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Most of my turning to this point has been pepper mills and pens. Wait a minute,,, ALL of my turning to this point has been pepper mills and pens!
As I look for more interesting wood, I notice that some isn't kiln dried and probably has a high moisture content. If I wanted to turn a pepper mill using this wood, would I need to let it dry out first? Or,,, would I turn it green and then let it dry? In either case, is there an merit in trying to accelerate its drying, or would that just invite cracks?
 

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Wood may be kiln dried,,air dried or green. Kiln dry should have lower moisture content than air dry which should have lower moisture content than green.

Green wood is normally recently felled, or has not been allowed to dry due to sealing the ends, etc.

Green wood has two types of moisture - free and bound. A given species may contain more or less free moisture.

The free moisture is between the cells and will fly all over the place as you turn.

The bound moisture is within the cells and this takes time to dry.

Any time the moisture content of the wood is different than the surroundings, the wood will want to loose or gain moisture. For most people the wood is higher in moisture than the surroundings, so the wood looses moisture.

If you have a moisture meter, measure the wood when received.

If you do not have a moisture meter and are concerned about the wood moving as it dries, cut off a piece and weigh the item. Note the weight. Every week take another weight reading. If the piece is loosing weight, it is still drying.

If you turn a piece to finished shape and dimension and it looses moisture, you have the risk of warping, cracking, generally changing the shape.

Most people rough turn green wood. Set the piece aside for weeks or months and then when it has reached equilibrium they turn to final shape and dimensions.

One method to accelerate drying is soaking the piece in alcohol, often called DNA (DeNatured Alcohol). Here is one article by David R Smith on this topic.

http://alcoholsoaking.blogspot.com/
 

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Wow, Dave! Good summary. Save that response to use again.

Since Dave's fingers got tired I'll throw in the microwave technique which can have pretty good success if you are careful. I bat about 500 with it so I don't try it with precious wood. The idea is to heat the water evenly throughout the wood to the point of steaming and letting it cool in the oven, a paper bag, an open plastic bag or something to keep the surface from drying to fast. Several cycles can dry a small blank in an afternoon, theoretically. There are many variations of this technique so I'd advise searching for and reading a few threads about it before trying it.
 

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Wow, Dave! Good summary. Save that response to use again.

Since Dave's fingers got tired I'll throw in the microwave technique which can have pretty good success if you are careful. There are many variations of this technique so I'd advise searching for and reading a few threads about it before trying it.
Thanks trying to cover most of the bases. :thumbsup:

I was pondering about microwave drying, but since I almost burned up my microwave with my first experiment I decided to leave this alone.

A recent meeting of the local woodturners club had a bowl which looked great on the outside and for most of the inside, but at the bottom was a burned spot.

The person had been drying in the microwave, and forgot that microwave heats from the inside out, so he burned the inside. He smelled something burning, but did not seen any damage, until he turned the bowl and exposed the burnt spot.

Microwave drying can work, but you need to be careful. Only heat for short periods of time, as in a few seconds. Then let rest for e.g., a minute and repeat.

Look on the internet for more information and as Bonanza35 said - try this on an inexpensive piece first. A piece which you are willing to convert to scrap. :icon_smile:
 

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Microwave drying can work, but you need to be careful. Only heat for short periods of time, as in a few seconds. Then let rest for e.g., a minute and repeat.
I have a "workshop microwave" (don't try this with the one in your kitchen :no:) and have had success the 3 times I've tried it.

Here's how I would do a rough-turned bowl (say 9" diameter, about 1" thick walls.)

First, I weigh the piece. (Digital scale from Harbor Freight, in the region of $12 on sale.)

Then blast it for 90 seconds -- leaning backwards some, open the door of the microwave to let the steam out.

Take the piece out, weigh it. Allow it to cool down for a couple of minutes, weigh it again, put it back in the microwave.

Repeat. After a couple of circuits, I cut the time back to 60 seconds of microwaving.

When I see the weight change from each session getting smaller than 20 grams or so, I shorten the cooking time again.

At some point, you'll want to start using gloves because the thing gets pretty hot ... shorten the cooking time again.

Once there is no weight change, I stop.

Just realize that at this point the wood is most likely drier than equilibrium, so it's probably a good idea to wait a couple of days before finish turning the piece, because it will re-absorb moisture from the air.

HTH
 
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