Table Top Edge Jointing

[Anonymous]

Another query,

I do alot of edgeto edge jointing on solid wood table tops.

I never use dowels or biscuits, only PVA, rub joint and sash cramps.

The reason I don't use the above is mainly due to the time factor.

I don't think this way of doing it is any less strong. Also, Victorian and Georgian cabinet makers very rarely used dowels, just relying on the glue
itself and scotch glue at that!

Anyone agree? or would you always use the biscuits and dowels and think that glue on its own is weaker?

Regards

 

[sawdustalley]

Personally I pretty much ALWAYS use biscuits, as they are so simple.

In ye olde days they often used tounge and grooves. But with todays modern glues, your edge joining is probably fine. I always pass the board through my jointer aswell, this keeps the joint nice and snug and tight, so minimal stress is on the joint...

 

[Anonymous]

"always pass the board through my jointer"

Don't bother with these new fangled machines! I Do it all by hand with a Jointer Plane!!

I wish I didnt have to do it by hand, but because I'm using old table leaves most of the time they are not always flat. If planing them on a machine, if the face of the leaf is out then it would be very difficult to get a square edge. Very tricky!!

Actually you're making me think a bit here. I'm assuming I'm right?

 

[johnelliott]

This is a good subject for me. I like making table tops. I start by cutting one straight edge on the board (easy with my EB PKF255), then rip the other edge parallel, then plane and thickness on my Kity 1637. Then I lay the boards out to select the best grain arrangement. I mark face with the planing direction. Next I plane the edge on the Kity, in the marked direction, then turn the adjacent board around and plane it the other way, so that any inaccuracy setting the fence cancel out, and so on across all the boards.
When all is ready I set up the Plano glue press, glue the edges and load the boards into the press. If I didn't have the Plano I would probably use biscuits, but only to help aligning the edges, they really aren't necessary for strength.
I realise you guys have equally sucessful methods, the above is mine. I tried it once with sash cramps many years ago, didn't get on with them very well. When I first saw the Plano at a show I couldn't afford it, but I knew I wanted it.


Matstro, I don't understand about your method re the warped table leaves. Surely you must have to pull the faces flat when you glue them, which would mean that the edges wouldn't be straight anymore?

John

 

[sawdustalley]

Yeah. I've been in a shop and used the Plano clamps before. Very good.

Biscuits actually swell up in the joint, and do form a stronger joint because of this, and also because of the increased glue surface area.

 

[Anonymous]

biscuits dont add that much strength to laminated (edge jointed) table tops, but they make lining the joints up a damn site easier. the time you spend biscuiting loses itselfe when you come to clean the table top up.
just a quick note on old glue versus new. pearl glue isnt always 'weaker' than pva, just a bit more hassle to use. I would tend to use a uf resin (cascamite.....) for laminating table tops, pva is still plastic when it dries and can alow joinst to 'creep' apart .

doughnut

 

[Anonymous]

John,

Its an interesting subject!

Bear in mind I'm a restorer not a maker so not dealing with wood I can prep nicely!

The problem goes like this. I make up leaves for antique diningtables, usually wind out ones. I start out with old leaves from other sources ie other tables, wardrobe sides etc. Because these leaves are old, they are often cupped, warped, twisted, wavy along the length or across the width!
Not too much but just enough to matter. Often I have to join parts of leaves. If the part leaf is slightly warped etc I have to shoot the edge bearing in mind how bad the warp is. ie You either shoot the edge at right angles to the face and when you cramp you make sure the whole lots flat. On releasing the cramps in this case the glued timber will warp again but will be pulled down again flat to the frame when fixing. If the warp is bad then when pulled down flat sometimes the glue line will break.

The other way is, as said ,if the warp is bad, I dont plane the edge 100% square to the face. ie I average it. You then get left with a top that can be slightly corrigated. Very, very slightly that is!

The above is the problem. Machines are precise, all or nothing and little leeway, whereas by hand you can adjust and adapt as you go, bearing in mind the way the wood is.

This whole business has me tearing my hair out at times. Granted I havnt used a machine for this. I instinctively feel I'm asking for probs. if I do!

The only thing I'm going to ensure by machine is a dead straight edge. No small thing BTW!

I must admit, talking about it has me thinking though!!

Get back if you disagree! I'm always open to better methods!!

Regards

 

[Anonymous]

Doughnut,

To be contoversial? I wanted to come back about the cascamite?

I've used casamite loads in the past. The thing is cos it dries hard and brittle, its got no give. ie its either glued or its not. Sometimes you need a slight flexibiliy eg chair frames. PVA on the other hand because its slightly flexable will withstand knocks and jarring and not "break apart".

Actually PVA does dry pretty hard I think, when its dried properly.

I've used cascamite on jobs and joints have "cracked" on me. Don't use it nowadays.

Scotch is good if you work like lightening and in the summer only!!
Trouble is I have to use it alot in my trade because its what was used in the furniture originally. Very stressful, gluing up a chair on a cold winters day when the glue gels soon as it comes out of the pot!

I wonder what others think?

 

[Anonymous]

Oh yes I agree 8) We woodworkers should stick together :lol:

Steve

 

[Anonymous]

If you have ever veneered with pva (especially bookmatching) you will realise it creeps. PVA feels hard when it sets, but trust me. Its NOT.
As for cascamite cracking. Yes it does if you have a wide glue line. If your joint is good, it wont crack. (hand shooting of edges is required for a perfect joint.)

Doughnut

 

[sawdustalley]

While were on the discussion of glues. What do you think about plyurethene glues. Like gorrilla glue, or titebond?

Personally I like them.

 

[johnelliott]

I've used a variety of glues, eg at one time I used Aerolite 306 to join rosewood to maple (guitar fingerboards). For edge to edge joining I have always found PVA to be entirely adequate, as long as the edges meet properly
John

 

[Anonymous]

Ok Doughnut, fair enough! Don't think I'll use much of the cascamite though cos I've still got to mix it up!

James,
Polyurethane Glue.

Personally I hate it!

I use dTitebond for the first time the other month. Cost me a fortune to buy. I absoloutley hated the stuff. There seems no strength at all if there is any amount of gap filling happening. Its quite soft and crumbles dosnt it? Apart from anything else, getting it on your fingers is a disaster!
Horrible, horrible, horrible!!! Back to the extra fast PVA I think. When not using Scotch, that is!

Regards

 

[Anonymous]

Just to throw a spanner in the works, and make a few purists spit :lol:
The other year I was sent a stick chair to repair. The glue line had dissapeared ages ago, and the chair had been holding together under its own weight. With no glue to hold the joints the spigots gradually wore smaller and smaller in their holes, and eventually the chair fell to pieces. whenIi came to repair the chair, the gaps between the joints were so big no ordinary glue would bridge them.
In the days before the chair was delivered to me, I had been doing a second fix joinery job (skirting dados etc), and I had half a tube of 'GRIPFILL' left :twisted: . Lets just say that after two years of daily use, the chair is still as stable as the day it left the workshop.

Doughnut

 

[kityuser]

ah gripfill................

commonly known as "shop-fitters mate"

wonderful stuff, sets like concrete and makes a superbly strong joint.

good for construction, not sure about cabinetry though :?

 

[Anonymous]

Doughnut,

A belated reply to your gripfill suggestion!

As a result of what you have said, I'm going to go out and buy a tube.
Ordinary glue for this type of application is useless, the legs always work loose again.

I'm always open to fresh suggestions and its important not to get consumed with whats "the right way" and "whats the wrong way" to do things.

So, just to say thanks for the info! Mind you, if I try it and it doesn't work I'm coming back on here to tell you that I think it's a rubbish suggestion and that it's rubbish!!!

Regards