Box joints for hanging cabinet

On Monday, February 17, 2020 at 7:25:49 PM UTC-6, Robbie Brusso wrote:
> Thanks J. So should I use box joints for joining the top and sides and a dado for the bottom? There's no real rhyme or reason for my design, I just wanted to try a new join.

Bathroom cabinets made with box joints for aesthetic reasons are fairly standard, are they not?

Awesome - thanks for your help!

On 2/19/2020 5:35 PM, DerbyDad03 wrote:
> On Wednesday, February 19, 2020 at 4:53:57 PM UTC-5, Scott Lurndal wrote:
>> John McGaw <[email protected]> writes:
>>> On 2/19/2020 12:20 PM, Scott Lurndal wrote:
>>>> John McGaw <[email protected]> writes:
>>>>> On 2/18/2020 4:21 PM, Leon wrote:
>>>>>> On 2/18/2020 1:06 PM, Robbie Brusso wrote:
>>>>>>> The french cleat idea is a great one (and one I'll likely use instead of
>>>>>>> my idea of a nailer inside the cabinet). Would it be considered sacrilege
>>>>>>> to put a brad into the box joints? Would it risk splitting?
>>>>>>>
>>>>>>
>>>>>>
>>>>>>
>>>>>> Keep in mind that a French cleat, to be the safest install, still needs a
>>>>>> screw or two to hold it into position.  The cabinet could be pulled out
>>>>>> from the wall and fall if not permanently fastened.  That said the French
>>>>>> cleat is still a good way for one person to hang a cabinet.  This is not
>>>>>> furniture so screws, brads, etc are acceptable.
>>>>>
>>>>> I don't see why you couldn't use a brad or a nail or a screw in the box
>>>>> joint.
>>>>
>>>> A tightly fitting, correctly glued box joint should be stronger than
>>>> the wood around it. I don't see the necessity of additional reinforcement.
>>>>
>>> Assuming that the joint is fitted well and the glue involved is guaranteed
>>> to never creep under constant load then reinforcement is not needed.
>>
>> Even if it creeps- how long would it take for 12 inches of 3/4" box joints
>> on a 3/4" stock to creep enough that you can even see a gap? Considering
>> the number of faces glued to each other, I suspect that would take centuries.
>
> Scott,
>
> This cabinet is going above a toilet. Those glue joints may need to support
> multiple rolls of toilet paper. If the OP uses 2-ply paper, there will be
> substantial sheer force on those joints. The creep might be an issue in a
> relatively short amount of time, maybe a couple of eons at most. ;-)
>

I would be more concerned with the 2 ply paper sheer resistance to a
middle finger poking through. ;~)

On 2/19/2020 11:50 AM, John McGaw wrote:
> On 2/19/2020 12:20 PM, Scott Lurndal wrote:
>> John McGaw <[email protected]> writes:
>>> On 2/18/2020 4:21 PM, Leon wrote:
>>>> On 2/18/2020 1:06 PM, Robbie Brusso wrote:
>>>>> The french cleat idea is a great one (and one I'll likely use
>>>>> instead of
>>>>> my idea of a nailer inside the cabinet). Would it be considered
>>>>> sacrilege
>>>>> to put a brad into the box joints? Would it risk splitting?
>>>>>
>>>>
>>>>
>>>>
>>>> Keep in mind that a French cleat, to be the safest install, still
>>>> needs a
>>>> screw or two to hold it into position.  The cabinet could be pulled
>>>> out
>>>> from the wall and fall if not permanently fastened.  That said the
>>>> French
>>>> cleat is still a good way for one person to hang a cabinet.  This
>>>> is not
>>>> furniture so screws, brads, etc are acceptable.
>>>
>>> I don't see why you couldn't use a brad or a nail or a screw in the box
>>> joint.
>>
>> A tightly fitting, correctly glued box joint should be stronger than
>> the wood around it.   I don't see the necessity of additional
>> reinforcement.
>>
> Assuming that the joint is fitted well and the glue involved is
> guaranteed to never creep under constant load then reinforcement is not
> needed.

I don't use glue that is guaranteed not to creep. In 40 years of
serious woodworking I have never had an issue with creep. I only see it
when gluing 2 pieces of wood that expand in different directions. The
joint is still rock solid but now, 10 year, later I can feel the joint.

Glue creep is IMHO something that happens but is not an issue for an
application like the OP is concerned about. Kinda falls under the
assumption that clamping too tightly will starve a joint of glue. Again
nothing I have ever witnessed. The strongest glue line is a thin glue line.


>
> I don't see the necessity of security blankets but if it makes the OP
> feel better about it, what is the harm? I back my computers up to three
> different destinations and keep copies of my data in a bank vault.
> Necessary? Maybe not but it lets me sleep better at night.
>

Agreed but one could have 5 different destinations and be even safer.
You learn what is necessary and what is not with experience.

On Tuesday, February 18, 2020 at 1:06:09 PM UTC-6, Robbie Brusso wrote:
> The french cleat idea is a great one (and one I'll likely use instead of my idea of a nailer inside the cabinet). Would it be considered sacrilege to put a brad into the box joints? Would it risk splitting?

Maybe drill a 1/8 hole and drive in a 1/8 dowel.

Thanks J. So should I use box joints for joining the top and sides and a dado for the bottom? There's no real rhyme or reason for my design, I just wanted to try a new join.

The french cleat idea is a great one (and one I'll likely use instead of my idea of a nailer inside the cabinet). Would it be considered sacrilege to put a brad into the box joints? Would it risk splitting?

On Monday, February 17, 2020 at 6:37:09 PM UTC-6, Robbie Brusso wrote:
> I had planned on using box joints to build the frame of a hanging cabinet=
(top, bottom, sides). However, I'm starting to wonder about the weight bea=
ring ability of the bottom frame member. The tapers of a dovetail would mak=
e me feel a little better but with a box joint I wonder about the load bear=
ing ability of the bottom member. Thoughts?

Well made box joints will easily hold up the weight and then some.

On Tuesday, February 18, 2020 at 1:06:09 PM UTC-6, Robbie Brusso wrote:
> The french cleat idea is a great one (and one I'll likely use instead of my idea of a nailer inside the cabinet). Would it be considered sacrilege to put a brad into the box joints? Would it risk splitting?

Here's Norm making a medicine cabinet using box joints. You'll need the required belt sander and brad nailer.

https://www.youtube.com/watch?v=z2FEthi8X64

On 2/18/2020 1:06 PM, Robbie Brusso wrote:
> The french cleat idea is a great one (and one I'll likely use instead of my idea of a nailer inside the cabinet). Would it be considered sacrilege to put a brad into the box joints? Would it risk splitting?
>



Keep in mind that a French cleat, to be the safest install, still needs
a screw or two to hold it into position. The cabinet could be pulled
out from the wall and fall if not permanently fastened. That said the
French cleat is still a good way for one person to hang a cabinet. This
is not furniture so screws, brads, etc are acceptable.

John McGaw <[email protected]> writes:
>On 2/18/2020 4:21 PM, Leon wrote:
>> On 2/18/2020 1:06 PM, Robbie Brusso wrote:
>>> The french cleat idea is a great one (and one I'll likely use instead of
>>> my idea of a nailer inside the cabinet). Would it be considered sacrilege
>>> to put a brad into the box joints? Would it risk splitting?
>>>
>>
>>
>>
>> Keep in mind that a French cleat, to be the safest install, still needs a
>> screw or two to hold it into position.  The cabinet could be pulled out
>> from the wall and fall if not permanently fastened.  That said the French
>> cleat is still a good way for one person to hang a cabinet.  This is not
>> furniture so screws, brads, etc are acceptable.
>
>I don't see why you couldn't use a brad or a nail or a screw in the box
>joint.

A tightly fitting, correctly glued box joint should be stronger than
the wood around it. I don't see the necessity of additional reinforcement.

On 2/17/2020 6:37 PM, Robbie Brusso wrote:
> I had planned on using box joints to build the frame of a hanging cabinet (top, bottom, sides). However, I'm starting to wonder about the weight bearing ability of the bottom frame member. The tapers of a dovetail would make me feel a little better but with a box joint I wonder about the load bearing ability of the bottom member. Thoughts?
>


Whaaat?

Frame of a cabinet? Is that the face frame you are talking about? Or
are you you talking about the carcass?

On 2/18/2020 4:41 PM, DerbyDad03 wrote:
> On Tuesday, February 18, 2020 at 11:08:34 AM UTC-5, Leon wrote:
>> On 2/17/2020 7:20 PM, Robbie Brusso wrote:
>>> Haha sorry for the confusion - I guess my concern is the cabinet floor (bottom of the cabinet). I've usually just used pocket holes and joined to the sides that way. However I wanted to use box joints this time. But then I started to wonder if glue alone would secure the bottom of the cabinet to the sides. If it helps at all, this is a wall mounted cabinet that will go above a toilet in a bathroom.
>>>
>>
>> As long as you are "not" only using glue with a butt joint you should
>> have a relatively strong joint.
>>
>> Normally the bottom fits into a dado on each side. And a face frame, if
>> you will be using that too, will add strength.
>>
>
> Don't you mean 2 face frames? ;-)
>


I doubt he is building how I do. :~)

John McGaw <[email protected]> writes:
>On 2/19/2020 12:20 PM, Scott Lurndal wrote:
>> John McGaw <[email protected]> writes:
>>> On 2/18/2020 4:21 PM, Leon wrote:
>>>> On 2/18/2020 1:06 PM, Robbie Brusso wrote:
>>>>> The french cleat idea is a great one (and one I'll likely use instead of
>>>>> my idea of a nailer inside the cabinet). Would it be considered sacrilege
>>>>> to put a brad into the box joints? Would it risk splitting?
>>>>>
>>>>
>>>>
>>>>
>>>> Keep in mind that a French cleat, to be the safest install, still needs a
>>>> screw or two to hold it into position.  The cabinet could be pulled out
>>>> from the wall and fall if not permanently fastened.  That said the French
>>>> cleat is still a good way for one person to hang a cabinet.  This is not
>>>> furniture so screws, brads, etc are acceptable.
>>>
>>> I don't see why you couldn't use a brad or a nail or a screw in the box
>>> joint.
>>
>> A tightly fitting, correctly glued box joint should be stronger than
>> the wood around it. I don't see the necessity of additional reinforcement.
>>
>Assuming that the joint is fitted well and the glue involved is guaranteed
>to never creep under constant load then reinforcement is not needed.

Even if it creeps- how long would it take for 12 inches of 3/4" box joints
on a 3/4" stock to creep enough that you can even see a gap? Considering
the number of faces glued to each other, I suspect that would take centuries.

On 2/17/2020 7:20 PM, Robbie Brusso wrote:
> Haha sorry for the confusion - I guess my concern is the cabinet floor (bottom of the cabinet). I've usually just used pocket holes and joined to the sides that way. However I wanted to use box joints this time. But then I started to wonder if glue alone would secure the bottom of the cabinet to the sides. If it helps at all, this is a wall mounted cabinet that will go above a toilet in a bathroom.
>

As long as you are "not" only using glue with a butt joint you should
have a relatively strong joint.

Normally the bottom fits into a dado on each side. And a face frame, if
you will be using that too, will add strength.

If you want a clean look, box joints, and or DT joints will be plenty
strong.

Alternatively, biscuits, Domino's to reinforce butt joints will work
well too.

On 2/17/2020 8:20 PM, J. Clarke wrote:
> On Mon, 17 Feb 2020 16:46:21 -0800 (PST), Michael
> <[email protected]> wrote:
>
>> On Monday, February 17, 2020 at 6:37:09 PM UTC-6, Robbie Brusso wrote:
>>> I had planned on using box joints to build the frame of a hanging cabinet (top, bottom, sides). However, I'm starting to wonder about the weight bearing ability of the bottom frame member. The tapers of a dovetail would make me feel a little better but with a box joint I wonder about the load bearing ability of the bottom member. Thoughts?
>>
>> Well made box joints will easily hold up the weight and then some.
>
> If it's the bottom, you're loading a glue line in shear. If you are
> using a glue that absolutely positively does not creep (which lets out
> just about any PVA glue) you might be OK. But that's what dado joints
> are made for.
>

The cabinet will be suspended by what? The top, as in a French cleat or
will there be some sort of support from the sides? Will the weight of the
contents be supported by the sides or will everything be sitting in the
bottom? All of that matters a lot. Personally, I don't screw around and use
dovetails all-round as my preferred method of support is via French cleat
which applies much of its force to the top (and a little to the back and
sides but that eventually gets applied to the top too).

Not the most inspiring piece ever but this is my first try at a wall-hung
display case. It uses half-blind dovetails to join top/bottom to sides:

http://johnmcgaw.com/ww/furniture24.html

--
Bodger's Dictum: Artifical intelligence
can never overcome natural stupidity.

On Wednesday, February 19, 2020 at 4:53:57 PM UTC-5, Scott Lurndal wrote:
> John McGaw <[email protected]> writes:
> >On 2/19/2020 12:20 PM, Scott Lurndal wrote:
> >> John McGaw <[email protected]> writes:
> >>> On 2/18/2020 4:21 PM, Leon wrote:
> >>>> On 2/18/2020 1:06 PM, Robbie Brusso wrote:
> >>>>> The french cleat idea is a great one (and one I'll likely use inste=
ad of
> >>>>> my idea of a nailer inside the cabinet). Would it be considered sac=
rilege
> >>>>> to put a brad into the box joints? Would it risk splitting?
> >>>>>
> >>>>
> >>>>
> >>>>
> >>>> Keep in mind that a French cleat, to be the safest install, still ne=
eds a
> >>>> screw or two to hold it into position.=C3=82=C2=A0 The cabinet could=
be pulled out
> >>>> from the wall and fall if not permanently fastened.=C3=82=C2=A0 That=
said the French
> >>>> cleat is still a good way for one person to hang a cabinet.=C3=82=C2=
=A0 This is not
> >>>> furniture so screws, brads, etc are acceptable.
> >>>
> >>> I don't see why you couldn't use a brad or a nail or a screw in the b=
ox
> >>> joint.
> >>=20
> >> A tightly fitting, correctly glued box joint should be stronger than
> >> the wood around it. I don't see the necessity of additional reinforc=
ement.
> >>
> >Assuming that the joint is fitted well and the glue involved is guarante=
ed=20
> >to never creep under constant load then reinforcement is not needed.
>=20
> Even if it creeps- how long would it take for 12 inches of 3/4" box joint=
s
> on a 3/4" stock to creep enough that you can even see a gap? Considerin=
g
> the number of faces glued to each other, I suspect that would take centur=
ies.

Scott,

This cabinet is going above a toilet. Those glue joints may need to support
multiple rolls of toilet paper. If the OP uses 2-ply paper, there will be=
=20
substantial sheer force on those joints. The creep might be an issue in a
relatively short amount of time, maybe a couple of eons at most. ;-)

On Mon, 17 Feb 2020 16:46:21 -0800 (PST), Michael
<[email protected]> wrote:

>On Monday, February 17, 2020 at 6:37:09 PM UTC-6, Robbie Brusso wrote:
>> I had planned on using box joints to build the frame of a hanging cabinet (top, bottom, sides). However, I'm starting to wonder about the weight bearing ability of the bottom frame member. The tapers of a dovetail would make me feel a little better but with a box joint I wonder about the load bearing ability of the bottom member. Thoughts?
>
>Well made box joints will easily hold up the weight and then some.

If it's the bottom, you're loading a glue line in shear. If you are
using a glue that absolutely positively does not creep (which lets out
just about any PVA glue) you might be OK. But that's what dado joints
are made for.

On Tuesday, February 18, 2020 at 11:08:34 AM UTC-5, Leon wrote:
> On 2/17/2020 7:20 PM, Robbie Brusso wrote:
> > Haha sorry for the confusion - I guess my concern is the cabinet floor =
(bottom of the cabinet). I've usually just used pocket holes and joined to =
the sides that way. However I wanted to use box joints this time. But then =
I started to wonder if glue alone would secure the bottom of the cabinet to=
the sides. If it helps at all, this is a wall mounted cabinet that will go=
above a toilet in a bathroom.
> >=20
>=20
> As long as you are "not" only using glue with a butt joint you should=20
> have a relatively strong joint.
>=20
> Normally the bottom fits into a dado on each side. And a face frame, if=
=20
> you will be using that too, will add strength.
>=20

Don't you mean 2 face frames? ;-)

Haha sorry for the confusion - I guess my concern is the cabinet floor (bot=
tom of the cabinet). I've usually just used pocket holes and joined to the =
sides that way. However I wanted to use box joints this time. But then I st=
arted to wonder if glue alone would secure the bottom of the cabinet to the=
sides. If it helps at all, this is a wall mounted cabinet that will go abo=
ve a toilet in a bathroom.

On Mon, 17 Feb 2020 17:20:40 -0800 (PST), Robbie Brusso
<[email protected]> wrote:

>Haha sorry for the confusion - I guess my concern is the cabinet floor (bottom of the cabinet). I've usually just used pocket holes and joined to the sides that way. However I wanted to use box joints this time. But then I started to wonder if glue alone would secure the bottom of the cabinet to the sides. If it helps at all, this is a wall mounted cabinet that will go above a toilet in a bathroom.

Use a dado. If the bottom lets go and drops Madame's whatever was on
the botttom shelf in the toilet you'll never hear the end of it. If
it bonks Madame on the head in the process you might wish you had
constructed a heated doghouse instead.

On 2/18/2020 6:21 PM, John McGaw wrote:
> On 2/18/2020 4:21 PM, Leon wrote:
>> On 2/18/2020 1:06 PM, Robbie Brusso wrote:
>>> The french cleat idea is a great one (and one I'll likely use instead
>>> of my idea of a nailer inside the cabinet). Would it be considered
>>> sacrilege to put a brad into the box joints? Would it risk splitting?
>>>
>>
>>
>>
>> Keep in mind that a French cleat, to be the safest install, still
>> needs a screw or two to hold it into position.  The cabinet could be
>> pulled out from the wall and fall if not permanently fastened.  That
>> said the French cleat is still a good way for one person to hang a
>> cabinet.  This is not furniture so screws, brads, etc are acceptable.
>
> I don't see why you couldn't use a brad or a nail or a screw in the box
> joint. I've done it with pegs in both box and dovetail joints in drawers
> when I was concerned about wear over years of use. There are so many
> ways to join wood in an application like this and so many variations
> that could be applied to each that one could spend a lifetime trying
> them all out (if you work as slowly as I do, anyway). Here is an
> old-school way of doing pegged box joints although using rectangular
> ebony pegs is kind of out there if you are looking for simple:
>
> https://www.finewoodworking.com/readerproject/2009/01/18/tool-tote
>
> Done properly is is very pretty, you must admit.
>
I think pegging of the joint is best described in your last sentence. I
think for any other reason may be overkill. There is a LOT of glue
surface in a box joint, triple, IIRC.

On Mon, 17 Feb 2020 17:25:46 -0800 (PST), Robbie Brusso
<[email protected]> wrote:

>Thanks J. So should I use box joints for joining the top and sides and a dado for the bottom? There's no real rhyme or reason for my design, I just wanted to try a new join.

That's reasonable.

On Wednesday, February 19, 2020 at 9:50:15 AM UTC-8, John McGaw wrote:
> On 2/19/2020 12:20 PM, Scott Lurndal wrote:
> > John McGaw <[email protected]> writes:

> > A tightly fitting, correctly glued box joint should be stronger than
> > the wood around it. I don't see the necessity of additional reinforcement.
> >
> Assuming that the joint is fitted well and the glue involved is guaranteed
> to never creep under constant load then reinforcement is not needed.

It's hard to be sure that a cross-grain joint (box joint) won't be stressed, internally,
by wood movement in addition to a constant load stress. That makes it a little
less certain than a dovetail (where some wood could do brittle breakage), and
a lot less certain than a dado (where a 12" shelf has a half inch under its dado socket)
that must make a 12" long check that splits 6 square inches of wood faces.

For what it's worth, old box joints do NOT stand up; hide glue gets eaten by fungus,
in about 150 years...

On 2/18/2020 4:21 PM, Leon wrote:
> On 2/18/2020 1:06 PM, Robbie Brusso wrote:
>> The french cleat idea is a great one (and one I'll likely use instead of
>> my idea of a nailer inside the cabinet). Would it be considered sacrilege
>> to put a brad into the box joints? Would it risk splitting?
>>
>
>
>
> Keep in mind that a French cleat, to be the safest install, still needs a
> screw or two to hold it into position.  The cabinet could be pulled out
> from the wall and fall if not permanently fastened.  That said the French
> cleat is still a good way for one person to hang a cabinet.  This is not
> furniture so screws, brads, etc are acceptable.

I don't see why you couldn't use a brad or a nail or a screw in the box
joint. I've done it with pegs in both box and dovetail joints in drawers
when I was concerned about wear over years of use. There are so many ways
to join wood in an application like this and so many variations that could
be applied to each that one could spend a lifetime trying them all out (if
you work as slowly as I do, anyway). Here is an old-school way of doing
pegged box joints although using rectangular ebony pegs is kind of out
there if you are looking for simple:

https://www.finewoodworking.com/readerproject/2009/01/18/tool-tote

Done properly is is very pretty, you must admit.

--
Bodger's Dictum: Artifical intelligence
can never overcome natural stupidity.

On 2/19/2020 12:20 PM, Scott Lurndal wrote:
> John McGaw <[email protected]> writes:
>> On 2/18/2020 4:21 PM, Leon wrote:
>>> On 2/18/2020 1:06 PM, Robbie Brusso wrote:
>>>> The french cleat idea is a great one (and one I'll likely use instead of
>>>> my idea of a nailer inside the cabinet). Would it be considered sacrilege
>>>> to put a brad into the box joints? Would it risk splitting?
>>>>
>>>
>>>
>>>
>>> Keep in mind that a French cleat, to be the safest install, still needs a
>>> screw or two to hold it into position.  The cabinet could be pulled out
>>> from the wall and fall if not permanently fastened.  That said the French
>>> cleat is still a good way for one person to hang a cabinet.  This is not
>>> furniture so screws, brads, etc are acceptable.
>>
>> I don't see why you couldn't use a brad or a nail or a screw in the box
>> joint.
>
> A tightly fitting, correctly glued box joint should be stronger than
> the wood around it. I don't see the necessity of additional reinforcement.
>
Assuming that the joint is fitted well and the glue involved is guaranteed
to never creep under constant load then reinforcement is not needed.

I don't see the necessity of security blankets but if it makes the OP feel
better about it, what is the harm? I back my computers up to three
different destinations and keep copies of my data in a bank vault.
Necessary? Maybe not but it lets me sleep better at night.

--
Bodger's Dictum: Artifical intelligence
can never overcome natural stupidity.

On 2/17/2020 8:20 PM, Robbie Brusso wrote:
> Haha sorry for the confusion - I guess my concern is the cabinet floor (bottom of the cabinet). I've
usually just used pocket holes and joined to the sides that way. However
I wanted to use box joints this time. But then I started to wonder if
glue alone would secure the bottom of the cabinet to the sides. If it
helps at all, this is a wall mounted cabinet that will go above a toilet
in a bathroom.
>
Box joints are more than strong enough for this purpose. You're wringing
your hands for nothing. If you're thinking the glue will fail, (it
won't) you could pin them with a dowel which will even enhance the
esthetics of the joint. My first workbench with drawers I built the
drawers this way (45 years ago), before I realized how strong glue was.
Box joints have lots of good gluing surface, making the joint very
strong. MUCH stronger than pocket hole joints.

--
Jack
In Youth we Learn; In Age we Understand

On 2/18/2020 7:28 AM, Jack wrote:
> On 2/17/2020 8:20 PM, Robbie Brusso wrote:
>> Haha sorry for the confusion - I guess my concern is the cabinet floor=
=20
>> (bottom of the cabinet). I've
> usually just used pocket holes and joined to the sides that way. Howeve=
r=20
> I wanted to use box joints this time. But then I started to wonder if=20
> glue alone would secure the bottom of the cabinet to the sides. If it=20
> helps at all, this is a wall mounted cabinet that will go above a toile=
t=20
> in a bathroom.
>>
> Box joints are more than strong enough for this purpose. You're wringin=
g=20
> your hands for nothing.=C2=A0 If you're thinking the glue will fail, (i=
t=20
> won't) you could pin them with a dowel which will even enhance the=20
> esthetics of the joint.=C2=A0 My first workbench with drawers I built t=
he=20
> drawers this way (45 years ago), before I realized how strong glue was.=
=20
> =C2=A0Box joints have lots of good gluing surface, making the joint ve=
ry=20
> strong. MUCH stronger than pocket hole joints.
>=20
I think if you do some research in many cases glue joints are stronger=20
that the wood that they are holding together.

On 2/18/2020 1:06 PM, Robbie Brusso wrote:
> ...Would it be considered sacrilege to put a brad into the box joints? ...

Only 'til the glue dries.

--

On Tue, 18 Feb 2020 12:53:56 -0500, John McGaw <[email protected]>
wrote:

>On 2/17/2020 8:20 PM, J. Clarke wrote:
>> On Mon, 17 Feb 2020 16:46:21 -0800 (PST), Michael
>> <[email protected]> wrote:
>>
>>> On Monday, February 17, 2020 at 6:37:09 PM UTC-6, Robbie Brusso wrote:
>>>> I had planned on using box joints to build the frame of a hanging cabinet
>>>>(top, bottom, sides). However, I'm starting to wonder about the weight bearing
>>>> ability of the bottom frame member. The tapers of a dovetail would make
>>>> me feel a little better but with a box joint I wonder about the
>>>> load bearing ability of the bottom member. Thoughts?
>>>
>>> Well made box joints will easily hold up the weight and then some.
>>
>> If it's the bottom, you're loading a glue line in shear. If you are
>> using a glue that absolutely positively does not creep (which lets out
>> just about any PVA glue) you might be OK. But that's what dado joints
>> are made for.
>>
>
>The cabinet will be suspended by what? The top, as in a French cleat or
>will there be some sort of support from the sides? Will the weight of the
>contents be supported by the sides or will everything be sitting in the
>bottom? All of that matters a lot. Personally, I don't screw around and use
>dovetails all-round as my preferred method of support is via French cleat
>which applies much of its force to the top (and a little to the back and
>sides but that eventually gets applied to the top too).
>Not the most inspiring piece ever but this is my first try at a wall-hung
>display case. It uses half-blind dovetails to join top/bottom to sides:
>http://johnmcgaw.com/ww/furniture24.html
>

Yours made me think of a way OP could still use his box joints -
attach a second bottom or moulding to make it look like it's
trimmed on 3 edges but actually screwed up into the sides
for a little extra strength ? .. might make the box joints look odd
though ... out-of-place ..
John T.

On Tue, 18 Feb 2020 08:21:58 -0500, knuttle
<[email protected]> wrote:

>On 2/18/2020 7:28 AM, Jack wrote:
>> On 2/17/2020 8:20 PM, Robbie Brusso wrote:
>>> Haha sorry for the confusion - I guess my concern is the cabinet floor
>>> (bottom of the cabinet). I've
>> usually just used pocket holes and joined to the sides that way. However
>> I wanted to use box joints this time. But then I started to wonder if
>> glue alone would secure the bottom of the cabinet to the sides. If it
>> helps at all, this is a wall mounted cabinet that will go above a toilet
>> in a bathroom.
>>>
>> Box joints are more than strong enough for this purpose. You're wringing
>> your hands for nothing.  If you're thinking the glue will fail, (it
>> won't) you could pin them with a dowel which will even enhance the
>> esthetics of the joint.  My first workbench with drawers I built the
>> drawers this way (45 years ago), before I realized how strong glue was.
>>  Box joints have lots of good gluing surface, making the joint very
>> strong. MUCH stronger than pocket hole joints.
>>
>I think if you do some research in many cases glue joints are stronger
>that the wood that they are holding together.

They are and aren't. If you glue a couple of pieces of wood together
and then bust the joint, it will fail in the wood. However if you
take the same two pieces, hang them by a hole in one and hang a weight
on the other, so the glue is loaded in shear, you may find that after
a while they have come apart. It's called "creep"--slow movement of a
joint loaded in shear under continuous stress.

On 2/18/2020 1:54 PM, [email protected] wrote:
> On Tue, 18 Feb 2020 12:53:56 -0500, John McGaw <[email protected]>
> wrote:
>
>> On 2/17/2020 8:20 PM, J. Clarke wrote:
>>> On Mon, 17 Feb 2020 16:46:21 -0800 (PST), Michael
>>> <[email protected]> wrote:
>>>
>>>> On Monday, February 17, 2020 at 6:37:09 PM UTC-6, Robbie Brusso wrote:
>>>>> I had planned on using box joints to build the frame of a hanging cabinet
>>>>> (top, bottom, sides). However, I'm starting to wonder about the weight bearing
>>>>> ability of the bottom frame member. The tapers of a dovetail would make
>>>>> me feel a little better but with a box joint I wonder about the
>>>>> load bearing ability of the bottom member. Thoughts?
>>>>
>>>> Well made box joints will easily hold up the weight and then some.
>>>
>>> If it's the bottom, you're loading a glue line in shear. If you are
>>> using a glue that absolutely positively does not creep (which lets out
>>> just about any PVA glue) you might be OK. But that's what dado joints
>>> are made for.
>>>
>>
>> The cabinet will be suspended by what? The top, as in a French cleat or
>> will there be some sort of support from the sides? Will the weight of the
>> contents be supported by the sides or will everything be sitting in the
>> bottom? All of that matters a lot. Personally, I don't screw around and use
>> dovetails all-round as my preferred method of support is via French cleat
>> which applies much of its force to the top (and a little to the back and
>> sides but that eventually gets applied to the top too).
>> Not the most inspiring piece ever but this is my first try at a wall-hung
>> display case. It uses half-blind dovetails to join top/bottom to sides:
>> http://johnmcgaw.com/ww/furniture24.html
>>
>
> Yours made me think of a way OP could still use his box joints -
> attach a second bottom or moulding to make it look like it's
> trimmed on 3 edges but actually screwed up into the sides
> for a little extra strength ? .. might make the box joints look odd
> though ... out-of-place ..
> John T.
>

I'm sure that we could figure out a score of different joining methods and,
with the right materials and workmanship, any of them would probably do the
job as long as the cabinet wasn't going to be used to hold vast weights.
And molding and trim can cover a multitude of sins so that even unsightly
joints could be forgiven. Guess it all depends on what the OP has to work
with more than anything else.

When I made mine I was working with material salvaged from a kitchen
demolition so almost anything goes. I used blind dovetails because I have
the jig and the resulting joint is pretty much indestructible as well as
invisible.

--
Bodger's Dictum: Artifical intelligence
can never overcome natural stupidity.