In a dicussion at one of our woodworker group meetings, the issue of
using
biscuits for tabletops came up. I know this has been discussed
in many ways, but not sure if this particular hint ever came up:
The suggestion was to use biscuits as a LOCATING aid, vs
as a glueup aid. Meaining don't put glue in/on the biscuits and
the slots, leave them dry. Put glue along the edge and use
that as the glue joint. The point being is that glue never seems
to dry completely in the slots and that at some point (don't
remember exactly what was said) the biscuit will shrink
leaving a small dimple in the top. I know Norm
has said he doesn't use biscuits anymore
in tabletops because they telegraph through.
Curious as to other experiences you might have had
with biscuits and tabletops.
I have some projects in the wind and will need to glue
up some panels and want to use biscuits, but now
I'm not sure. I've glued up panels with just a clean rip
cut and dowels but thought biscuits were the way to
go.
Comments?
MJ Wallace
On 15 Nov 2005 10:36:15 -0800, [email protected] wrote:
>
>Curious as to other experiences you might have had
>with biscuits and tabletops.
>
>Comments?
>
>MJ Wallace
I never heard of that. So I just did an inspection of all the
furniture I have in the house that I made with glued up biscuit
panels. Some cherry, some walnut, some oak. I couldn't find any
dimples and while no tables, some of the panels were large glue ups.
I did, however, find a couple of splits in side panels from ignoring
the cross grain gluing law. Oh well, gives them that antique look.
and they'll close back up next spring.
Frank
Makes no sense to not glue the biscuits, IMHO, unless they are such a
tight fit in the groove that, on swelling after getting wet, they
distort the piece enough to be seen.
This might happen in balsa, or where you glue it, finish it, and ship
it. Without any scraping, sanding, planing, whatever. Unlikely enough
to be irrelevant.
Every bit of joint strength is valuable.
Norm still abuses brads.
J
<[email protected]> wrote in message
news:[email protected]...
> In a dicussion at one of our woodworker group meetings, the issue of
> using
> biscuits for tabletops came up. I know this has been discussed
> in many ways, but not sure if this particular hint ever came up:
>
> The suggestion was to use biscuits as a LOCATING aid, vs
> as a glueup aid. Meaining don't put glue in/on the biscuits and
> the slots, leave them dry. Put glue along the edge and use
> that as the glue joint. The point being is that glue never seems
> to dry completely in the slots and that at some point (don't
> remember exactly what was said) the biscuit will shrink
> leaving a small dimple in the top. I know Norm
> has said he doesn't use biscuits anymore
> in tabletops because they telegraph through.
>
> Curious as to other experiences you might have had
> with biscuits and tabletops.
>
> I have some projects in the wind and will need to glue
> up some panels and want to use biscuits, but now
> I'm not sure. I've glued up panels with just a clean rip
> cut and dowels but thought biscuits were the way to
> go.
>
> Comments?
>
> MJ Wallace
They work fine. The telegraphing happened to me once, pine top and way to
much glue on the biscuit. I've more tops but now I brush a thin coat of
glue in the slot and on the biscuits. No problems.
Dave
Biscuits is all I use, a couple dozen panels now, and nary a biscuit
showing.
That might be because in this very newsgroup someone asked how come he
had little depressions everywhere in the tabletop that had a biscuit,
and someone said it was probably because he sanded a few hours after he
glued up. Everyone else in that thread allowed how they'd always waited
at least a day before they sanded their panels, and never had a
problem. I've kept to that habit.
The theory is, the biscuits do swell when you glue 'em, and then after
ten or twelve hours, they shrink back to normal. If you flatten the top
when they're swelled up, there'll be a depression everywhere there's a
biscuit.
Norm says he doesn't do biscuits any more because they leave
depressions. I'd tell him it was probably because he doesn't let it sit
long enough, but I know he's on a tight schedule.
If you're using a composite core I think the original statement here
might hold some wieght..
meaning a veneered flake panel or MDF... but in most solids, I would
say a glued biscuit
in the edge center, properly set, will probably never show in our
lifetime or in your great grandchildrens
for that matter...
health n laughter
On 15 Nov 2005 10:36:15 -0800, [email protected] wrote:
>In a dicussion at one of our woodworker group meetings, the issue of
>using
>biscuits for tabletops came up. I know this has been discussed
>in many ways, but not sure if this particular hint ever came up:
>
>The suggestion was to use biscuits as a LOCATING aid, vs
>as a glueup aid. Meaining don't put glue in/on the biscuits and
>the slots, leave them dry. Put glue along the edge and use
>that as the glue joint. The point being is that glue never seems
>to dry completely in the slots and that at some point (don't
>remember exactly what was said) the biscuit will shrink
>leaving a small dimple in the top. I know Norm
>has said he doesn't use biscuits anymore
>in tabletops because they telegraph through.
>
>Curious as to other experiences you might have had
>with biscuits and tabletops.
>
>I have some projects in the wind and will need to glue
>up some panels and want to use biscuits, but now
>I'm not sure. I've glued up panels with just a clean rip
>cut and dowels but thought biscuits were the way to
>go.
>
>Comments?
>
>MJ Wallace
I use biscuits for panel glueups, and I apply glue to both the biscuit
and the slot. I've never had one telegraph.
this doesn't mean that it won't happen in your shop though. I live in
arizona. the glue in the slot definitely dries completely- and
quickly, too.
[email protected] wrote:
>
> In a dicussion at one of our woodworker group meetings, the issue of
> using
> biscuits for tabletops came up. I know this has been discussed
> in many ways, but not sure if this particular hint ever came up:
>
> The suggestion was to use biscuits as a LOCATING aid, vs
> as a glueup aid. Meaining don't put glue in/on the biscuits and
> the slots, leave them dry. Put glue along the edge and use
> that as the glue joint. The point being is that glue never seems
> to dry completely in the slots and that at some point (don't
> remember exactly what was said) the biscuit will shrink
> leaving a small dimple in the top. I know Norm
> has said he doesn't use biscuits anymore
> in tabletops because they telegraph through.
>
> Curious as to other experiences you might have had
> with biscuits and tabletops.
>
> I have some projects in the wind and will need to glue
> up some panels and want to use biscuits, but now
> I'm not sure. I've glued up panels with just a clean rip
> cut and dowels but thought biscuits were the way to
> go.
>
> Comments?
>
> MJ Wallace
Don't see any reason they couldn't be used that way---that's they're
primary function for most edge-line gluing anyway.
I've heard the stories of biscuits "showing through" too, but never seen
it even here in a very dry area where stuff dries out more than in most
other areas for anything 3/4" or more in thickness.
IMO, that it is a problem is the woodshop equivalent of the urban
legend. I could see it for a very thin piece or a biscuit inserted near
the surface of a thicker piece (such as two rows of biscuits) but just
don't see it as a problem.
[email protected] wrote:
>
> Makes no sense to not glue the biscuits, IMHO, unless they are such a
> tight fit in the groove that, on swelling after getting wet, they
> distort the piece enough to be seen.
The usual "showthrough" that is complained of is after finishing the
area over the biscuit is claimed to be slightly sunken, not raised,
owing to the subsequent loss of the residual glue moisture from the
biscuit.
> This might happen in balsa, or where you glue it, finish it, and ship
> it. Without any scraping, sanding, planing, whatever. Unlikely enough
> to be irrelevant.
I agree it seems far fetched except as I noted in another response that
the thickness above the biscuit to the finished surface is quite thin.
I can also only presume it would happen if the piece were finished in
such a short time frame after glue up that the residual glue moisture
hadn't reached equilibrium. In a production shop environment I suppose
that's realistic--in a hobby/rec environment I don't believe so...
> Every bit of joint strength is valuable.
A typical 3/4" well fitting glue line joint is stronger than the wood,
anyway...
> Norm still abuses brads.
:)
How thick is your board and where are you putting the biscuit? Also do you
glue the slot AND the biscuit or just the slot?
Regards,
Rumpty
"Charley" <[email protected]> wrote in message
news:[email protected]...
> OK Rumpty, now try it with a pine top and see what happens. I have the
> trouble with PINE tops, do a lot of colonial pine stuff here.
>
> --
I too have given up using glue on the biscuits in panel or tabletop
assembly. I've had 3 occasions where they showed in the finished work. These
panels were 3/4 pine and I had surface sanded them within 2 days of the
glue-up. Since the dimple isn't ever visible until sometime after the
project is completed, this has been a very disturbing situation for me
because it wasn't possible for me to go back and replace the defective
panels. I now glue only the board edges when I'm assembling panels and use
the biscuits dry, for alignment purposes only. If I build something that
requires a biscuit for strength I'll glue it, but I'm much more careful
about when and where I use the glue.
--
Charley
<[email protected]> wrote in message
news:[email protected]...
> In a dicussion at one of our woodworker group meetings, the issue of
> using
> biscuits for tabletops came up. I know this has been discussed
> in many ways, but not sure if this particular hint ever came up:
>
> The suggestion was to use biscuits as a LOCATING aid, vs
> as a glueup aid. Meaining don't put glue in/on the biscuits and
> the slots, leave them dry. Put glue along the edge and use
> that as the glue joint. The point being is that glue never seems
> to dry completely in the slots and that at some point (don't
> remember exactly what was said) the biscuit will shrink
> leaving a small dimple in the top. I know Norm
> has said he doesn't use biscuits anymore
> in tabletops because they telegraph through.
>
> Curious as to other experiences you might have had
> with biscuits and tabletops.
>
> I have some projects in the wind and will need to glue
> up some panels and want to use biscuits, but now
> I'm not sure. I've glued up panels with just a clean rip
> cut and dowels but thought biscuits were the way to
> go.
>
> Comments?
>
> MJ Wallace
>
In my shop I have spec'ed biscuits in tops for 23 years now and we don't
have complaints or problems. The first table I built 23 years ago with
biscuits sits in my office and as close as I look I can't see any problem
with the joint or the biscuit showing.
R
<[email protected]> wrote in message
news:[email protected]...
> In a dicussion at one of our woodworker group meetings, the issue of
> using
> biscuits for tabletops came up.
<[email protected]> wrote in message
news:[email protected]...
> In a dicussion at one of our woodworker group meetings, the issue of
> using
> biscuits for tabletops came up. I know this has been discussed
> in many ways, but not sure if this particular hint ever came up:
>
> The suggestion was to use biscuits as a LOCATING aid, vs
> as a glueup aid. Meaining don't put glue in/on the biscuits and
> the slots, leave them dry. Put glue along the edge and use
> that as the glue joint. The point being is that glue never seems
> to dry completely in the slots and that at some point (don't
> remember exactly what was said) the biscuit will shrink
> leaving a small dimple in the top. I know Norm
> has said he doesn't use biscuits anymore
> in tabletops because they telegraph through.
>
> Curious as to other experiences you might have had
> with biscuits and tabletops.
>
> I have some projects in the wind and will need to glue
> up some panels and want to use biscuits, but now
> I'm not sure. I've glued up panels with just a clean rip
> cut and dowels but thought biscuits were the way to
> go.
>
I have never seen it, even on very thin wood.
Some people say you should wait a day before sanding it give the wood a
chance to get back to normal after gluing; but that is true even without
biscuits. Otherwise you can show a slight slot at the glue line.
I probably have never sanded immediately just because of time requirements.
OK Rumpty, now try it with a pine top and see what happens. I have the
trouble with PINE tops, do a lot of colonial pine stuff here.
--
Charley
"Rumpty" <[email protected]> wrote in message
news:[email protected]...
> In my shop I have spec'ed biscuits in tops for 23 years now and we don't
> have complaints or problems. The first table I built 23 years ago with
> biscuits sits in my office and as close as I look I can't see any problem
> with the joint or the biscuit showing.
>
> R
>
>
> <[email protected]> wrote in message
> news:[email protected]...
> > In a dicussion at one of our woodworker group meetings, the issue of
> > using
> > biscuits for tabletops came up.
>
>