Does wood age?

[Suffolkboy]

My father stores oak timbers for boats underwater in his dock, keeping them submerged means that when they are steamed they go really pliable and rubbery, you could probably tie a knot in some of them. They don't suffer any ill effects.

 

[Sgian Dubh]

My father stores oak timbers for boats underwater in his dock, keeping them submerged means that when they are steamed they go really pliable and rubbery, you could probably tie a knot in some of them. They don't suffer any ill effects.

That's interesting. Presumably he's a boat builder, and I'm guessing it's his business, or he's a serious amateur?

It's a fact that wet wood steam bends significantly easier than dry wood, and the drier it is, the less compliant it wants to be, and that even applies to some extent if very dry wood has been allowed to regain moisture up to FSP prior to steaming. This is because of a hysteresis effect whereby cell walls that have become very dry (say to about the US furniture wood kilning target of 7% MC) never again become quite as supple as wood that's never gone below FSP.

From a furniture maker's point of view, probably the best compromise in terms of dryness, is wood that's been air dried to about 20% MC prior to steaming. This means that some of the drying distortions and other faults that occur during seasoning can show themselves, and if necessary be rejected, but the wood remains that bit more amenable to steam bending than very dry wood.

Of course, very dry wood can still be steamed and bent, but it tends to be a bit harder to execute than with wetter wood, and more likely to show larger crumpling on the concave side of the bend, and similarly, more likely to experience long grain splitting and tearing on the convex face. I've steam bent both dry and wet wood myself several times over the years, although it's never been an everyday practice for me - just as and when needed. And I've more than two or three times demonstrated to learners that it is possible to tie a loose knot in something like steamed beech dowelling that was roughly 12 mm in diameter. Slainte.

 

[Andy Kev.]

I went to a play on Friday night which was staged in the castle near where I live. At least half of the chairs looked to be well over a hundred years old: tremendously ornately carved backs and legs with more turning than you could shake a short stick at. I actually wondered about potential fragility and chose something more modern looking with a woven seat.

Across the aisle from me one of the ancient looking chairs had attracted a fat bloke. About half an hour into the performance the inevitable happened: there was a loud crack followed by a nearly as loud boomph and then there was a fat bloke on the floor surrounded by unjoined bits of joinery. The bloke behind him was clutching one of the highly turned legs, not quite knowing what to do with it.

There might be a moral to this story and I wouldn't like to say exactly what the implications are for the ageing of wood but it does seem a bit relevant. Oh, and I managed not to laugh.

 

[MJP]

I wonder, Kev -was the failure initiated by the glue or the wood?

Martin.

 

[Suffolkboy]

Yes he's a boatbuilder, it's his business, so was my grandfather and great grandfather. I have worked for dad on and off in the past and my brother has gone into it. I don't really possess the skill/patience to turn out the standard of work that they do but I still pursue some woodwork as a hobby though.