I'm in the process of replacing one set of DIY'd desks (wall-to-wall
computer desks) with a new, "better" pair.

I've previously seen (and was tempted by) pre-made oak desk-tops, formed
by glueing several PSE boards together with a double row of biscuits.
This seemed like a good idea, so I trotted down to the local timber
merchants to price up oak, and other hardwoods, in order to do the same
(cost of delivery of the pre-mades being the major factor, here, plus,
I've fancied dabbling with a bit of woodwork for a while).

Now, whilst chatting to the guy at the timberyard, who suggested he used
to do "a lot of this" in a previous life, he suggested that he would
never use biscuits because... (at this point, his quiet nature, the
sound of the timber yard, my age-induced deafness and nack of
interrupting at inopportune times) meant I missed the whole explanation,
but it centred around some argument of the strength of the glued joint
being so much more than the strength of the wood...

Can anyone explain in a more clear way (to me) the rationale behind this?

As an alternative approach, he suggested (I think the phrase was...) a
false tongue using a hard-wood fillet (using a circular/table saw to cut
a groove along each edge of the boards, and inserting (and presumably
glueing) a hard-wood insert to form the tongue.... ASCII art alert:-


########## =========
####### +++++ ======
########## =========

# : 1st board
= : 2nd board
+ : fillet


Which would require me to knock up a jig for doing this (or borrowing my
dad's table-saw.... there's an idea)


....or... to use a rebate joint, glued...

############## =========
############## =========
####### =================
####### =================

Which I could do easily enough with a router, I'm sure.


Now, the false tongue - I can understand, although is it not simply a
"very long biscuit"?, so why's this preferable to a double-row of biscuits?

The rebate joint just... I dunno... doesn't feel right - it relies
completely on the strength of the glue bond to provide the strong
work-surface needed for a desk-top.

Any comments? (would be gratefully received - it's a lot of expensive
wood that I'm about to start molesting, and this is my first experiment
beyond pine/soft-wood)

Mike

"Mike Dodd" wrote in message
...
I'm in the process of replacing one set of DIY'd desks (wall-to-wall
computer desks) with a new, "better" pair.

Any comments? Mike

Yes, what is it you are asking? No need for a lecture, speech,
extracts of conversations with yourself or sentences interrupted by
brackets.

Do you just want to know how to join pieces of wood?

Ian wrote:
"Mike Dodd" wrote in message
...
I'm in the process of replacing one set of DIY'd desks (wall-to-wall
computer desks) with a new, "better" pair.

Any comments? Mike

Yes, what is it you are asking? No need for a lecture, speech,
extracts of conversations with yourself or sentences interrupted by
brackets.

Do you just want to know how to join pieces of wood?




Well... yes.

Although I explained my initial idea - to use biscuits, and questioned
why that might be considered a bad idea.

Then presented one suggestion, which appeared to be an expansion of the
first idea (false/loose tongue) - and questioned why that was considered
better.

Then a third, easier suggestion, which doesn't sound right to me, but if
others have had successful experience of this, then it's a good option.

Sorry for presenting too much info.

Ian wrote:

"Mike Dodd" wrote in message
...
I'm in the process of replacing one set of DIY'd desks (wall-to-wall
computer desks) with a new, "better" pair.

Any comments? Mike

Yes, what is it you are asking? No need for a lecture, speech,
extracts of conversations with yourself or sentences interrupted by
brackets.

Do you just want to know how to join pieces of wood?

Why not troll elsewhere, you arsewipe?

Mike Dodd wrote:

Then a third, easier suggestion, which doesn't sound right to me, but if
others have had successful experience of this, then it's a good option.

Sorry for presenting too much info.

Don't apologise to the Beale arsewipe. He's a known troll from other
newsgroups and can't tell arse from elbow.

I'm not a great fan of glued block worktops. I have used them and I have
made them in the past. But they're a lot of fiddling about to come up
with something that (IMO) doesn't look that good and doesn't work well
either. In general they're cheaper to buy than to make, Ikea offer
suitable tops at a reasonable price. They're useless for the purpose
that Ikea sell them for - kitchen worktops - because the glue they use
isn't fully waterproof, but they do make decent (ish) desktops.

If making them yourself then IMO it's fairly academic whether you join
them by simply glueing PSE, biscuit jointed, dowelled, or joined with a
fillet or T&G as you suggest or think the bloke at the yard suggested.

It's possible to buy cutters for spindle moulders to create the tongue
and groove or to machine a comb edge to increase the glued surface, a
small spindle moulder will cost about £100.

A good quality oak worktop 3m x 950mm x 38mm will cost you about £250.

In an earlier contribution to this discussion,
Mike Dodd wrote:


As an alternative approach, he suggested (I think the phrase was...) a
false tongue using a hard-wood fillet (using a circular/table saw to
cut a groove along each edge of the boards, and inserting (and presumably
glueing) a hard-wood insert to form the tongue.... ASCII art alert:-


I've no experience of biscuit joints - but the 'false tongue' approach would
work ok.

Don't use a table saw to cut the grooves though - use a router. It's pretty
dangerous using a table saw because you'd have to remove the guard - and not
very accurate because it's difficult to handle wooden planks edgeways on.
--
Cheers,
Roger
______
Email address maintained for newsgroup use only, and not regularly
monitored.. Messages sent to it may not be read for several weeks.
PLEASE REPLY TO NEWSGROUP!

Mike Dodd wrote:
I'm in the process of replacing one set of DIY'd desks (wall-to-wall
computer desks) with a new, "better" pair.

I've previously seen (and was tempted by) pre-made oak desk-tops, formed
by glueing several PSE boards together with a double row of biscuits.
This seemed like a good idea, so I trotted down to the local timber
merchants to price up oak, and other hardwoods, in order to do the same
(cost of delivery of the pre-mades being the major factor, here, plus,
I've fancied dabbling with a bit of woodwork for a while).

Now, whilst chatting to the guy at the timberyard, who suggested he used
to do "a lot of this" in a previous life, he suggested that he would
never use biscuits because... (at this point, his quiet nature, the
sound of the timber yard, my age-induced deafness and nack of
interrupting at inopportune times) meant I missed the whole explanation,
but it centred around some argument of the strength of the glued joint
being so much more than the strength of the wood...

Can anyone explain in a more clear way (to me) the rationale behind this?

As an alternative approach, he suggested (I think the phrase was...) a
false tongue using a hard-wood fillet (using a circular/table saw to cut
a groove along each edge of the boards, and inserting (and presumably
glueing) a hard-wood insert to form the tongue.... ASCII art alert:-


########## =========
####### +++++ ======
########## =========

# : 1st board
= : 2nd board
+ : fillet


Which would require me to knock up a jig for doing this (or borrowing my
dad's table-saw.... there's an idea)


...or... to use a rebate joint, glued...

############## =========
############## =========
####### =================
####### =================

Which I could do easily enough with a router, I'm sure.


Now, the false tongue - I can understand, although is it not simply a
"very long biscuit"?, so why's this preferable to a double-row of biscuits?

A hardwood tongue is cut cross grain, so you need a series of them for a
long joint. Using a sawbench the ends of the tongue would be visible

The rebate joint just... I dunno... doesn't feel right - it relies
completely on the strength of the glue bond to provide the strong
work-surface needed for a desk-top.

Any comments? (would be gratefully received - it's a lot of expensive
wood that I'm about to start molesting, and this is my first experiment
beyond pine/soft-wood)

Mike

In article ,
Mike Dodd wrote:
Any comments? (would be gratefully received - it's a lot of expensive
wood that I'm about to start molesting, and this is my first experiment
beyond pine/soft-wood)

Look round the sheds etc for some end of range engineered solid oak
flooring. Clamp and glue that together and to a MDF etc base. Edge with
the same stuff planed to fit. You should be able to get it for about 15
quid a sq mtr. It probably wouldn't stand getting soaked in water - but
will be fine for your job.

--
*Work like you don't need the money. Love like you've never been hurt.

Dave Plowman London SW
To e-mail, change noise into sound.

Mike Dodd wrote:
Ian wrote:
"Mike Dodd" wrote in message
...
I'm in the process of replacing one set of DIY'd desks (wall-to-wall
computer desks) with a new, "better" pair.

Any comments? Mike

Yes, what is it you are asking? No need for a lecture, speech,
extracts of conversations with yourself or sentences interrupted by
brackets.

Do you just want to know how to join pieces of wood?




Well... yes.

Although I explained my initial idea - to use biscuits, and questioned
why that might be considered a bad idea.

Then presented one suggestion, which appeared to be an expansion of the
first idea (false/loose tongue) - and questioned why that was considered
better.

Then a third, easier suggestion, which doesn't sound right to me, but if
others have had successful experience of this, then it's a good option.

Sorry for presenting too much info.

rebating is good BUT you meed to screw from underneath otherwise
differential movement will split the joint apart.

The key to glue joins is to always have them in shear. That way they are
strong. They are NOT strong in tension, and will often pull the top
layer off the wood or fail in te glue itself.

Also, even a glued mortice and tenon join should not be relied upon:
again differential expansion in changing humidity can split these apart
eventually.

I have to say that when making *functional* stuff out of hardwoods, I
tend to screw the ruddy things together hard.


For a simple table or desktop I'd probably set a router up to T & G the
boards, and then make very soliid cross braces to go underneath. Or buy
the block kitchen unit tops.

Or use veneered MDF or ply. Its actually very realistic if combined with
real wood pieces.

Mike Dodd coughed up some electrons that declared:

I'm in the process of replacing one set of DIY'd desks (wall-to-wall
computer desks) with a new, "better" pair.

It's not very DIY but I got a couple of these:

http://www.ikea.com/gb/en/catalog/products/80089003

Because they have solid wood tops, 25mm thick, I had the choice to mount the
tops off-centre front-back giving a nice overhang on the front (less
squidging of the vitals and somewhere to clamp stuff, eg a vice).

Trimmed one table down by 4cm lengthwise and a quick sand and a wipe of
danish oil on the cut surface and you can't even tell it wasn't made that
way. Both tables end to end fit my "lab" perfectly and are fantastic for
computer and electronics related wibblings.

The frame is very solid - halfway good enough for light (ok very light)
workshop use.

Just a lateral thought...

Cheers

Tim

We were somewhere around Barstow, on the edge of the desert, when the
drugs began to take hold. I remember "Ian"
saying something like:

Do you just want to know how to join pieces of wood?

As if you'd know how.
--
Dave
GS850x2 XS650 SE6a

"It's a moron working with power tools.
How much more suspenseful can you get?"
- House

Dave Plowman (News) wrote:
In article ,
Mike Dodd wrote:
Any comments? (would be gratefully received - it's a lot of expensive
wood that I'm about to start molesting, and this is my first
experiment beyond pine/soft-wood)

Look round the sheds etc for some end of range engineered solid oak
flooring. Clamp and glue that together and to a MDF etc base. Edge
with the same stuff planed to fit. You should be able to get it for
about 15 quid a sq mtr. It probably wouldn't stand getting soaked in
water - but will be fine for your job.

Not a good idea. The natural wood will expand/contract at a different rate
to the MDF and cause the surface to bow badly.

BTDTGTTS. Not something I've ever done, but saw a whole bedroom full of
home made wardrobe doors made like that. They had all bowed badly & beyond
redemption.


--
Dave - The Medway Handyman
www.medwayhandyman.co.uk

Mike Dodd wrote:
I'm in the process of replacing one set of DIY'd desks (wall-to-wall
computer desks) with a new, "better" pair.

I've previously seen (and was tempted by) pre-made oak desk-tops,
formed by glueing several PSE boards together with a double row of
biscuits. This seemed like a good idea, so I trotted down to the local
timber
merchants to price up oak, and other hardwoods, in order to do the
same (cost of delivery of the pre-mades being the major factor, here,
plus, I've fancied dabbling with a bit of woodwork for a while).

Now, whilst chatting to the guy at the timberyard, who suggested he
used to do "a lot of this" in a previous life, he suggested that he
would never use biscuits because... (at this point, his quiet nature, the
sound of the timber yard, my age-induced deafness and nack of
interrupting at inopportune times) meant I missed the whole
explanation, but it centred around some argument of the strength of
the glued joint being so much more than the strength of the wood...

Can anyone explain in a more clear way (to me) the rationale behind
this?
As an alternative approach, he suggested (I think the phrase was...) a
false tongue using a hard-wood fillet (using a circular/table saw to
cut a groove along each edge of the boards, and inserting (and presumably
glueing) a hard-wood insert to form the tongue....

Biscuit joining is the modern version of the false tongue joint. Easier,
faster & safer to cut. You can use a router but a biscuit joiner is far
better. Even a cheap one works OK
http://www.aldi.co.uk/uk/html/offers/58_7440.htm

I've never, ever heard of, or had any problems with biscuit joins.

This bloke in the timber yard sounds like he was stuck in a 1950's time
warp. His name wasn't Tanner OP was it?


--
Dave - The Medway Handyman
www.medwayhandyman.co.uk

The Medway Handyman wrote:

Biscuit joining is the modern version of the false tongue joint.
Easier, faster & safer to cut.

The one advantage that I can see with a false tongue, over biscuits, is
a larger surface area for the glue.

Even a cheap one works OK

That's good, the missus bought me a cheap one many xmas's ago. Maybe
time to dust off the box.


This bloke in the timber yard sounds like he was stuck in a 1950's time
warp. His name wasn't Tanner OP was it?

In fairness to the guy, he did sound pretty clued-up, and helpful. He
also offered that if I was to bring my router in, that he'd show me how
to set-up and keep a watchful eye over the proceedings. In honesty,
though, if I'm going to f*k up a load of wood, I'd rather do it in the
privacy of my own home. When I go to collect the wood, I may just bend
his ear a bit more.

Roger Mills wrote:
In an earlier contribution to this discussion,
Mike Dodd wrote:

As an alternative approach, he suggested (I think the phrase was...) a
false tongue using a hard-wood fillet (using a circular/table saw to
cut a groove along each edge of the boards, and inserting (and presumably
glueing) a hard-wood insert to form the tongue.... ASCII art alert:-


I've no experience of biscuit joints - but the 'false tongue' approach would
work ok.

Don't use a table saw to cut the grooves though - use a router. It's pretty
dangerous using a table saw because you'd have to remove the guard - and not
very accurate because it's difficult to handle wooden planks edgeways on.

Thanks to all of the (constructive) replies, so far,

I'm favouring the loose/false tongue approach at this time, using a
router to run up/down each board. I *think* this will be stronger than
biscuits, and not significantly harder to achieve. One book that I have
that describes this for joining manufactured boards recommends 6mm ply
for the tongue, as the ply structure is stronger in bending than a
long-grained section of hardwood (answering, to some degree, Stuart Noble).

Answering Dave Plowman - I've considered several variations to your
theme, up to sourcing a load of veneer (that avenue quickly got
complicated), but the desk is not purely one of function, but also the
pleasure of hitting bits of wood wi' hammer. Despite the low cost, and
stability, and eminent suitability of MDF, I have a personal hatred of
the stuff.

That answers, Tim S, also - in fact, a (different) local timber yard
offers oak worktops at £200 for 3m lengths. There's a slight problem
that I need a total of 3.6m (although formed as 2x 1.8m desktops -
his&hers), but as said in the original post - I fancy dabbling with a
bit of woodwork at the same time (besides, the router hasn't paid for
itself, yet, since its only real use for fitting the kitchen worktops -
jointing, and sink/hob cutouts).

Answering Steve Firth - the timber is to be supplied cut at 2m lengths
(for 1.8m finish - I like having a bit to play with), so it won't be
block-work, but single-staves (is that the phrase - for running the
length of the desk?). Regarding the spindle-moulder, would love to have
one, but simply don't have the space for it. I have, however, been
pondering over similar cutters in Screwfix for the router.

Answering Natural Philosopher - I agree about the cross-braces - it's
how I've done the existing desk-tops, and would provide a key into the
existing support-strips on the walls. Veneered MDF/ply - I can source
veneered ply for around £60/sheet, but the timber is coming in not
*substantially* more than that, and I like having the option to form
edges easily (e.g. bull-nose the working edge and cable holes, and maybe
sweep one edge of the desk into an arc) - the existing desktops are made
this way from veneered block-board, and the faffing about with edging
mouldings is part of the reason for replacing them. I have seen
info/movies online for the use of real pieces to edge shaped
veneered/manufactured boards, and until yesterday this was the approach
I was favouring, however, the low price differential from real timber vs
board (~£80/desk vs £60) makes me more inclined to try the real-wood
approach.


Anyhow, if I cock it up, I can hopefully learn from the experience.

Regards,

Mike

Mike Dodd wrote:
The Medway Handyman wrote:

Biscuit joining is the modern version of the false tongue joint.
Easier, faster & safer to cut.

The one advantage that I can see with a false tongue, over biscuits,
is a larger surface area for the glue.

Biscuits leave more of the edge timber available for glue. The idea is they
hold the boards 'level' while the glue dries.

Even a cheap one works OK

That's good, the missus bought me a cheap one many xmas's ago. Maybe
time to dust off the box.


--
Dave - The Medway Handyman
www.medwayhandyman.co.uk

Roger Mills wrote:
In an earlier contribution to this discussion,
Mike Dodd wrote:

As an alternative approach, he suggested (I think the phrase was...) a
false tongue using a hard-wood fillet (using a circular/table saw to
cut a groove along each edge of the boards, and inserting (and presumably
glueing) a hard-wood insert to form the tongue.... ASCII art alert:-


I've no experience of biscuit joints - but the 'false tongue' approach would
work ok.

Don't use a table saw to cut the grooves though - use a router. It's pretty
dangerous using a table saw because you'd have to remove the guard - and not
very accurate because it's difficult to handle wooden planks edgeways on.

Not difficult at all, and hardly dangerous with the blade set so low. A
router does have the advantage that you can stop the groove though

In an earlier contribution to this discussion,
stuart noble wrote:

Roger Mills wrote:
In an earlier contribution to this discussion,
Mike Dodd wrote:


Don't use a table saw to cut the grooves though - use a router. It's
pretty dangerous using a table saw because you'd have to remove the
guard - and not very accurate because it's difficult to handle
wooden planks edgeways on.

Not difficult at all, and hardly dangerous with the blade set so low.
A router does have the advantage that you can stop the groove though

Yes, I know it *can* be done - and I've done it myself - but a router is far
safer and, as you say, can be stopped.

I don't think that we'd ought to be *recommending* people to run table saws
with the guards removed!
--
Cheers,
Roger
______
Email address maintained for newsgroup use only, and not regularly
monitored.. Messages sent to it may not be read for several weeks.
PLEASE REPLY TO NEWSGROUP!

"Mike Dodd" wrote in message
...


8

Have you looked at http://www.ikea.com/gb/en/catalog/products/10123675

In article ,
The Medway Handyman wrote:
Look round the sheds etc for some end of range engineered solid oak
flooring. Clamp and glue that together and to a MDF etc base. Edge
with the same stuff planed to fit. You should be able to get it for
about 15 quid a sq mtr. It probably wouldn't stand getting soaked in
water - but will be fine for your job.

Not a good idea. The natural wood will expand/contract at a different
rate to the MDF and cause the surface to bow badly.

BTDTGTTS. Not something I've ever done, but saw a whole bedroom full of
home made wardrobe doors made like that. They had all bowed badly &
beyond redemption.

I've done it with great success. Of course if the conditions in the area
are strange - high humidity etc - anything can happen.

--
*Never miss a good chance to shut up *

Dave Plowman London SW
To e-mail, change noise into sound.

In article ,
Mike Dodd wrote:
Answering Dave Plowman - I've considered several variations to your
theme, up to sourcing a load of veneer (that avenue quickly got
complicated), but the desk is not purely one of function, but also the
pleasure of hitting bits of wood wi' hammer. Despite the low cost, and
stability, and eminent suitability of MDF, I have a personal hatred of
the stuff.

*Not* a veneer - but solid wood flooring. It's about 7/16ths thick. But
made up of smaller bits glued together.
You can use ply as a base. Or blockboard.

--
*I finally got my head together, now my body is falling apart.

Dave Plowman London SW
To e-mail, change noise into sound.

It seems to me that this is pretty much the same as making joints in
kitchen worktops. For these, biscuits and clamps work very well and
are very easy to do with a router.
The tricky part about the long tongue would seem to be making sure the
fillet is a good fit, so perhaps there's a compromise of routing a
groove along each board using a biscuit joint cutter, then stacking
the biscuits along the groove.. Be a good idea to hold the boards
together 'laterally' though, somehow (if you got some of the Ikea
worktops, a kitchen clamp would be just the job as they're thick
enough.)

In article ,
The Medway Handyman wrote:
Look round the sheds etc for some end of range engineered solid oak
flooring. Clamp and glue that together and to a MDF etc base. Edge
with the same stuff planed to fit. You should be able to get it for
about 15 quid a sq mtr. It probably wouldn't stand getting soaked in
water - but will be fine for your job.

Not a good idea. The natural wood will expand/contract at a different
rate to the MDF and cause the surface to bow badly.

Just to add that's how some 'wood' flooring is made anyway.

--
*How can I miss you if you won't go away?

Dave Plowman London SW
To e-mail, change noise into sound.

Dave Plowman (News) wrote:
In article ,
The Medway Handyman wrote:
Look round the sheds etc for some end of range engineered solid oak
flooring. Clamp and glue that together and to a MDF etc base. Edge
with the same stuff planed to fit. You should be able to get it for
about 15 quid a sq mtr. It probably wouldn't stand getting soaked in
water - but will be fine for your job.

Not a good idea. The natural wood will expand/contract at a
different rate to the MDF and cause the surface to bow badly.

Just to add that's how some 'wood' flooring is made anyway.

I'm only talking from my experience. A house I was working in had wardrobe
doors made from 8' x 2' contiboard covered with T&G cladding across the 2'
width. Each strip had been glued down with no more nails.

It contracted so badly the contiboard had taken the shape of a longbow, even
to the point of pulling a hinge out on one door.


--
Dave - The Medway Handyman
www.medwayhandyman.co.uk

In article ,
The Medway Handyman wrote:
Just to add that's how some 'wood' flooring is made anyway.

I'm only talking from my experience. A house I was working in had
wardrobe doors made from 8' x 2' contiboard covered with T&G cladding
across the 2' width. Each strip had been glued down with no more nails.

It contracted so badly the contiboard had taken the shape of a longbow,
even to the point of pulling a hinge out on one door.

Contiboard? That's what I'd call melamine faced chipboard. And T&G
cladding is normally the cheapest ever whitewood. I can imagine the two
reacting very differently to the ambient room conditions.

All I can say is I've done what I said without problems.

--
*Geeks shall inherit the earth *

Dave Plowman London SW
To e-mail, change noise into sound.

Dave Plowman (News) wrote:
In article ,
The Medway Handyman wrote:
Just to add that's how some 'wood' flooring is made anyway.

I'm only talking from my experience. A house I was working in had
wardrobe doors made from 8' x 2' contiboard covered with T&G cladding
across the 2' width. Each strip had been glued down with no more
nails.

It contracted so badly the contiboard had taken the shape of a
longbow, even to the point of pulling a hinge out on one door.

Contiboard? That's what I'd call melamine faced chipboard. And T&G
cladding is normally the cheapest ever whitewood. I can imagine the
two reacting very differently to the ambient room conditions.

All I can say is I've done what I said without problems.

Then we shall agree to differ in a civilised way, like the gentlemen we both
are :-)


--
Dave - The Medway Handyman
www.medwayhandyman.co.uk

In an earlier contribution to this discussion,
The Medway Handyman wrote:


I'm only talking from my experience. A house I was working in had
wardrobe doors made from 8' x 2' contiboard covered with T&G cladding
across the 2' width. Each strip had been glued down with no more
nails.
It contracted so badly the contiboard had taken the shape of a
longbow, even to the point of pulling a hinge out on one door.

I assume that the T&G must have had a high moisture content when fitted, and
shrank when it dried out.

Even so, I would have expected it to come apart at the tongues and grooves
rather than staying together and bowing the contiboard.
--
Cheers,
Roger
______
Email address maintained for newsgroup use only, and not regularly
monitored.. Messages sent to it may not be read for several weeks.
PLEASE REPLY TO NEWSGROUP!

Dave Plowman (News) wrote:
In article ,
The Medway Handyman wrote:
Just to add that's how some 'wood' flooring is made anyway.

I'm only talking from my experience. A house I was working in had
wardrobe doors made from 8' x 2' contiboard covered with T&G cladding
across the 2' width. Each strip had been glued down with no more nails.

It contracted so badly the contiboard had taken the shape of a longbow,
even to the point of pulling a hinge out on one door.

Contiboard? That's what I'd call melamine faced chipboard. And T&G
cladding is normally the cheapest ever whitewood. I can imagine the two
reacting very differently to the ambient room conditions.

All I can say is I've done what I said without problems.

T & G is DREADFUL

I put some up and painted it..come the winter there were 2mm white lines
where the T's had shrunk out of the G's. In summer they go back again.

1% movement across the grain, particularly in tangentially sawn
softwood, from summer to winter, is not uncommon.

Oak IS better. My enigeenered laminate floor made of softwood ply with a
5mm oak veneer, only moved about 5mm over 5 meters. So 0.1% total.

Chip and contiboard would be more or less impervious to moisture..so the
combination is very likely to bow.

Roger Mills wrote:
In an earlier contribution to this discussion,
The Medway Handyman wrote:


I'm only talking from my experience. A house I was working in had
wardrobe doors made from 8' x 2' contiboard covered with T&G cladding
across the 2' width. Each strip had been glued down with no more
nails.
It contracted so badly the contiboard had taken the shape of a
longbow, even to the point of pulling a hinge out on one door.

I assume that the T&G must have had a high moisture content when
fitted, and shrank when it dried out.

Even so, I would have expected it to come apart at the tongues and
grooves rather than staying together and bowing the contiboard.

No More Nails had been used...



--
Dave - The Medway Handyman
www.medwayhandyman.co.uk

The Medway Handyman wrote:
Roger Mills wrote:
In an earlier contribution to this discussion,
The Medway Handyman wrote:

I'm only talking from my experience. A house I was working in had
wardrobe doors made from 8' x 2' contiboard covered with T&G cladding
across the 2' width. Each strip had been glued down with no more
nails.
It contracted so badly the contiboard had taken the shape of a
longbow, even to the point of pulling a hinge out on one door.
I assume that the T&G must have had a high moisture content when
fitted, and shrank when it dried out.

Even so, I would have expected it to come apart at the tongues and
grooves rather than staying together and bowing the contiboard.

No More Nails had been used...



But was the T&G applied to both surfaces?

--
Rod

Hypothyroidism is a seriously debilitating condition with an insidious
onset.
Although common it frequently goes undiagnosed.
www.thyromind.info www.thyroiduk.org www.altsupportthyroid.org

Rod wrote:
The Medway Handyman wrote:
Roger Mills wrote:
In an earlier contribution to this discussion,
The Medway Handyman wrote:

I'm only talking from my experience. A house I was working in had
wardrobe doors made from 8' x 2' contiboard covered with T&G
cladding across the 2' width. Each strip had been glued down with
no more nails.
It contracted so badly the contiboard had taken the shape of a
longbow, even to the point of pulling a hinge out on one door.
I assume that the T&G must have had a high moisture content when
fitted, and shrank when it dried out.

Even so, I would have expected it to come apart at the tongues and
grooves rather than staying together and bowing the contiboard.

No More Nails had been used...



But was the T&G applied to both surfaces?

No, just the front. Each piece had been glued to the contiboard & had glued
T&G joints.



--
Dave - The Medway Handyman
www.medwayhandyman.co.uk

The Medway Handyman wrote:
Rod wrote:
The Medway Handyman wrote:
Roger Mills wrote:
In an earlier contribution to this discussion,
The Medway Handyman wrote:

I'm only talking from my experience. A house I was working in had
wardrobe doors made from 8' x 2' contiboard covered with T&G
cladding across the 2' width. Each strip had been glued down with
no more nails.
It contracted so badly the contiboard had taken the shape of a
longbow, even to the point of pulling a hinge out on one door.
I assume that the T&G must have had a high moisture content when
fitted, and shrank when it dried out.

Even so, I would have expected it to come apart at the tongues and
grooves rather than staying together and bowing the contiboard.
No More Nails had been used...



But was the T&G applied to both surfaces?

No, just the front. Each piece had been glued to the contiboard & had glued
T&G joints.



Right - might not have been quite so bad if both sides had been done -
they might have managed to balance each other - or perhaps both would
have peeled off?

--
Rod

Hypothyroidism is a seriously debilitating condition with an insidious
onset.
Although common it frequently goes undiagnosed.
www.thyromind.info www.thyroiduk.org www.altsupportthyroid.org

In article ,
The Medway Handyman wrote:
Even so, I would have expected it to come apart at the tongues and
grooves rather than staying together and bowing the contiboard.

No More Nails had been used...

IMHO ordinary PVA wood glue will do a better job. For less money.

--
*I'm pretty sure that sex is better than logic, but I can't prove it.

Dave Plowman London SW
To e-mail, change noise into sound.

Rod wrote:
The Medway Handyman wrote:
Rod wrote:
The Medway Handyman wrote:
Roger Mills wrote:
In an earlier contribution to this discussion,
The Medway Handyman wrote:

I'm only talking from my experience. A house I was working in had
wardrobe doors made from 8' x 2' contiboard covered with T&G
cladding across the 2' width. Each strip had been glued down with
no more nails.
It contracted so badly the contiboard had taken the shape of a
longbow, even to the point of pulling a hinge out on one door.
I assume that the T&G must have had a high moisture content when
fitted, and shrank when it dried out.

Even so, I would have expected it to come apart at the tongues and
grooves rather than staying together and bowing the contiboard.
No More Nails had been used...



But was the T&G applied to both surfaces?

No, just the front. Each piece had been glued to the contiboard & had
glued T&G joints.



Right - might not have been quite so bad if both sides had been done -
they might have managed to balance each other - or perhaps both would
have peeled off?

I've never known contiboard bow unless it gets wet. Come to that I've
never known cladding to bow, mainly because it's usually pretty dry by
virtue of its thinness (is that a word?)

Dave Plowman (News) wrote:
In article ,
The Medway Handyman wrote:
Even so, I would have expected it to come apart at the tongues and
grooves rather than staying together and bowing the contiboard.

No More Nails had been used...

IMHO ordinary PVA wood glue will do a better job. For less money.

I'd agree - I didn't do the job, I was called in to (amongst other jobs) try
& straighten the doors out - and failed.


--
Dave - The Medway Handyman
www.medwayhandyman.co.uk

The Medway Handyman wrote:
Rod wrote:
The Medway Handyman wrote:
Roger Mills wrote:
In an earlier contribution to this discussion,
The Medway Handyman wrote:

I'm only talking from my experience. A house I was working in had
wardrobe doors made from 8' x 2' contiboard covered with T&G
cladding across the 2' width. Each strip had been glued down with
no more nails.
It contracted so badly the contiboard had taken the shape of a
longbow, even to the point of pulling a hinge out on one door.
I assume that the T&G must have had a high moisture content when
fitted, and shrank when it dried out.

Even so, I would have expected it to come apart at the tongues and
grooves rather than staying together and bowing the contiboard.
No More Nails had been used...



But was the T&G applied to both surfaces?

No, just the front. Each piece had been glued to the contiboard & had glued
T&G joints.



The mistake was gluing the T's & G's.

In an earlier contribution to this discussion,
The Medway Handyman wrote:

Rod wrote:
The Medway Handyman wrote:
Roger Mills wrote:

Even so, I would have expected it to come apart at the tongues and
grooves rather than staying together and bowing the contiboard.

No More Nails had been used...



But was the T&G applied to both surfaces?

No, just the front. Each piece had been glued to the contiboard &
had glued T&G joints.


That probably explains it. I assumed that the boards were just stuck to the
conti - *not* to each other as well!
--
Cheers,
Roger
______
Email address maintained for newsgroup use only, and not regularly
monitored.. Messages sent to it may not be read for several weeks.
PLEASE REPLY TO NEWSGROUP!

On 4 Oct, 18:02, Mike Dodd wrote:
I'm in the process of replacing one set of DIY'd desks (wall-to-wall
computer desks) with a new, "better" pair.

I've previously seen (and was tempted by) pre-made oak desk-tops, formed
by glueing several PSE boards together with a double row of biscuits.
This seemed like a good idea, so I trotted down to the local timber
merchants to price up oak, and other hardwoods, in order to do the same
(cost of delivery of the pre-mades being the major factor, here, plus,
I've fancied dabbling with a bit of woodwork for a while).

Now, whilst chatting to the guy at the timberyard, who suggested he used
to do "a lot of this" in a previous life, he suggested that he would
never use biscuits because... (at this point, his quiet nature, the
sound of the timber yard, my age-induced deafness and nack of
interrupting at inopportune times) meant I missed the whole explanation,
but it centred around some argument of the strength of the glued joint
being so much more than the strength of the wood...

Can anyone explain in a more clear way (to me) the rationale behind this?

As an alternative approach, he suggested (I think the phrase was...) a
false tongue using a hard-wood fillet (using a circular/table saw to cut
a groove along each edge of the boards, and inserting (and presumably
glueing) a hard-wood insert to form the tongue.... ASCII art alert:-

########## =========
####### +++++ ======
########## =========

# *: 1st board
= *: 2nd board
+ *: fillet

Which would require me to knock up a jig for doing this (or borrowing my
dad's table-saw.... there's an idea)

...or... to use a rebate joint, glued...

############## =========
############## =========
####### =================
####### =================

Which I could do easily enough with a router, I'm sure.

Now, the false tongue - I can understand, although is it not simply a
"very long biscuit"?, so why's this preferable to a double-row of biscuits?

The rebate joint just... I dunno... doesn't feel right - it relies
completely on the strength of the glue bond to provide the strong
work-surface needed for a desk-top.

Any comments? (would be gratefully received - it's a lot of expensive
wood that I'm about to start molesting, and this is my first experiment
beyond pine/soft-wood)

Mike

Hello,
I have had good results with veneered ply which comes in useful long
lengths
and widths in various veneers from a specialist ply supplier in your
area.
Remains only to make a nice job of gluing on some edge material also
supplied by the specialists to match.
Looks good...even works nicely with curved fronts or ends.
Good luck.