mike hide wrote:

A tight joint in my book is as perfect a fit as one can get, that is not a
force fit..

A loose tenon in my book is a sloppy or ill fitting joint and that is what
this thread is about isn't it?
obviously CW and David disagree....mjh


Nope - it's about an end grain to edge grain mortise and tenon
joint that puts a mortise in both parts and then a separate
piece of wood to go into those mortises.. "Loose' menas that
the tenon is not part of either piece to be joined together..

charlie b

George wrote:

You don't. Best is to leave the pins square, so they cut rather than wedge
against the face grain. Sam principle as cut ends on a nail.

Since we're talking about a 1/32 - 1/16th offset between
the hole in the mortised piece and the hole in the tenon, and the
the tenon may be 1/2" thick, I don't think a wooden "nail"
cut end or not, will "cut" that much wood. And if it could,
if it's a through peg, it'd also "cut" the other side of the
mortise as well?

I suggested chamfering both the peg and the tenon's hole
to make drawing the joint easier - remember, we're
talking about a draw peg M&T joint and I had a through
draw pegged joint in mind. I made the chamferring
the hole suggestions based on splitting the end of a
walnut peg in a draw peg M&T joint on my work bench
base unit. Of course the tenons were 3/4" thick maple and
the mortise was in a 3x3 spruce leg - not your typical
M&T joint.

More info please as to peg cutting cross grain.

charlie b

"LRod" wrote in message
...
On Mon, 23 May 2005 11:49:18 -0400, "mike hide"
wrote:


"David" wrote in message
...
I never said to make a "sloppy joint". But "as tight as you can make
them"? I take that to mean you'd make a glued M&T so tight you have to
"persuade" it together. If by "as tight.." you meant, PROPERLY snug,
then we are in agreement.

Dave

A tight joint in my book is as perfect a fit as one can get, that is not
a
force fit..

A loose tenon in my book is a sloppy or ill fitting joint and that is
what
this thread is about isn't it?

No, actually, it isn't. It was a discussion of the loose tenon method
of joinery employed by David Marks. Loose tenon, as in two mortises
and a separate tenon glued into each. I suspect that you're not so
completely dense as to have missed that and are just being your usual
obtuse self.

obviously CW and David disagree....

And rightly so. You're the one who's screwed up


--
LRod

Being my usual Obtuse self, I read the original post by Stoutman, perhaps
you should also . There is no mention of the method of constuction, just
that they are loose tenons

..Even though I have never seen David Mark's program let alone ever heard of
him . So what would a brilliant person like yourself by name a loose tenon
might be ? surely not a lousy fitting tenon.....mjh

On Mon, 23 May 2005 16:02:58 -0400, "mike hide"
wrote:

"LRod" wrote in message
.. .

On Mon, 23 May 2005 11:49:18 -0400, "mike hide"
wrote:

A loose tenon in my book is a sloppy or ill fitting joint and that is
what this thread is about isn't it?

No, actually, it isn't. It was a discussion of the loose tenon method
of joinery employed by David Marks. Loose tenon, as in two mortises
and a separate tenon glued into each. I suspect that you're not so
completely dense as to have missed that and are just being your usual
obtuse self.

obviously CW and David disagree....

And rightly so. You're the one who's screwed up

Being my usual Obtuse self, I read the original post by Stoutman, perhaps
you should also . There is no mention of the method of constuction, just
that they are loose tenons

The one whose subject is "David Marks and Loose Tenons" as can clearly
be seen in the subject line of this post as well as the others to
which you've responded? I read it.

.Even though I have never seen David Mark's program let alone ever heard of
him.

Then what earthly reason is there for you to insert yourself in a
thread in which fully half of the subject concerns David Marks and the
other half a process with which you are clearly unknowledgable?

You're as bad as toller giving electrical advice.

--
LRod

Master Woodbutcher and seasoned termite

Shamelessly whoring my website since 1999

http://www.woodbutcher.net

Proud participant of rec.woodworking since February, 1997

"charlie b" wrote in message
...
George wrote:

You don't. Best is to leave the pins square, so they cut rather than
wedge
against the face grain. Sam principle as cut ends on a nail.

Since we're talking about a 1/32 - 1/16th offset between
the hole in the mortised piece and the hole in the tenon, and the
the tenon may be 1/2" thick, I don't think a wooden "nail"
cut end or not, will "cut" that much wood. And if it could,
if it's a through peg, it'd also "cut" the other side of the
mortise as well?

I suggested chamfering both the peg and the tenon's hole
to make drawing the joint easier - remember, we're
talking about a draw peg M&T joint and I had a through
draw pegged joint in mind. I made the chamferring
the hole suggestions based on splitting the end of a
walnut peg in a draw peg M&T joint on my work bench
base unit. Of course the tenons were 3/4" thick maple and
the mortise was in a 3x3 spruce leg - not your typical
M&T joint.

More info please as to peg cutting cross grain.

Principle is well-known. Round peg in round hole splits. Square edge,
breaks fiber to make passage.

David Marks calls them 'Loose Tenon'. As does Gary Rogowski in his book
JOINERY.

http://www.djmarks.com/stories/djm/L...nery_90627.asp

Above is a link to Marks's web page with an explanation for his madness. I
found it AFTER i posted my question.





"Patriarch" wrote in message
. 97.136...
"mike hide" wrote in
:

A loose tenon in my book is a sloppy or ill fitting joint and that is
what this thread is about isn't it?

Loose tenons and floating tenons are often used as synonymns, hence some
of
the confusion.

For example: http://www.taunton.com/finewoodworking/pages/w00118.asp

I disagree with none of what you, Mike, have written in this thread.

Patriarch

"LRod" wrote in message
...
On Mon, 23 May 2005 16:02:58 -0400, "mike hide"
wrote:

"LRod" wrote in message
.. .

On Mon, 23 May 2005 11:49:18 -0400, "mike hide"
wrote:

A loose tenon in my book is a sloppy or ill fitting joint and that is
what this thread is about isn't it?

No, actually, it isn't. It was a discussion of the loose tenon method
of joinery employed by David Marks. Loose tenon, as in two mortises
and a separate tenon glued into each. I suspect that you're not so
completely dense as to have missed that and are just being your usual
obtuse self.

obviously CW and David disagree....

And rightly so. You're the one who's screwed up

Being my usual Obtuse self, I read the original post by Stoutman, perhaps
you should also . There is no mention of the method of constuction, just
that they are loose tenons

The one whose subject is "David Marks and Loose Tenons" as can clearly
be seen in the subject line of this post as well as the others to
which you've responded? I read it.

.Even though I have never seen David Mark's program let alone ever heard
of
him.

Then what earthly reason is there for you to insert yourself in a
thread in which fully half of the subject concerns David Marks and the
other half a process with which you are clearly unknowledgable?

You're as bad as toller giving electrical advice
Proud participant of rec.woodworking since February, 1997

Again read the first post in this thread by Stoutman ,not the one you choose
to suit your purposes.

I was not concerned with the author but with the subject, loose tenons. I
assure you I do know what a tenon is and exactly what a loose tenon is by
general woodworking standards.

Your assumption that I am unknowledgable about " Loose Tenons" as defined
by Marks has absolutely no basis ,you have no idea what I do or not know.

As a matter of fact you would appear to be a nasty little know-it-all
yourself., Being that it is surprizing you bother with mister Marks or the
subject matter as it all has to be old hat to you.....mjh

On Mon 23 May 2005 05:18:59p, "George" george@least wrote in
:

Principle is well-known. Round peg in round hole splits. Square edge,
breaks fiber to make passage.

Yah but, but, I thought the whole idea was to apply pressure on the
mortised board so the whole thing stayed together better. If you
deliberately whack the pin in so a piece of it actually breaks off, then
you basically got nothing but a pinned mortise, not a drawbored one.

Mike may not know (probably) what a "loose" tenon is, but he sure knows
how to back pedal.

On Mon 23 May 2005 08:37:15p, (John) wrote in news:17300-
:

Mike may not know (probably) what a "loose" tenon is, but he sure knows
how to back pedal.


Hm?
Oh. I think you're looking for the Loose Tenon Definition subthread further
down. This is the Drawbored Tenon subthread, which has degraded to the
Square Pins vs Chamfered Pins in Drawbored Tenons subthread. Sorry.

To every one who made a comment here tonight on M&T, thank you from
someone who is trying to learn somethin,
Glad to see none of that@$&^%(*@ stuff back and forth. This is enjoyable
reading.
Looking forward to more and again thank you all

Accidently sent this to Mike instead of here. So -this is sort of
like trying to hold a conversation with a 10 hour delay between
parties. Hopefully the diagrams that show the six degrees of
freedom of movement which must be resisted and which parts
of the M&T joint resists which movement.


This may clarify things a little - showing the six (yup - six) degrees
of freedom of movement that need to be fixed if two pieces of wood
are to be joined together and not come apart. A mortise and tenon
joint resists 5 of the six.

http://home.comcast.net/~charliebcz/MtPrimer4.html

As for having a "sloppy joint" - there are instances where a little
"slop" actually can be a good idea - a table apron to leg joint for
example. Having a little slop at the top of the tenon gives the
tenon a place to expand without blowing the top of the leg off.
You've got vertical grain for the legs and horizontal grain
for the apron. The cross grain in the tenon will expand more
than the vertical grain in the leg. If there's not place set
aside for that expansion it will try anyway. The tenon will
either compress and get tighter OR it will make the space
by moving some wood above it at the top of the leg.

It seems "spit tight" is what to shoot for. The tenon should
fit snug enough to go in and out with just moderate hand
pressure - no dead blow hammer, no mallet whacking etc..
But if you spit on the tenon and then seat it, it should
swell enough to make getting the joint apart difficult.

And tight also means leaving some place for a) glue inside
to go (mortise a little deeper than the tenon is long) and
b) some place for compressing the air trapped in front
of the tenon as it seats or someway for it to get out of the
joint.

The beauty of "traditional joinery" is that it lets you
dry fit things and the parts will a)self align and
b) be self supporting. That's real handy if you make
things "on the fly" - make step 1, make parts for
step 2 to fit what you have in step 1 and so on. Has
the advantage of letting you see things at full scale
each step of the way.

If you've ever worked from a "plan" and cut all your
parts BEFORE putting them together you know that
somewhere amongst all the given dimensions there's
at least one that's wrong. Working progressively
you can get dimensions off what you have. It isn't
important that a part be 22 31/32nds but rather
that if fit between the parts it's suppose to fit between.

I can "take the line", "split the line" and "leave the
line" more often than I can read a tape properly ; )
(ok - tell me you've never made a part an inch short)

charlie b

Dan wrote in
:

On Mon 23 May 2005 08:37:15p, (John) wrote in
news:17300- :

Mike may not know (probably) what a "loose" tenon is, but he sure
knows how to back pedal.


Hm?
Oh. I think you're looking for the Loose Tenon Definition subthread
further down. This is the Drawbored Tenon subthread, which has
degraded to the Square Pins vs Chamfered Pins in Drawbored Tenons
subthread. Sorry.

When do we degrade to wiring for 220? ;-)

"charlie b" wrote in message
...


As for having a "sloppy joint" - there are instances where a little
"slop" actually can be a good idea - a table apron to leg joint for
example. Having a little slop at the top of the tenon gives the
tenon a place to expand without blowing the top of the leg off.
You've got vertical grain for the legs and horizontal grain
for the apron. The cross grain in the tenon will expand more
than the vertical grain in the leg. If there's not place set
aside for that expansion it will try anyway. The tenon will
either compress and get tighter OR it will make the space
by moving some wood above it at the top of the leg.

This is where all of the discussion here about wood swelling with moisture
etc., goes a little astray. First off - yes it does swell with moisture, I
am aware. But... look at the myriad of jointery around you that has
survived decades or longer without suffering the expansion problems that are
talked about here so frequently and ask yourself what is wrong with this
picture that there is so much discussion about 1/8" of movment across grain,
or 8% humidity, etc. but there are so few broken joints in the furniture
around you. We get so focused on one aspect of things that we sometimes
overlook everything else. Sure, moisture causes swelling - to exposed and
uncontrolled wood. Wood that is secured as a tenon in a mortice does not
absorb moisture in the same way that unsecured wood does. The rates that we
see published for wood expansion and moisture absorbtion are for raw,
unsecured wood. They do not apply to sealed wood and they do not apply to
wood that is secured as in a mortice and tenon. The mortice acts to keep
the tenon compressed such that it can only absorb a certain amount of
moisture, therefore a very controlled amount of expansion. Throw it under
water if you want, but unless the glue disolves, the joint is not going to
fail due to moisture absorbtion until the entire asssembly absorbs enough
water to distort the whole piece. That would be far more than you'd ever
see in environmental changes. Joined pieces of wood (with such interactive
techniques as mortice and tenon) are simply not the same as raw wood and do
not behave the way wood charts would imply for moisture absorbtion. Once
again - look around at how few joints you can see that have actually failed,
and then look to see why they failed. Most did not fail due to the joint
being too tight and not allowing for moisture absorbtion.


It seems "spit tight" is what to shoot for. The tenon should
fit snug enough to go in and out with just moderate hand
pressure - no dead blow hammer, no mallet whacking etc..
But if you spit on the tenon and then seat it, it should
swell enough to make getting the joint apart difficult.

That does indeed make for a nice, precision fit, but it would not be correct
to suggest that a dead blow tight fit is somehow less strong or long lived.
I have put many joints together that took some pretty good persuasion to
fit, and years and years later, they are still there, just as they were when
the project was built. I have to admit, when I have to resort to a little
persuasion, it's generally because I'm rushing it along in some way and
simply did not want to spend any more time to make it that little bit more
perfect - but - the joint does not fail.


And tight also means leaving some place for a) glue inside
to go (mortise a little deeper than the tenon is long) and
b) some place for compressing the air trapped in front
of the tenon as it seats or someway for it to get out of the
joint.

I agree but I generally find that all jointery has that required amount of
slop just by the nature of the woodworking and the material at hand.


If you've ever worked from a "plan" and cut all your
parts BEFORE putting them together you know that
somewhere amongst all the given dimensions there's
at least one that's wrong. Working progressively
you can get dimensions off what you have. It isn't
important that a part be 22 31/32nds but rather
that if fit between the parts it's suppose to fit between.

Now that's a man that's talking some good stuff!


I can "take the line", "split the line" and "leave the
line" more often than I can read a tape properly ; )
(ok - tell me you've never made a part an inch short)


All right Charlie - you've been looking over my shoulder, haven't you?

--

-Mike-

"Dan" wrote in message
...
On Mon 23 May 2005 05:18:59p, "George" george@least wrote in
:

Principle is well-known. Round peg in round hole splits. Square edge,
breaks fiber to make passage.

Yah but, but, I thought the whole idea was to apply pressure on the
mortised board so the whole thing stayed together better. If you
deliberately whack the pin in so a piece of it actually breaks off, then
you basically got nothing but a pinned mortise, not a drawbored one.

No. The idea is to get the shoulders of the tenon to register against the
face of the mortised board and keep them there.

When you don't have clamps, or the clamps would be too large, as in house
framing, you draw bore.

You really need to learn some woodworking, and it will involve some
thinking.

If you drive a round peg into an undersized round hole it will split the
piece. Force is applied evenly around the peg, finds the weakest place -
along the grain - to gain room. With a traditional square or whittled peg,
the force on the edges pushes fibers aside or even severs them to make room
without splitting.

"Mike Marlow" wrote in message
...
This is where all of the discussion here about wood swelling with moisture
etc., goes a little astray. First off - yes it does swell with moisture,
I
am aware.

The rates that we
see published for wood expansion and moisture absorbtion are for raw,
unsecured wood. They do not apply to sealed wood and they do not apply to
wood that is secured as in a mortice and tenon.

You are incorrect. The fibers will expand and contract when the moisture
gets to them, and at the same rate, less compression set. You may slow the
arrival with occlusive finishes, but wood loves water and will find a way.

The reason M/T joints work loose is related to this reality. What went
together "spit tight" at 12% MC is less so at 8 or 4. The joint may then be
subject to racking strain, compressing some contact areas which will make
the joint sloppy even when the MC returns to 12%. That's why the glue and
pegs - to deny motion even when the tenon tries to become smaller in the
mortise.

Works the other way, too, though more slowly. Joints made at 4%, if the
don't split the wood getting to 12, begin to develop some compression set
which remains after the cycle returns to 4, progressively loosening the
joint.

Glue or surface fiber will eventually succumb, but the M/T will still bear
load in design direction, and if pegged, should not withdraw.

On Mon, 23 May 2005 20:56:02 -0400, "mike hide"
wrote:

Again read the first post in this thread by Stoutman ,not the one you choose
to suit your purposes.

Is this the post to which you refer?:

:"stoutman" wrote in message
.com...
: This has probably been asked before, but...

: I recently started watching David Marks on DIY. I have yet to see him cut a "real" tenon. Always loose tenons using a multi router.

: Why is this? Is there an advantage to loose tenons that I am unaware of? Does he just like to show off his multi router? Are they just easier to make?

: I use to only watch Nahmmy and I have learned 90% of what I know from him. Nahmmy "rarely" made loose tenons.

: Confused...

I read it...again.

I was not concerned with the author but with the subject, loose tenons. I
assure you I do know what a tenon is and exactly what a loose tenon is by
general woodworking standards.

Well, there it is. The subject says loose tenons, the first paragraph
says loose tenons. The second paragraph says loose tenons. The third
paragraph says loose tenons. It seems pretty clear that the subject
was loose tenons. Not the fit of conventional, integral mortise and
tenons, but loose tenons as a joinery technique. By general
woodworking standards.

A huge clue that it was indeed a loose (or floating, as someone else
called it) tenon thread was the mention (twice) of the multi router.

Your assumption that I am unknowledgable about " Loose Tenons" as defined
by Marks has absolutely no basis ,you have no idea what I do or not know.

Your words say otherwise. For example, you said you don't even know
who Marks is ("[e]ven though I have never seen David Mark's program
let alone ever heard of him"). Therefore, one can only conclude that
you are unknowledgable about loose tenons as defined by Marks, by
definition.

And that's what the subject was and you were off the subject. Even
David and CW thought so.

As a matter of fact you would appear to be a nasty little know-it-all
yourself., Being that it is surprizing you bother with mister Marks or the
subject matter as it all has to be old hat to you.

Ah, ad hominem attack. That'll prove your case

--
LRod

Master Woodbutcher and seasoned termite

Shamelessly whoring my website since 1999

http://www.woodbutcher.net

Proud participant of rec.woodworking since February, 1997

On Tue, 24 May 2005 00:20:28 -0500, the inscrutable Patriarch
spake:

Dan wrote in
1:

On Mon 23 May 2005 08:37:15p, (John) wrote in
news:17300- :

Mike may not know (probably) what a "loose" tenon is, but he sure
knows how to back pedal.


Hm?
Oh. I think you're looking for the Loose Tenon Definition subthread
further down. This is the Drawbored Tenon subthread, which has
degraded to the Square Pins vs Chamfered Pins in Drawbored Tenons
subthread. Sorry.

When do we degrade to wiring for 220? ;-)

Tenons got 'lektricity now? Well I'll be.

P.S: Clams got legs!

-
The only reason I would take up exercising is || http://diversify.com
so that I could hear heavy breathing again. || Programmed Websites

Joinery That Held Together for Thousands of Years
vs
A / C

I grew up in the tropics, the place formerly known as the
Panama Canal Zone (sounds sort of like the artist formerly
known as Prince), where the temperature ranged from
maybe 78 degrees up to perhaps 94 degrees. The humidity
stayed in the 90 to 100 percent range because the Isthmus
is only 50 miles wide with a lot of water on both sides
(we only had two seasons, Dry Season and Rainy Seasno.
..Dry Season usually was on a Thursday).

I grew up with solid wood, (teak, mahogany, rosewood,
cedar etc.) often carved, furniture from India and China
- all done with traditional joinery, and some quite
complicated and all done with hand tools. Even the delicate
stuff hung together well UNTIL air conditioning became
available. Within 2 years the joinery started opening up
on the more delicate stuff and a drop lid desk with drawers
had the lid warp and split, stretches get loose, drawers get
loose etc. The range of change in relative humidity and the
resulting change in % MC was just too great for the joinery,
given that it was probably made with a %MC of 14 - 18 and
in an A/C environment was probably down to 4%.

For some reason, some of the Chinese furniture, the ones
with triple mitered corners, frame and panel with mitered
frames held up despite the AC.

So, I'm guessing that it's not wood expansion that I need
to accomodate, but rather wood shrinkage - at least for
"house furniture" (as opposed to "just shop furniture").
Guess I'll shoot for Spit Tight rather than Snug or
CTSBTF (Cut To Size, Beat To Fit).

Oh, BTW - if you're going to use half blind dovetails
for a wall hanging tool cabinet, DO NOT put the pins
on the sides and the tails on the top and bottom -
especially not the bottom! Nails, even finishing nails,
detract from the dovetails - just a little bit.

Interesting discussion.

charlie b

"John" wrote in message
Mike may not know (probably) what a "loose" tenon is, but he sure knows
how to back pedal.

In case there is any doubt in most of you newbie's minds about whether Mike
Hide knows of what he speaks, there is NO doubt that most of you are not
even worthy of carrying the man's sandpaper.

Take a look, weep, and be humbled in the presence of someone who _really_
does know what he is talking about.

http://members.tripod.com/mikehide2


--
www.e-woodshop.net
Last update: 5/14/05

charlie b wrote:

Interesting discussion.


And the diagram on your web site is one of the best I've ever seen. I'v
bookmarked the site. Thanks.

"George" george@least wrote in message
...

"Dan" wrote in message
...
On Mon 23 May 2005 05:18:59p, "George" george@least wrote in
:

Principle is well-known. Round peg in round hole splits. Square
edge,
breaks fiber to make passage.

Yah but, but, I thought the whole idea was to apply pressure on the
mortised board so the whole thing stayed together better. If you
deliberately whack the pin in so a piece of it actually breaks off, then
you basically got nothing but a pinned mortise, not a drawbored one.

No. The idea is to get the shoulders of the tenon to register against the
face of the mortised board and keep them there.

When you don't have clamps, or the clamps would be too large, as in house
framing, you draw bore.

You really need to learn some woodworking, and it will involve some
thinking.

If you drive a round peg into an undersized round hole it will split the
piece. Force is applied evenly around the peg, finds the weakest place -
along the grain - to gain room. With a traditional square or whittled
peg,
the force on the edges pushes fibers aside or even severs them to make
room
without splitting.

"Swingman" wrote in message
...
"John" wrote in message
Mike may not know (probably) what a "loose" tenon is, but he sure knows
how to back pedal.

In case there is any doubt in most of you newbie's minds about whether
Mike
Hide knows of what he speaks, there is NO doubt that most of you are not
even worthy of carrying the man's sandpaper.

Take a look, weep, and be humbled in the presence of someone who _really_
does know what he is talking about.

http://members.tripod.com/mikehide2


--
www.e-woodshop.net
Last update: 5/14/05

Thanks for the kind words, at times like this it is good to have a bribable
brother who does not have the same last name ...mjh

"George" george@least wrote in message
...

"Dan" wrote in message
...
On Mon 23 May 2005 05:18:59p, "George" george@least wrote in
:

Principle is well-known. Round peg in round hole splits. Square
edge,
breaks fiber to make passage.

Yah but, but, I thought the whole idea was to apply pressure on the
mortised board so the whole thing stayed together better. If you
deliberately whack the pin in so a piece of it actually breaks off, then
you basically got nothing but a pinned mortise, not a drawbored one.

No. The idea is to get the shoulders of the tenon to register against the
face of the mortised board and keep them there.

When you don't have clamps, or the clamps would be too large, as in house
framing, you draw bore.

You really need to learn some woodworking, and it will involve some
thinking.

If you drive a round peg into an undersized round hole it will split the
piece. Force is applied evenly around the peg, finds the weakest place -
along the grain - to gain room. With a traditional square or whittled
peg,
the force on the edges pushes fibers aside or even severs them to make
room
without splitting.


It is even better if the square pin is the same width as the hole diameter
then there is no chance of splitting. I have chairs made in the 1730s that
have pegged tenons and they are as tight now as the day they were made .the
offset between the motice and tenon hole is about 1/32" to 1/16"...mjh

"Patriarch" wrote in message
. 97.136...
Dan wrote in
:

On Mon 23 May 2005 08:37:15p, (John) wrote in
news:17300- :

Mike may not know (probably) what a "loose" tenon is, but he sure
knows how to back pedal.


Hm?
Oh. I think you're looking for the Loose Tenon Definition subthread
further down. This is the Drawbored Tenon subthread, which has
degraded to the Square Pins vs Chamfered Pins in Drawbored Tenons
subthread. Sorry.

When do we degrade to wiring for 220? ;-)

Right after kickback safety and sawstops.

--

-Mike-

"George" george@least wrote in message
...

"Mike Marlow" wrote in message
...
This is where all of the discussion here about wood swelling with
moisture
etc., goes a little astray. First off - yes it does swell with
moisture,
I
am aware.

The rates that we
see published for wood expansion and moisture absorbtion are for raw,
unsecured wood. They do not apply to sealed wood and they do not apply
to
wood that is secured as in a mortice and tenon.

You are incorrect. The fibers will expand and contract when the moisture
gets to them, and at the same rate, less compression set. You may slow
the
arrival with occlusive finishes, but wood loves water and will find a way.

This does not make sense George. Wood fibers that are constrained can only
absorb water to the point that they equal the force placed on them by the
joint. At that point they effectively reach their saturation level. Wood
does not continue to obsorb moisture until it reaches the point that its
moisture content is equal to the surrounding air, it absorbs it to a maximum
it can hold and that maximum is limited by the cell's ability to contain
that moisture. Constrain those cells and they are capable of holding less
moisture. Like I said, look at how many mortice and tenon joints have held
up for decades and longer without showing effects of changes in humidity.
Look at wood that is nailed in place. The wood does not move between the
nails, it moves where it extends beyond the nails. It moves where it is
unconstrained.

If you could wring out a piece of wood what would happen? Just like a rag,
it would lose its water due to the squeezing process. Cells and fibers
under pressure cannot hold the same amount of moisture that cells and fibers
not exposed to the same pressures can. Wring partially and you evacuate
some of the water, wring more and you evacuate more until you reach the
point that you evacuate all of the water that you can under the pressure
that you're able to exert by wringing. Likewise with wood. Fit tight
tenons and the increase in moisture will only swell the wood to the point
where the pressure exerted on the mortise and the tenon does not exceed the
cell's and the fiber's ability to hold water. The tighter the joint, the
less this ability. Both the mortise and the tennon are going to expand from
the increase in moisture, and both are going to contract by the absence of
it. Looser joints will allow for more movement resultant from the changes
but in either case, the wood is going to be constrained in its ability to
absorb moisture by the pressure exerted on the joint, by the joint. Fit the
joints tightly, and you create a joint that effectively reduce this movement
to the point where it is negligable. There is too much joinery out there
that does not open up gaps in dry weather and close up tightly under higher
humidity to deny that the pressures exerted on wood does not affect movement
from moisture.


The reason M/T joints work loose is related to this reality. What went
together "spit tight" at 12% MC is less so at 8 or 4. The joint may then
be
subject to racking strain, compressing some contact areas which will make
the joint sloppy even when the MC returns to 12%. That's why the glue and
pegs - to deny motion even when the tenon tries to become smaller in the
mortise.

This agress with what I said originally, and with what I elaborated on
above. My point originally was that the pressure factors on the joint have
as much or perhaps more to do with what these movements are than relative
humidity does. I suggest that we find way more mortise and tenon joints
that work loose from mechanical stresses (think of a dining room chair) than
we do from wood movement related to moisture levels. That mechanical stress
works the joint regardless of the moisture content. It's an entirely
different issue.


Works the other way, too, though more slowly. Joints made at 4%, if the
don't split the wood getting to 12, begin to develop some compression set
which remains after the cycle returns to 4, progressively loosening the
joint.

This is the point that I suggest is less of an issue in the real world than
is often discussed. I suggest that within certain limits these conditions
will not have the adverse affect on the joint that is often suggested. This
of course, assumes that the joint is constructed reasonably correct in the
first place. The joint has to enjoy mortises and tenons that are
constructed of the proper proportions in the first place. That assumption
allowed, the joint will not see moisture levels vary as much as a raw piece
of wood will. The expansion and contraction within the joint will be much
less than the tables attempt to indicate.

This is why wood products of all sorts can be and are, shipped from all over
the world to all over the world, and do not fall apart. These products are
around us every day of our lives, everywhere we go. The proof of this is
easy to see.

My point does not suggest that moisture content is not a factor to be
considered in woodworking and in joinery, rather it is that this one factor
is too often spoken of in isolation and not considerate of other factors
that play into the issues of wood joinery. Moisture tables are only part of
the story, and like everything else, they need to be taken in a context.
What I've tried to say in this conversation is that interactive joints such
as a mortise and tenon are affected by factors other than just what is
suggested in the moisture tables.

--

-Mike-

"charlie b" wrote in message
...
mike hide wrote:

I meant exactly what I said.

In the past ,and I have furniture to prove it Mand T joints had no glue
,they were secured by pegs anything but a perfect fit would ensure the
structure would "rock" and secondly would soon fail...mjh


If you double draw pegged them they wouldn't

charlie b

I am not familiar with the term "double draw pegged" What I refer to is the
standard practice of chairmakers at the time was to bore a hole normal to
the mortice insert the tenon and "spot" the hole center on the tenon .Then
remove the tenon and bore it with the same drill a thirty second or so
closer to the tenon shoulder, so when the peg [usually square] is inserted
it draws the joint together tight....mjh

"Mike Marlow" wrote in message
...
You are incorrect. The fibers will expand and contract when the
moisture
gets to them, and at the same rate, less compression set. You may slow
the
arrival with occlusive finishes, but wood loves water and will find a
way.

This does not make sense George.

It does to wood technologists. RH correlates directly to moisture content.


Wood fibers that are constrained can only
absorb water to the point that they equal the force placed on them by the
joint. At that point they effectively reach their saturation level. Wood
does not continue to obsorb moisture until it reaches the point that its
moisture content is equal to the surrounding air, it absorbs it to a
maximum
it can hold and that maximum is limited by the cell's ability to contain
that moisture. Constrain those cells and they are capable of holding less
moisture.

Incorrect again. The fibers adsorb moisture at the molecular level, binding
to the cellulose. There is a lot of air left inside any board, indeed,
inside the cells themselves, which spaces are shrunken by the inexorable
gathering of moisture, though they do compression set - they don't return to
full expansion - which condition exacerbates the one caused by shrinkage of
the fibers themselves once the wood begins to seek EMC with lower RH.

Wonderful, well-documented stuff here
http://www.fpl.fs.fed.us/documnts/fp.../fplgtr113.htm to read.
Start with chapters 2 and 3.

In article , Larry Jaques
says...
On Sat, 21 May 2005 16:24:11 -0700, the inscrutable charlie b
spake:

stoutman wrote:

This has probably been asked before, but...

I recently started watching David Marks on DIY. I have yet to see him cut a
"real" tenon. Always loose tenons using a multi router.

Why is this? Is there an advantage to loose tenons that I am unaware of?
Does he just like to show off his multi router? Are they just easier to
make?

I use to only watch Nahmmy and I have learned 90% of what I know from him.
Nahmmy "rarely" made loose tenons.

Confused...

Several advantages in most situations to use loose tenon
joinery.

1. The parts that would otherwise have tenons can
be their actual length NOT their actual length
PLUS the tenon lengths Two less chances to
make a mistake

Yeah, and two fewer chances, too. gd&r


2. With a piece of stock ripped to the desired tenon
width and planed to the needed thickness you
can cut off what you need on a chop saw or cross
cut them on the table saw. If you blow it you're
not out an entire tenoned part. Think of the
wood you'd need if you blew the tenons on a bed
rail.

Ayup, and you can't just make the bed a bit shorter. Mattresses and
box springs don't squish much in length.


3. You can make the loose tenons out of any wood
you want and maybe scrap at that. Want the
tenon really strong - try ebony!

Wouldn't you want the same (or physically similar) wood so they had
the same expansion/contraction rates? That's what I've always read.

I've noticed that David Marks always seems to use the same wood for
the tenons as the pieces he's joining. I wondered if that was the
reason why, or if it was just because there was usually plenty of
scrap available. But why else use something expensive for the tenons
since they don't show? Is there another reason or is it for stability?

(He also always veneers both sides of his base stock, and has
explicitly said that's for stability, but often uses a different
(nice, but cheaper) wood for the side that doesn't show.)


-
The only reason I would take up exercising is || http://diversify.com
so that I could hear heavy breathing again. || Programmed Websites


--
John

John Santos wrote:
....
I've noticed that David Marks always seems to use the same wood for
the tenons as the pieces he's joining. I wondered if that was the
reason why, or if it was just because there was usually plenty of
scrap available. But why else use something expensive for the tenons
since they don't show? Is there another reason or is it for stability?

....
I would expect he does it for all the above reasons. It certainly is
"safer" to use the same material from the standpoint of reliability.
The amount of material used is insignificant in terms of saved cost.
Plus, he may (probably is?) like many of the rest of us--whether it
shows to anybody else or not isn't material--he knows what the
interior is.

A similar case is wiring inside a wall--many make it as neat as they can
"just because" even though it all gets covered over and the electrons
don't care...

On Fri, 27 May 2005 10:29:10 GMT, the inscrutable John Santos
spake:

I said:
Wouldn't you want the same (or physically similar) wood so they had
the same expansion/contraction rates? That's what I've always read.

I've noticed that David Marks always seems to use the same wood for
the tenons as the pieces he's joining. I wondered if that was the
reason why, or if it was just because there was usually plenty of
scrap available. But why else use something expensive for the tenons
since they don't show? Is there another reason or is it for stability?

Stability, but there's always scrap which can be used from each
project. By using the same wood in the same grain direction, he keeps
from having any trouble with different expansion rates. His loose
tenons don't explode the wood they're in during the humid seasons.


(He also always veneers both sides of his base stock, and has
explicitly said that's for stability, but often uses a different
(nice, but cheaper) wood for the side that doesn't show.)

Right. It lessens cupping.


--
REMEMBER: First you pillage, then you burn.
---
http://diversify.com Full Service Website Development

Duane Bozarth wrote in news:42972420.7B6094D2
@swko.dot.net:
snip
A similar case is wiring inside a wall--many make it as neat as they can
"just because" even though it all gets covered over and the electrons
don't care...

And another thread devolves into an electrical wiring discussion... ;-)

Patriarch wrote:

Duane Bozarth wrote in news:42972420.7B6094D2
@swko.dot.net:
snip
A similar case is wiring inside a wall--many make it as neat as they can
"just because" even though it all gets covered over and the electrons
don't care...

And another thread devolves into an electrical wiring discussion... ;-)

Oh, you're now saying the electrons do care???

In article , David
wrote:

We're talking Fuji apples vs McIntosh apples.

Versus Apple's Macintosh. ;-)

Kevin