Gluing timber to make bigger boards?

[goldeneyedmonkey]

Hello again all, Here's the situation:

I've been edge-gluing timber boards (7"x1") to make larger panels for chests of drawers sides etc. I've been using enough clamps and making sure they were all level etc, but they always seem to split to some degree on the seams between the boards. Not always a big problem, but when they change temperature from the workshop (a rather cold cellar) they split a bit, only hairline but it's annoying. I've just upgraded from using standard D4 PVA stylee wood-glue to Titebond Premium Wood Glue.

So is the problem the cold workshop or am i missing a trick?

Thanks for your time & any help.

_Dan

 

[SNight]

Maybe try using biscuits, or a tongue to join, as these will help align the joint, provide a larger surface area for glue, and also the biscuit joint will help hold together. There are also some router bits that produce a finger joint for this purpose, which again provides a larger surface area for glue. Hope this helps.

 

[goldeneyedmonkey]

Cheers, I think i will use dowels or biscuits. I know that a less than room temp' workshop is not ideal, but it's all I can afford @ the moment. As long as the piece is moved into room temp' for a week or so after it's glued it should be ok I think. Thanks again. _Dan.

 

[mailee]

How are you jointing the edges before you glue them together?

 

[Digit]

Some months ago I glued up some ten inch wide boards, some four feet long, as I expected your problem I used pocket hole screws to hold the lot together.
Now I know that the problem with pocket holes is that the timber can move as the screws go in, so I tried a different approach.
I made the pockets, the timber already having been thicknessed to finish size, then glued them together making certain that the result was flat. When the glue had cured, then I inserted the screws.
No problems so far.

Roy.

 

[9fingers]

Some months ago I glued up some ten inch wide boards, some four feet long, as I expected your problem I used pocket hole screws to hold the lot together.
Now I know that the problem with pocket holes is that the timber can move as the screws go in, so I tried a different approach.
I made the pockets, the timber already having been thicknessed to finish size, then glued them together making certain that the result was flat. When the glue had cured, then I inserted the screws.
No problems so far.

Roy.

Now that is what I call lateral thinking although maybe more correctly "lateral screwing"

Bob

 

[big soft moose]

I know that a less than room temp' workshop is not ideal, but it's all I can afford @ the moment.

couple of oil filled radiators in the workshop shopuld bring the temp up nicely - and they are cheap (less than 20 notes fropm aldi) - then you can leave one on low to keep the temp reasonable and whack them up to high when you are in the 'shop

 

[TEO]

Some months ago I glued up some ten inch wide boards, some four feet long, as I expected your problem I used pocket hole screws to hold the lot together.
Now I know that the problem with pocket holes is that the timber can move as the screws go in, so I tried a different approach.
I made the pockets, the timber already having been thicknessed to finish size, then glued them together making certain that the result was flat. When the glue had cured, then I inserted the screws.
No problems so far.

Roy.

Hey Roy, this lateral thinking/screwing is intriguing and I still don't quite get it, any chance of a pic please?
Cheers,
T

 

[Digit]

I can do some pics Ted but it was simply a case of cutting the pockets in the normal way then gluing up as for 'rubbed' joints, followed by the screws when there was no chance of the joint slipping.
Does that make sense?

Roy.

 

[TEO]

I can do some pics Ted but it was simply a case of cutting the pockets in the normal way then gluing up as for 'rubbed' joints, followed by the screws when there was no chance of the joint slipping.
Does that make sense?

Roy.

Thanks Roy, sort of make sense, at least I think I'm thinking what you're thinking, I'm still a little puzzled (maybe just V thick!), in a 1" thick board, how do you get the angle flat enough to pull the boards together? I don't have a pocket hole jig so maybe I'm just underestimating their capabilities.
If you can do a pic without too much trouble (say's he who looks forward to each camera/computer communication session with dread) then that'd be great.

 

[Alf]

As long as the piece is moved into room temp' for a week or so after it's glued it should be ok I think.

Better to do it before it's glued; with an unheated workshop and knowing the piece is going to be in a heated house, I've only moved the timber into the workshop as I worked it, moving it back indoors between times before now, otherwise you're just lining up trouble. Total pain in the posterior of course, but worth it. Just how cold is your workshop, 'cos that could play havoc with your glue too. Done glue ups indoors before now as well. And as mailee asked, how are you jointing the edges? A properly jointed board and modern glues should make any need for splines, biscuits and - heaven help us - screws totally superfluous.

 

[Digit]

The jig automatically gives the necessary angle to the pockets TEO, I'm afraid pics won't help much on that. I'll look later and see if I can find any vids on Google to show you.

Roy.

 

[9fingers]

Toby,
There is a picture of a pocket hole screw set up here.
http://www.woodnet.net/tips/assembly/dr ... ick-stock/

If you think of the right hand piece being another board, and the screw depth carefully controlled, maybe you can visualise Roy's method.

Bob

 

[newt]

I am with Alf on this one, if the edge of the boards are flat and square and the boards have been indoors for a few days; then there should not be a problem using a PVA glue. If the boards are machined in the cold possibly damp workshop, then brought indoor the edges need to be checked for flat and square before glue up. I would not glue up with PVA much below 10 degrees, you could always glue up a test piece first.

 

[goldeneyedmonkey]

Thanks for all the info chaps... I've freed up a room in the house for gluing, and getting boards adjusted to room temp. I think I will still stick to a more premium wood glue as it's not much difference price-wise, and I want the extra security as it will be in transit through a courier company when it's finished. I think the workshop is proving to be too cold in these winter months to justify gluing, so I'll just use it to work the wood.

Thanks again, you lot prove v.helpful. _Dan

 

[Benchwayze]

Gluing up boards:

In the winter I always glue up indoors, because SWIMBO allows this, as long as I take the necessary precautions to avoid glue drips!

You can get away without using biscuits or whatever, but the joints must be prepared properly, and also cramped up correctly.

To me that means 'T' bar cramps every 12" at most, across the job; on top and underneath, and two 50mm square battens across each end with large G cramps to flatten the work and keep it flat while it dries.
(You can never have too many cramps!)

Smaller jobs (skinny material) with a proper rubbed joint don't need cramping at all, as long as the air is removed by the rubbing. Just prop them against a wall, as soon as the glue grabs. If you need to join more than two lengths like this, do them in pairs. Less chance of the pieces folding up, which usually happens overnight!

HTH
John

 

[TEO]

Thanks Roy and Bob,
It is as I'd imagined I'd just not thought you'd be able to get flat enough to the first board to get a decent bite with a screw on the next one.
I've always used biscuits and so far I've not had a problem with joints moving or splitting, there's always a first time, fingers crossed it won't be on anything too important.
Cheers,
T