What % of Weight is Water in Green Hickory

Q

quinton

Joined
Nov 4, 2006
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Say I have a green Hickory stave that weighs 10 lbs., at what weight will it be down to 8-10% moisture?
 
The moisture content of green hickory will vary between types of hickory, and will vary within the same type of hickory. Some data:

books

from The commercial hickories, by Anton Theophilus Boisen and John A. Newlin, U.S. Dept. of Agriculture, Forest Service, 1910

So, to run an example, assume it's an average Shagbark Hickory with an moisture content of about 60% when green, and about 10% moisture content when air dry. If the green weight is 10 pounds, what's the weight when air dry? The math isn't as simple as I first thought it would be.

When green, the 60% moisture content means that the water weight is 1.5 times the (totally dry) wood weight.

When air dry, the 10% moisture content means that the (totally dry) wood weight is 9 times the water weight.

Solving for the total weight when "air dry", I get a result of 4.4 pounds.
(Your mileage may vary.)
 
Put it in a warm place and weigh it every few days, when it stops losing weight it is dry. You can speed it up also depemding on how you dry it or store it.
 
Steve Tall said:
The moisture content of green hickory will vary between types of hickory, and will vary within the same type of hickory. Some data:

books

from The commercial hickories, by Anton Theophilus Boisen and John A. Newlin, U.S. Dept. of Agriculture, Forest Service, 1910

So, to run an example, assume it's an average Shagbark Hickory with an moisture content of about 60% when green, and about 10% moisture content when air dry. If the green weight is 10 pounds, what's the weight when air dry? The math isn't as simple as I first thought it would be.

When green, the 60% moisture content means that the water weight is 1.5 times the (totally dry) wood weight.

When air dry, the 10% moisture content means that the (totally dry) wood weight is 9 times the water weight.

Solving for the total weight when "air dry", I get a result of 4.4 pounds.
(Your mileage may vary.)
Click to expand...

I may cut a block of green Shagbark, to exactly 10 lbs., let it dry for a year or so and see how close you are. Or, heck, I may gather 10 lbs. of Shagbark chips and oven dry them so we can find out much sooner!
 
garry3 said:
Put it in a warm place and weigh it every few days, when it stops losing weight it is dry. You can speed it up also depemding on how you dry it or store it.
Click to expand...

The free water in wood goes fast in warm dry place, but the cellular moisture slows down to a snails pace.

The reason for this thread was because my son and I found some tension wood in a Shagbark we were splitting over the weekend. We noticed the sapwood was much thicker on one side of the round, on closer inspection we discovered 4 growth rings per inch. We split a couple of staves off of that thicker side for hatchet hafts...can't wait to work with it!
 
quinton said:
We noticed the sapwood was much thicker on one side of the round, on closer inspection we discovered 4 growth rings per inch.
Click to expand...


That's a bit faster growth than is recommended for top notch hickory. The usual spec is 5-20 growth rings per inch. I bet you'd be fine at 4 grpi, just not optimal.


"The strength at maximum load is not so great with the most rapid-growing wood...."


Growth%20rings%20-%20mechanical%20properties%20of%20wood.jpg
 
Square_peg said:
That's a bit faster growth than is recommended for top notch hickory. The usual spec is 5-20 growth rings per inch. I bet you'd be fine at 4 grpi, just not optimal.


"The strength at maximum load is not so great with the most rapid-growing wood...."


Growth%20rings%20-%20mechanical%20properties%20of%20wood.jpg
Click to expand...

I'm not talking about regular fast growing Hickory, I'm talking about tension wood in a leaning tree. This tree had been leaning over a small creek for years, it finally up-rooted and fell last year.

Reaction wood may be laid down in wider than normal annual increments, so that the cross section is often asymmetric or elliptical. The structure of cells and vessels is also different, resulting in additional strength. The effect of reaction wood is to help maintain the angle of the bent or leaning part by resisting further downward bending or failure.

There are two different types of reaction wood, which represent two different approaches to the same problem by woody plants:
In angiosperms reaction wood is called tension wood. Tension wood forms on the side of the part of the plant that is under tension, pulling it towards the affecting force (upwards, in the case of a branch). It has a higher proportion of cellulose than normal wood. Tension wood may have as high as 60% cellulose.[3]
Click to expand...
 
You can not look at a chart to tell you the specific gravity of wood. It varies alot from one tree to the next. The amount of moisture will be quite different from summer to winter, even the phase of the moon has an effect. The size of the tree also. A million factors.
How much cambium layer is on your stave?
Was it dormant?
Fast growing or slow?
Early wood to late wood ratio?
Sap wood to heart wood?

Way to many factors to say.

This I do know. Dry it until it reaches equilibrium and you will probably be right around 8%. Final moisture content will depend on your climate and drying conditions.
I was silly enough at one time to buy a moisture meter. Worthless for my purposes.
Any one that deals with wood products will have a moisture meter. Check it out for your self.
 
quinton said:
I'm not talking about regular fast growing Hickory, I'm talking about tension wood in a leaning tree. This tree had been leaning over a small creek for years, it finally up-rooted and fell last year.
Click to expand...

It's ineresting that you bring up tension and compression in a tree. From a self wood bowyer perspective its good and very bad.

The underside will have the wider growth rings to help support the tree or limb and a natural reflex, the outer layer being the back of the bow. So with a ring porous hard wood(like osage) we work through the sap wood and stop in a heart wood ring. The big rings and natural reflex(depending on how it was dried) can decieve us. That stave will not make a first class bow, it wants to follow the string.

Now the tension wood wants to pull into a refex, its much superior to the down hill stave even though the growth rings are smaller and the late wood to early wood ratio might not be as good. Thats why if I cut a tree that is leaning I notch the down hill side of it, ruining it for a bow so that I don't waste my time.

I have also heard of such wood being called "reaction wood".
 
garry3 said:
You can not look at a chart to tell you the specific gravity of wood. It varies alot from one tree to the next. The amount of moisture will be quite different from summer to winter, even the phase of the moon has an effect. The size of the tree also. A million factors.
How much cambium layer is on your stave?
Was it dormant?
Fast growing or slow?
Early wood to late wood ratio?
Sap wood to heart wood?

Way to many factors to say.

This I do know. Dry it until it reaches equilibrium and you will probably be right around 8%. Final moisture content will depend on your climate and drying conditions.
I was silly enough at one time to buy a moisture meter. Worthless for my purposes.
Any one that deals with wood products will have a moisture meter. Check it out for your self.
Click to expand...
I'm going to air dry my staves over the winter, then move it to my greenhouse with a fan blowing over it through the summer. It should be dry enough to use next fall.
 
garry3 said:
It's ineresting that you bring up tension and compression in a tree. From a self wood bowyer perspective its good and very bad.

The underside will have the wider growth rings to help support the tree or limb and a natural reflex, the outer layer being the back of the bow. So with a ring porous hard wood(like osage) we work through the sap wood and stop in a heart wood ring. The big rings and natural reflex(depending on how it was dried) can decieve us. That stave will not make a first class bow, it wants to follow the string.

Now the tension wood wants to pull into a refex, its much superior to the down hill stave even though the growth rings are smaller and the late wood to early wood ratio might not be as good. Thats why if I cut a tree that is leaning I notch the down hill side of it, ruining it for a bow so that I don't waste my time.

I have also heard of such wood being called "reaction wood".
Click to expand...

Reaction wood is different between hardwoods and conifers. In hardwoods, the reaction wood with wide rings forms on the upward side of the tree in an effort to "pull" or hold the tree upright, it is called tension wood. In conifers, the reaction wood forms on the underside or leaning side of the tree in an effort to "push" the tree upright. In conifers, this also forms compression wood on the backside of the tree.

Reaction wood in pine and spruce is horrible stuff, I work with some form of it most every day.

The Hickory tension wood I have described in this thread looks similar to the Ash photo in this link.
http://www.treedictionary.com/DICT2003/HTMLFILES/compressionwood-1.html
 
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Easiest way to pace your expectations of when wood ought to be sufficiently air-dried is by reckoning on one year per inch thickness of the boards or staves. Obviously a 3 foot diameter 'green' tree trunk is going to take almost forever and is going to check badly and split while it's doing it. Coat the stave or board ends with wax or paint so as to slow down differential drying rates and maybe even bag the wood in a thin plastic wrapper/garbage bag. Plastic does release moisture (that's what freezer burn is all about) but at a much slower rate.

Or you can go nuts and 'nuke' the stave in a microwave oven in order to boil off the water! Kiln-dried wood (so I was told 40 years ago by an old canoe paddle maker) is not as strong as air-dried because of cell structure rupture that has occurred.
 
quinton said:
Reaction wood is different between hardwoods and conifers. In hardwoods, the reaction wood with wide rings forms on the upward side of the tree in an effort to "pull" or hold the tree upright, it is called tension wood. In conifers, the reaction wood forms on the underside or leaning side of the tree in an effort to "push" the tree upright. In conifers, this also forms compression wood on the backside of the tree.

Reaction wood in pine and spruce is horrible stuff, I work with some form of it most every day.

The Hickory tension wood I have described in this thread looks similar to the Ash photo in this link.
http://www.treedictionary.com/DICT2003/HTMLFILES/compressionwood-1.html
Click to expand...

Osage stump.
032_zps0e41dcf0.jpg
[/URL][/IMG]
 
300Six said:
Easiest way to pace your expectations of when wood ought to be sufficiently air-dried is by reckoning on one year per inch thickness of the boards or staves. Obviously a 3 foot diameter 'green' tree trunk is going to take almost forever and is going to check badly and split while it's doing it. Coat the stave or board ends with wax or paint so as to slow down differential drying rates and maybe even bag the wood in a thin plastic wrapper/garbage bag. Plastic does release moisture (that's what freezer burn is all about) but at a much slower rate.

Or you can go nuts and 'nuke' the stave in a microwave oven in order to boil off the water! Kiln-dried wood (so I was told 40 years ago by an old canoe paddle maker) is not as strong as air-dried because of cell structure rupture that has occurred.
Click to expand...

My experience with heating wood has been the same as the old paddle makers, though there are many bowyers that heat there staves and force them into shapes that make them easier to tiller and and end up with good shooting bows. The ones I have done this with have not stood the test of time. I will only heat the non bending sections.

I find that staves will dry much faster with the bark removed. If it is spring or summer cut when the sap is up I will sometimes give the back a coat of elmers glue. I use the white glue. I always seal the ends. I have found that some woods will turn into spaghetti if cut when the sap is up and then split before some drying first.
My experience with plastic has been that it does not breath enough for my purpose and can lead to mold.

Winter cut wood I don't have much problem with. Cut, split, seal the ends, keep bark on or remove.
 
garry3 said:
. . .
My experience with plastic has been that it does not breath enough for my purpose and can lead to mold.
. . .
.
Click to expand...

Agree about not using plastic. I know that a lot of bowl turners will rough out a bowl with green wood. Then put them in brown paper bags to dry.
 
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garry3 said:
My experience with heating wood has been the same as the old paddle makers, though there are many bowyers that heat there staves and force them into shapes that make them easier to tiller and and end up with good shooting bows. The ones I have done this with have not stood the test of time. I will only heat the non bending sections.

I find that staves will dry much faster with the bark removed. If it is spring or summer cut when the sap is up I will sometimes give the back a coat of elmers glue. I use the white glue. I always seal the ends. I have found that some woods will turn into spaghetti if cut when the sap is up and then split before some drying first.
My experience with plastic has been that it does not breath enough for my purpose and can lead to mold.

Winter cut wood I don't have much problem with. Cut, split, seal the ends, keep bark on or remove.
Click to expand...

I haven't made a bow since I was prolly 10 years old.:) I have also never worked with Osage, but it sounds a lot like Hickory and Cherry as far as drying defects go. If a person is not careful as you have outlined, the wood can be rendered unusable.

I learned some valuable lessons on drying wood when I was younger. One spring I had a Cherry log sawn into boards for a project I had planned for the winter. I figured I could speed the drying process along if I placed it in a greenhouse. I stacked and stickered the green lumber on a greenhouse bench, then set up a fan blowing across it to help remove the moisture as the 100 degree temps. of the greenhouse cooked it. The whole stack became super-dry kindling by fall! It twisted, bowed, checked, and warped severely! I then learned that wood needs to slowly air dry for several months before it can safely be kiln dried.
 
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