Old (really old) boards warping after sizing and planing - huh???

CelticRambler

For a simple jewellery box project, I thought I'd salvage some very old boards that I know had lovely colour and grain. Everything started well, planed them down from 20mm to about 8-10mm and left them to one side. A few days later, they're warped, all of them! :eek:

What's happening here ... and will it continue?

These are either oak (probably) or chestnut, about 300 years old, of which about 200 years were spent as the floor of an attic, smothered in a lime-and-straw levelling compound. Removed from the attic 15 years ago, they've been stored in a disorderly heap outdoors but under cover since then.

As far as this project is concerned, I can work with the warp (need relatively small pieces), but I'd planned to use the bigger boards for bookshelves and other furniture and really don't want those ending up twisted "artistically!" :pac:

tabby aspreme

If they have been brought inside you need to let the air get to both sides, to allow to dry out evenly, or they will warp, if you are planing them take an equal amount off both faces

magicbastarder

yeah, if they've been outside, it's been exceptionally damp of late and they've probably absorbed moisture. if you have a moisture tester, it's probably worth comparing some from outside vs. some from inside.

CelticRambler

tabby aspreme wrote: »

If they have been brought inside you need to let the air get to both sides, to allow to dry out evenly ...

magicbastarder wrote: »

yeah, if they've been outside, it's been exceptionally damp of late and they've probably absorbed moisture

I probably should indicate that there isn't really any difference between "inside" and "outside" here where I live! Doors open most of the day, no heating, no damp course (terra cotta tiles laid on a bed of sand over clay)!

Will try the moisture meter test out of interest.

recipio

Sounds like you live in a hot climate ?:D There are two problems. When you reduce wood down to small dimensions there are tensions in the wood that are then released . Some woods are worse than others although oak is fairly stable as a rule.
Secondly if the wood is stored outside it probably has a moisture content of 14 - 20 % .For stability indoors it should be about 8 - 10 %. I'm afraid warping is inevitable as the wood dries out.
Your best bet is to bring the wood indoors for about a month before working on it
and plane it evenly on both sides.
A moisture meter is a good investment even if they are pricey little items.

CelticRambler

It's 7°C outside in the shade at the moment, -2°C overnight!

Unfortunately, my moisture meter has decided to go a bit weird this week so I can't check anything, but I do seriously doubt that there'd be much difference between indoor and outdoor storage. I'll sometimes move cardboard boxes out into the barn to stop them from going mouldy when they're left indoors! I also have a huge stock of American softwood scavenged from a building site, stored in the same place, that doesn't warp after ripping and planing ... but that's not as wide as these boards.

It does seem like I need to build a more complete database of moisture levels for both rooms and stock though.