Brian Henderson wrote:
: Upscale wrote:
: "Brian Henderson" wrote in message
: Domino. Ooh look, it makes loose tenon joints easy! Sure, but does it
: make them strong? Not according to all the tests I've seen.
:
: Perhaps, you'd like to quote those tests depicting some of those weaker
: joints?

: They did one a month or so ago in Popular Woodworking, if I'm not
: mistaken, comparing the strength of different joints. The Domino did
: not perform very well. I'm just not anywhere where I can go back and
: look at the moment.


Found it: Fine Woodworking, January 2009.
http://www.taunton.com/finewoodworki....aspx?id=31926
http://www.taunton.com/finewoodworki.../011203036.pdf

and letters and discussion he

http://www.taunton.com/finewoodworki....aspx?id=31926


There's another interesting discussion here, which includes a suggestion
that the culprit is the indentations on the dominos:

http://festoolownersgroup.com/index....e;topic=7083.0


-- Andy Barss

"Brian Henderson" wrote:

Most modern glues are stronger than the woods we use them on, if
something fails, it's invariably the wood, not the glue itself.
Therefore, the consideration, as you point out, is the joints we
use, we cannot put forces on the joints that exceed their breaking
strength and far too many people overestimate the strength of joints
because they're fast or easy.

Having spent a few years doing machine design in my youth, was taught
to avoid depending on a weld or fasteners alone to carry the load.

As a result, joints were designed to put the material in compression
and welds were designed to be in shear.

The same design concepts apply to wood and adhesives used in
furniture/cabinet designs.

Glue joints are very strong when placed in shear.

Glue joints are not nearly as strong when placed in tensile loading.

Simple and straight forward, but sometimes we forget to apply the
basics.

Lew

Lew Hodgett wrote:
"Brian Henderson" wrote:

Most modern glues are stronger than the woods we use them on, if
something fails, it's invariably the wood, not the glue itself.
Therefore, the consideration, as you point out, is the joints we
use, we cannot put forces on the joints that exceed their breaking
strength and far too many people overestimate the strength of joints
because they're fast or easy.

Having spent a few years doing machine design in my youth, was taught
to avoid depending on a weld or fasteners alone to carry the load.

As a result, joints were designed to put the material in compression
and welds were designed to be in shear.

The same design concepts apply to wood and adhesives used in
furniture/cabinet designs.

Glue joints are very strong when placed in shear.

Glue joints are not nearly as strong when placed in tensile loading.

Simple and straight forward, but sometimes we forget to apply the
basics.

Further, the statement that "the glue is stronger than the wood itself"
applies to commonplace species of wood glued into face grain. Gluing some
of the exotics is problematical, and gluing end grain is as well. Note that
in the Fine Woodworking test the butt joint was the only one that failed in
the glue line.

Then there's the issue of creep--keep PVA under constant load and it moves,
slowly, if the design of the joint doesn't prevent it from doing so.

On Jul 15, 10:12*am, Jack Stein wrote:
J. Clarke wrote:
dpb wrote:
Jack Stein wrote:
...
... There is
little doubt that a properly fitted biscuit joint is comparable to a
properly fitted mortise and tenon joint. *...
I think there's a _great_deal_ of doubt about that. *I don't think the
biscuits will even remotely approach a m&t, loose tenon or not...

OK, now you've done it; I'm going to have to go see if the FWW tests
included biscuits--I don't recall.

A mortise and tenon will support weight without any glue, will a biscuit
joint do that?

I don't think a stub tenon will support much weight w/o glue? *Stub
tenons are common in cabinet door construction.

I don't own a biscuit machine, don't plan on buying one. *I'm still
wondering if I should spend the cash on a decent rail and stile set for
my shaper. *Having said that though, it appears that a properly fitted
biscuit joint is comparable to a properly fitted M&T joint. *Reading
Robotoys article:

http://www.woodworking.org/WC/GArchi...abstract1.html

I noted that a guy that makes exterior doors and gates has found after 3
1/2 years of using plate joinery that he has had NO failures. *That
would indicate that while M&T may be stronger, plate joints are strong
enough for most applications.

--
Jack
Using FREE News Server:http://www.eternal-september.org/http://jbstein.com

Also, one must do a proper M&T joint for it to have all this 'magic'
strength. A poorly fitted, poorly proportioned M&T can be quite
fragile.

J. Clarke wrote:
dpb wrote:
Jack Stein wrote:
...
... There is
little doubt that a properly fitted biscuit joint is comparable to a
properly fitted mortise and tenon joint. ...
I think there's a _great_deal_ of doubt about that. I don't think the
biscuits will even remotely approach a m&t, loose tenon or not...

OK, now you've done it; I'm going to have to go see if the FWW tests
included biscuits--I don't recall.

A mortise and tenon will support weight without any glue, will a biscuit
joint do that?

I don't think a stub tenon will support much weight w/o glue? Stub
tenons are common in cabinet door construction.

I don't own a biscuit machine, don't plan on buying one. I'm still
wondering if I should spend the cash on a decent rail and stile set for
my shaper. Having said that though, it appears that a properly fitted
biscuit joint is comparable to a properly fitted M&T joint. Reading
Robotoys article:

http://www.woodworking.org/WC/GArchi...abstract1.html

I noted that a guy that makes exterior doors and gates has found after 3
1/2 years of using plate joinery that he has had NO failures. That
would indicate that while M&T may be stronger, plate joints are strong
enough for most applications.

--
Jack
Using FREE News Server: http://www.eternal-september.org/
http://jbstein.com

MikeWhy wrote:
"dpb" wrote in message
...
Jack Stein wrote:

... There is little doubt that a properly fitted biscuit joint is
comparable to a properly fitted mortise and tenon joint. ...

I think there's a _great_deal_ of doubt about that. I don't think the
biscuits will even remotely approach a m&t, loose tenon or not...

OK, now you've done it; I'm going to have to go see if the FWW tests
included biscuits--I don't recall.

Biscuits came out far worse than loose tenons. Loose tenons in turn are
slightly, but consistently and measurably weaker than real tenons. He
tested both initial failure and residual strength after first failure.

OK, then the question would be, is a biscuit joint weaker to the point
it makes a difference? It would seem to me that if the joints were
failing, no one would be using the $700 biscuit joiner? I know they are
not needed for strength in long grain joints such as the original poster
was asking, but assume they must work for end gain joints or why would
anyone spend $700 on a Festool Domino, or a $30 HF for that matter?

--
Jack
Using FREE News Server: http://www.eternal-september.org/
http://jbstein.com

Jack Stein wrote:
....
OK, then the question would be, is a biscuit joint weaker to the point
it makes a difference? It would seem to me that if the joints were
failing, no one would be using the $700 biscuit joiner? I know they are
not needed for strength in long grain joints such as the original poster
was asking, but assume they must work for end gain joints or why would
anyone spend $700 on a Festool Domino, or a $30 HF for that matter?

Yes.

They're fine for face frames, light panels, etc., etc., etc., ... Their
main advantage and why they're used as much as are is quick and easy and
accurate.

They won't/don't replace m&t for anything that has any actual
load--heavy doors, chair rails, etc., ...

--

StephenM wrote:
OK, now you've done it; I'm going to have to go see if the FWW tests
included biscuits--I don't recall.
A mortise and tenon will support weight without any glue, will a biscuit
joint do that?

That's a silly question.

I agree.

You would never use a biscuit w/o glue. Biscuits
are compressed at manufacture so that the glue will expand them for a tight
fit upon *proper* installation.

I hear this all the time, and always wonder what happens when the
moisture in the glue evaporates and the swelling recedes? Ideally, I
would want the tenon to be stable, and the mortise to shrink around the
tenon, not the other way around. I guess the glue itself could remain
keeping the swelling up, but still, any moisture will eventually
evaporate, and swelling should recede, right?

In other words, if the swelling DOESN'T last more than 4 hours, should I
call the doctor?

So... you are asking how well a product performs when improperly installed.

By contrast the M&T joint was designed before the invention of modern glue.
Back in the day, when glue could be expected to fail over time, that was a
real consideration.

Really though, glue simply doesn't work well on end grain, ergo the
reason for M&T, plate, pocket screws, dowels and so on are still in use
today. Glue failures cause all joints (dependent on glue) to fail, so
joining techniques haven't changed joint failure rates much, but glue
has. (Not sure that came out right, but I'm in a hurry)

Pocket screws do not require glue at all, and watching the TV guys apply
a pint of glue (clear white glue so you can't see it when it oozes out
all over your wood until you stain it at which point the folly of your
ways has GOT to bite you in the ass, but not enough to keep you off the
tv) always gives me pause to chuckle.

--
Jack
Using FREE News Server: http://www.eternal-september.org/
http://jbstein.com

J. Clarke wrote:
StephenM wrote:
OK, now you've done it; I'm going to have to go see if the FWW tests
included biscuits--I don't recall.
A mortise and tenon will support weight without any glue, will a
biscuit joint do that?


That's a silly question. You would never use a biscuit w/o glue.
Biscuits are compressed at manufacture so that the glue will expand
them for a tight fit upon *proper* installation.

So... you are asking how well a product performs when improperly
installed.

Google "rhetorical question".

By contrast the M&T joint was designed before the invention of modern
glue. Back in the day, when glue could be expected to fail over time,
that was a real consideration.

ROF,L. If you think that glue never fails you have a big fat surprise
coming.

If you think a M&T joint will be working after the glue fails, you also
have a big surprise coming.

--
Jack
Using FREE News Server: http://www.eternal-september.org/
http://jbstein.com

"Jack Stein" wrote in message
...
StephenM wrote:
You would never use a biscuit w/o glue. Biscuits are compressed at
manufacture so that the glue will expand them for a tight fit upon
*proper* installation.

I hear this all the time, and always wonder what happens when the moisture
in the glue evaporates and the swelling recedes? Ideally, I would want
the tenon to be stable, and the mortise to shrink around the tenon, not
the other way around. I guess the glue itself could remain keeping the
swelling up, but still, any moisture will eventually evaporate, and
swelling should recede, right?

Biscuits are mechanically compressed and dried. They don't shrink back to
their manufactured size even after redrying in a kiln. They need to be
stored in closed containers to minimize swelling from the moisture in the
air.

In other words, if the swelling DOESN'T last more than 4 hours, should I
call the doctor?

Simplest test: wet one with a sponge and see what happens at the end of 4
hours. Try baking it for those 4 hours, just to be sure. (I haven't tried
it. Just passing on my understanding of biscuits.)

On Sat, 11 Jul 2009 20:11:35 -0700 (PDT), Sonny
wrote:

Here is Rockler's Dowel Pro Jig -
http://www.rockler.com/product.cfm?p...65730&pn=65730

And their Porter-Cable Bisquit Jointer-
http://www.rockler.com/product.cfm?p...90224&pn=90224

How much better (and faster) is using bisquits, for keeping boards
aligned, than is using dowels? I don't have a bisquit jointer, but I
do have the dowel jig. I'm considering getting the bisquit jointer.

I have 1200 bd ft of mahogany and am drawing out plans for an
entertainment center (12'W X 8'H X 25"D) .... no plywood on this
project. I have had, somewhat, similar panel projects in the past,
but not as big.

Is using bisquits a faster process than using dowels. To me, in the
past, using dowels took lots of time, since I seem to measure and cut
each one individually, more so than using a standard measure/stop for
drilling holes and cutting the dowels (or most of them) to a set
length.

Thanks.
Sonny


When I glue up solid wood panels I pay a lot of attention to stock
prep. Eliminate all cup, crook and bow on the jointer, or with a
plane. Get everything to the same thickness by making a final pass
through the planer or sander using the same setup for all the stock to
be machined. Rip all the pieces with a blade that will give you a
glue line edge.

I machine biscuit slots about two inches in from a line that coincides
with what the finished ends will be and about every twelve inches
throughout the length. I use one biscuit on the centerline for boards
up to about 5/4 and a pair of biscuits set no less than 1/4 from the
faces above that thickness.

Here is where I differ from what some guys do:
In my opinion, and it is only an opinion but it is based on
observation and experience; I don't count on the biscuits for
strength, I think the glue line provides the strength. I use the
biscuits to reduce the clamp time so that I can have a quicker turn
around time on the glued up panels. I also don't count on the
biscuits for alignment, except in a very rough sense. I use a Lamello
biscuit joiner and Lamello biscuits, which I believe to be more
consistent in their properties than others that I have tried - and I
still can't count on perfect alignment. So, what I do is drive finish
nails into one edge of each of the boards , more or less in the center
of the edge of the board and more or less on the centerline between
the biscuit slots. Then I nip the heads off, leaving about a heavy
eighth inch standing proud of the board edge. When I carefully
assemble the boards together during a later step the pins will keep
the boards even along their faces as I apply clamping pressure. It
doesn't take very much time and it works.

I almost always use cauls top and bottom - this provides my final
check for flatness of the glue up - but the pins help avoid all the
beating and hollering that too often goes on at this point.

As always,

YMMV


Regards,

Tom Watson
http://home.comcast.net/~tjwatson1/

On Jul 11, 8:11*pm, Sonny wrote:
Here is Rockler's Dowel Pro Jig -http://www.rockler.com/product.cfm?page=9976&filter=65730&pn=65730

And their Porter-Cable Bisquit Jointer-http://www.rockler.com/product.cfm?page=1309&filter=90224&pn=90224
snip

Thank you Sonny for starting a thread that ended with more than 50
replies dedicated to woodworking, including a relatively reasoned
debate on the merit of various joints.

Thanks,

Luigi

On Wed, 15 Jul 2009 06:48:53 -0700 (PDT), Robatoy
wrote:

On Jul 15, 10:12*am, Jack Stein wrote:
J. Clarke wrote:
dpb wrote:
Jack Stein wrote:
...
... There is
little doubt that a properly fitted biscuit joint is comparable to a
properly fitted mortise and tenon joint. *...
I think there's a _great_deal_ of doubt about that. *I don't think the
biscuits will even remotely approach a m&t, loose tenon or not...

OK, now you've done it; I'm going to have to go see if the FWW tests
included biscuits--I don't recall.

A mortise and tenon will support weight without any glue, will a biscuit
joint do that?

I don't think a stub tenon will support much weight w/o glue? *Stub
tenons are common in cabinet door construction.

I don't own a biscuit machine, don't plan on buying one. *I'm still
wondering if I should spend the cash on a decent rail and stile set for
my shaper. *Having said that though, it appears that a properly fitted
biscuit joint is comparable to a properly fitted M&T joint. *Reading
Robotoys article:

http://www.woodworking.org/WC/GArchi...abstract1.html

I noted that a guy that makes exterior doors and gates has found after 3
1/2 years of using plate joinery that he has had NO failures. *That
would indicate that while M&T may be stronger, plate joints are strong
enough for most applications.

--
Jack
Using FREE News Server:http://www.eternal-september.org/http://jbstein.com

Also, one must do a proper M&T joint for it to have all this 'magic'
strength. A poorly fitted, poorly proportioned M&T can be quite
fragile.


Do you know why I am convinced that Bruno Hauptmann did not kidnap the
Lindbergh baby? Because he, when shown the crudely made ladder that
was allegedly used to gain access to the child's room, stated that it
could not be possible that he had made that ladder, "Because I am a
carpenter!"

Why do I use mortise and tenon joinery, and why do I take great care
with the proportions, machining and gluing? Because, "I am a
cabinetmaker!"


Next case.







Regards,

Tom Watson
http://home.comcast.net/~tjwatson1/

On Jul 15, 10:36*am, Tom Watson wrote:
*I also don't count on the
biscuits for alignment, except in a very rough sense. *I use a Lamello
biscuit joiner and Lamello biscuits, which I believe to be more
consistent in their properties than others that I have tried - and I
still can't count on perfect alignment. *So, what I do is drive finish
nails into one edge of each of the boards , more or less in the center
of the edge of the board and more or less on the centerline between
the biscuit slots. *Then I nip the heads off, leaving about a heavy
eighth inch standing proud of the board edge. *When I carefully
assemble the boards together during a later step the pins will keep
the boards even along their faces as I apply clamping pressure. *It
doesn't take very much time and it works.

How do you get the pins to go into the spot that creates perfect
alignment? The slightest pressure up or down could create an extremely
shallow "V", resulting into slightly misaligned boards. I don't know
if I'm explaining myself properly, but if you don't clamp with exact
even pressure, you might get misaligned boars. I.e. What do you mean
by "carefully assemble the boards together".

I almost always use cauls top and bottom - this provides my final
check for flatness of the glue up - but the pins help avoid all the
beating and hollering that too often goes on at this point.

I would think that the pins might create some beating and hollering
rather than avoiding it. Sorry, I don't get it???

I am also happy to note that after a gazillion years of people saying
that they use biscuits "for alignment" in panel glue ups, that
everybody is fessing up that they actually cause a slight
misalignment. So it's not only me or my biscuit joiner or my
biscuits. :-)

Luigi

On Wed, 15 Jul 2009 14:28:15 -0700 (PDT), Luigi Zanasi
wrote:


How do you get the pins to go into the spot that creates perfect
alignment? The slightest pressure up or down could create an extremely
shallow "V", resulting into slightly misaligned boards. I don't know
if I'm explaining myself properly, but if you don't clamp with exact
even pressure, you might get misaligned boars. I.e. What do you mean
by "carefully assemble the boards together".

I have the boards resting flat on the bottom cauls and I push them
together, one at a time. It doesn't seem to be a problem in practice.
I find that most misalignment problems show up when you try to clamp
the panel assembly up. The way that I do this is to put both the top
and bottom cauls in place and apply moderate pressure with the clamps
that go on the cauls, with the intent of keeping the panel flat.. Then
I apply the side clamping pressure. What I see too many guys do is
apply the side pressure before the cauls are engaged in keeping stuff
planar. Then, if they don't use pins, the joint lines creep and they
have so much clamping pressure applied that the caul clamps have a
hard time making up the difference. That's when most of the beating
and hollering occurs.


I am also happy to note that after a gazillion years of people saying
that they use biscuits "for alignment" in panel glue ups, that
everybody is fessing up that they actually cause a slight
misalignment. So it's not only me or my biscuit joiner or my
biscuits. :-)


Well, it's true in a general sense. It is a lot easier to align a
face frame to a carcase using biscuits than it is to just slap on some
glue and try to clamp it up. Of course, you still need the judicious
application of force to get things into final alignment. That's why I
own a three pound dead blow. My goal is to get panels or assemblies
like the face frame to carcase to line up good enough that a few
scrapes with a cabinet scraper is all that is needed.




Regards,

Tom Watson
http://home.comcast.net/~tjwatson1/

"Lew Hodgett" wrote in message
...

"Sonny" wrote:

How much better (and faster) is using bisquits, for keeping boards
aligned, than is using dowels? I don't have a bisquit jointer, but I
do have the dowel jig. I'm considering getting the bisquit jointer.

You don't need to buy a busquit joiner if you have a router.

A 5/32" slot cutter and a 5/32 straight bit and you you're covered for #20
biscuits.

Lew

Being new to the craft, can you explain how this is done?

Thank you

"SBH" wrote:

Being new to the craft, can you explain how this is done?

What part of a router bit doing it's job (cutting wood) do you need
explained?

Lew

"Lew Hodgett" wrote

"SBH" wrote:

Being new to the craft, can you explain how this is done?

What part of a router bit doing it's job (cutting wood) do you need
explained?

The router bit goes round and round, round and round, round and round.

On Jul 15, 6:10*pm, "SBH" wrote:
"Lew Hodgett" wrote in message

...

"Sonny" wrote:

How much better (and faster) is using bisquits, for keeping boards
aligned, than is using dowels? *I don't have a bisquit jointer, but I
do have the dowel jig. *I'm considering getting the bisquit jointer.

You don't need to buy a busquit joiner if you have a router.

A 5/32" slot cutter and a 5/32 straight bit and you you're covered for #20
biscuits.

Lew

Being new to the craft, can you explain how this is done?

Thank you

I think you 'll be able to find an explanation when you do a Google
search. (Don't tell anybody, but the natives get a little cranky
sometimes....)
=0)

Robatoy wrote:
: On Jul 15, 6:10*pm, "SBH" wrote:
: "Lew Hodgett" wrote in message
:
: ...
:
: "Sonny" wrote:
:
: How much better (and faster) is using bisquits, for keeping boards
: aligned, than is using dowels? *I don't have a bisquit jointer, but I
: do have the dowel jig. *I'm considering getting the bisquit jointer.
:
: You don't need to buy a busquit joiner if you have a router.
:
: A 5/32" slot cutter and a 5/32 straight bit and you you're covered for #20
: biscuits.
:
: Lew
:
: Being new to the craft, can you explain how this is done?
:
: Thank you

: I think you 'll be able to find an explanation when you do a Google
: search. (Don't tell anybody, but the natives get a little cranky
: sometimes....)
: =0)


Good suggestion, but the basics for the original poster a

The advantage of a dedicated biscuit joiner are that you can put
slots into the edge of a piece of wood or plywood (there is a fence that
pivots down; fence is placed against the wide part of the board,
and the spring-mounted joiner is pushed into the wood, cuting a slot),
and the face of a piece of wood, by clamping a fence (i.e. another
piece of wood) across the board, retracting the joiner's fence,
and placing the joiner up against the board.

You can do the same operations, but not quite as comfortably, with a
plunge router (assuming you have one). For edge jointing,
you use a bit that has a narrow, wide cutter (like an
upside down T, with the upright part the shaft of the router
bit), which cuts into the wood's edge.

For slots in the middle of a board, you plunge a straight bit into the wood and
move the router along a fence so it's the right length.

Personally, I'd use a biscuit joiner if I have more than a few of
these slots to cut.

-- Andy Barss

MikeWhy wrote:

Loose tenons in turn are
slightly, but consistently and measurably weaker than real tenons.

In all published tests I've seen there is usually less than 1%
difference in measured strength between the two, which, and depending
upon the project, makes for a favorable comparison when taking into
account other factors like convenience and speed, particularly when
doing "production runs" in a small shop setting.

--
www.e-woodshop.net
Last update: 10/22/08
KarlC@ (the obvious)

"Swingman" wrote in message
...
MikeWhy wrote:

Loose tenons in turn are slightly, but consistently and measurably weaker
than real tenons.

In all published tests I've seen there is usually less than 1% difference
in measured strength between the two, which, and depending upon the
project, makes for a favorable comparison when taking into account other
factors like convenience and speed, particularly when doing "production
runs" in a small shop setting.


AND I would think stronger where you are using harder stronger tennons than
the wood they are joining.

Somebody wrote:
Loose tenons in turn are slightly, but consistently and measurably
weaker than real tenons.

Hard maple loose tenons, epoxied in place, gets my vote for simplicity
and highest strength.

TiteBondII for shortest clamp time.

Lew

"Swingman" wrote in message
...
MikeWhy wrote:

Loose tenons in turn are slightly, but consistently and measurably weaker
than real tenons.

In all published tests I've seen there is usually less than 1% difference
in measured strength between the two, which, and depending upon the
project, makes for a favorable comparison when taking into account other
factors like convenience and speed, particularly when doing "production
runs" in a small shop setting.

The specific reference was to the recent FWW article, apparently not on your
reading list. That's almost ironic, thinking back to our past conversations.
Come to think of it, I don't particularly recall *where* I read it. The test
featured dovetails, M&T, biscuits, and loose tenons. I'm pretty sure it was
FWW, probably December or January.

Repeatable 1% variation even between two joints of the same type would be
something to really crow about. If you can find a credible cite for 1%
variability from M&T to loose tenon, I'll eat this keyboard I'm typing this
on, every last sharp, broken shard of it, including the lead contents of its
electronics. You wouldn't by chance care to restate what you wrote? I'm sure
I read it wrong.

"MikeWhy" wrote in message
...
"Swingman" wrote in message
...
MikeWhy wrote:

Loose tenons in turn are slightly, but consistently and measurably
weaker than real tenons.

In all published tests I've seen there is usually less than 1% difference
in measured strength between the two, which, and depending upon the
project, makes for a favorable comparison when taking into account other
factors like convenience and speed, particularly when doing "production
runs" in a small shop setting.

The specific reference was to the recent FWW article, apparently not on
your reading list. That's almost ironic, thinking back to our past
conversations. Come to think of it, I don't particularly recall *where* I
read it. The test featured dovetails, M&T, biscuits, and loose tenons. I'm
pretty sure it was FWW, probably December or January.

Repeatable 1% variation even between two joints of the same type would be
something to really crow about. If you can find a credible cite for 1%
variability from M&T to loose tenon, I'll eat this keyboard I'm typing
this on, every last sharp, broken shard of it, including the lead contents
of its electronics. You wouldn't by chance care to restate what you wrote?
I'm sure I read it wrong.

Think about it, loose tennons are typically made out of a straight grain
hard wood. The tennon sculpted from the end of the typical board very very
often has been done with less than desirable grain orientation. The loose
tennon is glued inside "both" pieces, not just the in the one piece so
regardless of the type wood you are using you get a more consistent strength
tennon.

MikeWhy wrote:
"Swingman" wrote in message
...
MikeWhy wrote:

Loose tenons in turn are slightly, but consistently and measurably
weaker than real tenons.

In all published tests I've seen there is usually less than 1%
difference in measured strength between the two, which, and depending
upon the project, makes for a favorable comparison when taking into
account other factors like convenience and speed, particularly when
doing "production runs" in a small shop setting.

The specific reference was to the recent FWW article, apparently not on
your reading list. That's almost ironic, thinking back to our past
conversations. Come to think of it, I don't particularly recall *where*
I read it. The test featured dovetails, M&T, biscuits, and loose tenons.
I'm pretty sure it was FWW, probably December or January.

Repeatable 1% variation even between two joints of the same type would
be something to really crow about. If you can find a credible cite for
1% variability from M&T to loose tenon, I'll eat this keyboard I'm
typing this on, every last sharp, broken shard of it, including the lead
contents of its electronics. You wouldn't by chance care to restate what
you wrote? I'm sure I read it wrong.

OK, let's take your particular "specific reference" then, where the
strength differential is less than 3% ... doing NOTHING whatsoever to
change the thrust/point of my statement.

And check those panties, Bubba ... untwisted, they'll improve your
attitude/demeanor by at least that much.

--
www.e-woodshop.net
Last update: 10/22/08
KarlC@ (the obvious)

"Jack Stein" wrote in message
...
Luigi Zanasi wrote:



I find it amazing anyone even uses a biscuit joiner, let alone a $700
Festool domino? I always knew they were not needed in the least for
strength in panel glue ups, but thought they would work nicely for
alignment, but knew from experience I could glue up table tops and door
panels easily with just clamps and cauls.


LOL, No you certainly don't need any of them but they do make life easier
and speed up production. Think about trading your TS in for a hand saw.
;~) The biscuit joiner is mostly helpful for alignment but does in deed add
significant strength when gluing end grain. The biscuit adds strength to 45
degree mitered joints and to butt joints. I have had 2 biscuit joiners and
eventually got the Domino. Now I have a machine that does what the biscuit
joiner did and a machine that affords me the opportunity to quickly and
easily make floating tennon joints which do indeed add lots of strength to
any joint


I guess thats why I never bought one, but really, I like tools and could
have talked myself into buying one eventually. This thread pretty much
convinced me I don't need one at all. Sort of like a nail gun, I really,
really want one (two), but have no use for it (them)...

;~) I started with one finish nailer 20 years ago, I have added a palm
nailer, brad nailer, air stapler, pinner, and framing nailer since. Can I
do the work with out them? Absolutely. If one broke today would I replace
it? Probably before the end of the day. It's one of those deals where you
wonder how you did with out them after you start using them. The
specialized tools open up more opportunities.

Luigi Zanasi wrote:

I am also happy to note that after a gazillion years of people saying
that they use biscuits "for alignment" in panel glue ups, that
everybody is fessing up that they actually cause a slight
misalignment. So it's not only me or my biscuit joiner or my
biscuits. :-)

I find it amazing anyone even uses a biscuit joiner, let alone a $700
Festool domino? I always knew they were not needed in the least for
strength in panel glue ups, but thought they would work nicely for
alignment, but knew from experience I could glue up table tops and door
panels easily with just clamps and cauls.

I guess thats why I never bought one, but really, I like tools and could
have talked myself into buying one eventually. This thread pretty much
convinced me I don't need one at all. Sort of like a nail gun, I
really, really want one (two), but have no use for it (them)...

--
Jack
Using FREE News Server: http://www.eternal-september.org/
http://jbstein.com

"Jack Stein" wrote in message
...
Tom Watson wrote:

When I glue up solid wood panels I pay a lot of attention to stock
prep. Eliminate all cup, crook and bow on the jointer, or with a
plane. Get everything to the same thickness by making a final pass
through the planer or sander using the same setup for all the stock to
be machined. Rip all the pieces with a blade that will give you a
glue line edge.

At this point, I definitely have no need for anything but glue, clamps and
cauls. Hardly need cauls if everything is prepped to perfection..


Jack consider also that when thinking about a joint even an edge joint we
typically do not consider lthe board having a less than desirable edge. I
work with a lot of red oak and the edge of a perfectly straight board may
very well have grain that runs at an angle to the edge and eventually will
open up on the edge of the board. It is true that glue is most often
stronger than the wood itself so the joint line is unlikely to break. BUT
the wood itself is often weaker than the glue line and the extra tennon and
or biscuit in that joint adds strength to the board in from the joint line .
I have seen glued up boards break right beside the joint line along a weak
grain line. The better tennon or biscuit will help to reinforce the weaker
areas of of the board near the joint line.

Tom Watson wrote:

When I glue up solid wood panels I pay a lot of attention to stock
prep. Eliminate all cup, crook and bow on the jointer, or with a
plane. Get everything to the same thickness by making a final pass
through the planer or sander using the same setup for all the stock to
be machined. Rip all the pieces with a blade that will give you a
glue line edge.

At this point, I definitely have no need for anything but glue, clamps
and cauls. Hardly need cauls if everything is prepped to perfection.

I machine biscuit slots about two inches in from a line that coincides
with what the finished ends will be and about every twelve inches
throughout the length. I use one biscuit on the centerline for boards
up to about 5/4 and a pair of biscuits set no less than 1/4 from the
faces above that thickness.

Wow!

Here is where I differ from what some guys do:
In my opinion, and it is only an opinion but it is based on
observation and experience; I don't count on the biscuits for
strength, I think the glue line provides the strength.

Yet you put one (or two) every 12"?

I use the biscuits to reduce the clamp time so that I can have a quicker turn
around time on the glued up panels.

Not sure how that helps much, but OK. I generally do other things while
the glue dries, and there is seldom enough time for me to get other
stuff done. Also, if the glue isn't dry enough, I don't think I would
depend on biscuits much to keep things together...

I also don't count on the biscuits for alignment, except in a very
rough sense. I use a Lamello
biscuit joiner and Lamello biscuits, which I believe to be more
consistent in their properties than others that I have tried - and I
still can't count on perfect alignment.

So then the whole purpose of biscuits is to reduce gluing time, because
alignment ain't it, and strength ain't it?

So, what I do is drive finish nails into one edge of each of the boards
, more or less
in the center of the edge of the board and more or less on the
centerline between
the biscuit slots. Then I nip the heads off, leaving about a heavy
eighth inch standing proud of the board edge. When I carefully
assemble the boards together during a later step the pins will keep
the boards even along their faces as I apply clamping pressure. It
doesn't take very much time and it works.

Yes, that sounds like an idea. Personally, I like cauls and clamps, and
really like as little metal as possible in my woodwork. I think the
nail pins you use would be particularly useful if one had no planer, or
sander to insure perfect equal thickness of the boards and needed one
face flat, and the other could vary a bit. Then a domino, or pins would
be helpful to get one flat face.

I almost always use cauls top and bottom - this provides my final
check for flatness of the glue up - but the pins help avoid all the
beating and hollering that too often goes on at this point.

A little beating and hollering gives a piece character, or at least
keeps the wife and kids out of your way:-)

--
Jack
Using FREE News Server: http://www.eternal-september.org/
http://jbstein.com

Robatoy wrote:

Jack Stein wrote:

I noted that a guy that makes exterior doors and gates has found after 3
1/2 years of using plate joinery that he has had NO failures. That
would indicate that while M&T may be stronger, plate joints are strong
enough for most applications.

Also, one must do a proper M&T joint for it to have all this 'magic'
strength. A poorly fitted, poorly proportioned M&T can be quite
fragile.

I watched Norm build an exterior door out of like 2" Mahogany and he
used floating tenons. He made 3/8" mortises 2 1/2 deep in the rails and
styles. He then glued in the floating tenons in each style. They were
a perfect fit in thickness, but had about a 1/4" play on each side of
the mortise. He said that was not important... I guess he is right but
I never saw that done before. More often, I've seen the tenon sides
rounded over for a prefect fit in the router made mortise.

Just thought I'd mention that...

BTW, the only hard part in making the exterior door was paying for the
wood, which Norm said was "expensive". My guess is it was just a bit
under a wheelbarrow full in Obama money. Certainly not even a billion...

--
Jack
Using FREE News Server: http://www.eternal-september.org/
http://jbstein.com

MikeWhy wrote:

Biscuits are mechanically compressed and dried. They don't shrink back
to their manufactured size even after redrying in a kiln. They need to
be stored in closed containers to minimize swelling from the moisture in
the air.

I never knew this. Do they come in a hermetically sealed mayonnaise jar
(asks Jack wearing his best Johnny Carson turban hat?) Seriously, a
good idea then would be to store them in a mayonnaise jar, with some of
that desiccant thing-ees that come with pills or packaged with some
tools and electronic things. I store those small tubes of super glue
gel in baby food jars or old pill containers with those things in them
to keep the moisture away...

In other words, if the swelling DOESN'T last more than 4 hours, should
I call the doctor?

Simplest test: wet one with a sponge and see what happens at the end of
4 hours. Try baking it for those 4 hours, just to be sure. (I haven't
tried it. Just passing on my understanding of biscuits.)

--
Jack
Using FREE News Server: http://www.eternal-september.org/
http://jbstein.com

On Fri, 17 Jul 2009 02:43:31 -0500, "MikeWhy"
wrote:

snip

Come to think of it, I don't particularly recall *where* I read it.

snip

Repeatable 1% variation even between two joints of the same type would be
something to really crow about. If you can find a credible cite for 1%
variability from M&T to loose tenon, I'll eat this keyboard I'm typing this
on, every last sharp, broken shard of it, including the lead contents of its
electronics. You wouldn't by chance care to restate what you wrote? I'm sure
I read it wrong.



Don't do what you are doing right now while eating Cheetos.

They'll turn your pecker orange.



Regards,

Tom Watson
http://home.comcast.net/~tjwatson1/

"Swingman" wrote in message
...
MikeWhy wrote:
"Swingman" wrote in message
...
MikeWhy wrote:

Loose tenons in turn are slightly, but consistently and measurably
weaker than real tenons.

In all published tests I've seen there is usually less than 1%
difference in measured strength between the two, which, and depending
upon the project, makes for a favorable comparison when taking into
account other factors like convenience and speed, particularly when
doing "production runs" in a small shop setting.

The specific reference was to the recent FWW article, apparently not on
your reading list. That's almost ironic, thinking back to our past
conversations. Come to think of it, I don't particularly recall *where* I
read it. The test featured dovetails, M&T, biscuits, and loose tenons.
I'm pretty sure it was FWW, probably December or January.

Repeatable 1% variation even between two joints of the same type would be
something to really crow about. If you can find a credible cite for 1%
variability from M&T to loose tenon, I'll eat this keyboard I'm typing
this on, every last sharp, broken shard of it, including the lead
contents of its electronics. You wouldn't by chance care to restate what
you wrote? I'm sure I read it wrong.

OK, let's take your particular "specific reference" then, where the
strength differential is less than 3% ... doing NOTHING whatsoever to
change the thrust/point of my statement.

And check those panties, Bubba ... untwisted, they'll improve your
attitude/demeanor by at least that much.

shrug Your "1%" is complete bull****. Just man up and say so.

"Leon" wrote in message
news

"MikeWhy" wrote in message
...
"Swingman" wrote in message
...
MikeWhy wrote:

Loose tenons in turn are slightly, but consistently and measurably
weaker than real tenons.

In all published tests I've seen there is usually less than 1%
difference in measured strength between the two, which, and depending
upon the project, makes for a favorable comparison when taking into
account other factors like convenience and speed, particularly when
doing "production runs" in a small shop setting.

The specific reference was to the recent FWW article, apparently not on
your reading list. That's almost ironic, thinking back to our past
conversations. Come to think of it, I don't particularly recall *where* I
read it. The test featured dovetails, M&T, biscuits, and loose tenons.
I'm pretty sure it was FWW, probably December or January.

Repeatable 1% variation even between two joints of the same type would be
something to really crow about. If you can find a credible cite for 1%
variability from M&T to loose tenon, I'll eat this keyboard I'm typing
this on, every last sharp, broken shard of it, including the lead
contents of its electronics. You wouldn't by chance care to restate what
you wrote? I'm sure I read it wrong.

Think about it, loose tennons are typically made out of a straight grain
hard wood. The tennon sculpted from the end of the typical board very
very often has been done with less than desirable grain orientation. The
loose tennon is glued inside "both" pieces, not just the in the one piece
so regardless of the type wood you are using you get a more consistent
strength tennon.

FWIW, the author also expressed surprise. I was more interested in the
dovetail tests.

"Jack Stein" wrote in message
...
MikeWhy wrote:

Biscuits are mechanically compressed and dried. They don't shrink back to
their manufactured size even after redrying in a kiln. They need to be
stored in closed containers to minimize swelling from the moisture in the
air.

I never knew this. Do they come in a hermetically sealed mayonnaise jar
(asks Jack wearing his best Johnny Carson turban hat?) Seriously, a good
idea then would be to store them in a mayonnaise jar, with some of that
desiccant thing-ees that come with pills or packaged with some tools and
electronic things. I store those small tubes of super glue gel in baby
food jars or old pill containers with those things in them to keep the
moisture away...


I have a box of Lamello biscuits sitting in the original shipping container,
a cardboard box with no liner.

"Jack Stein" wrote in message
...
Tom Watson wrote:

When I glue up solid wood panels I pay a lot of attention to stock
prep. Eliminate all cup, crook and bow on the jointer, or with a
plane. Get everything to the same thickness by making a final pass
through the planer or sander using the same setup for all the stock to
be machined. Rip all the pieces with a blade that will give you a
glue line edge.

At this point, I definitely have no need for anything but glue, clamps and
cauls. Hardly need cauls if everything is prepped to perfection.

I machine biscuit slots about two inches in from a line that coincides
with what the finished ends will be and about every twelve inches
throughout the length. I use one biscuit on the centerline for boards
up to about 5/4 and a pair of biscuits set no less than 1/4 from the
faces above that thickness.

Wow!

Here is where I differ from what some guys do:
In my opinion, and it is only an opinion but it is based on
observation and experience; I don't count on the biscuits for
strength, I think the glue line provides the strength.

Yet you put one (or two) every 12"?

It's for face alignment during the glue up, not strength afterward. There's
nothing scientific about it. For an edge joint 3' or 4' long, 3 biscuits
"feels" too few; 4 biscuits works out to about a foot or so between each; 5
feels a bit over done.

On Fri, 17 Jul 2009 08:49:21 -0500, Jack Stein
wrote:

Tom Watson wrote:

I use the biscuits to reduce the clamp time so that I can have a quicker turn
around time on the glued up panels.

Not sure how that helps much, but OK. I generally do other things while
the glue dries, and there is seldom enough time for me to get other
stuff done. Also, if the glue isn't dry enough, I don't think I would
depend on biscuits much to keep things together...


The Lamello biscuits are compressed beech and are intended to be used
with a white or yellow glue (aliphatic resin). The moisture from the
glue expands the biscuits to the degree that the clamps can be removed
in about half the usual time without the panel relaxing and damaging
the partially cured glue line.

This is important in a situation where you are making a number of
panels and want to keep production moving. I usually set up four
gluing stations and by the time I have the fourth panel in clamps the
first panel is ready to be removed from clamps.

BTW - biscuits have been around far longer than you might think. I've
disassembled door casings from the 30's that had what were referred to
as "Lemon Splines", essentially the same as biscuits but they were
machined with horizontal slotters and the lemon splines were not
compressed. Theses mitered joints were still in very good condition.




Regards,

Tom Watson
http://home.comcast.net/~tjwatson1/