On Jul 28, 10:59*am, Phisherman wrote:
On Mon, 28 Jul 2008 06:15:06 -0700 (PDT), JacksonD
wrote:





On Jul 28, 9:05*am, Limp Arbor wrote:
On Jul 27, 11:27*pm, "jack" wrote:

"JacksonD" wrote in message

...Ijust bought a biscuit joiner.
Need to join (salvaged) 3/4" pine boards to make kitchen cabinet.

What size biscuits to use?
I'm guessing #20s.
How to space them?
How far center of first biscuit from edge of board?
After that. how far to center of next one etc. ?

There is controversy over whether biscuit add strength or not. *I won't get
into it.

The primary use is alignment; getting your boards together evenly so you
don't have to plane/sand 1/8" off to get them even. *If your boards are
perfectly flat, 2 or 3 biscuits will be fine. *If they are not (and even
properly jointed and planed board can warp pretty quickly) then you will
need more than that to keep things reasonably even. *I can't tell you from
here what you need. *But get them as close to the edge as you can because
that is where alignment is needed the most. *If the edges will be seen, be
careful because biscuit scars can't be hidden if you cut through one..

I ran out of 20s and have been using a big box of 10s I got for nothing at
an auction. *If you only want them for alignment, I can't see that it makes
a difference. *For strength... oh lets not go there.

Oh come on lets go there. *Somebody move the 'do biscuits add
strength' thread to rec.woodworking. *It will be fun.

To me the depth difference between a 10 & 20 isn't that much so if
biscuits do add strength the added strength a 20 would give over a 10
is insignificant. *Use whatever you have.

If the edges of your boards aren't straight it won't matter what size
you use because the joint will most likely fail.- Hide quoted text -

- Show quoted text -

If biscuits add no strength, and are solely for alignment, then why do
we glue them in?
Why not just let them "float"? *What is the glue on the biscuit for
then?

It adds *some* strength, but it is the glue that does the holding
power. *The glue on the biscuit causes the biscuit to swell inside the
slot helping the lock the joint in place. *For thinner stock biscuits
should not be used as this may cause a raised area from the swelling.
There have been situations where I left the biscuit float due to
possible excess wood movement (eg, breadboard ends).- Hide quoted text -

- Show quoted text -

Phisherman:

Please explain why breadboard end is a special case.
Thank you.