Traditional Mortise & Tenon Joints: A Treatise

Rob-GB

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I posted a while back that I would do a write up on tenons as there are some areas of misinformation on the net.
Several Fora have repeat posts about the subject and the forthcoming replies are often erroneous. Hopefully this post can be a source of information for beginners and experienced woodworkers alike.
Please take it as it is meant, a way to understand the (possibly) most common form of tried and tested woodworking joint. Of course any constructive criticism will be welcome as this is the first time I have done this kind of writing.
Thank you, Rob.

[attachurl=#] Click second link below, this one no longer works, for some reason
 

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Many thanks for this.  Woodworking is only a hobby for me, but I've been asked to make a gate for some neighbours next month, and this will be invaluable.

Andrew
 
interesting read, i have saved a copy of that for reference as i dont really do that type of joinery but would like to for some of my own stuff at home. like many others i knew about 1/3 rule but there is sooo much more info than that.

thankyou
 
Thanks Rob, for an excellent post.  I shall certainly have this at hand next time I build a door!

For the benefit of those new to mortise and tenon joinery, I would emphasize a point you made in your article.  The rules for tenon width and thickness are useful and will keep you in safe waters, but don't take them too literally.  Particularly on thickness, size your tenons to fit the tooling (router bits or chisels) that you have available.

As an aside, what's your view on pegging?  I have respected friends who differ on this, some think a drawbored pin greatly improves the joint while others fear that over the long term the pin will loosen and actually weaken the joint.  

Thanks again.
Jesse
 
Nicely done, Rob. Thank you! 
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Jesse

I do make a lot of doors with the exact methods that Rob has written so expertly (Rob, are you a school teacher) & i never peg tenons on a door.  I do however peg my tenons on the joint between a newel post & a stringer when making stairs.

Nice work Rob,

Woodguy.
 
Many thanks for the feedback, so far, chaps. Much appreciated and glad that it will be of use to you.

Jesse:- Pegging is a tricky subject, so many differing methods to suit the different applications.
From my experience machine made pegs/dowels cause the most problems, for post and beam pegged joints all advice is to use riven pegs.
That is pegs that are driven through a sharpened tube or metal plate drilled to suit the size required, so that the peg is formed following the natural grain direction. This makes for a stronger peg.(So should be employed in all similar applications) The next problem is shrinkage. Not always to do with the peg shrinking but with the main timbers not being acclimatised to their enviroment.
On smaller works, if the drawbore is offset correctly to suit the timber being used the joint will pull up nicely, the correct adhesive will finish the job. Then if the peg shrinks, the joint will remain intact unless the glue fails. I am in danger of doing another few pages so will stop for dinner here [wink]
Regards Rob.
 
woodguy7 said:
Jesse

I do make a lot of doors with the exact methods that Rob has written so expertly (Rob, are you a school teacher) & i never peg tenons on a door.  I do however peg my tenons on the joint between a newel post & a stringer when making stairs.

Nice work Rob,

Woodguy.

I am just a simple carpenter and joiner. I love what I do.
I recently had to adapt some pegged doors, the glue was long failed, so I could ease out the wedges with a 6mm chisel and drill out the pegs. Part of the problem was that the doors had been dipped to strip the paint, not good for old animal glues!
Stair strings to newels and where possible handrails to newels are drawbored due to the strength it brings to the construction. But that's the reason you do it too! [smile]
 
Thanks Rob. Good write-up which I really enjoyed.

Just one tiny note, you referred to the vertical pieces as muntins but they are in fact mullions. Muntins are the thin strips of wood or metal that divide glass panes into smaller panes. In the UK the words are sometimes incorrectly interchanged but it is nonetheless incorrect. 

A horizontal piece would be a transom.

Richard.

 
Richard Leon said:
Thanks Rob. Good write-up which I really enjoyed.

Just one tiny note, you referred to the vertical pieces as muntins but they are in fact mullions. Muntins are the thin strips of wood or metal that divide glass panes into smaller panes. In the UK the words are sometimes incorrectly interchanged but it is nonetheless incorrect.  

A horizontal piece would be a transom.

Richard.
Hey Richard

Rob has done a great piece on this and he obviously trained as a joiner as I did and as far as I was taught a mullion refers to the vertical division in a window frame.

A muntin is the interior vertical division of a door or similar framing.

The thin strips of wood that divide glass panes into smaller panes are called glazing bars.
I have just checked this with the "Joiners Bible" "Modern Practical Joinery by George Ellis", a bit dog eared and dusty now but accurate.

Maybe lost in translation to Canadian!! [tongue] [tongue]

 
 
Muntin
From Wikipedia, the free encyclopedia

Muntin or Muntin bar is a strip of wood or metal separating and holding panes of glass in a window. Muntins are also called "glazing bars", "muntin bars", or "sash bars". Muntins can be found in doors, windows and furniture, typically in western styles of architecture. Muntins create a grid system used to divide small panes of glass, called "lights" or "lites", into a single window sash or casement.

Windows with "true divided lights" make use of thin muntins, typically 1/2" to 7/8" wide in residential windows, positioned between individual panes of glass. In wooden windows, a fillet is cut into the outer edge of the muntin to "stop" the pane of glass in the opening, and putty or thin strips of wood or metal are then used to hold the glass in place. The inner sides of wooden muntins are typically milled to traditional profiles. In the U.S., the thickness of window muntins has varied historically, ranging from very slim muntins in 19th century Greek revival buildings to thick muntins in 17th and early 18th century buildings.

Until the middle of the 19th century, it was economically necessary to use smaller panes of glass, which were much more affordable to produce, and fabricate into a grid to make large windows and doors.[2] However, many considered the division of a window or glazed door into smaller panes to be more architecturally attractive than use of large panes. In the UK and other countries, muntins (typically called "glazing bars" in the UK, or "astragals" in Scotland) were nevertheless removed from the windows of thousands of older buildings during the nineteenth century in favor of large panes of plate glass. Restoration of these buildings in the following century increasingly included reinstatement of the glazing bars, which many now see as an essential architectural element in period buildings.

Muntins are often confused with "mullions" (which separate complete window units), and "astragals" (which close the gap between two leaves of a double door). Many companies use the term "grille" when referring to a set of decorative muntin bars that are added to the outside of a large, single pane of glass to give a sash the appearance of a "true divided light". In the UK, the term "grille" tends to be used only when there are bars sandwiched within the insulated glass glazing unit, and not stuck to the outsides of it.

Double or triple layer insulated glass can be used in place of ordinary single panes in a window divided by muntins, though this reduces the effectiveness of the insulation. Other insulating glass arrangements include insertion of a decorative grid of simulated metal, wooden or plastic muntins sandwiched between two large panels of glass, sometimes adding an additional grid of simulated wood muntins facing the interior to produce a more convincing divided light appearance.
 
Hey Guy, I'm a Brit. I just live in Canada!

I am pretty sure I am right, but I don't to upset anyone, and I certainly would not want a vocab discussion to spoil a good thread.

I know a lot of these words are interchanged in common usage, and because muntins are not used anymore in windows, they are used synonymously with mullions. My original post was perhaps pedantic, but really it was intended for the North Americans who just use mullion. A muntin is the same as a glazing bar, or a grille in the UK.

The only reason I came across this was because my Granny's house had old-style windows with the diamond panes- which needed replacing and we had this whole muntin discussion at the time.

Anyway, no offense (US)/ offence (UK) meant and none taken!

 
Richard Leon said:
Hey Guy, I'm a Brit. I just live in Canada!

I am pretty sure I am right, but I don't to upset anyone, and I certainly would not want a vocab discussion to spoil a good thread.

I know a lot of these words are interchanged in common usage, and because muntins are not used anymore in windows, they are used synonymously with mullions. My original post was perhaps pedantic, but really it was intended for the North Americans who just use mullion. A muntin is the same as a glazing bar, or a grille in the UK.

The only reason I came across this was because my Granny's house had old-style windows with the diamond panes- which needed replacing and we had this whole muntin discussion at the time.

Anyway, no offense (US)/ offence (UK) meant and none taken!
just checked the carpenters assistant and in there it is called muntin, montant or mounting.
 
Hi Richard

None taken or infered.

Maybe we could start our own Fog translation system (Muntin/Mullion = the sticky up bit in the middle!)  [poke] [bite tongue]
 
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