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Gluing end grain is stronger than you think.

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sometimewoodworker

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It’s no big deal, I was just commenting on your first line of your post which said :

Finger joints are closer to long grain joints and it’s been pretty conclusively proved that that kind of joint…”

I was just trying to point out that they are aren’t really closer to end grain joints at all as they rely on the surface of the cross grain for their strength .
Maybe I’ve misunderstood your post and thought you were referring to finger joints as end grain joints.
I apologise if I have but I was simply making a reply to the point of the thread without no attempt at contradicting you.
I assumed that the highlighted text above was clear that I wasn’t remotely suggesting that they have any significant end grain constituent and I didn’t use the term end grain at all in my post Your term cross grain suggests a much shorter (45 degree angle) joint than is used here in the Far East, I agree that close to long grain is also not exact.

I have hundreds if not thousands of them in use in many projects as rubber wood sheets make an excellent construction material and it’s available in a range of thickness and grades and is about equal in price to reasonable quality plywood. The joints never fail, though in some panels the 1 or 2 of the long grain joints has partly missed the glue application
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TheTiddles

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I don't think I've read a discussion, book, or watched an instructional video on gluing ups where someone didn't say long grain joints are strong and end grain joints are weak.
And that’s absolutely true, the part you are missing is the relativity.
Long grain joints are strong, in fact they’re usually stonger than the wood.
End grain joints are weak, in that they’re weaker than the wood.
 

AESamuel

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And that’s absolutely true, the part you are missing is the relativity.
Long grain joints are strong, in fact they’re usually stonger than the wood.
End grain joints are weak, in that they’re weaker than the wood.
Again, you're missing the entire point of the video. I don't think I can help you understand it at this point :rolleyes:
 

sometimewoodworker

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Again, you're missing the entire point of the video. I don't think I can help you understand it at this point :rolleyes:
I think that it is you that you are missing the entire point of the video.
yes end grain to end grain glue joints are stronger than has been assumed. But it still doesn’t matter.
no they are not strong relative to any unjointed piece of wood
they remained a poor choice, you still can’t make boards longer by using end grain but joints.
and yes long grain joints are stronger than the wood so making wide boards by gluing is still a good choice.
 

AESamuel

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I think that it is you that you are missing the entire point of the video.
yes end grain to end grain glue joints are stronger than has been assumed. But it still doesn’t matter.
no they are not strong relative to any unjointed piece of wood
they remained a poor choice, you still can’t make boards longer by using end grain but joints.
and yes long grain joints are stronger than the wood so making wide boards by gluing is still a good choice.
If you read my previous posts in this thread you will see that you are confirming everything I've been asserting, thankyou.
 

Felipe

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Well, I think things can be severely simplified by looking at the graph he presented:

Glue closely is as weak as side grain, long grain is stronger.
Now you just need to plain your joints thinking of the leverage you will apply to the side grain or glued surface. If the leverage is high you need long grain to reinforce. And that is what everyone already does.
 

Pineapple

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In a weird way I kind of miss Trump…in a voyeuristic political car crash sort of way.
The fact that the Americans voted Trump into the White House in the first place effectively highlights the serious shortcomings in the American education system !
 
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