Primitive Archer
Main Discussion Area => Bows => Topic started by: JoJoDapyro on May 25, 2015, 05:38:50 pm
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I've been curious about water curing wood for some time now. Has anyone tried it? Was it in a controlled setting or at the bottom of a lake or pond? Thanks in advance.
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I dunno about science, but there sure is a lot of opinion!
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From what I have heard it wasn't necessarily curing in the water more so keeping it in the water to prevent bug damage and checking if the wood wasn't to be used soon. Purely opinions I gathered from another thread.
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I've always thought it was kinda like drinking a dozen beer to sober up >:D
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I've always thought it was kinda like drinking a dozen beer to sober up >:D
LOL, there are a lot of things in this olde world that I don't know, but curing wood under water makes me think someone needs to revisit botany 101 and brush up on their wood technology ;-)
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Why is curing and drying taken for the same thing?
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How do you "cure" wood without drying it?
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My under, is that drying removes the water. Curing involves the evaporation of other compounds and the molecular changes that take place in the lignin and so on.
To my mind, they are inextricably linked much like the upper and lower crusts of a pie. You could sink a log and the water stays in the log, but some of the other compounds may disperse or dilute. Then you have to dry the water from the wood. In effect, you are baking your pie twice in order to get both bottom crust and lower crusts done. Seems to me to be like an old Scandanavian saying about cutting down some trees to build a bridge over a creek so you can cross over to draw a pail of water from the well on the other side.
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JW, interesting perspective on curing wood. So do you cure wood in a specific manner which controls those other chemical changes so as to produce a finished product with particular properties.......other than a low moisture content?
My life experiences have taught me that curing wood is the process of drying wood. The need of the finished product can range from dry firewood to a high quality cabinet or bow wood that is dried in such a manner to yield the highest quality finished product with the fewest defects......including internal stress reduction.
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I was always under the impression the natives 'water cured' staves in a running stream to drive out the sap, and then sat the bow out in the air a short time later to remove the water. Correct me if I'm mistaken though.
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Here we go, seasoning/curing or drying. Love this subject. ::) Break out the pop corn. :)I have put it in the pond or creek to keep if from checking until I could get to it and care for it properly, but that was only for a short time, maybe a few days. :) Eddie [Mullet] will chime in on this one soon I bet. ;) ;D ;D
Pappy
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I have always suspected it was to kill bug larva, not too much diazanon around in ancient times. Considering how much damage my untreated wood can sustain, imagine how frustrating the same kind bug onslaught would be to some stone age guy who spent two days chopping down a tree with a stone ax.
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I tgink wood dries from the middle out and if you soak it a good while it will equalize the moisture helping to prevent checking
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No Drewster, I really do not. I can't even get information online about what all different chemical compounds there are in different species of woods, what their evaporative rates are, or even what effect their evaporation/oxidation/reduction has on the wood. No, I just like to leave wood to slowly air dry for a few months, then if I have to, hurry the drying process by moving it into sunlight and wind, or sometimes even putting the wood in a car in the sun to bake to a finish!
Now I have seen firsthand what effects long term curing can have on woods such as osage and douglas fir. I was able to work some 100+ yr old osage beams from a cow shed once. Under a draw knife, taking off growthrings, the wood almost seemed brittle as it flew off the stave! It was an absolute cakewalk to chase a growthring. Beautiful wood, virtually impossible to get grain tear-out! The douglas fir were arrow shafts from a fellow here in South Dakota. The wood came from boards that lay in a barn loft for almost 100 years. They were stickered between layers and the sheer weight of the bunk of wood had kept it pressed tight and resistant to warping. After how many seasons of variable humidity, the wood absorbing and releasing relative humidity, it was as stable as you could get. Tom ripped blanks with a saw, ran 'em thru a doweling machine and matched for spine. He never straightened! From a dozen shafts, I would have three or four that needed a small correction, the rest were ready to shoot. (That wood is all gone now. I weep. It was true old growth...one arrow shaft had over 50 rings in it's 11/32ths thickness. I had to cut it at a steep angle and count rings using a magnifying glass)
I can't add any knowledge to the basics of curing wood:
1) Keep the bugs out of it
2) keep the back sealed to prevent checking
3) keep it out of excessive heat and out of the rain
4) keep it off the ground
5) keep your mitts off it as long as you possibly can.
If I had the patience, the materials, and the conditions, I would love to age one sister stave in my garage for 20 yrs and the other at 400 ft of depth in Lake Michigan. But that is beyond me at this time.
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one of the elders in our Cherokee tribe spoke of burying a stave in mud by a creek to cure..I havent tried it but suppose to make the wood easier to work, is the only reason I can think of....of course they were using stone tools back then too...gut
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JW, I certainly appreciate what you're saying about wood that has been seasoned for decades......premium stuff. I have some walnut that has been air drying for 25 years with beautiful, beautiful color. You will NOT find kiln dried walnut with that kind of rich color.
Have you ever contacted the US Forest Products lab for the technical info you're looking for? They are a wealth of information and research on wood. I have had them ID wood for me microscopically in the past. Don't know if they will still do that or not.
Buddy, wood dries from the outside in. If you cut a cross section piece and then check the MC of the different areas you will find out the the center will have the highest MC.......until that piece has time to completely equalize to its environment........and even then it will change seasonally. That's why you have to seal the back of most bow woods once you remove the bark. The outer layers will dry faster than the internal rings, shrink more quickly and open up checks.
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Drew that was actually what i meant to write, if you soak keeping the outer wood wet it should reduce checking some what, that is in the round like ocean spray, splitting would be a differant matter
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Here we go, seasoning/curing or drying. Love this subject. ::) Break out the pop corn. :)I have put it in the pond or creek to keep if from checking until I could get to it and care for it properly, but that was only for a short time, maybe a few days. :) Eddie [Mullet] will chime in on this one soon I bet. ;) ;D ;D
Pappy
think I'll sit back with a bowl of popcorn myself, Pappy. See how long it takes till the discussion starts debating the merits of soaking wood in Buffalo urine and salt water.
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Dead wood is soaking in water throughout the life of the tree. All wood does is carry water. I don't see how soaking it for an extra month or year is going to make any difference. It is effective at keeping the wood from checking thats about all I can see to it.
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It may stop checking while it's in the water but is it just delaying the inevitable? If I cut a piece of plum and put it in a creek and after a month I cut another piece of plum, pull the one out of the creek and dry them together, will there be any difference?
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It may stop checking while it's in the water but is it just delaying the inevitable? If I cut a piece of plum and put it in a creek and after a month I cut another piece of plum, pull the one out of the creek and dry them together, will there be any difference?
I would imagine they will be the same. I wrap plum in sirhan wrap and cut just a few slits in it. I add slits every couple of weeks for several months.
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It may stop checking while it's in the water but is it just delaying the inevitable? If I cut a piece of plum and put it in a creek and after a month I cut another piece of plum, pull the one out of the creek and dry them together, will there be any difference?
Yes it would depending on species of the wood....Here is a article of the functions of sap/heartwood in trees.http://northernwoodlands.org/articles/article/what_is_the_difference_between_sapwood_and_heartwood I would think soaking wood to start at a even MC could aid in the drying process, the inner and outer pieces of wood shrinking faster than one another, would result in cracks I would think.
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I like your way of explaining this JW. One thing I saw a while back was divers recovering old logs from shipwrecks in lake superior. The wood was in high demand from violin makers and others who needed the best wood money can buy. I know part of this is it is old growth trees, but there was also a reason this wood was so desirable due to water curing.
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Begs the question....does violin wood make good bow wood?
Or are we comparing apples and orange VW microbuses?
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Dang Eddie you disappointed me. ??? :-\ ;) :)
Pappy
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I will go out on a limb and say that I believe that bow wood and instrument wood would be looking for the same qualities. Vibration is key to the process in making either. Thanks for all of the information so far. Perhaps a test is in order.
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The reason salvaged logs from lakes and rivers are so valuable is because over time minerals are deposited into the wood, often times staining it in a unique way. My guess is water curing is simply to equalize the MC content. I know they steam wooden bowls before drying them to achieve the same thing.
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Thanks Jensen. JW, With apples or oranges we still want to store em in a place where they keep the longest. Wood is wood
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This i s my opinion on the matter:
Water curing is a method to get rid of a lot of bug food in wood and to allow better drying when you do get it out of the water.
Basically, the soluble starch and sugars (and a lot of other water-soluble organic molecules) in the wood matrix slowly dissolve into the water (like tea from a tea bag and a cube of sugar in coffee), part of it is also decayed by bacterial activity. Also, the cell wall lining becomes degraded, as a result of which cells become more permeable to water. Hence, they hydrate and dehydrate faster (you get to equilibrium moisture more rapidly). This means that the wood doesn't check as badly when it is finally air-dried, as the inside of the wood will dry nearly as fast as the outside. Checking results from very uneven drying of wood from the outside to the inside.
In addition, I guess that water-cured logs are more resistant to fungal attack or insect boring, as there's just less food for the critters left to munch on (because it's dissolved into the water), and they won't colonize the logs as easily.
If you leave the wood too long under water, the cellulose itself will slowly decay spontaneously as well (requiring many years, not talking about weeks to months)
See http://nautarch.tamu.edu/CRL/conservationmanual/File6.htm and http://maliposamusic.com/Stradwoodcuring.htm for more info.
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Begs the question....does violin wood make good bow wood?
Or are we comparing apples and orange VW microbuses?
I think they are completely different. Violins don't have to bend much.
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None the less, both are "bowed".
BOOM.
dropping the mike as I leave the stage
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None the less, both are "bowed".
BOOM.
dropping the mike as I leave the stage
As he walked off the stage, no one said a word. All you could hear was the sound of disappointment. :(
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The only thing that bow and violens have in common that I can think of is that they both like low histerisis wood. The only problem is that most low histerisis woods also tend to chrysal.
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What is histerisis wood?
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joachimM, interesting articles you attached to your post. The "Wood Conservation" article states "In anaerobic waterlogged environments, however, wood undergoes profound chemical changes and alterations that result in a significant loss of strength while retaining overall shape and form." It doesn't state how long this "significant loss of strength" takes to happen. Do you have any research data on the time line for these changes to take place?
If it starts to take place fairly quickly, then water curing wood seems like a highly undesirable process. Anything that weakens wood is not good for a bow from my point of view. Perhaps some of the chemical and physical changes that take place in this process do help the resonance of wood which is so highly desirable in a violin, but I still haven't seen any evidence that this "curing process" will help a bow preform better.
It does make sense that storing a log or stave under water could delay shrinkage and checking of the wood until you have time to properly process and dry the wood. Beyond that, I don't see much advantage.
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Could it have possibly been a technique to help get the bark off of a stubborn stave?
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What is histerisis wood?
Hysteresis (in bowmaking) is internet friction within the wood that explains the difference between the energy necessary to draw back the limb versus the slightly lower amount of energy it returns when released. Best example of this ever was exhibited by hanging a known weight from a rubber band. Measure the length of stretch and write it down. Now hang another known weight and measure again. When you remove that second weight and measure the amount of return, you see that the second measurement is greater than the first. The rubber band did not return to the exact length as before it was stretched. That is due to elastic hysteresis. The entry on Wikipedia for hysteresis explains it better than me, but just for starters a shorthand explanation is "internal friction in the wood that robs you of a portion of the energy stored".
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....as opposed to hysteric, which I tend to become as I get close to a deadline for a bow trade.
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Deep/real deep. ;) :) :)
Pappy
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Internet friction? ;)
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Internet friction? ;)
That's in the knapping posts.
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I have no idea if what I am about to say translates to wood curing/ drying or not, but they are both plants and are made of the same types of cells more or less so I suspect it does.
I water cure certain medicinal herbs and teas for multiple reasons. First it will remove water soluble materials that would remain trapped if simply dried. Sometimes this is necessary for taste and other times essential for survival/ health reasons. The second reason is that after soaking in water(that is changed daily for 3-5 days), the controlled dry time afterwards is reduced to a few hours from it's normal 5-7 days. The reason most likely that plain/pure water evaporates faster than water full of dissolved material. This only works on herbs and plants who's desired chemicals/substances are not water soluble. Otherwise, you flush out the good part.
If water curing had any advantages to primitive man, I suspect it's the reduction of dry time. Transporting and caring for staves would have been burdensome, especially if we're taking nomadic cultures. Plus if one is in desperate need of a bow, waiting a year is not an option. I've actually noticed this quick dry phenomenon before with drift wood. A piece of completely water logged wood washes ashore and is dry a few days or a week later without much checking. I've been meaning to try water curing a stave and I may have just been motivated by this thread.
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How many bows are made of drift wood? The Inuit were forced to use it, lacking a whole lotta anything treelike in their environs. Even they ended up using all kinds of engineering miracles in order to get a reasonable shooting bow from it.
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I suppose that hiding staves in water would keep the enemy from finding them and keep the bugs off of them so you could bring them out in the winter when the bugs were dormant..
I know wood sure looks different that has been under water for 30-40 years..
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How many bows are made of drift wood? The Inuit were forced to use it, lacking a whole lotta anything treelike in their environs. Even they ended up using all kinds of engineering miracles in order to get a reasonable shooting bow from it.
It's a far cry from a piece of naturally occurring drift wood to a fresh cut stave that was carefully cured in water. I would imagine most driftwood was standing dead wood for quite some time before it made it's way to the lake. I wasn't suggesting using driftwood to make bows, I was simply using it as an example of how quickly wood dries after some of the starches, sugars, and waxes are removed. I am going to keep my eye out for a piece that may be bow worthy. I haven't noticed any yet, but old driftwood root clusters certainly have amazing figure once they are squared off and sanded. The make really nice knife scales. The major drawback of driftwood is it's really hard to identify what species of tree it was with no bark or leaves attached.
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Thanks, I was confused because I know the word hysteresis in another way, the difference MC of wood vs ambient moisture depending on how dry it became and where it is on a wetting/drying curve. It must be a generic term to describe similar relationships.
Here is the hysteresis curves for drying and wetting wood. I betcha the curves for internal friction looks the same.
http://www2.nau.edu/~doetqp-p/courses/env302/lec18/18fig5.gif
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I suppose that hiding staves in water would keep the enemy from finding them and keep the bugs off of them so you could bring them out in the winter when the bugs were dormant..
I know wood sure looks different that has been under water for 30-40 years..
I think if I was raiding another village and had a chance of getting killed, I'd be carrying off an armload of eighteen year old maiden before I'd haul away a stash of heavy, soggy wood. This whole theory seems like a lot of work for NA's when they have a BIG choice of wood everywhere. At least more then we have and most of us have buildings full.
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Thanks, I was confused because I know the word hysteresis in another way, the difference MC of wood vs ambient moisture depending on how dry it became and where it is on a wetting/drying curve. It must be a generic term to describe similar relationships.
Here is the hysteresis curves for drying and wetting wood. I betcha the curves for internal friction looks the same.
http://www2.nau.edu/~doetqp-p/courses/env302/lec18/18fig5.gif
It is a term used in many situations, even economics. One area of study of hysteresis is in job growth...economy is at "X", but fails to thrive and falls to X-Y% and you lose a number of jobs. When the economy returns to X, the jobs gain is less than what was lost...a hysteresis. I love reading economists' writings, they are incredible at predicting what HAPPENED!
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Makes sense. Thanks!