In article <[email protected]>, Jeff
Gorman <[email protected]> wrote:
> Such joints will have greater gluing area, but are more difficult to cramp
> up at gluing-up time. To keep the shoulders close, cramps are needed along
> both the stiles and rails and a 'g' cramp (or similar) is needed to prevent
> the flanks of the slot from spreading.
>
> Hence, like other features in joints, ease of assembly is a fundamental
> design feature.
Wonderful explanation, Jeff.
djb
--
Is it time to change my sig line yet?
Well then the answer is even easier. For one reason or another all the
joints you have been looking at, "mostly from one guy", is that it's the one
guy's preferred joint.
While I think it is overkill and see no advantage in it for the extra work
to joint an apron to a leg that one guy probably does. Then again, there's
no law against overkill in joints.
--
Mike G.
[email protected]
Heirloom Woods
www.heirloom-woods.net
"tmbg" <[email protected]> wrote in message
news:[email protected]...
> I'm talking aside from frame/panel applications where you need some way to
> fill the groove, like joining table aprons to legs. I've been looking at
> a lot of table designs, and a lot (mostly all one guy) use haunched tenons
> for the table apron to leg joint, and the haunch seems unnecessary, and
> maybe even a liability...
>
> On Thu, 05 Feb 2004 19:26:36 -0500, Mike G wrote:
>
> > the haunch covers the end of the dado in the stile that holds the panel.
As
> > an extra added attraction it also gives you more glue area which
strengthens
> > the joint.
>
"tmbg" <[email protected]> wrote
: what's the advantage to haunched tenons, other than filling the groove in
: the end of stiles in frame/panel joinery? I see a lot of designs, and it
: almost seems like the haunch was thrown in arbitrarily.
Haunched tenons ('thrown in' for centuries) are used at the corners of
framed panels.
The haunch is the wood between the end of the mortise and the end of the
stile.
If there was no haunch, the end of the stile (of a through jointed frame)
would consist of a slot, the joint becoming in effect a bridle joint.
Such joints will have greater gluing area, but are more difficult to cramp
up at gluing-up time. To keep the shoulders close, cramps are needed along
both the stiles and rails and a 'g' cramp (or similar) is needed to prevent
the flanks of the slot from spreading.
Hence, like other features in joints, ease of assembly is a fundamental
design feature.
Jeff G
--
Jeff Gorman, West Yorkshire, UK
Email address is username@ISP
username is amgron
ISP is clara.co.uk
Website www.amgron.clara.net
John Crea wrote:
>
> Basically PRETTY is the only reason for haunched tenons. They really
> are NOT significantly stronger than the non-haunced ones
>
> John
WRONG!
Think of the joint at the top of a table legand the apron flush
up against the bottom of the table top. Now think twisting.
A saddle joint would work on the table leg/apron joint
but a haunched tenon does add significant resistance to twisting.
In the table leg/apron example you've got a limited amount of
space for the two tenons. If you offset them vertically you
have to reduce the width of each tenon to increase the length.
If you you gave them intersect within the leg you have to shorten
them. Either way, having some additional tenon surface are in
contact with a mortise, even if it's a stepped or haunched mortise
adds siginificant resistance to twisting. This becomes more
significant as the furniture becomes more refined and delicate -
Arts and Crafts compared to chinese furniture as an example.
Most joints were developed for a purpose and few of the traditional
joints were not "just for show".
Hell, just go here and specifically look at #4 - Six Degrees of
Freedom.
http://home.comcast.net/~charliebcz/MTPrimer0.html
I don't mean to start a pissing match but IMHO this response is
misleading.
charlie b
Jeff Gorman wrote:
>
> Haunched tenons ('thrown in' for centuries) are used at the corners of
> framed panels.
>
> The haunch is the wood between the end of the mortise and the end of the
> stile.
>
> If there was no haunch, the end of the stile (of a through jointed frame)
> would consist of a slot, the joint becoming in effect a bridle joint.
>
> Such joints will have greater gluing area, but are more difficult to cramp
> up at gluing-up time. To keep the shoulders close, cramps are needed along
> both the stiles and rails and a 'g' cramp (or similar) is needed to prevent
> the flanks of the slot from spreading.
>
> Hence, like other features in joints, ease of assembly is a fundamental
> design feature.
>
> Jeff G
>
For the newbies in the group - when Mr. Gorman responds to a post you
can rest assured that you can take what he says as the gospel truth.
charlie b
Basically PRETTY is the only reason for haunched tenons. They really
are NOT significantly stronger than the non-haunced ones
John
On Thu, 05 Feb 2004 23:39:46 GMT, tmbg <[email protected]> wrote:
>what's the advantage to haunched tenons, other than filling the groove in
>the end of stiles in frame/panel joinery? I see a lot of designs, and it
>almost seems like the haunch was thrown in arbitrarily.
On Fri, 06 Feb 2004 07:56:37 -0700, Wes Stewart <n7ws@_arrl.net>
wrote:
>On Fri, 06 Feb 2004 00:39:29 GMT, tmbg <[email protected]> wrote:
>
>|I'm talking aside from frame/panel applications where you need some way to
>|fill the groove, like joining table aprons to legs. I've been looking at
>|a lot of table designs, and a lot (mostly all one guy) use haunched tenons
>|for the table apron to leg joint, and the haunch seems unnecessary, and
>|maybe even a liability...
>|
>
>It is my understanding (and thus why I'm using them on a table I'm
>building) that the haunch gives extra resistance to twisting of a wide
>apron, while allowing a narrower tenon. If a wider tenon was used the
>glue joint could fail due to wood movement.
>
>But what do I know, I'm a realative novice at this [g].
>
>Wes Stewart
In addition to wider tenon, it allows the deep part of the mortise to
be kept further from the top of the leg. When the top of mortise is
too close to top of leg you have a situation where that thin piece can
be blown out in the process of fitting and gluing the apron. I like
to have at least 1/2 inch on top and often keep tops of legs long and
then trim to flush with apron after fitting is done but before gluing.
"tmbg" <[email protected]> wrote in message
news:[email protected]...
> what's the advantage to haunched tenons, other than filling the groove in
> the end of stiles in frame/panel joinery? I see a lot of designs, and it
> almost seems like the haunch was thrown in arbitrarily.
My understanding is that traditionally the frame (rails and stiles) for a
panel would have been grooved with a plough plane. A plough plane doesn't
allow for a stopped groove, so the groove goes the distance of the rail or
stile. So you guessed it, the simplest way to fill this groove is a haunched
tenon.
HTH,
Jeffo
Pretty has nothing to do with it - they are not even visible in most
applications. They help with resistance to racking in some
applications.
On Thu, 05 Feb 2004 20:00:15 -0600, John Crea <[email protected]>
wrote:
>Basically PRETTY is the only reason for haunched tenons. They really
>are NOT significantly stronger than the non-haunced ones
>
>John
>
>On Thu, 05 Feb 2004 23:39:46 GMT, tmbg <[email protected]> wrote:
>
>>what's the advantage to haunched tenons, other than filling the groove in
>>the end of stiles in frame/panel joinery? I see a lot of designs, and it
>>almost seems like the haunch was thrown in arbitrarily.
On Thu, 5 Feb 2004 19:33:41 -0500, "Jeffo"
<[email protected]> wrote:
>
>"tmbg" <[email protected]> wrote in message
>news:[email protected]...
>> what's the advantage to haunched tenons, other than filling the groove in
>> the end of stiles in frame/panel joinery? I see a lot of designs, and it
>> almost seems like the haunch was thrown in arbitrarily.
>
>My understanding is that traditionally the frame (rails and stiles) for a
>panel would have been grooved with a plough plane. A plough plane doesn't
>allow for a stopped groove, so the groove goes the distance of the rail or
>stile. So you guessed it, the simplest way to fill this groove is a haunched
>tenon.
>
>HTH,
>Jeffo
>
I believe the point of the haunch, especially in non frame/panel apps,
is to provide extra stability in the form of resistance to racking w/o
having to weaken the mortise by removing too much wood. IOW, you can
get a taller tenon w/o getting the mortise so close to the top as to
risk blowout in fitting/gluing. Consequently haunches are sometimes
used in situations where there may not even be groove needing fill.
I'm talking aside from frame/panel applications where you need some way to
fill the groove, like joining table aprons to legs. I've been looking at
a lot of table designs, and a lot (mostly all one guy) use haunched tenons
for the table apron to leg joint, and the haunch seems unnecessary, and
maybe even a liability...
On Thu, 05 Feb 2004 19:26:36 -0500, Mike G wrote:
> the haunch covers the end of the dado in the stile that holds the panel. As
> an extra added attraction it also gives you more glue area which strengthens
> the joint.
On Fri, 06 Feb 2004 00:39:29 GMT, tmbg <[email protected]> wrote:
|I'm talking aside from frame/panel applications where you need some way to
|fill the groove, like joining table aprons to legs. I've been looking at
|a lot of table designs, and a lot (mostly all one guy) use haunched tenons
|for the table apron to leg joint, and the haunch seems unnecessary, and
|maybe even a liability...
|
It is my understanding (and thus why I'm using them on a table I'm
building) that the haunch gives extra resistance to twisting of a wide
apron, while allowing a narrower tenon. If a wider tenon was used the
glue joint could fail due to wood movement.
But what do I know, I'm a realative novice at this [g].
Wes Stewart
the haunch covers the end of the dado in the stile that holds the panel. As
an extra added attraction it also gives you more glue area which strengthens
the joint.
--
Mike G.
[email protected]
Heirloom Woods
www.heirloom-woods.net
"tmbg" <[email protected]> wrote in message
news:[email protected]...
> what's the advantage to haunched tenons, other than filling the groove in
> the end of stiles in frame/panel joinery? I see a lot of designs, and it
> almost seems like the haunch was thrown in arbitrarily.