Woodworkers Advice Please - Oak Table Heat Shrinkage

[SwingsitlikeHogan]

An extendable oak dining table we have in our conservatory was subject to a lot of heat during the very hot spell and developed a 4” crack in one of the table top leafs, and the two leafs have ‘shrunk’ and now don‘t come together. More accurately the edges of each leaf touch and the rest has shrunk back. Are we scuppered on either or both of the crack and the two leafs.

 

[GreiginFife]

An extendable oak dining table we have in our conservatory was subject to a lot of heat during the very hot spell and developed a 4” crack in one of the table top leafs, and the two leafs have ‘shrunk’ and now don‘t come together. More accurately the edges of each leaf touch and the rest has shrunk back. Are we scuppered on either or both of the crack and the two leafs.

The crack, yes most definitely. That won't knit together again. There is a very minor possibility that any form of humidity will swell the wood again to resolve the shrinking, but it's unlikely.

Wood moves, you can't stop it. All you can do is plan for it and try and prevent it. Carpenters will use methods like smaller boards (narrower) alternated in growth ring pattern to try and prevent cupping and moving. Or using dowels/dominos/biscuits to try and stop movement. None of them are full proof. Oak is especially difficult to work with and probably maintains a 8-12% moisture content when all is well. But left in direct heat, any changes to that content will cause movement (always across a board, not along it).

For the crack, assuming it's not 4" wide and is long but narrow, you can either sand the table top or get a piece of oak and sand it, collect the sanding dust and then mix the dust with white wood glue to make a "self colouring" filler.

 

[SwingsitlikeHogan]

The crack, yes most definitely. That won't knit together again. There is a very minor possibility that any form of humidity will swell the wood again to resolve the shrinking, but it's unlikely.

Wood moves, you can't stop it. All you can do is plan for it and try and prevent it. Carpenters will use methods like smaller boards (narrower) alternated in growth ring pattern to try and prevent cupping and moving. Or using dowels/dominos/biscuits to try and stop movement. None of them are full proof. Oak is especially difficult to work with and probably maintains a 8-12% moisture content when all is well. But left in direct heat, any changes to that content will cause movement (always across a board, not along it).

For the crack, assuming it's not 4" wide and is long but narrow, you can either sand the table top or get a piece of oak and sand it, collect the sanding dust and then mix the dust with white wood glue to make a "self colouring" filler.

Cheers. My dad (was an old school cabinetmaker) showed me how to do the sawdust thing to fill cracks so I’ll do that. Can’t see there being anything I can do to pull the leaves together… And though my dad did showed me how he could bend wood i don’t think it’d work for what I need - even with v long clamps.

 

[GreiginFife]

Cheers. My dad (was an old school cabinetmaker) showed me how to do the sawdust thing to fill cracks so I’ll do that. Can’t see there being anything I can do to pull the leaves together… And though my dad did showed me how he could bend wood i don’t think it’d work for what I need - even with v long clamps.

Steaming the wood (or submerging in hot water) is, as you say, for bending the wood by relaxing the grain along it's length (hence the bend) but won't do anything for shrinkage, which is across the grain. If you have a tumble drier, you could run it in the same room as the table with no vent to try and create false humidity. But that could risk damage to walls and other things.

Re-making the table top is an option. But with the prices of oak, that's maybe not palatable.

 

[fundy]

another post for the ask Greig anything thread

 

[BrianM]

If you are ever up this neck of the woods Greig, give us a shout, my old man has a workshop and makes bespoke furniture, staircases, doors and windows.
We do loads of work for historic Scotland, mainly sash and case windows.
Get you in for a visit and see what other toys you need ??

 

[Tashyboy]

another post for the ask Greig anything thread

I started it though ??