happen overnight even when wood movement is ignored. 

Simon

In my opinion, the reason everyone thinks end grain to end grain is weak, is because they always break at the joint. Side grain to side grain always breaks somewhere else. The end grain joint is just as strong as the side grain joint. The difference is the wood is much weaker in the side grain glue up and so breaks in the wood vs the joint. The end grain wood is far stronger and either and so breaks at the glue joint.

A piece of long grain butt glued will have a weak spot at the joint, compared to the rest of the board. An edge grain glue up will be as strong throughout the board. The difference is not the weakness of the joint, but rather the difference of the strength of the wood in a given direction.

I think the takeaway is that there may be times when an end grain glue up is appropriate vs an attitude that an end grain glue up has no strength.
"Mongo only pawn in game of life."        Mongo
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#16
  Re: Interesting video that may change your mind by clovishound (Long grain to long g...)
End grain joints are weak primarily because the amount of square inches tends to be few.  Whereas face grain joints tend to involve long joints with a correspondingly large square inches of glue area.

Take for instance picture frames.  The joints have just a couple of square inches of glue surface.  Compare that with a tabletop which might be 72" or longer and might have 54 square inches or more in glue area.

And a final observation.  I've made plywood boxes with miter joints.  Those boxes in 3/4" thick ply have alternating direction plies.  So 3/8" is face grain to face grain and 3/8" is end grain to end grain.  I have found that they make fairly substantial joints.
No animals were injured or killed in the production of this post.
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#17
  Re: Interesting video that may change your mind by clovishound (Long grain to long g...)
Quite interesting. Thanks for posting
Jim
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#18
  Re: Interesting video that may change your mind by clovishound (Long grain to long g...)
Interesting yes, but not "real world" as relates to actual woodworking joinery and the purpose it serves.

Mark Spagnolo (Wood Whisperer) just posted a response to the above video
https://www.youtube.com/watch?v=Fuvq0FDs...b_imp_woyt
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#19
  Re: Interesting video that may change your mind by clovishound (Long grain to long g...)
I also suspect the "myth" might have something to do with the fact that PVA glues weren't invented until the early 1900's and didn't gain wide use until the mid to late 50's.  

He'd have to test hide glues and the like to really gain a historical perspective .
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#20
  Re: Interesting video that may change your mind by clovishound (Long grain to long g...)
I don't see why an end grain to end grain joint couldn't just be replaced with a longer board.  The glued joint is far weaker than a board the same length.  Side grain to side grain is just a wider board, and it's stronger than the board in that direction.  There aren't too many end grain to side grain joints in use, and I'm sure that is weaker than any joint I would use.

So the video is mildly interesting, but it misrepresents what people mean when they say that end grain joints are bad.
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