Hi all.
For my exterior door frame project....
I will be butting together two lengths of sapele/mahog.
The individual pieces are about 22mm x 140mm and 1040cm long...and joining
them on the long edges to make 260mm wide panels.
Should I buy a jointing router bit or can I get away with using biscuits.
Once they are joined i will be fielding them.

Thanks.

Arthur

Arthur2 wrote:

I will be butting together two lengths of sapele/mahog.
The individual pieces are about 22mm x 140mm and 1040cm long...and joining
them on the long edges to make 260mm wide panels.
Should I buy a jointing router bit or can I get away with using biscuits.
Once they are joined i will be fielding them.

You don't need either...just glue should be fine. You can certainly use
biscuits for alignment, but they don't help at all as far as strength of
the joint.

Chris

You'll just need to get good flat and straight edges and do a good
glue and clamp job. Personally I would not do anything but that.
Biscuits can help with alignment and a tounge and groove or spline
joint also adds some strength but a panel in a door won't be taking
any stresses and even so, a glue joint is probably 90% as strong as
one with a mechanical joint if porperly glued and clamped. Be sure to
use a waterproof glue since this is an exterior application..

On Aug 6, 10:56*am, "Arthur2" wrote:
Hi all.
For my exterior door frame project....
I will be butting together two lengths of sapele/mahog.
The individual pieces are about 22mm x 140mm and 1040cm long...and joining
them on the long edges to make 260mm wide panels.
Should I buy a jointing router bit or can I get away with using biscuits.
Once they are joined i will be fielding them.

Thanks.

Arthur

On Aug 6, 1:37 pm, Chris Friesen wrote:

You don't need either...just glue should be fine.

True enough.

You can certainly use
biscuits for alignment, but they don't help at all as far as strength of
the joint.

NOT true at all. This seems to be a widely quoted myth parroted
around here amongst the literati.

One minute of research will get EMPIRICAL research to show
differently.
You can get started he

http://tinyurl.com/6qjcu9

But please don't stop there. There is a lot of easily obtained
information about the strength of a biscuit joint when properly
executed for the right type of joining.

Note that method, project design and understanding of the joints made
by this machine are important when maximizing the use of it, just as
it is with any other machine.

I think this stuff started when couple of these limp assed woodworking
for idiots magazines (including an op-ed piece by Rockler that
compared it to the Dowel Max) tested the biscuit joiner to see if it
was the do all, end all device for every single application.
Obviously it is not, nor is any other joining machine.

But to dismiss it out of hand as being useless is absurd.

Robert

wrote in message
...
On Aug 6, 1:37 pm, Chris Friesen wrote:

You don't need either...just glue should be fine.

True enough.

You can certainly use
biscuits for alignment, but they don't help at all as far as strength of
the joint.

NOT true at all. This seems to be a widely quoted myth parroted
around here amongst the literati.

One minute of research will get EMPIRICAL research to show
differently.
You can get started he

http://tinyurl.com/6qjcu9


I disagree. I did the same test as in figure 2. Used two large, (#20?) PC
biscuits, not three. pieces were 2X4, about 15' long. Set 48 hours with
Titebone #2. I was surprised how easily they (biscuits) broke, 1/2 in each
piece of 2x4. Did not use a scale to measure force. Nothing failed but the
biscuits. I asked the question about the difference between Lamello and PC
here about a year ago. That was not answered, but got all kinds of reasons
it failed. None applicable. After that, biscuits were for alignment, the
added strength was secondary.
I still would like to know if there is a diff between Lamello and PC
biscuits.

skreiv:
On Aug 6, 1:37 pm, Chris Friesen wrote:

You don't need either...just glue should be fine.

True enough.

You can certainly use
biscuits for alignment, but they don't help at all as far as strength of
the joint.

NOT true at all. This seems to be a widely quoted myth parroted
around here amongst the literati.

Do you realise that there is a difference between gluing end grain
to side grain and gluing side grain to side grain?

On Aug 7, 1:17 am, name wrote:

Do you realise that there is a difference between gluing end grain
to side grain and gluing side grain to side grain?

After many years of doing this for a living, yes. Check out the link,
do some quick research.

Robert

wrote

On Aug 6, 1:37 pm, Chris Friesen wrote:

You don't need either...just glue should be fine.

True enough.

You can certainly use
biscuits for alignment, but they don't help at all as far as strength of
the joint.

NOT true at all. This seems to be a widely quoted myth parroted
around here amongst the literati.

One minute of research will get EMPIRICAL research to show
differently.
You can get started he

http://tinyurl.com/6qjcu9

But to dismiss it out of hand as being useless is absurd.

Absolutely agree! ... to suggest that properly applied biscuit joinery adds
no strength whatsoever to the joint under question defies reason, logic,
personal practical experience, and more than one published testing.

There seems to be a proliferation of journalist woodworkers spouting these
"truisms" that are more former than latter.

I'll say it again: You gotta love the "wired world" ... the more "facts"
available from which to draw wrong conclusions, the more wrong conclusions
there are available as "facts".

--
www.e-woodshop.net
Last update: 5/14/08
KarlC@ (the obvious)

wrote in message
...
On Aug 6, 1:37 pm, Chris Friesen wrote:

You don't need either...just glue should be fine.

True enough.

You can certainly use
biscuits for alignment, but they don't help at all as far as strength of
the joint.

NOT true at all. This seems to be a widely quoted myth parroted
around here amongst the literati.


Agreed, biscuits add considerable strength to butt joints, and miter joints.
Today Domino's work even better. ;~)

On Thu, 7 Aug 2008 09:02:26 +0300, "Rick Samuel"
wrote:


wrote in message
...
On Aug 6, 1:37 pm, Chris Friesen wrote:

You don't need either...just glue should be fine.

True enough.

You can certainly use
biscuits for alignment, but they don't help at all as far as strength of
the joint.

NOT true at all. This seems to be a widely quoted myth parroted
around here amongst the literati.

One minute of research will get EMPIRICAL research to show
differently.
You can get started he

http://tinyurl.com/6qjcu9


I disagree. I did the same test as in figure 2. Used two large, (#20?) PC
biscuits, not three. pieces were 2X4, about 15' long. Set 48 hours with
Titebone #2. I was surprised how easily they (biscuits) broke, 1/2 in each
piece of 2x4. Did not use a scale to measure force. Nothing failed but the
biscuits. I asked the question about the difference between Lamello and PC
here about a year ago. That was not answered, but got all kinds of reasons
it failed. None applicable. After that, biscuits were for alignment, the
added strength was secondary.
I still would like to know if there is a diff between Lamello and PC
biscuits.

Richard,

I am not sure how your test disproved the data when your test was not
the same (2 vs three busuits) and you did not do a comparison with a
non-biscuit joint to compare amount of pressure required to break the
joint.

Of course none of that would change the fact that you were surprised
at how easy the joint broke, but just pointing out that it was not
"the same" test and not neccesarily conclusive.
-Chef Juke
"EVERYbody Eats when they come to MY house!"
http://www.chefjuke.com

Chef Juke wrote:
On Thu, 7 Aug 2008 09:02:26 +0300, "Rick Samuel"
wrote:


wrote in message
...
On Aug 6, 1:37 pm, Chris Friesen wrote:

You don't need either...just glue should be fine.

True enough.

You can certainly use
biscuits for alignment, but they don't help at all as far as
strength of the joint.

NOT true at all. This seems to be a widely quoted myth parroted
around here amongst the literati.

One minute of research will get EMPIRICAL research to show
differently.
You can get started he

http://tinyurl.com/6qjcu9


I disagree. I did the same test as in figure 2. Used two large,
(#20?) PC biscuits, not three. pieces were 2X4, about 15' long.
Set 48 hours with Titebone #2. I was surprised how easily they
(biscuits) broke, 1/2 in each piece of 2x4. Did not use a scale to
measure force. Nothing failed but the biscuits. I asked the
question about the difference between Lamello and PC here about a
year ago. That was not answered, but got all kinds of reasons it
failed. None applicable. After that, biscuits were for alignment,
the added strength was secondary.
I still would like to know if there is a diff between Lamello and
PC
biscuits.

Richard,

I am not sure how your test disproved the data when your test was
not
the same (2 vs three busuits) and you did not do a comparison with a
non-biscuit joint to compare amount of pressure required to break
the
joint.

Of course none of that would change the fact that you were surprised
at how easy the joint broke, but just pointing out that it was not
"the same" test and not neccesarily conclusive.

Besides that with a 15-foot moment arm he could have broken _any_
rigid joint between 2 2x4s joined 90 degrees without much effort.

The biscuits broke, he said. If it had been a mortise and tenon the
tenon would have broken. "Stronger than a butt joint" doesn't mean
"infinitely strong".

-Chef Juke
"EVERYbody Eats when they come to MY house!"
http://www.chefjuke.com

--
--
--John
to email, dial "usenet" and validate
(was jclarke at eye bee em dot net)

Swingman wrote:
wrote

But to dismiss it out of hand as being useless is absurd.


Absolutely agree! ... to suggest that properly applied biscuit joinery adds
no strength whatsoever to the joint under question defies reason, logic,
personal practical experience, and more than one published testing.

Huh? The original poster is edge-gluing long grain to long grain to
make a panel. The glue alone is at least as strong as the wood. How
would biscuits possibly make the joint any stronger?

Chris

wrote:
On Aug 6, 1:37 pm, Chris Friesen wrote:

You can certainly use
biscuits for alignment, but they don't help at all as far as strength of
the joint.


NOT true at all. This seems to be a widely quoted myth parroted
around here amongst the literati.

One minute of research will get EMPIRICAL research to show
differently.
You can get started he

http://tinyurl.com/6qjcu9

The original poster is edge-gluing two boards to make a panel. The
article you linked to says, "Modern adhesives can glue long or side
grain areas of wood together making a joint stronger than the wood itself."

Chris

On Wed, 6 Aug 2008 22:11:28 -0700 (PDT), "
wrote:


NOT true at all. This seems to be a widely quoted myth parroted around here amongst the literati.
snip tech info
Robert

When I got my first biscuit jointer, I did a few experiments with it... just
curious if the things were any good..

I built a couple of different size frames out of 1x4 scrap, using biscuits and
Titebond for assembly..
I let then sit for a week or so and them started flexing and bending them until
a few joints failed, and every joint that I managed to break had the wood
breaking and the biscuit still glued in place on both boards..
I have no scientific basis for the holding power, but it impressed the ****
outta me..

BTW: Robert, WTF is a literati?



mac

Please remove splinters before emailing

On Thu, 7 Aug 2008 07:37:13 -0500, "Leon" wrote:

snip
Agreed, biscuits add considerable strength to butt joints, and miter joints.
Today Domino's work even better. ;~)

Leon, it's less expensive to have YOU do the joints, and pay labor and shipping,
then buy a Domino..
Yeah, it's tool envy.. [ sigh ]


mac

Please remove splinters before emailing

On Thu, 07 Aug 2008 08:39:40 -0700, mac davis
wrote:


BTW: Robert, WTF is a literati?



More than one literato...





Regards, Tom.

Thos. J. Watson - Cabinetmaker
http://home.comcast.net/~tjwatson1/
tjwatson1ATcomcastDOTnet

On Aug 7, 9:49 am, Chris Friesen wrote:

The original poster is edge-gluing two boards to make a panel. The
article you linked to says, "Modern adhesives can glue long or side
grain areas of wood together making a joint stronger than the wood itself."

Please take a moment an reread. You will see that I agree with that.

On Aug 6, 1:37 pm, Chris Friesen wrote:

You don't need either...just glue should be fine.

True enough.

The second comment was mine. I agreed with you until that point.

When I started in the trades back in the early 70's, we certainly did
not have biscuits. Yet our work did not fall apart over time.

Yellow woodworking glue was just getting easy to find around here and
we were considered heretics because we joined long pieces with glue
only once we got that stuff.

This was not an innovative experiment on my part. Based on the test
results he had read, the structural engineer favored by the GC I
worked for specified exact construction methods and materials for wood
beams and other wood structural components.

Personally I didn't see any difference between the yellow carpenter's
glue and the Elmer's Professional Super Strength, but that's another
topic.

Regardless, I still don't believe in any situation that biscuits
add nothing to the strength of the joint. As J.Clarke said above,
using a biscuit for joining doesn't make the joint infinitely
stronger.

And again, if you read just that one article I linked and take a few
moments to read even more, I think you will be surprised just how
strong those little devils are when properly applied.

Robert

wrote:
On Aug 7, 9:49 am, Chris Friesen wrote:

The original poster is edge-gluing two boards to make a panel. The
article you linked to says, "Modern adhesives can glue long or side
grain areas of wood together making a joint stronger than the wood itself."


Please take a moment an reread. You will see that I agree with that.


Regardless, I still don't believe in any situation that biscuits
add nothing to the strength of the joint. As J.Clarke said above,
using a biscuit for joining doesn't make the joint infinitely
stronger.

And again, if you read just that one article I linked and take a few
moments to read even more, I think you will be surprised just how
strong those little devils are when properly applied.

Oh, I've got nothing against biscuits. My roll around drill press
cabinet is made of MDF and biscuits...no screws.

My point was simply that in the context of a panel glue-up, if you've
already got a joint that is "stronger than the wood itself", then the
biscuits can't buy you any useful additional strength. If the panel is
stressed hard enough that something breaks, it won't break at the glue
line. Biscuits won't change that.

Chris

"Chris Friesen" wrote

My point was simply that in the context of a panel glue-up, if you've
already got a joint that is "stronger than the wood itself", then the
biscuits can't buy you any useful additional strength.

Other than your sudden introduction of the phrase "useful additional
strength" (which proves you really didn't believe your original contention
that none whatsoever is added. ), let's see some proof of your contention
that ALL glue joints of this type will be "stronger than the wood itself"
.... or have you simply not yet experienced joint failure?

It's safe to say that, in joinery, a lot of small strengths add up to
contribute to total "joint strength.

To declare, unequivocably, that there are NO corcumstance/factors (including
the obvious ones of wood type/species, moisture content, grain, defects, the
glue, its type, quality, age, application, etc.) where any added strength
from biscuits , no matter how slight, may prove to be a "useful" additive to
the ultimate strength of the joint, simply cannot be supported as a
statement of fact.

If the panel is stressed hard enough that something breaks, it won't break
at the glue
line. Biscuits won't change that.

Fine ... then let's see some emprical evidence/test results that
verify/prove these exceedingly broad, all encompassing statements.

--
www.e-woodshop.net
Last update: 5/14/08
KarlC@ (the obvious)

"mac davis" wrote in message
...
On Thu, 7 Aug 2008 07:37:13 -0500, "Leon"
wrote:

snip
Agreed, biscuits add considerable strength to butt joints, and miter
joints.
Today Domino's work even better. ;~)

Leon, it's less expensive to have YOU do the joints, and pay labor and
shipping,
then buy a Domino..
Yeah, it's tool envy.. [ sigh ]


;~), boy that Domino saved me lot's of time on my last job. I think I put
in about 28 loose tennons on just the legs on the walnut desk. Throw in
probably 54 for the top and shelves for aligning the pieces of wood and
another 28 for the shelf skirts. Biscuits would have worked on the top and
shelf panels but it would have been over 100 mortises done on the mortiser
for the shelf and leg skirts. On this job alone the Domino probably saved
me 1 full day of work and that is about 1/3 the cost of the Domino.

"mac davis" wrote in message
...
On Wed, 6 Aug 2008 22:11:28 -0700 (PDT), "
wrote:


BTW: Robert, WTF is a literati?


Ain't that plural for literature? Hippopotamus, Hippopotami. LOL

"Arthur2" wrote in message
...
Hi all.
For my exterior door frame project....
I will be butting together two lengths of sapele/mahog.
The individual pieces are about 22mm x 140mm and 1040cm long...and joining
them on the long edges to make 260mm wide panels.
Should I buy a jointing router bit or can I get away with using biscuits.
Once they are joined i will be fielding them.

Thanks.

Arthur



Thanks very much for all advice.

Arthur

On Aug 7, 10:39 am, mac davis wrote:

When I got my first biscuit jointer, I did a few experiments with it... just
curious if the things were any good..

Somewhere back here in the archives I put on the data on my home
tests. Like you, I had to see. I had been using my biscuit machine
for a while, and liked it a lot, but in all honesty never battle
tested the joints I made using them. I read some of the opinions that
started cropping up on Woodweb, Woodworkers forum, Sawmill, etc, a few
years ago (amazing how many copy and paste from forum to forum) about
the lack of integrity of a biscuit joint.

I was using my BJ in my business, and got a little shaky in using it.
I sure didn't want to go back to dowels for connectors. But the bane
of any service business has to be warranty. I couldn't stand the
thought of a lawyer's bookcase (remember when we all had to build
those damn things?), built in cabs, or anything else failing.

As time went on, more and more piling on came about with the "biscuits
are useless" tribe. Based on nothing except what they had heard on
another forum, it was one of the more well traveled stories of the
internet. I finally got nervous enough (and biscuits are SOOOO cheap)
that I had to do some testing of my own.

I edge glued 2x12 pine from left over shelving together. One test
group had no biscuits, the other had biscuits every 4 inches. I let
them dry, and place the them parallel to my sawhorses with the long
edges riding on the sawhorses and the joint in the middle. I stacked
weight on them until they broke.

True enough, neither broke at the glue joint, but the un-biscuited
joint failed with significantly more weight on it. I could only guess
that it was because (from observation) the one without the biscuits
flexed more than the other when under stress. I only did that one
test and seeing how strong the biscuit joint was, I was relieved. I
wanted to try it with hardwood, but that stuff is now and always has
been gold around here.

So... since filling 4d nail holes in the stiles of cabinets are always
a pain, and sometimes obvious after finishing, I decided to glue
stiles on with and without biscuits on test piece of cabinet plywood
to mock up a carcass. When pulling the 1X2 away from edge of the
plywood, there was significantly better hold with the biscuits. But
the biscuits pulled out hunks of plywood after a pry bar was used. I
was happy knowing that my clients would never take a pry bar to the
cabinets.

But where the biscuits on plywood really did their stuff was when I
try to shear off the 1X2 in a motion that was perpendicular to the
plywood. Now good sir, that was some real holding power. Hercules
would have had a good time with that.

My test results were like yours. Properly glued, properly set, etc.,
I was actually surprised. Then (sure wish I had it now!) I ran across
a university study that compared modern joining methods. If you want
to see a kick ass joint that will hold up well past any expectations,
double or triple the biscuits. Wow. They tried biscuits v. dowels,
biscuits v. mortise and tenon (like the link I posted) and some
others. It was obvious that the biscuit joiner had great value.

Triple biscuit that 2X4 test miter you did and try to tear them apart
after drying. Then you will see how much holding power those little
*******s have. This is also amply shown in one of the graphics on the
supplied link.

But I think it is important to remember, like today's Domino, the BJ
came about to allow a woodworker (probably a professional since they
started making them in the 30's or 40's in Europe for the furniture
industry) to make fast, accurate joints. The joints made with this
machine were not made to replace a welder, 10" lag screws in 8x8
posts, or other types of joining methods.

To me, the beauty of the biscuit joiner is that it takes no time to
master and it makes accurate, repeatable and durable joinery fast and
easy to do. I have literally never had a biscuit joint fail. If they
did, I didn't know about it.

That includes edge gluing as well. I don't believe that something
that works as well as it does with so little hassle for certain joints
doesn't bring anything to the project except alignment reference
points.

But I was worried enough to spend a few off hours testing for my own
satisfaction. I have never heard of most of these 0.03 a word
computer jockeys that write these contributing pieces and simply don't
trust most of what I read in their respective bird cage protectants.
Besides, when I had to lab test my biscuit joiner I had been using it
for about 3 years or so and had just bought another 1000 biscuits!

I was almost convinced I had purchased a boat anchor and didn't know
it.

It isn't the end all machine for all joining, but it has served me
very well. I don't actually use it that much, but it serves me well
when I do. It has proven to be 100% reliable.

I have no scientific basis for the holding power, but it impressed the ****
outta me..

Good for you for wood shedding that product, though! How many have
actually done that? Probably most don't have any idea what any of
their tools are actually capable (or incapable) of doing...


BTW: Robert, WTF is a literati?

Well, I like Tom's answer better. Heh, heh... literato.

Anyway, to me a the literati are the folks that think they are "in the
know", the folks that have read mountains of information on a subject
or two and deem themselves "experts" of sorts. In the case of those I
was referring to, rarely do those "in the know" have much hands on
experience, nor do they have any practical usage time to support their
opinion.

Yet they will argue endlessly to defend their point of view simply
because they know no better. But being well read on a subject, they
feel like they know a lot about it, so therefore they are an expert.

This applies to just about any subject, BTW.

In this case, I would wonder how many of the folks that have repeated
over and over that biscuits are just alignment tools have actually
used one for anything more than a weekend bookcase or coffee table.

Every time I see the alignment tool myth start up, I think of Homer J.
Simpson.

(Think of a whining voice) "Ohhhh.... but Marge, it HAS to be
true.... I read it on the internet!"

Robert

wrote:

In this case, I would wonder how many of the folks that have repeated
over and over that biscuits are just alignment tools have actually
used one for anything more than a weekend bookcase or coffee table.

In the specific context of panel glue-ups, (or even face frame to
cabinet joints) do you think that biscuits are more than alignment tools?

I'm no expert, but from everything I've read and researched, glue alone
should be plenty strong in both of those cases.

For miter joints, edge-to-face, end-to-face, end-to-end, etc. I fully
agree that biscuits can add significant strength as compared to glue alone.

Chris

"Chris Friesen" wrote

In the specific context of panel glue-ups, (or even face frame to
cabinet joints) do you think that biscuits are more than alignment tools?

Depends ... not "one size fits all" situations.

I'm no expert, but from everything I've read and researched, glue alone
should be plenty strong in both of those cases.

No question about that ... it is most often _all_ you need ... if that is
all you're after.

For miter joints, edge-to-face, end-to-face, end-to-end, etc. I fully
agree that biscuits can add significant strength as compared to glue
alone.

Do the following with regard to edge to edge panel gluing:

1. Lay out your panel boards side by side, with no biscuits and no glue on
the edges.

Now try and pick up all boards at the same time and notice, other than
friction, and for all practical purposes, there is no "joint strength"
whatsoever.

2. Lay out your panel boards side by side, with biscuits, but no glue on
either the biscuits or the board edges.

Now try and pick up all boards at the same time and notice that adding the
friction attributable to the glueless biscuits in their slots has added a
small, but measurable amount of "joint strength" over 1 above, particularly
in shear strength, which is one of the ideal components in a joint of this
type.

3. Lay out your panel boards side by side, this time with biscuits properly
glued in, but no glue on the board edges.

Now try and pick up all boards at the same time and notice, after sufficient
clamping/drying, a relatively significant amount of increase in "joint
strength" over 1 and 2 above.

4. Lay out your panel boards side by side, with biscuits properly glued in,
and with glue properly applied to the edges. After sufficient
clamping/drying, measure the joint strength.

Now tell me, with a straight face and clear conscience, that steps 2 and 3
added NOTHING in strength whatsoever to the final "joint strength" in 4!



Granted, you may not need it, but it won't hurt and it just may be there
when you do (and easy/cheap insurance for those who prefer a belt and
suspenders approach for posterities sake).

That said, there are other reasons for adding biscuits to a panel glue-up,
other than "alignment" and the arguable possibility of added "joint
strength":

Joint "creep" .. which, IME, is particularly noticeable in wood cut off the
log in a manner that much of the dimensional instability is reflected in
movement in thickness (as you often experience in quarter sawn woods),
instead of across the grain width.

IME, there is a noticeable decrease, over time, in the effects of this
phenomena when using biscuits in panel glue-ups.

YMMV ...

--
www.e-woodshop.net
Last update: 5/14/08
KarlC@ (the obvious)

"Swingman" wrote:

snip lab experiment description

It wears me out just reading the instructions, much less perform the
experimentsG

Lew

"Lew Hodgett" wrote in message

"Swingman" wrote:

snip lab experiment description

It wears me out just reading the instructions, much less perform the
experimentsG

No pain, no gain.


--
www.e-woodshop.net
Last update: 5/14/08
KarlC@ (the obvious)

On Thu, 07 Aug 2008 10:18:18 -0600, Chris Friesen
wrote:


My point was simply that in the context of a panel glue-up, if you've
already got a joint that is "stronger than the wood itself", then the
biscuits can't buy you any useful additional strength. If the panel is
stressed hard enough that something breaks, it won't break at the glue
line. Biscuits won't change that.

Chris


let me ask you a question, Chris.

In all the tests that I have seen, although it is true that the glue
line does not break, the break is always near the glue line. It does
not appear to be the case that the break is in another part of the
panel that is away from the glue line.

What's up with that?



Regards, Tom.

Thos. J. Watson - Cabinetmaker
http://home.comcast.net/~tjwatson1/
tjwatson1ATcomcastDOTnet

On Aug 6, 1:56*pm, "Arthur2" wrote:
Hi all.
For my exterior door frame project....
I will be butting together two lengths of sapele/mahog.
The individual pieces are about 22mm x 140mm and 1040cm long...and joining
them on the long edges to make 260mm wide panels.
Should I buy a jointing router bit or can I get away with using biscuits.
Once they are joined i will be fielding them.

Thanks.

Arthur

There you go, Arthur. You now have the answer.
I would like to add, that cheapo biscuits often have random grain
orientation as opposed to a diagonal to the oval shape, like 'select'
biscuits such as the Lamellos.
If a biscuit breaks along its length in your application, it would add
less strength than if it was inclined to break on the diagonal. The
change of grain direction along the stress line, adds strength....
assuming that the biscuit was installed properly, i.e. the slot
(pocket) wasn't unnecessarily big. You want to take away as little of
the original material as possible without running into a hydro-locking
condition.

I have used thousands upon thousands of biscuits and conducted many
tests and read/archived many such tests. The DO add strength to a
joint, and in certain properly executed applications, can get close in
performance to a floating tenon.

The drawback, of course, is that when you use biscuits to make a
panel, you can see the telegraphed shape of the biscuit after you sand
and finish the panel.

r-Zebco 6, 4' graphite ultra-light.

Tom Watson wrote:
....

let me ask you a question, Chris.

In all the tests that I have seen, although it is true that the glue
line does not break, the break is always near the glue line. It does
not appear to be the case that the break is in another part of the
panel that is away from the glue line.

What's up with that?
....

Every test I've seen the two pieces are the same width so the joint is
in the middle. When the board is loaded and supported on the edges, the
point of highest stress is then in the middle; hence unless there is a
weak point farther towards one edge or another, the most likely place
for the failure is near the point of highest stress, the middle.

Since as noted, the glue joint actually is generally as strong as or
stronger than the material, typically it is slightly to one side or the
other of the joint where the break occurs.

Simply physics of the test geometry is the basic explanation...

The more interesting test that is illuminating is the one of the bridle
joint joint loaded perpendicularly to the grain on one piece -- even
there it is typically either the wood that breaks or a combination
rather than a glue-line failure for well machined joints.

--


--

A little ancient history from our own resources.

Please note the concepts of grain direction and the relieved
shoulders.



"This history on the development of the plate joiner system was
originally posted to rec.woodworking on February 12, 1988 in response
to a discussion comparing the strength of biscuits to dowels. The
author is Sherman Whipple, who has graciously allowed the
republication of his exposition on the development of the plate joiner
system.



There is an elderly gentleman by the name of Herman Stiener who lives
in Switzerland. He would probably get the greatest kick from reading
all the threads about biscuits vs. dowels, tenons, etc. You see it was
Herman Steiner who started this whole thread back in 1955, two years
before there even was an Internet and after 43 years, it is still
going on; he's the guy who invented the things.

He also adapted a right-angle grinder to invent the first gadget to
index the slots, as well. He also made a neat clamping system, defect
patcher, and quite a number of other woodworking devices and
techniques. Mr. Steiner was by profession an engineer, and from what I
have been told was quite good at it. Cabinetmaking for him, as for
most of us, was just a hobby. He invented it in his home workshop.

The design of the joining plate and the secret of its strength are
based upon very sound engineering. For example, wood's greatest
strength is against the bias. We all know it is weakest with the
grain, but most of us assume that it would be strongest across the
grain: wrong. It is strongest with the grain angled 45 degrees and
beech is one of the strongest in this orientation. One would also
imagine that a rectangular plate would add greater strength than the
football shape. In dealing with wood, however, if the base of the slot
were square, as in a long spline with the grain, the wood would be
weakened. The elliptical slots prevent splitting. Basically the design
of the plate provides the maximum spreading of the load and a better
glue surface. The addition of the compression and swelling properties
and the tread pattern to open the wood fibers all came later.

It is my understanding that when Herman began to share his invention
he was met with considerable disbelief from the local cabinetmakers.
To prove it, he would have them make a couple of simple "T" joints.
One with the technique they thought would be strongest and one with
his "lamellae" which means thin plate. After the glue had set he would
challenge them to break the joint. Every time, the plates won the
challenge. Every cabinetmaker became a customer and he started a
business to make plates called Steiner Lamello. Soon after he
introduced the indexing base and then the first dedicated
plate-joining machine.

The first Lamello machines did not begin to appear in the US until the
mid-to- late 1960's, but it was not until about 1977 that they started
to see wide acceptance. This was mostly in industrial applications.
The rest of course, is history. We don't know who invented the wheel,
or figured out how to cut the first dovetail, but we do know who made
the joining plate, biscuit, lemon spline, or Lamello. It was a guy
just like us by the name of Herman Steiner.





Sherman Whipple

Whipple, Sargent & Associates Strategic Services

37 Derby Street, Suite 7B Hingham, MA 02043

Phone: 781-740-4025 Fax: 781-749-9474

E-Mail:





For more information about biscuit joinery see:
http://www.ameritech.net/users/hankm/wme.htm"





Regards, Tom.

Thos. J. Watson - Cabinetmaker
http://home.comcast.net/~tjwatson1/
tjwatson1ATcomcastDOTnet

On Aug 7, 7:18 pm, Tom Watson wrote:

In all the tests that I have seen, although it is true that the glue
line does not break, the break is always near the glue line. It does
not appear to be the case that the break is in another part of the
panel that is away from the glue line.

What's up with that?

Somewhere in this thread, are my personal results from just such a
hypothesis that was put to experiment.

My personal results completely agree with the tests you have seen. I
am no engineer so I have no great, informed answer. All I know is
them's the facts, and that's good enough for me.

Robert

On Thu, 07 Aug 2008 19:24:12 -0500, dpb wrote:

Tom Watson wrote:
...

let me ask you a question, Chris.

In all the tests that I have seen, although it is true that the glue
line does not break, the break is always near the glue line. It does
not appear to be the case that the break is in another part of the
panel that is away from the glue line.

What's up with that?
...

Every test I've seen the two pieces are the same width so the joint is
in the middle. When the board is loaded and supported on the edges, the
point of highest stress is then in the middle; hence unless there is a
weak point farther towards one edge or another, the most likely place
for the failure is near the point of highest stress, the middle.

Since as noted, the glue joint actually is generally as strong as or
stronger than the material, typically it is slightly to one side or the
other of the joint where the break occurs.

Simply physics of the test geometry is the basic explanation...

The more interesting test that is illuminating is the one of the bridle
joint joint loaded perpendicularly to the grain on one piece -- even
there it is typically either the wood that breaks or a combination
rather than a glue-line failure for well machined joints.

--


Tomorrow I'm going to glue up a panel like I would use for a raised
panel door.

I'll let it set up for a day or so and then apply force to the center
of the entire panel, which will not be the same as applying a force to
a single glue line.

I'll be interested to see what happens.





Regards, Tom.

Thos. J. Watson - Cabinetmaker
http://home.comcast.net/~tjwatson1/
tjwatson1ATcomcastDOTnet

On Thu, 7 Aug 2008 17:32:39 -0700 (PDT), "
wrote:

On Aug 7, 7:18 pm, Tom Watson wrote:

In all the tests that I have seen, although it is true that the glue
line does not break, the break is always near the glue line. It does
not appear to be the case that the break is in another part of the
panel that is away from the glue line.

What's up with that?

Somewhere in this thread, are my personal results from just such a
hypothesis that was put to experiment.

My personal results completely agree with the tests you have seen. I
am no engineer so I have no great, informed answer. All I know is
them's the facts, and that's good enough for me.

Robert



My suspicion is that the very act of gluing creates a weakness in the
wood fibers close to the glue line.

It's like a woodworking application of the uncertainty principle.




Regards, Tom.

Thos. J. Watson - Cabinetmaker
http://home.comcast.net/~tjwatson1/
tjwatson1ATcomcastDOTnet

On Thu, 07 Aug 2008 20:38:33 -0400, Tom Watson
wrote:

It's like a woodworking application of the uncertainty principle.


Please do not respond to me with posts that explain the workings of
the actual uncertainty principle.

It was an attempt at humorous analogy.




Regards, Tom.

Thos. J. Watson - Cabinetmaker
http://home.comcast.net/~tjwatson1/
tjwatson1ATcomcastDOTnet

On Aug 7, 7:31 pm, Tom Watson wrote:
A little ancient history from our own resources.

SNIP of great stuff

Regards, Tom.

I don't know how or where you found that or if you took the time to
type it from your archives, but thanks for posting that piece.

Neat stuff.

Robert

On Thu, 7 Aug 2008 17:41:12 -0700 (PDT), "
wrote:

I don't know how or where you found that or if you took the time to
type it from your archives, but thanks for posting that piece.

Neat stuff.



I did a search for "lemon splines" which was the old name for
biscuits.

When I was a young fella a lemon splined joint in the corners of the
door casing was taken as a mark of quality, and also an indication
that the trim had been run up in a cabinet / millwork shop prior to
its arrival onsite.




Regards, Tom.

Thos. J. Watson - Cabinetmaker
http://home.comcast.net/~tjwatson1/
tjwatson1ATcomcastDOTnet

Tom Watson wrote:
On Thu, 07 Aug 2008 20:38:33 -0400, Tom Watson
wrote:
It's like a woodworking application of the uncertainty principle.


Please do not respond to me with posts that explain the workings of
the actual uncertainty principle.

It was an attempt at humorous analogy.
....



Being a nuclear engineer/physicist by training, I'll refrain (w/
difficulty)... vbg

The actual is owing to the general test layout and the physics of plate
bending as noted in an earlier thread. If the material were actually
entirely uniform as we all know wood isn't, the bending stresses would
be perfectly symmetric and a solid piece of the same dimensions would
bend then break right down the middle.

There's a small effect at the edge owing to the discontinuity of the
fibers across the joint but w/ reasonably straight-grained wood it's a
secondary issue. The glue joint is, in fact, stronger than the breaking
strength and which side the test sample breaks upon depends on which
board has the weaker point flaw assuming even loading.

If you look at some of the web sides that have the "sagulator"
calculators for beam loading, some of them also have stress/strain
curves associated with them for various loading patterns. For
simply-supported ends and point load in the middle, the bending moment
diagram is linear from the endpoints to the middle, then decreases in
the other direction to zero again at the other edge. Something like

Load
|
\|/
------------- Beam/panel

\ / -- 0 (zero bending moment)
\ /
\ /
\ /
\ /
\ / ------ M (max bending moment)

--

On Aug 7, 6:33 pm, "Swingman" wrote:

SNIP of the second Manhattan project

Now tell me, with a straight face and clear conscience, that steps 2 and 3
added NOTHING in strength whatsoever to the final "joint strength" in 4!



Hell, I'm tuned in. Chris, you're surrounded!!

;^)

All in good fun sir, but with a lot of good info attached.


Granted, you may not need it, but it won't hurt and it just may be there
when you do (and easy/cheap insurance for those who prefer a belt and
suspenders approach for posterities sake).

Well, that would be me. I am not as bad as I used to be, but I think
somewhere in my old German bloodline there must have been some
woodworker that was convinced it was only worthwhile to build things
for the ages.

After I started paying for all the extra fasteners, glue, materials
and time on the project to get it "right", I decided to trust some of
the old ways. Not completely, though.

IME, there is a noticeable decrease, over time, in the effects of this
phenomena when using biscuits in panel glue-ups.

I can't quantify how much, but it seems that way to me as well. I
have built display cases (hey... who could afford a 1X24 piece of
black walnut?) that were constructed in different styles. One guy
that still has his where I can see him when I go to his office only
has one tiny line that raises about a thousandth or so when they keep
the building closed up for a holiday with the AC turned to 82.

When it is in the AC at 73 (the normal temp) it moves back into
place.

Earlier efforts that are in the hands of family don't necessarily fare
as well. I made a coffee table from edge glued 1X6s from soft pine
and it held up well for a few years. Yet continued use caused the
joints to fail. Not completely, but they did open up.

Subsequent efforts to make country style coffee/tea cabinets to pay
for gas when I was struggling as a carpenter worked better than no
other support. I would cut down a piece of wood to 3/4" X 1" (saw
this on a piece of furniture at an antique show) and lay them
perpendicular to the edge glued wood and glue them on, nailing with a
million 4ds.

My sister has one of those cabinets left, and it doesn't move at all.

But it was a lot of work for longer layups. I HATED doweling edges as
even with my cute little gizmo I couldn't get every single dowel to
line up perfectly.

I tried the biscuit joiner after a friend of mine that built furniture
got a Lamello and loved it. Next project I needed to do a big glue up
on, I used it and have found a lot of uses for it since.

Robert

On Thu, 07 Aug 2008 20:00:01 -0500, dpb wrote:

Tom Watson wrote:
On Thu, 07 Aug 2008 20:38:33 -0400, Tom Watson
wrote:
It's like a woodworking application of the uncertainty principle.


Please do not respond to me with posts that explain the workings of
the actual uncertainty principle.

It was an attempt at humorous analogy.
...



Being a nuclear engineer/physicist by training, I'll refrain (w/
difficulty)... vbg

The actual is owing to the general test layout and the physics of plate
bending as noted in an earlier thread. If the material were actually
entirely uniform as we all know wood isn't, the bending stresses would
be perfectly symmetric and a solid piece of the same dimensions would
bend then break right down the middle.

There's a small effect at the edge owing to the discontinuity of the
fibers across the joint but w/ reasonably straight-grained wood it's a
secondary issue. The glue joint is, in fact, stronger than the breaking
strength and which side the test sample breaks upon depends on which
board has the weaker point flaw assuming even loading.

If you look at some of the web sides that have the "sagulator"
calculators for beam loading, some of them also have stress/strain
curves associated with them for various loading patterns. For
simply-supported ends and point load in the middle, the bending moment
diagram is linear from the endpoints to the middle, then decreases in
the other direction to zero again at the other edge. Something like

Load
|
\|/
------------- Beam/panel

\ / -- 0 (zero bending moment)
\ /
\ /
\ /
\ /
\ / ------ M (max bending moment)


I am mindful of your explication.

My point, and I would say, my premise, is that the act of gluing
introduces some deterioration to the fibers along the line.

The test that I have planned should be interesting in either proving
it out to a degree that it becomes a theory, or putting the idea to
bed.

I would be disinclined to bring Heisenberg into this discussion beyond
saying that every time that I would try to look at my experiment the
parameters would change - and that would **** me off.



Regards, Tom.

Thos. J. Watson - Cabinetmaker
http://home.comcast.net/~tjwatson1/
tjwatson1ATcomcastDOTnet