Gluing Cross Grain

[dzj]

Most people adhere to the practice of gluing only a few inches and fastening
the remaining length in one of the known ways.
I live in a place with continental climate and moisture levels do not change that much over the year,
so when making a piece for myself, I have the luxury of not always staying true to the accepted canon.
For example, 20 or so years ago, I built a coffee table out of beech and glued the 60cm wide top directly to the aprons.
A practice you'd be flunked at school for, but in spite of central heating, the table has no noticeable cracks or deformations of any kind.
Or these 35cm wide cherry side tables, with the tops attached in the same manner.

But I see I'm not the only one that does this:

So, I was just wondering, what are your experiences and can anyone else get away with this?

 

[MikeG.]

"Gett(ing) away with this", as you put it, isn't really my approach to woodworking.

I have lived in highly insulated, mechanically ventilated houses for the last 30 years. The internal environment is extremely stable, both in terms of temperature and humidity (none of these house would lose a degree in temperature over 24 hours if it was freezing outside and the heating had failed). Even in these conditions I have seen a glued-in panel split, and a poorly made boarded door bow slightly. I think that if you are making quite small items you'll be fine, but what are the chances of something you make remaining in your house for the whole of its life? Given the chance that it will end up elsewhere, I now take the view that building it with the traditional ways of allowing for wood movement is sensible........and frankly it is so easy that I can't see what the incentive is to do it any other way.

 

[stuartpaul]

From my experience the one thing you can guarantee is that wood will move and if you don't plan/allow for that movement you will find yourself having to carry out repairs and/or modifications.

You might have got away with it but wouldn't even try.

Interesting to see Mr Sellers apparently fully gluing an edge. Is that solid or laminated (veneered) he's gluing to?

 

[MikeG.]

There is actually no harm at all in fully gluing one edge, so long as the opposite edge is allowed to move. This is fully in line with all of the age old advice on the matter.

 

[Phil Pascoe]

Also in P. Seller's picture he is gluing a breadboard end with PVA. The PVA will allow a certain amount of movement and the tenons are undoubtedly over sized to allow for it as well.

 

[dzj]

Also in P. Seller's picture he is gluing a breadboard end with PVA. The PVA will allow a certain amount of movement and the tenons are undoubtedly over sized to allow for it as well.

Would you say that the amount of movement PVA allows is similar to that of seasonal expansion?

 

[Phil Pascoe]

I don't truthfully know - I've never tested anything to destruction.

 

[dzj]

From my experience the one thing you can guarantee is that wood will move and if you don't plan/allow for that movement you will find yourself having to carry out repairs and/or modifications.

Yes, this is the sensible thing to do. When working for a client it is also the path I take, as I don't have the luxury of doing a job twice.
Having said that, there are times when cross grain gluing works, even though WW theory suggests otherwise.
I was hoping people might share any experiences when such glue-ups didn't self-destruct.

 

[dzj]

There is actually no harm at all in fully gluing one edge, so long as the opposite edge is allowed to move. This is fully in line with all of the age old advice on the matter.

Why would he glue only one edge?

 

[Sheffield Tony]

Before I knew better, I tried to do something very similar to what Mr Sellers appears to be doing with a hinged lid made from beech. When brought in from the workshop the mitres opened and looked awful. I ended up sawing the ends off and replacing with wider, proper, breadboard ends, like so:

It has always seemed to me that design to produce stable structures, using a material which moves constantly but in known ways, is what woodworking is all about.

 

[custard]

I do quite a bit of inlay and stringing work. I've seen cross grain stringing that's just 50mm long pop out of it's groove after a few years. Consequently if I want to run cross grain stringing I go to the enormous hassle of cutting the inlay itself cross grain so it lines up with the base timber. It adds a huge amount of effort, time, and frustration to a job; but I think it's worth it.

Where as it's true that the risk of timber shrinkage is often overstated, neither do I believe in being cavalier about it.

 

[thetyreman]

another important point to add is that sellers deliberately uses real mahogany for that table, it's not sapele! making it a lot more stable, that decreases the risk of the mitre shrinking massively.

 

[MikeG.]

There is actually no harm at all in fully gluing one edge, so long as the opposite edge is allowed to move. This is fully in line with all of the age old advice on the matter.

Why would he glue only one edge?

My mistake. I completely mis-read the photo. I thought he was gluing a top onto a cabinet.

 

[Phil Pascoe]

I did a double take on that - it wasn't just you.

 

[dzj]

another important point to add is that sellers deliberately uses real mahogany for that table, it's not sapele! making it a lot more stable, that decreases the risk of the mitre shrinking massively.

The choice of material does affect the amount of expansion. If one is to trust US Forestry dept. charts, a 40cm wide Mahogany
panel will expand/ contract about 2-3mm in the course of a year. WW theory suggests that constricting such movement by gluing the entire length of the breadboards is asking for trouble. And yet he does it.

 

[dzj]

I do quite a bit of inlay and stringing work. I've seen cross grain stringing that's just 50mm long pop out of it's groove after a few years.

Do luthiers in your area have similar problems with purfling on cellos or DBs?

 

[Mr T]

So, I was just wondering, what are your experiences and can anyone else get away with this?

To address the OP's original point. My first ventures in woodwork, other than at school, was at an evening class in 1975 where I made a sewing box in Japanese oak (more common then than now). The teacher was quite cavalier about wood movement so the top, with mitred bread board ends, was glued the whole length. I have always been amazed that it hasn't suffered with movement as we have moved from house to house over the years but it seems to have held well. It's 430mm x 320.

The mitres have also held.

The sides, 290 deep, where also glued the whole length. One has held up well.

But the other has not.

This is a good illustration that sometimes you get away with it, but others you don't. It's for the times you don't that you take precautions, bit like sex and contraception I suppose!

As for Mr Sellars, it just goes to show that even saints are fallible!

(Not sure why a couple of pics came out sideways! Or why there's an extra one at the end!)

Chris

 

[dzj]

But the other has not.

Chris

Greene, in his book American Furniture of the 18th Century mentions a technique sometimes employed when
gluing wide sides of casepieces:
"When the piece is being assembled, the sides can be clamped tightly across the
grain to put the entire side into compression.The clamps are left in place until the glue in the
joints has cured. Once the clamps have been removed and the joints have been pegged, the
sides will continue to be in compression. When the piece is exposed to lower humidity, the
compressive force will decrease. The precompression will prevent or at least drastically
reduce the possibility that the side will experience enough tension to crack as its moisture
content drops."

Haven't tried it, but sounds like it might work.