;~) Probably not equivalent but more than likely better than hand crafted. Becauseeeeee, the domino tennons are all basically the same, straight grained wood without defects. A tennon cut on the end of a board can be good or it could be terrible because of what you have to work with at the end of the board. Not all boards have good ends for tennons.
2 mortises and a tenon joint?
They look great, though. It's pretty much the only reason I use them. Yellow glue isn't likely to fail within my lifetime.
With a "pinned" mortise and tenon joint, it's not going to be the pin, round or square, that fails - it's the wood between it and the end of the tenon that will fail if the joint is subjected to enough Pull The Tenon Out Of The Mortise force.
With modern glues, there have been plenty of tests that show that, with a properly fit mortise and tenon joint, it's the wood fibers on one or both sides of the glued surface that fails, the glued interface is stronger than the adjacent wood fiber connections.
Now about the pin - square peds, oriented so a face on the peg is square to the grain direction, it will distribute Pull Apart forces over more surface area of end grain - than would a round peg - which concentrates forces to a single point.
But backing up, who here is building furniture to hold up to normal day to day forces - for a hundred or more years? And if that is the case, do you think the piece will be valued highly enough to be cared for - for 5 generations? People move two or three or more times in their lifetime. And over five generations there's bound to be changes in the temperature and humidity the piece will live in over the 100 years. And over that 100 years, tastes will change and unless the piece is a Maloof or a Krenov and has not just senitmental value - it's going to leave the family at some point - and become just another piece.
I'm for making things I can use and looks good to my eye. After me - I won't be around to have to fix it if something loosens up.
In the barn I'm working on there are several pinned mortise and tenon joints that are in the process of coming apart--generally the tenon split out behind the pin. This is on 8x8 post and beam construction.
Whether the pin or the tenon is weaker depends on the dimensions of the joint.
It's true that glue can fail. So can a pin. So can a mortise. So can a tenon.
Glue adds a level of resistance to pull out equal to the strength of solid wood. A pin adds less.
Racking forces also tear away at the pin.
Simple physics does not say that the joint is stronger. It is only stronger if the glue has failed.
And why would a glue joint be "weakened" in 100 years if it was properly made? I'm restoring a bookcase right now that's older than that and the hide glue joints on it are still for the most part perfectly sound. The only one that has failed is on a molding and it's clear that somebody pried really hard on it to get it to fail.
Certainly use a pin if it fits the style or if it makes you feel better, but don't delude yourself that it is stronger than an epoxy joint.
What's the issue? Who is the audience?
They look great, though. It's pretty much the only reason I use them. Yellow glue isn't likely to fail within my lifetime.
Acsolutely agree that the pins look great!
A chairmaker doesn't want to mislead his customers by making false claims in both his printed matter and website content.
=A0 =A0 =A0 =A0 =A0 =A0--John Adams
Never said glue isn't strong. Never said I have experienced a joint failure. I speculated that a pinned joint is stronger than a not pinned joint. None of the tests you point to have anything to do with pinned vs not pinned. So your claims are just retoric just like mine.
Never said pin won't rot. Said pinned joint is stronger than non pinned joint, especially in the long run. Thanks for agreeing.
And how many of those joints would have already totally failed if the pin wasn't there as a last resort mechanical assist? I don't think you can say but it seems you are proving my point and at the least have offer no imperical proof I am wrong. And I am certainly not deluded and neither are a few hundred, maybe thousands of years of craftsman who have pinned their joints.
Yes glue is strong. Where is the one test you can point to that says a non-pinned joint is as strong or strongetthan a pinned joint? I read lots of these reports and haven't seen one yet.
I only made it through the first year and 1/2 of my engineering education but later in life also worked with FEA analysis software and I think you have things quite wrong. Backwards actually. The rounded surface will produce a much more evenly distributed force than flat surfaces.
Sorry you like to build crap. I build quality pieces that will last many generations if the holders wish them to do so.
The pin is not a "last resort mechanical assist", it was the only fastener holding the joint together until some cables with turnbuckles were installed.
And the reason it was used is not that it was strong, it was that the joint can be disassembled when the barn needs repair.
If the joints had been tightly fitted and glued they likely would not have come apart at all. But they also would not be amenable to disassembly at need.
You might want to take a look at in which tests showed that chairs with pinned tenons were weaker than with unpinned. Fine Woodworking's test showed similar results.
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Ya know, I was ready to eat some crow and enjoy the taste if someone finally brought a gun to this knife fight and offered up some real supporting evidence. However, this report compares pinned joints with no glue vs glued joints with no pins. Furthermore, it finds the pinned joints are 80% to 90% as strong as the glued joint method (IIRC). So you have just proven my point in a way because if the pin itself is nearly as strong as a glued joint, is adding a pin to a glued joint going to make it stronger... the crowd shouts YES!
Please reference my original and simple point that an unpinned joint is not 100% as strong as a pinned joint and don't take the argument off on some tangent just to find a supporting point, which seems ro be difficult... slice!
OK, maybe I'm wrong... sorta.
This study
Also pin closer to the shoulder is better because the tenon is what breaks, not the mortised piece. Also good wide shoulders add strength.
In my defense, if the glue ever faild the pin would add strength because the way this test was done glued and non glued joinst were the same strength because it was twist not pull. I like it that way sometimes too.
The guys site is amazing
I liken glue on wood to welding on metal. They both make two pieces into one. My thoughts are that pins could only decrease the overall strength of the piece. Pinned joints can be very strong, but a glued joint will always be stronger.
I refer you to the parts of those tests which indicate that the wood breaks before the glue joint and ask you how the pin could ever come into action as a strengthener, given a good glueup. I submit that it can -never- do so.
I guess we'll have to agree that we disagree on the point.
-- "Human nature itself is evermore an advocate for liberty. There is also in human nature a resentment of injury, and indignation against wrong. A love of truth and a veneration of virtue. These amiable passions, are the latent spark. If the people are capable of understanding, seeing and feeling the differences between true and false, right and wrong, virtue and vice, to what better principle can the friends of mankind apply than to the sense of this difference?" --John Adams
I double-dog-DARE ya to test that on your own. Go ahead, discover physics, mon!
And have the leg break out instead? ;)
A pin could help -only- if the glue did, indeed, fail.
"Human nature itself is evermore an advocate for liberty. There is also in human nature a resentment of injury, and indignation against wrong. A love of truth and a veneration of virtue. These amiable passions, are the latent spark. If the people are capable of understanding, seeing and feeling the differences between true and false, right and wrong, virtue and vice, to what better principle can the friends of mankind apply than to the sense of this difference?" --John Adams
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Reading comprehension is clearly not your strong suit. Read the article again, and this time look at what is there instead of what you want to be there.
*chuckles*
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