# Strongest Wood joint from Fine Woodworking Mag.



## wormwood (Aug 6, 2008)

A few years ago Fine Woodworking did an article testing a dozen or so types of joints. IIRC, surprisingly, either the half lap or the bridle was the strongest. I can't find that issue.

Does anyone remember what joint won in that test?

Thanks fellas!


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## Woodworkingkid (Jan 8, 2011)

i am almost sure that it was the half lap


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## wormwood (Aug 6, 2008)

Woodworkingkid said:


> i am almost sure that it was the half lap


Thats what I'm thinking. 

I got a little project where I need strength>aesthetics.


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## cabinetman (Jul 5, 2007)

wormwood said:


> Thats what I'm thinking.
> 
> I got a little project where I need strength>aesthetics.


What's the project?












 







.


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## wormwood (Aug 6, 2008)

cabinetman said:


> What's the project?
> 
> 
> 
> ...


A cutting table for my wife's sewing with a big leaf on each end. Already have the top from one she bought, but the legs were crap and fell apart. So its just a utility piece. I'm going to made sled type legs with the lap or bridle joints.


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## Brink (Nov 22, 2010)

http://www.finewoodworking.com/ToolGuide/ToolGuidePDF.aspx?id=31926


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## wormwood (Aug 6, 2008)

Brink said:


> http://www.finewoodworking.com/ToolGuide/ToolGuidePDF.aspx?id=31926


Thanks Brink, thats the answer!


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## Brink (Nov 22, 2010)

That was a funny coincidence. I was just looking for an article (might have been a letter) they did on glue joints, specifically, jointing with bare equipment vs. waxed and buffed equipment. 

I couldn't find what I was looking for.


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## Tony B (Jul 30, 2008)

The lap joint is my favorite joint. It is easy and fast to make on a table saw with a Dado blade.


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## rrich (Jun 24, 2009)

Brink said:


> That was a funny coincidence. I was just looking for an article (might have been a letter) they did on glue joints, specifically, jointing with bare equipment vs. waxed and buffed equipment.
> 
> I couldn't find what I was looking for.


I remember reading the article. IMHO, the article was intended to be a glue strength article, the methodology used tested the physical structure of the joints and the gap filling abilities of glue.

In my shop using observations of having tearing apart some joints, there isn't much difference in the strength of modern glues. When following the directions of the glue, most glues are stronger than the wood that they are gluing together. (Using tight fitting joints and clamping for the required time seldom have the glue fail.) When I have forced a glue joint to fail it is almost always the wood that fails and not the glue. What I have noticed is that polyurethane glue is very strong in large areas but as the glued surface area decreases the likelihood of glue failure increases. This may be due to inadequate clamping pressure??? 

I use Titebond and Titebond III mostly in my shop. TB for mostly melamine panels and TB III for most wood uses. (TB III seems to be easier to remove after curing from corners using a chisel. TB III is a real bear to remove from melamine and Formica surfaces.)

If I'm gluing a non-structural component into an area that can not be sanded after the glue cures, my choice is polyurethane. The foam comes off easily with a chisel or Shur-Form scraper.

There is one interesting note about TB III from my experience. I was making a face frame out of Poplar. The joint structure was pocket screws with TB III. A joint was incorrectly marked and assembled in the wrong spot. The joint was a typical end grain to edge (long) grain like almost all joints in face frame construction. After about 45 minutes I took the joint apart. After I removed the pocket screws, the amazing part is that the glue did not fail in some places but rather the end grain pulled some of the edge grain loose.


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## phinds (Mar 25, 2009)

I'm really surprised to see a half lap quoted as stronger than a bridle joint. To me that just doesn't make sense, structurally.


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## mdntrdr (Dec 22, 2009)

phinds said:


> I'm really surprised to see a half lap quoted as stronger than a bridle joint. To me that just doesn't make sense, structurally.


 
I thought the same thing at first... but after thinkin on it a while I can see it. The actual wood members would be thicker for a "half" lap, for a bridle they would only be 1/3 the thickness of the stock. :smile:


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## TGRANT (Jan 25, 2011)

wormwood said:


> Thats what I'm thinking.
> I got a little project where I need strength>aesthetics.


 
Just another opinion to add. Testing for the ‘strongest joint’ is great for analyzing certain variables, but may not tell us all we need to know. I read the article years ago, and though I can’t remember the details, I remember thinking that the advantages of the mortise and tenon were not exploited in the test. The strength of the joint itself is only part of the process. The application and stresses and strains on the joint should also be factored in. We could have a situation where a certain joint is stronger than another in a test, but fail in real world situations. Some furniture sits in a corner for years while another is moved rather roughly several times a day.

Half lap joints are less able to withstanding twisting motions, so they would not be the best choice for certain applications. Consider the joint that attaches table legs to the table apron. Every time the table is dragged across the floor there will be twisting motion that would be better handled with a mortise and tenon rather than the half lap joint. Bridle joints are open at the end, and depend on glue strength rather than wood in certain motions. The wood to wood surface area is maximized with the bridle joint though, and does take advantage of modern glue strength.

So if you are joining table legs or using the joint in similar situations, I’d go with the mortise and tenon. There is a reason this joint has been used in this application for hundreds of years.


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## Tony B (Jul 30, 2008)

I never read the article but I doubt that these are sceintifically valid tests. In order to be valid they would have to be performed thousands of times. Just a few tests each will give us a good idea of what to expect but not be absolutely true. 
It is true though that modern glues will make the joints stronger. The real advantage of mechanical joints such as M & T in chairs and tables is that if the joint fails - and all will fail eventually - is that you will be aware of the failure well before the whole structure falls apart.


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## phinds (Mar 25, 2009)

Tony B said:


> I never read the article but I doubt that these are sceintifically valid tests. In order to be valid they would have to be performed thousands of times. Just a few tests each will give us a good idea of what to expect but not be absolutely true.
> It is true though that modern glues will make the joints stronger. The real advantage of mechanical joints such as M & T in chairs and tables is that if the joint fails - and all will fail eventually - is that you will be aware of the failure well before the whole structure falls apart.


Very good point, Tony.


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## starcyclist (Feb 7, 2013)

wormwood said:


> A few years ago Fine Woodworking did an article testing a dozen or so types of joints. IIRC, surprisingly, either the half lap or the bridle was the strongest. I can't find that issue.
> 
> Does anyone remember what joint won in that test?
> 
> Thanks fellas!


http://www.finewoodworking.com/how-to/article/fww-poll-the-strongest-joint.aspx
*7 of 10 woodworkers say a mortise and tenon makes the strongest joint*


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## Quillman (Dec 30, 2012)

Not the answer you wanted, just some additional information
*************************************************
It is interesting & important to study joinery.
The more you know about it, the easier it is to design your connections.
Just how a joint fails depends on a lot of variables. Load, pull, bend, compress, the lever, glue, quality of surfaces, surface area, time since bonding, + the metrology of the analysis.
I wrote a book on joinery, FWW did a good job on their studies. You folks have contributed here.
Notwithstanding, adding hardware can change the whole picture.
Since (& before) my book, I have been studying hardware assisted joinery.
Once steel enters the equation, everything changes, and my point.
A couple of screws and steel cross dowels can raise the pull strength of a bed rail from 500 pounds to the full tensile strength of the stock in the connection.
Whilst the strongest joinery for a particular connection is a very worthy study, adding a little steel changes everything. 
And most importantly you can compromise the design of the joint (shallow tenons e.g.) and if you add a little hardware you can exceed the strength of the most sophisticated configuration of said connection.
(Hopin' I haven't violated any protocol).


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