Thread: Confusion

If I understand correctly you want to glue an edge along some end grain or across the grain of the timber.
The reason that this is a no-no is that wood expands and contracts more across the grain than it does along the grain of the timber.
What then happens is that the two expand and contract at different rates and the structure pulls itself apart.
That's why in things like box lids that have a frame all the way around, the enclosed panel "floats" inside a groove allowing it to move as it swells and contracts.
Cheers
SG

Hey SG,
Thanks for your reply.

So if I edge jointed say 3 boards that were 500longx200mmwide for a table top. And inbetween each of those board I used a different type of wood say 500x20mm and glued it up. What I don't understand is why I then can't get another species of timber and glue it along the long grain? I understand if I glued it to the end grain it would create an inbalance in the movement as they expand and contract at different rates.

On a side note, do people glue their floating lids in boxes? I always allow 1-2mm for the lid to sit in the rebate and put a tiny bit of glue on the end grain?

Originally Posted by groeneaj

Hey SG,
Thanks for your reply.

So if I edge jointed say 3 boards that were 500longx200mmwide for a table top. And inbetween each of those board I used a different type of wood say 500x20mm and glued it up. What I don't understand is why I then can't get another species of timber and glue it along the long grain? I understand if I glued it to the end grain it would create an inbalance in the movement as they expand and contract at different rates.

OK, in this instance there is not really a problem as long as the timbers are compatible. Different timbers can still have different expansion rates even along the grain. I think it would work OK if the timber types were similar. You can imagine that say red-gum and cedar would not work.

On a side note, do people glue their floating lids in boxes? I always allow 1-2mm for the lid to sit in the rebate and put a tiny bit of glue on the end grain?

I usually put a drop of glue in the middle of each end of the panel to hold it in place - that's all - the rest floats and if it moves enough to break the little glue spot, well - no harm done.
Cheers
SG

Thanks for the reply

Have a look at the butchers block episode on here that uses end grain blocks. They are still cut at a taper so that expansion raises the bench surface rather than splits the sides of the 'frame'.

New Yankee Workshop Episodes

To find do a search on the site (Ctrl F) and use 'butcher' it will show you which NYWS episode.
Careful of the size though 54.4 MB.

Cheers.