Drying timber for furniture use

[Woodmatt]

I have a ready local supply of Air dried hardwoods at great prices and I am planning to make various piece of furniture.From what I have read the MC is likely to around 20% but needs to be around 8% for bedroom furniture. What would be my best course of action to be sure my final pieces will not warp,twist,shrink or swell when finally in use,Thanks in advance for any advice.

 

[Rhossydd]

Most advice for hobbyists I've read, and I follow myself, suggests rough cutting the timber then bringing it into the house and leaving it for several months to acclimatise before final cutting to size.
For a set of bedside cabinets I finished at the start of this year I bought air dried waney edged boards in Dec 13 and kept them in my garage workshop for a couple of months, then rough cut down and stacked the components under our bed for five months before cutting down to sizes much closer to the finished sizes, then leaving tehm again for a couple of months to see if anything moved, it didn't so then I could finish to size and get making.

 

[Woodmatt]

Thanks for your reply Rhossydd.Your advice is more or less what imagined I would need to do except the period of time after initial rough cut is much longer than I though it would be.

 

[Rhossydd]

the period of time after initial rough cut is much longer than I though it would be.

A lot will depend on how dry the timber is to start with. "Air dried" covers a big range of moisture content, similarly domestic houses vary a lot too. So don't assume my practice is 'normal', I wasn't in a hurry and could possibly have used the wood sooner.
Thickness of the timber will also make a difference to how quickly timber adjusts. Drying will be proportionally faster with thinner 1" boards than 3".

As discussed elsewhere on the forum at the moment, a relatively simple and reliable way to see how wood is drying is by weight. A cheap pair of digital kitchen scales covers up to 5kg with a high degree of accuracy. Try to cut a representative rough part within that range and weigh it, then weigh it every week or so to see how it changes. Once the weight starts getting stable, you can get on with construction knowing it's not going to go bananas.

Working with hardwood is hugely satisfying, but not always something for people in a rush. It's worth taking your time to get wood to a good MC, it makes working with it easier and you'll get less problems in the long term if it starts stable to it's environment.

 

[koemanrob]

Yep it takes a while, though it's always a bit of a guess without a moisture meter. I've seen someone use a makeshift kiln in a workshop made using foam insulation and a dehumidifier if you want to hurry things along a bit.

 

[Tetsuaiga]

Seems like getting the wood into an environment matching its final environment and then waiting till it stops losing water mass.

I want to try this myself but i'm not sure which scales I should use. Especially as I have some fairly large boards which I don't want to cut into smaller lengths yet. Maybe just some digital bathrooms scales would be good enough, when it comes to the actual numbers is where i'm lost, suppose I could just experiment and see if they sense a change.

 

[Woodmatt]

Thanks Rhossydd for the scales idea,like Tetsuaiga not to sure about the scales but will also try bathroom scales and let you know how it goes in a couple of weeks,hopefully after a change in weight.