I have read several books being a woodworking newbie and all. They all
describe glueing and clamping of solid wood. However, none of them
describe the process of glueing and assembling plywood.
Is there anything I need to do special? This is a 1.5(d)'x4'(h)x2'(w)
@3/4" thick box. Its AC Plywood. Do I need to sand or route the edges
before I put glue on them and clamp them? Do I need nails in addition
to glue? The front of the box will actually sit in a hole framed with
2x4s. I will support that back with a small 2x4 pedestal.
Also the wood was sitting outside in detroit where its cold and dry.
How long should it sit in my house where its warm and standard humidity
before I cut it, or before I glue it?
--
Thank you,
"Then said I, Wisdom [is] better than strength: nevertheless the poor
man's wisdom [is] despised, and his words are not heard." Ecclesiastes 9:16
In article <[email protected]>, CW
<[email protected]> wrote:
> Of course nails add strength to a joint. Those guys building houses figured
> this out a long time ago.
I thought the discussion was about building boxes, not framing walls.
There's a difference between carpentry and woodworking. Being able to
build things without using nails is part of that difference.
djb
--
Boycott Google for their support of communist censorship and repression!
In article <[email protected]>, CW
<[email protected]> wrote:
> Reread the thread. Part of what was being discussed was the strength of
> nails. In any case, lots of well made funiture has had nails used in the
> construction. Shaker funiture comes to mind.
Accepted. The fact that nails are used does not demonstrate joint
strength, however.
Can you point to studies that demonstrate that a well formed and
properly glued joint is any stronger when nails are used as well? How
many nails in what area or linear distance? What size nails in
proprotion to the dimensions of the wood?
It's been discussed to death here that a properly formed and glued
joint will fail AFTER the wood on either side of the glue line fails.
If you can demonstrate that nails add strength to such a joint, I'd
love to read the data.
djb
--
Boycott Google for their support of communist censorship and repression!
dnoyeB wrote:
> I have read several books being a woodworking newbie and all. They all
> describe glueing and clamping of solid wood. However, none of them
> describe the process of glueing and assembling plywood.
it's pretty similar to gluing solid wood. after all, plywood is made up
of thin sheets of solid wood...
>
> Is there anything I need to do special? This is a 1.5(d)'x4'(h)x2'(w)
> @3/4" thick box. Its AC Plywood. Do I need to sand or route the edges
> before I put glue on them and clamp them?
don't sand them if you can help it, and if you do, make sure you get
all of the sanding dust off before you put the glue on.
for glue to work, the parts have to fit together quite well. you
shouldn't be able to see light through a joint in 3/4" ply before the
glue goes on.
>Do I need nails in addition
> to glue?
if the glueup is perfect, no. if your jointery is even slightly less
than perfect, or if you want to be able to pull the box out of the
clamps before the glue is fully cured, or if you expect the box to
receive stresses beyond the glue's performance characteristics and want
it to fail a bit more gracefully, then use some nails. sometimes nails
can make an assembly easier to get together- like when you need to fit
several parts together, then turn the whole thing over, then fit
several more parts together, all before you can get the clamps on.
other times it's good to use redundant methods, like glue <and> nails
just to allow for a little sloppiness that may creep in to either
method.
so no, you don't necessarily need both, but it's often not a bad idea
anyway.
>The front of the box will actually sit in a hole framed with
> 2x4s. I will support that back with a small 2x4 pedestal.
is that hole part of a frame wall? if so, the wall can provide a lot of
strength. use shim shingles to fit the box (is it a cabinet?) into
location. allow 1/2" or so between the box and the frame opening for
the shims.
>
> Also the wood was sitting outside in detroit where its cold and dry.
> How long should it sit in my house where its warm and standard humidity
> before I cut it, or before I glue it?
depends how long it was out there. if this is new plywood, clean and in
good condition, a few days sitting inside might be enough. if this is
used material, or has been weathered or is dirty, you are going to have
more work to prepare it for use.
Toller wrote:
> > Forget nails, they just hold things in place until the glue dries.
> > If you use screws, be sure to pre-drill the holes so they don't split
> > the plywood.
>
> The first thing I ever built was a TV stand out of recycled plywood shelves.
> It had shallow dados with the shelves glued and nailed in place' no back, no
> glue blocks. I was a little scared to actually put a TV on something so
> rickety.
>
> Last year I was throwing it out, so I decided to see how much it would hold.
> I gradually put 200 pounds of steel chain on top; no problem. Then I fixed
> the bottom and "gently tapped" it sideways with a sledge hammer. I knocked
> it to a 30 degree angle before it collapsed. Presumably the glue had broken
> up long before that, and all that was holding together were the nails.
>
> So, nails do add "some" strength; in this case, quite a lot.
yep, the nails allowed it to fail a bit more gracefully.
"dnoyeB" <[email protected]> wrote in message
news:[email protected]...
>I have read several books being a woodworking newbie and all. They all
>describe glueing and clamping of solid wood. However, none of them
>describe the process of glueing and assembling plywood.
Glues fine, it's nails and screws into edges that it doesn't do as well as
solid wood. They're often worse for having been nailed.
If it needs to support itself as in a real box, you should consider a a
combination joint. Rabbet ends 3/8 x 3/8, dado sides 3/8 x 3/8 and as far
from the edge as will bring the surface of the other flush or vice-versa if
the static loading is on the sides. Easy stuff on a router table. Gives
you some mechanical strength and twice the glue surface.
>
> Is there anything I need to do special? This is a 1.5(d)'x4'(h)x2'(w)
> @3/4" thick box. Its AC Plywood. Do I need to sand or route the edges
> before I put glue on them and clamp them? Do I need nails in addition to
> glue? The front of the box will actually sit in a hole framed with 2x4s.
> I will support that back with a small 2x4 pedestal.
>
> Also the wood was sitting outside in detroit where its cold and dry. How
> long should it sit in my house where its warm and standard humidity before
> I cut it, or before I glue it?
>
It's wetter outside than in. Wood sees _relative_ humidity. Check the
weather report under relative humidity and see what the wood's experiencing.
You should bring it in early to warm it enough to get good glue adhesion,
and keep both faces open to the air.
"Dave Balderstone" <dave***@balderstone.ca> wrote in message
news:050220060043199905%dave***@balderstone.ca...
> In article <[email protected]>, CW
> <[email protected]> wrote:
>
>> Reread the thread. Part of what was being discussed was the strength of
>> nails. In any case, lots of well made funiture has had nails used in the
>> construction. Shaker funiture comes to mind.
>
> Accepted. The fact that nails are used does not demonstrate joint
> strength, however.
>
Especially when used into the edges of plywood, where they often follow
faults in the plies and peek out, or split the glue between plies and make
the whole structure weaker. Mechanical joints, fully glued are the best.
Of course, glue lines, when they fail, do so catastrophically, a nail just
sits there and bends.
dnoyeB wrote:
> I have read several books being a woodworking newbie and all. They all
> describe glueing and clamping of solid wood. However, none of them
> describe the process of glueing and assembling plywood.
>
> Is there anything I need to do special? This is a 1.5(d)'x4'(h)x2'(w)
> @3/4" thick box. Its AC Plywood. Do I need to sand or route the edges
> before I put glue on them and clamp them? Do I need nails in addition
> to glue? The front of the box will actually sit in a hole framed with
> 2x4s. I will support that back with a small 2x4 pedestal.
>
> Also the wood was sitting outside in detroit where its cold and dry. How
> long should it sit in my house where its warm and standard humidity
> before I cut it, or before I glue it?
>
Thanks for all the great comments folks. I think I can start now \o/
--
Thank you,
"Then said I, Wisdom [is] better than strength: nevertheless the poor
man's wisdom [is] despised, and his words are not heard." Ecclesiastes 9:16
Of course nails add strength to a joint. Those guys building houses figured
this out a long time ago.
<[email protected]> wrote in message
news:[email protected]...
>
> Toller wrote:
> > > Forget nails, they just hold things in place until the glue dries.
> > > If you use screws, be sure to pre-drill the holes so they don't
split
> > > the plywood.
> >
> > The first thing I ever built was a TV stand out of recycled plywood
shelves.
> > It had shallow dados with the shelves glued and nailed in place' no
back, no
> > glue blocks. I was a little scared to actually put a TV on something so
> > rickety.
> >
> > Last year I was throwing it out, so I decided to see how much it would
hold.
> > I gradually put 200 pounds of steel chain on top; no problem. Then I
fixed
> > the bottom and "gently tapped" it sideways with a sledge hammer. I
knocked
> > it to a 30 degree angle before it collapsed. Presumably the glue had
broken
> > up long before that, and all that was holding together were the nails.
> >
> > So, nails do add "some" strength; in this case, quite a lot.
>
> yep, the nails allowed it to fail a bit more gracefully.
>
"dnoyeB" <[email protected]> wrote in message
news:[email protected]...
>I have read several books being a woodworking newbie and all. They all
>describe glueing and clamping of solid wood. However, none of them
>describe the process of glueing and assembling plywood.
>
> Is there anything I need to do special? This is a 1.5(d)'x4'(h)x2'(w)
> @3/4" thick box. Its AC Plywood. Do I need to sand or route the edges
> before I put glue on them and clamp them? Do I need nails in addition to
> glue? The front of the box will actually sit in a hole framed with 2x4s.
> I will support that back with a small 2x4 pedestal.
>
> Also the wood was sitting outside in detroit where its cold and dry. How
> long should it sit in my house where its warm and standard humidity before
> I cut it, or before I glue it?
>
It will have to be very very flat and smooth for a decent glue joint.
Unless you are sure you can do that, you better plan on some mechanical
aids; such as nails or supports.
I would have it indoors for at least a couple days before using it.
Yes, I've see this too.
"Ba r r y" <[email protected]> wrote in message
news:[email protected]...
> On Sun, 05 Feb 2006 06:30:45 GMT, "CW" <[email protected]> wrote:
>
> >Reread the thread. Part of what was being discussed was the strength of
> >nails. In any case, lots of well made funiture has had nails used in the
> >construction. Shaker funiture comes to mind.
>
> Some of the authentic stuff I've seen in person made no attempt to
> hide the nails.
>
> Barry
> Forget nails, they just hold things in place until the glue dries.
> If you use screws, be sure to pre-drill the holes so they don't split
> the plywood.
The first thing I ever built was a TV stand out of recycled plywood shelves.
It had shallow dados with the shelves glued and nailed in place' no back, no
glue blocks. I was a little scared to actually put a TV on something so
rickety.
Last year I was throwing it out, so I decided to see how much it would hold.
I gradually put 200 pounds of steel chain on top; no problem. Then I fixed
the bottom and "gently tapped" it sideways with a sledge hammer. I knocked
it to a 30 degree angle before it collapsed. Presumably the glue had broken
up long before that, and all that was holding together were the nails.
So, nails do add "some" strength; in this case, quite a lot.
On Fri, 03 Feb 2006 18:16:00 -0500, dnoyeB <[email protected]>
wrote:
>describe the process of glueing and assembling plywood.
Biscuit jointer, lots of clamps, white rubber mallet to assemble it.
These are the best clamps to have
http://www.screwfix.com/sfd/i/cat/09/p1929409_x.jpg
They're aluminium extrusion and cheap, rather than strong. You can
afford plenty (You Can Never Have Too Many Clamps) and they're
lightweight enough that they don't make the box collapse or fall off the
bench under their own weight.
If you're making a habit of simple boxes, look into a biscuit jointer.
There's nothing quicker and easier.
>This is a 1.5(d)'x4'(h)x2'(w) @3/4" thick box.
3/4" is pretty thick for plywood boxes. Fine for coffins, might be a bit
heavy unless you really need it. I prefer to use expensive birch plywood
for 3/4" boxes, just because it's a bit lighter than cheap tropical
plywood. Plenty of space for biscuits though.
>Do I need nails in addition to glue?
You're going into end grain(sic) so nails aren't much use. Screws are
far better, so long as you use modern (European ?) parallel thread
woodscrews. Use single thread, not double.
http://www.screwfix.com/app/sfd/cat/cat.jsp?cId=A331379&ts=72064
--
Cats have nine lives, which is why they rarely post to Usenet.
On Sun, 05 Feb 2006 06:30:45 GMT, "CW" <[email protected]> wrote:
>Reread the thread. Part of what was being discussed was the strength of
>nails. In any case, lots of well made funiture has had nails used in the
>construction. Shaker funiture comes to mind.
Some of the authentic stuff I've seen in person made no attempt to
hide the nails.
Barry
Reread the thread. Part of what was being discussed was the strength of
nails. In any case, lots of well made funiture has had nails used in the
construction. Shaker funiture comes to mind.
"Dave Balderstone" <dave***@balderstone.ca> wrote in message
news:040220062324039194%dave***@balderstone.ca...
> In article <[email protected]>, CW
> <[email protected]> wrote:
>
> > Of course nails add strength to a joint. Those guys building houses
figured
> > this out a long time ago.
>
> I thought the discussion was about building boxes, not framing walls.
>
> There's a difference between carpentry and woodworking. Being able to
> build things without using nails is part of that difference.
>
> djb
>
> --
> Boycott Google for their support of communist censorship and repression!
Remember when you are designing your box that a glue joint to end grain has
essentially no strength at all. Only long fibers glued to long fibers have
any strength. And when you look at the edge of a piece of plywood, about
50% of is end grain wood. So, a glue joint will hold, but isn't the
strongest.
The box is fairly big--if it is going to hold heavy stuff, you may want to
reinforce your joints.
Forget nails, they just hold things in place until the glue dries.
If you use screws, be sure to pre-drill the holes so they don't split
the plywood.
Think about putting a glue block in the inside of the joint. That way
you have lots of long grain glue surface and MUCH more strength.
Otherwise, agree with other advice you got.
Walt C
"dnoyeB" <[email protected]> wrote in message
news:[email protected]...
>I have read several books being a woodworking newbie and all. They all
>describe glueing and clamping of solid wood. However, none of them
>describe the process of glueing and assembling plywood.
>
> Is there anything I need to do special? This is a 1.5(d)'x4'(h)x2'(w)
> @3/4" thick box. Its AC Plywood. Do I need to sand or route the edges
> before I put glue on them and clamp them? Do I need nails in addition to
> glue? The front of the box will actually sit in a hole framed with 2x4s.
> I will support that back with a small 2x4 pedestal.
>
> Also the wood was sitting outside in detroit where its cold and dry. How
> long should it sit in my house where its warm and standard humidity before
> I cut it, or before I glue it?
>
> --
> Thank you,
>
>
>
> "Then said I, Wisdom [is] better than strength: nevertheless the poor
> man's wisdom [is] despised, and his words are not heard." Ecclesiastes
> 9:16