Acclimatise

[srt]

Hello all again i have some oak semi prepared for a chair its all about 22-25 mm thick and i have it in the house to acclimatise,how long should i keep it in for before working with it roughly?

 

[Lord Kitchener]

Is it kiln dried? If it is, you won't need to keep it in the house for more than a couple of weeks, but if not, you are probably talking months, depending on how well dried it was. If you don't want to buy a moisture level meter, you can do quite well with a digital caliper, just measure a test piece, marking carefully where you place the caliper, making a note of the measurement to at least 0.1mm, then check it every week to see when it stops (or slows down to almost stopped) shrinking.

 

[woodbloke]

Hello all again i have some oak semi prepared for a chair its all about 22-25 mm thick and i have it in the house to acclimatise,how long should i keep it in for before working with it roughly?

If you don't know how dry it is, you're best playing safe. Air drying per " of thickness should take around a year to bring it down to 20%ish MC (moisture content) but this is not low enough for CH houses. Further conditioning in a moderately cool room (a bedroom is ideal) is needed to bring it down to around 8-9% which could take several months (at least over the winter) so that you'd be ready to start the making in the Spring (assuming that your 'shop has no heating) - Rob

 

[srt]

i bought this a couple of weeks ago from my local timber merchant and it is kiln dries but was siiting out in their timber shed.

 

[woodbloke]

i bought this a couple of weeks ago from my local timber merchant and it is kiln dries but was siiting out in their timber shed.

...in which case the MC will be higher than when originally kilned. Imagine timber as a sponge, soaking up and giving up moisture according to the prevailing conditions. If it was dry straight out of the kiln and it's been outside where there's more moisture in the air, the MC will have risen. Best to further condition it indoors for a few months at least, making sure that there are sticks 'twixt each board - Rob

 

[yetloh]

Another very simple and sensitive way to measure acclimatisation is simply to weigh the wood very week. When the weight stabilises you will know that the wood has acclimatised to its environment. I suspect that weghing will be a more sensitive method than using a digi caliper, but if you do use that method, measuring width will give you a more sensitive measure than thickness.

Jim

 

[condeesteso]

Very good point re weighing, and in say a bedroom (moderate cool house environment). There are experts who handle wood all day that can just tap it with a knuckle and guess within 2 percent or so. I'm not good enough to do that, but you can certainly hear the difference between crispy dry and 'not ready yet'. Worth a go as a side-line anyway and an impressive ability in those that really can judge the difference.