Drying time for pepper grinder blanks

[TongueTied]

I have some Mango wood salt and pepper grinder blanks. From what I can tell, they were cut in about August/September 2015 so they have been drying for a bit under a year now. I turned one today and as you drill out the centre with a fostner bit, it gets very hot, as you well know. Well, when I was nearly through drilling the blank, I noticed a lot of moisture at one end. There was so much, that it was seeping out and was all over the chuck. So, I guess, it isn't dry yet but it does make me wonder, how long would such a blank typically take to dry?

[Gabriel]

I did the exact same yesterday with some mulga that I have had in my possession for 3 years, and was seasoned for 4 years before I got hold of it. As you say, I too noticed some moisture. I have finished turning one of them, and haven't noticed any issues. I think, being pepper grinders that you drill the whole core out of it, may help with reducing checking (mine were whole branches with heartwood). I have had another (same moisture) finished gor about 4 weeks now and again no signs of warping or cracks.

So from my experience it shouldn't be an issue, but I'm certainly going to be interested in other people's opinions

Cheers
Gab

[John.G]

How long it takes to dry a piece of wood is subject to a lot of variables.
How thick is the piece of wood obviously has to be taken into account. There's an old rule of thumb around allowing an inch per year of thickness - but that can be down to 3 months for thin sections in some species and for thicknesses over 75mm it might take several years over the rule.
What species is the wood is a factor - water can just about run through some porous open grain species, but that also means that water can just about run back in: ie they'll dry fast but they will re hydrate fast too. Hard dense species dry far slower.
How the timber has been stored has a major influence: timber stored with little or no airflow wont dry as fast as timber with good air circulation around all sides.
Ventilation is a factor... the same air circulating around and around is not the same as fresh air circulating in.
Where you are is a factor: places with dry air make for better drying then places with wet air. Also it effects EMC, which means that the wood can be at EMC for where you are and is never going to get any drier but the local environment will not allow it to dry down further so its "dry for where you are" which might mean its still carrying a fair bit of moisture. The moisture content to which wood will dry is directly related to the external temperature and humidity.

You're on the Sunshine Coast, so my WAG would be EMC is around 10-12% depending on how far inland you are. Assuming good storage conditions with adequate airflow, a 75mm thick grinder blank in a species like mango would take probably the expected three years to dry. If the storage conditions dont allow for air circulation it might take 4 or 5.

This is why sawmills invest so much money in kilns: except for GOS framing there is little market for green timber, and we cant afford to have money tied up in "unusable because its not yet dry" boards for years.

[dai sensei]

JohnG is on the money. Time is a pain for the impatient, that's why I got one of these 8 Food Dehydrator Commercial Preserve Yogurt Fruit Dryer Jerky Maker | eBay (http://www.ebay.com.au/itm/8-Food-Dehydrator-Commercial-Preserve-Yogurt-Fruit-Dryer-Jerky-Maker-/350642208217?hash=item51a3e77dd9:g:CxsAAOSwll1WxQYD) Perfect for pen blanks but I take out every second tray and then it fits pepper grinder blanks.