Drying of pepper-mil blanks

[Willem Martins]

Purchased wet well waxed pepper mill blanks for a good deal in a few species. 3" x 12"

Started the first two Ambrosia Maple ones, turned them round and drilled a 3/4" hole right through. Left the ends fully waxed as supplied.

Weight each after turning around 1,200 grams, moisture meter gave me an "OL" reading whatever that meant?

Two weeks later, open in my shop lying on a roller stand the weight is now down to around 450 grams. Moisture meter says 18%. No cracks, very little deformation.

I thought this would take months, rather surprised at the progress.

Any experience from members appreciated?

[Roger Chandler]

The fact that you drilled the inside makes it possible to reach an equilibrium a lot faster and probably with more stability.........you have air to the inside and outside, so moisture can escape on an even basis. If I were you, I would weight them again in a few days and if they have not lost much more weight, I would go ahead and finish the mills.............you can put a finish on and they should be good to go!

[Pat Scott]

"OL" on a moisture meter means "Over Limit", meaning the reading is higher than the range the meter can read. A lot of meters top out at 30% or 40%; if you read OL then you are above these limits.

It's common for wood to lose a lot of moisture at first, but don't interpret this as the wood is dry and ready to turn. A 3" cylinder with a 3/4" hole in the middle still means there is 2-1/4" of thickness. While you might lose moisture faster from the area exposed to air, once you get down inside the wood it can still be wet. My Wagner moisture meter only measures down 3/4", so any deeper than this and I'm not able to measure with my meter. If you go by the common practice of "a year for every inch", then you'll want to wait a couple years for a 2-1/4" blank to air dry.

The problem you'll have making a peppermill with a blank that isn't completely dry is that as the wood dries out more it will move, and when it moves it will go oval - no matter how slight -and now the top can bind when turned. If you rush the process and turn the mill and apply finish, the finish will slow down moisture loss just like green wood sealer does, but it will not stop movement completely and you can still have a binding top.

I don't think moisture will escape on an even basis in this example. I can't see how air movement inside a 3/4" hole can be the same as the outside that is completely exposed to surrounding air. I say the inside will dry slower than the outside - even with a hole.

[Quinn McCarthy]

Roger is right.

This is justmy opinion I wouldn't use anything but KD wood for pepper mills. When they are dried to 7-8% they will be more stable and not twist or warp. I buy KD and still check with a Moisture meter. Most of my grinders are 18"+. SOme people think that the longer you air dry a piece of wood the drier it gets. That is incorrect. Once the blank reaches equilibrium it doesn't get any dryer.

Hope that helps.

Quinn

[Willem Martins]

"OL" on a moisture meter means "Over Limit", meaning the reading is higher than the range the meter can read. A lot of meters top out at 30% or 40%; if you read OL then you are above these limits.

It's common for wood to lose a lot of moisture at first, but don't interpret this as the wood is dry and ready to turn. A 3" cylinder with a 3/4" hole in the middle still means there is 2-1/4" of thickness. While you might lose moisture faster from the area exposed to air, once you get down inside the wood it can still be wet. My Wagner moisture meter only measures down 3/4", so any deeper than this and I'm not able to measure with my meter. If you go by the common practice of "a year for every inch", then you'll want to wait a couple years for a 2-1/4" blank to air dry.

The problem you'll have making a peppermill with a blank that isn't completely dry is that as the wood dries out more it will move, and when it moves it will go oval - no matter how slight -and now the top can bind when turned. If you rush the process and turn the mill and apply finish, the finish will slow down moisture loss just like green wood sealer does, but it will not stop movement completely and you can still have a binding top.

I don't think moisture will escape on an even basis in this example. I can't see how air movement inside a 3/4" hole can be the same as the outside that is completely exposed to surrounding air. I say the inside will dry slower than the outside - even with a hole.

Thanks for the detailed reply.

The thickness to dry is (3-3/4)/2 = 1 1/8"

Kiln dried is first prize, but hard to get with some species and figure.

I may stand the two drilled blanks up on one of my floor air conditioner vent outlets, to get some dry air flowing and hopefully speed up the process.

Will keep on weighing and update on progress.

PS. I do a lot of wet bowl blanks, dry this way and turn once dried.

Picture below. (Juniper 8" dia 5" high)

http://i300.photobucket.com/albums/nn2/Jellyrug/002-5.jpg (http://s300.photobucket.com/user/Jellyrug/media/002-5.jpg.html)

[Paul Williams]

That juniper is a neat looking bowl.

[Pat Scott]

Quinn I agree that "Once the blank reaches equilibrium it doesn't get any dryer", but the point I was trying to make is the inside is going to dry slower than the outside because there is not as much air movement through the hole as there will be on the outside.

Willem, you're right about the math, my bad.

[Willem Martins]

Progress so far:

May 7th = 1269 grams OL
May 19th = 915 grams 18%
May 26th = 812 grams 18%
June 5th = 755 grams 18%

So although we are coming down nicely in weight due to drying, the moisture meter stays around 18%. Guessing the water is coming from the inside and evaporates from the skin, leaving the moisture meter readings constant? No cracks so far, so good.

http://i300.photobucket.com/albums/nn2/Jellyrug/photo16_zpsabde75bf.jpg (http://s300.photobucket.com/user/Jellyrug/media/photo16_zpsabde75bf.jpg.html)

[Willem Martins]

Update

Lost patience and put this in my food de-hydrator for 3 days at 158F. Now it weighs 641 grams, still no cracks, but moisture is 0%. So now I have to wait for it to get back to around 8%. :p

Learnings here for future is dry wet blanks for a month, or to about 22% MC, then into dehydrator starting at 100 F and going up in temperature until it gets to around 8%.