desktop seam support question
 

Still working on my new desk: http://www.delorie.com/wood/desk/

Today's question is about supporting the center section of the top.
The primary support will be along the seam, held together with draw
bolts (although there's an arch across the widest part to help reduce
sagging). I want something along the seam that will align the
sections vertically as well as support the center section. My
original idea was just biscuits, but now I'm thinking floating tenons
would be better. Comments? Ideas? Suggestions?

desktop seam support question
 

"DJ Delorie" wrote in message
...

Still working on my new desk: http://www.delorie.com/wood/desk/

Today's question is about supporting the center section of the top.
The primary support will be along the seam, held together with draw
bolts (although there's an arch across the widest part to help reduce
sagging). I want something along the seam that will align the
sections vertically as well as support the center section. My
original idea was just biscuits, but now I'm thinking floating tenons
would be better. Comments? Ideas? Suggestions?


My personal preference is to use dowels. - which I guess, is really a form
of floating tenon.

diggerop

desktop seam support question
 

DJ Delorie wrote:
Still working on my new desk: http://www.delorie.com/wood/desk/

Today's question is about supporting the center section of the top.
The primary support will be along the seam, held together with draw
bolts (although there's an arch across the widest part to help reduce
sagging). I want something along the seam that will align the
sections vertically as well as support the center section. My
original idea was just biscuits, but now I'm thinking floating tenons
would be better. Comments? Ideas? Suggestions?

I'd probably go w/ a groove/spline (essentially the tenon except
probably 3/4's the length of the edges. And, I'd add a ledge underneath
(as an add-on moulding, most likely) so it'll take somebody getting up
there to hang a picture in the corner, etc.

--

desktop seam support question
 

dpb writes:
And, I'd add a ledge underneath (as an add-on moulding, most likely)
so it'll take somebody getting up there to hang a picture in the
corner, etc.

The design includes a back leg and arched brace, hopefully that will
be enough. The top is 1" thick solid hardwood (one's oak, the other
desks are maple).

desktop seam support question
 

How about: Biscuits or dowels with no glue. 1" angle iron along the
seams. If you ever need to move it, it can be easily disassembled.

Sonny

desktop seam support question
 

I wasn't going to glue it anyway, hence the draw bolts.

Angle iron?

desktop seam support question
 

DJ Delorie wrote:
dpb writes:
And, I'd add a ledge underneath (as an add-on moulding, most likely)
so it'll take somebody getting up there to hang a picture in the
corner, etc.

The design includes a back leg and arched brace, hopefully that will
be enough. The top is 1" thick solid hardwood (one's oak, the other
desks are maple).

Just need to have enough beef in the support to handle the
unexpected--somebody, sometime _will_ look at that hunk of oak and say
"I don't need no steenkin' ladder to change this-there blulb in
that-there light!" or somesuch...

--

desktop seam support question
 

dpb writes:
Just need to have enough beef in the support to handle the
unexpected--somebody, sometime _will_ look at that hunk of oak and
say "I don't need no steenkin' ladder to change this-there blulb in
that-there light!" or somesuch...

That someobody will probably be me, too.

desktop seam support question
 

"DJ Delorie" wrote in message
...

Still working on my new desk: http://www.delorie.com/wood/desk/

Today's question is about supporting the center section of the top.
The primary support will be along the seam, held together with draw
bolts (although there's an arch across the widest part to help reduce
sagging). I want something along the seam that will align the
sections vertically as well as support the center section. My
original idea was just biscuits, but now I'm thinking floating tenons
would be better. Comments? Ideas? Suggestions?

DJ,

I built some "L" shaped craft benches a couple of years back that I
aligned the two sections using two #20 biscuits on each seam. No glue,
assembled them dry so when / if they have to take things apart, they
can. I used two 1/2" diameter draw bolts on each seam to hold things
together. These benches have taken a beating and the seams haven't
budged.

Other ideas will certainly work but "simple" usually works better than
some "over-engineered" ideas.

Bob S.

desktop seam support question
 

dpb wrote:
DJ Delorie wrote:
dpb writes:
And, I'd add a ledge underneath (as an add-on moulding, most likely)
so it'll take somebody getting up there to hang a picture in the
corner, etc.

The design includes a back leg and arched brace, hopefully that will
be enough. The top is 1" thick solid hardwood (one's oak, the other
desks are maple).

Just need to have enough beef in the support to handle the
unexpected--somebody, sometime _will_ look at that hunk of oak and say
"I don't need no steenkin' ladder to change this-there blulb in
that-there light!" or somesuch...

The question to ask is "would I screw my wife on this?". If not then it's
not strong enough.

desktop seam support question
 

My first thought is your going to get quite a bit of expansion and
contraction with that wide of a hardwood top and I would want to have a web
frame under the center section as well as the sides that provides support
and a way to connect that allows the top move; otherwise you risk it
cracking on you. You have the back side covered but appears nothing to tie
to in the front. Either a divider in the front or a complete top web frame
would be the direction I would head in.. I would also incorporate some
cross members into the web frame for attaching the keyboard tray.

"DJ Delorie" wrote in message
...

Still working on my new desk: http://www.delorie.com/wood/desk/

Today's question is about supporting the center section of the top.
The primary support will be along the seam, held together with draw
bolts (although there's an arch across the widest part to help reduce
sagging). I want something along the seam that will align the
sections vertically as well as support the center section. My
original idea was just biscuits, but now I'm thinking floating tenons
would be better. Comments? Ideas? Suggestions?

desktop seam support question
 

Thanks!

desktop seam support question
 

On 10 Nov 2009 14:38:37 -0500, DJ Delorie wrote:

sections vertically as well as support the center section. My
original idea was just biscuits, but now I'm thinking floating tenons
would be better. Comments? Ideas? Suggestions?

How about some angle iron, maybe 3/4" in size? It could start a few
inches back so it's not noticeable.

desktop seam support question
 

DJ Delorie writes:
Idea... it occurs to me I could make the seam with rabbets to create a
narrow lap joint, say 1/4 deep or so.

It occurred to me that the front intersection isn't straight, so this
type of seam would be messed up there :-(

desktop seam support question
 

DJ Delorie wrote:
Still working on my new desk: http://www.delorie.com/wood/desk/

Today's question is about supporting the center section of the top.
The primary support will be along the seam, held together with draw
bolts (although there's an arch across the widest part to help reduce
sagging). I want something along the seam that will align the
sections vertically as well as support the center section. My
original idea was just biscuits, but now I'm thinking floating tenons
would be better. Comments? Ideas? Suggestions?

Probably too low tech for you but I'd just add a board under the side
modules that extends, say, 3/4" past the top. The corner module would then
sit on those and be held to the side modules with the draw bolts (which
might need a smidge of updown wobble). Alternatively, a couple of
threaded inserts along the underside of each side of the center module,
bolts through the added boards into them; taper the center module edges
slightly downward for easy bolt insertion and a "just grew there" look when
snugged up.

That would add a new problem in as much as ends of the boards would be
visible. Two solutions...

1. Make them maybe only 2/3 - 3/4 as long as the side modules are wide. Not
totally invisible but unless someone is crawling around on the floor they
wouldn't be seen.

2. Put a keyboard tray or drawer under the center module. This would get my
vote.

--

dadiOH
____________________________

dadiOH's dandies v3.06...
....a help file of info about MP3s, recording from
LP/cassette and tips & tricks on this and that.
Get it at http://mysite.verizon.net/xico

desktop seam support question
 

DJ Delorie wrote:
DJ Delorie writes:
Idea... it occurs to me I could make the seam with rabbets to create
a narrow lap joint, say 1/4 deep or so.

It occurred to me that the front intersection isn't straight, so this
type of seam would be messed up there :-(

Why would it be messed up?

--

dadiOH
____________________________

dadiOH's dandies v3.06...
....a help file of info about MP3s, recording from
LP/cassette and tips & tricks on this and that.
Get it at http://mysite.verizon.net/xico

desktop seam support question
 

"dadiOH" writes:
Why would it be messed up?

Where the two sections meet is an inside corner. Any non-flat edge
would have to be coped into the other section.

desktop seam support question
 

DJ Delorie wrote:
"dadiOH" writes:
Why would it be messed up?

Where the two sections meet is an inside corner. Any non-flat edge
would have to be coped into the other section.

I must be missing someting...I can't see that what you drew (and, sorta,
what I proposed) would present any problems, inside corner or not. Cut
rabbet in each, from top on one, from bottom of other and lay it on. You
are "coped" automatically.

I've done exactly that many times.

--

dadiOH
____________________________

dadiOH's dandies v3.06...
....a help file of info about MP3s, recording from
LP/cassette and tips & tricks on this and that.
Get it at http://mysite.verizon.net/xico

desktop seam support question
 

dadiOH wrote:
DJ Delorie wrote:
"dadiOH" writes:
Why would it be messed up?
Where the two sections meet is an inside corner. Any non-flat edge
would have to be coped into the other section.

I must be missing someting...I can't see that what you drew (and, sorta,
what I proposed) would present any problems, inside corner or not. Cut
rabbet in each, from top on one, from bottom of other and lay it on. You
are "coped" automatically.

And, of course, if you were to choose to do that in this instance
structurally you'd want the rabbet to be on the top of the center piece
so the unbroken surface is on the bottom for maximum strength. The
problem w/ this is that it would require the edges be parallel or one
end to go in first followed by the other for assembly or putting one of
the two tops on after in place which wouldn't be all that convenient.

So, given the top is 1" material, the choice would be to make the rabbet
fairly shallow so there's a thick-enough lip to support the way and the
aforementioned unanticipated weight issues above.

Which, all in all, is why I suggested the moulding as the primary
support and the spline to serve as the alignment initially...

--

desktop seam support question
 

"dadiOH" writes:
I must be missing someting...I can't see that what you drew

See photo: http://www.delorie.com/wood/desk/

Where the top sections meet at the seams, is where the desk turns the
corner. Which means I'd have to cut 22.5 degree angles in the parts
of the rabbets that go past the seam.

desktop seam support question
 

DJ Delorie wrote:
"dadiOH" writes:
I must be missing someting...I can't see that what you drew

See photo: http://www.delorie.com/wood/desk/

Where the top sections meet at the seams, is where the desk turns the
corner. Which means I'd have to cut 22.5 degree angles in the parts
of the rabbets that go past the seam.

So?

I'll reiterate after looking at the drawings again -- continue the front
moulding around the corner (mitered, of course) and it'll be all the
vertical support you need. And, doing so would really dress-up that
plain facing end, as well.

--

desktop seam support question
 

dpb writes:
I'll reiterate after looking at the drawings again -- continue the
front moulding around the corner (mitered, of course)

There is no front moulding, the top is solid slabs of hardwood. The
bits of trim you see at the top of each cabinet is just that - bits of
trim on the cabinets.

desktop seam support question
 

DJ Delorie wrote:
dpb writes:
I'll reiterate after looking at the drawings again -- continue the
front moulding around the corner (mitered, of course)

There is no front moulding, the top is solid slabs of hardwood. The
bits of trim you see at the top of each cabinet is just that - bits of
trim on the cabinets.

That's what I'm talking about--that's an applied moulding.

--

desktop seam support question
 

dpb wrote:
....
That's what I'm talking about--that's an applied moulding.
...so continue it around the sides of the pedestals and you've got your
support for the sides of the center section and a much nicer-looking end
panel on the end panel.

--

desktop seam support question
 

Hey DJ.. To me the most important consideration is expansion and
contraction of that hardwood top. The center section will expand and
contract across the grain towards the chair and as it does so the mitered
joints between the top sections will expand and contract a bit also... much
like any other mitered joint if it is not securely connected to the
adjoining part in some manner. If you simple use a lap joint and do not
fasten the pieces together, I'm pretty sure the seam will open with change
in humidity and season. To me, it seems necessary to securely connect the
top pieces together so this won't happen. Draw bolts with biscuits for
alignment as you suggested sounds to me like a very good way to accomplish
that. Basically you then have one tabletop and not three pieces. Since its
solid wood you can't just screw base cabinets to the top and not allow it to
expand and contract naturally or you risk the stress causing the top to
crack. So you need to build a framework, like a web frame, into the top of
the cabinets, and possibly but not necessarily, between the cabinets, that
will support the top and allow you to connect the two in a way that won't
prevent the top from expansion and contraction. There's a variety of ways
to fasten the top... wooden buttons, metal fasteners, so on. The top
basically floats on the cabinets. I think if you keep these considerations
in mind you can figure this out for yourself..


"DJ Delorie" wrote in message
...

Still working on my new desk: http://www.delorie.com/wood/desk/

Today's question is about supporting the center section of the top.
The primary support will be along the seam, held together with draw
bolts (although there's an arch across the widest part to help reduce
sagging). I want something along the seam that will align the
sections vertically as well as support the center section. My
original idea was just biscuits, but now I'm thinking floating tenons
would be better. Comments? Ideas? Suggestions?