DNA-Why You Are All Wrong

[John Hart]

Over the years, here in the friendly vortex of Sawmill Creek, there have been a number of discussions concerning the drying of wood using various methods. I try to stay out of these discussions because they always end up with the same result: Some people say DNA soaking doesn’t work….Some people say it does….Some people say Ethylene Glycol works better…Some say it doesn’t….Some tout scientific evidence….Some say it’s magic….Some say it’s based on faith…While others say it is fact.

I would like to introduce why everyone is wrong. And, I guess, it is also the reason that everyone is right. But hopefully, this little dissertation will put to rest, what the hubbub is all about.

Let’s start with fundamentals. The mighty tree. The tree is a plant. It has plant cells.

That’s it for the fundamentals.

Because after that….everything is different. And one of the reasons that there is so much disagreement, is because there are so many variables in this subject, that it is almost impossible for two people to be talking about the same thing at any given time.

What are some of the variables with regard to drying wood?
1. Wood Species
2. Wood Density
3. Wood Figure
4. Wood Flaws
5. Wood Age
6. Wood Orientation
7. Turning Shape
8. Turning Height
9. Turning Diameter
10. Ratio of End Grain to Face Grain
11. Wall Thickness
12. Ambient Humidity
13. Ambient Temperature
14. Starting Moisture Content
15. Dilution Percentage of the Alcohol
16. Type of Alcohol
17. Alcohol Soak Time
18. Air Dry Time

Wood Species
Believe it or not, all tree species are different. No…really. That’s why they all look different and why we give them different names. Different trees thrive in different environments, and those environments affect the nature of the tree and the constituent wood in that tree. Each tree species has specifications (which is why the words “species” and “specification” look so much alike). Specifications like color, density, height, longevity, leaves, fruit, etc., are all products of the molecular structure of that organism, and each one of those specifications, affect the nature of the wood itself.

Also, the wood of any particular tree species, has Electrical properties that can be measured. The fundamental electrical property of the wood is its ability to conduct electricity (conductance) which is also described in terms of its resistance to conduct electricity (resistance).

Water has near zero conductance (infinite resistance) but dirty bath water has lots of dissolved stuff in it, so dirty bath water has high conductance (low resistance). That’s why, if you step into a bath tub filled with pure water, and drop a toaster in it, you will not be electrocuted. But, if you’ve been bathing a while and your bath water is dirty…..dropping a toaster in there, results in your immediate demise. (If it’s plugged in)

So…back to wood. Each wood species has different Resistance. This Resistance is measured in a unit called the Ohm. (named after a guy named Ohm who discovered the relationship of volts and current and stuff). The wood Resistance is measured in Millions of Ohms. The more Ohms….the more Resistance. When the wood contains moisture, it has less resistance. So, you can take a common ohmmeter (or multimeter) and stick the probes into the wood about an inch apart, and the meter will measure the ohms of resistance that the wood offers over that inch of space. This is essentially how a moisture meter works. It is a very simple electrical measurement, and will actually reveal to you, the different nature of different wood. It will also reveal the nature of that wood with regard to absorption rate and drying rate.

Take a look at this chart developed by the US Department of Agriculture. It is the electrical resistance of various wood species at various moisture percentages. These resistance measurements are in Millions Of Ohms

191484
Just glancing at the table, you can see that all trees are different. These differences represent all the variables that constitute the tree specifications and effect on its absorption and drying rate.

But….don’t forget, that despite the fact that the Department of Agriculture went to great trouble and taxpayer expense to compile this data, it does not differentiate between a walnut tree that grew in the middle of a loamy-soil pasture, and a walnut tree that grew on the edge of a sandy creek. The chart shows a “typical” value for a “typical” tree in a “typical” area.

Which brings us to differences within a species.
Despite mother nature providing us with trees that follow certain genetic patterns, she also throws in different dirt…different weather…different water…deer antlers…ants…squirrels…birds….and people nailing barbed wire fences into them. These environmental variations cause each tree to grow differently, with different swirls of grain, knots, burl, holes, barbed wire…etc. Because each tree is unique due to these variables, its absorption, dry time, and resistance is going to vary somewhat…even within a species.

And as an extra twist….some trees are full of oils….others have sugar water…while others have a gooey, tar-like sap that works great for sealing ancient sailing vessels. These variations in sap and constituent fluids…also affect drying and absorption.

Back to fundamentals…Plant Cells.
The tree has plant cells. Those cells are somewhat pliable, which is what life is all about. The cells have moisture in them, and they are a certain shape. If you suck the moisture out of the cell, the cell starts to dry out….and just like a grape, turning into a raison, it changes shape. If you remove the moisture rapidly, the cell changes shape more drastically. Remove it slowly, and the cell tends to retain its shape better as the cell wall can harden while some fluid still exists. People who dry wood for a living know this very well. They know that air drying takes longer than kiln drying, but air drying causes less distortion. Kiln dryers will turn up the heat in the interest of shorter dry time….but know that their success rate will be less than a kiln that is 10 degrees cooler and taking a month longer.

And…believe it or not…people who run drying kilns know that maple dries at a different rate than pine. And, I’ll also take a leap that most people reading this, already knew that too.

Alcohol
What is the relationship between water and alcohol? The molecular formula for Water is H2O. For Isopropyl Alcohol(IPA) it is C3H8O. Those formulas mean absolutely nothing to most people (me included) but to the molecular biologist or the organic chemist, it means that if one comes in contact with the other, the water molecule will bond to the alcohol molecule…creating a new compound.
Water boils at 212 degrees Fahrenheit and Alcohol boils at about 150 degrees F. Alcohol evaporates readily around 60 degrees, where Water evaporates at the same rate at about 140 degrees. So, with the compound of water and alcohol, you get a “somewhere in between” evaporation rate.

BUT!!! And this is a big but. Water will maintain the pliability of the cell wall. Alcohol will dry the cell wall by bonding with the water, so while the cell might be filled with a fluid (alcohol/water) it will begin to behave like it is dry, and harden. The beauty of this is, the cell hardens in its original state….and to you and I, this means No Warping. But that’s the perfect world.

We humans do not behave in accordance with Perfect World Parameters.

In order for the perfect world to exist, the entire piece of wood…through and through, must be alcohol-saturated, and, the molecular exchange must take place with 100% of the existing water. Theoretically, if you submerge your turning in 99.9% pure IPA and let it sit until it is completely saturated, all the cell walls will become rigid while submerged.
Cool huh? But, we don’t do that….we are human. We soak for 24 hours and guess that it’s done, then let it dry for a month. Also…we don’t use 99.9% pure IPA, we normally use DNA (Denatured Alcohol) which has some water already in it, but it’s at Home Depot…so….there ya are.

Be advised….99.9% pure IPA causes nervous system damage, is highly flammable, explosive, and breathing the fumes can cause death. So be sure to wear your ear protection in case someone yells at you for using it.

The IPA sold in drugstores is generally 50% water….and while it is safe to clean your face with…it won’t be very effective in drying wood.

So What About Absorption?

Absorption of alcohol into wood is a function of some other variables. The wood absorbs more readily through the End Grain. Basically, the wood fibers are like itty-bitty straws that wick up the liquid like a oil lamp wick. The time it takes for the wood to absorb this liquid is a function of ambient temperature, humidity, existing moisture content of the wood, atmospheric pressure, and wood type.

The total time to completely absorb, depends on the orientation of the turning. If you have a 10 inch diameter Face Grain bowl that is 3 inches tall, the alcohol needs to traverse 10 inches through the End Grain (or 5 inches from each side)

However, if it is a 10inch diameter End Grain bowl that is 3 inches tall, the alcohol only needs to traverse 3 inches (or 1.5 inches from each side)

Common sense says, one of these scenarios takes longer than the other.

Also…Burls ain’t gonna absorb as quick as Clear Grain. Burls are dense (but not stupid) and Clear Grain sucks stuff up readily.

Cocobolo is dense and oily…it will absorb slower than Pine, which is gooey and not as stupid. But soft maple will absorb faster than both, because it is sugar water based.

Ambient Temperature, pressure and humidity.

If you live in Phoenix Arizona, you will have better luck than those who live in Wahiawa Hawaii (extreme humidity difference). Sea Level works better than mountains due to atmospheric pressure. Hot works better than cold.

So, in a nutshell…I think I’ve said what I wanted to say. People ask all the time, “Does DNA drying work?” And you know what?...the answer should be, “Well, it depends”.

The person who says, “I soaked my bowl in DNA and it still cracked…Why?” You can simply answer with this:
“I’ll need the temperature, humidity, pressure, species, density, orientation, dimensional data, where the tree grew up, what the electrical resistance is, purity of the DNA, starting moisture content of the wood, all the descriptions and percentages of knots, burl, curl, birdseye, sapwood, heartwood, pith content, how long you soaked, how long you dried, and finally, what was the physical environment throughout the entire endeavor…..before I can answer you.

[bob svoboda]

Clap, clap, clap, clap, clap, clap. Well said, John!

[Dan Hintz]

Bit of a misleading title there, John... not everyone is wrong (some are), they're just not looking at the entire picture. I'm happy to ignore differences in soak time between species, figure, etc. by soaking extra long for all woods. From an academic standpoint it would be great to have a better grasp on how they all affect soak time, but spending an extra couple of days in the bath is much easier than running a five-year study (or waiting for someone else to). I don't much care what the electrical resistance of the wood is, either, unless it tells me something that drastically changes my steps... a higher resistance means I have to soak for 10% longer means diddly if I always soak 25% longer than needed on every blank. A lower resistance may mean more water, or it may mean more mineral content... I don't care, unless it affects my time drastically.

That said, from an academic view your point is well taken. It would be lovely to have a huge study run to determine what affect, if any, these different variables have on things. But again, only the high-throughput wood processors (kilns, etc.) will care about shaving 15% off of their working time. So we work with extended values and be relatively happy with them.


Water will maintain the pliability of the cell wall. Alcohol will dry the cell wall by bonding with the water, so while the cell might be filled with a fluid (alcohol/water) it will begin to behave like it is dry, and harden. The beauty of this is, the cell hardens in its original state….and to you and I, this means No Warping.
I've often wondered about the interaction of the alcohol and the cell wall itself (i.e., is is strictly mechanical by removing water from the cellular structure, or is there also a low-level chemical reaction), so you can bet I'll be raising this issue with some of our microbiologists and see what kind of a discussion I can get going on it... I'm guessing they'll have an interesting view.

[Gary Conklin]

Well, someone had some time on their hands today!!! Well done Sir!!!

[Thom Sturgill]

Very good John, but I tend to agree with Dan. If you soak long enough, with pure enough alcohol it *will* dry faster, and with less warping - in theory. As to whether the total time decreases - as you said - it just depends!
FWIW, I've had mixed results.

[Scott Lux]

Well said, sir! There are other variables too. I'd be willing to bet cell chemistry changes seasonally so that season harvested would effect things too.

I have a friend (surprising I know) who is a molecular botanist. I'll show him this thread. He loves stuff like this.

[tom martin]

Thanks John,
I've developed a new drying protocol thanks to you! Now after I rough out a bowl, I read your post and by the time I'm done, the bowl is ready for finish turning!:D (I'm a slow reader)

Tom

[Tim Rinehart]

Nice synopsis John. Good thing you were able to keep it brief.;)

In all truth, if folks read what I think is the bottom line here, it's that you can't generalize what will work for one and not another and expect same results for someone else, let alone yourself unless you have a 'control' group of the same identical wood.

Great job of spelling out so many of the variables and shedding some light to those who have unsuccessful attempts at DNA or dishwashing liquid, etc.

Back to the microwave!:D

[Jim Burr]

HmmmTurned wet to 3/4...DNA's for 5 days, wraped and stored for 3 weeks...Look ma...no checks!!!191486 Maybe I'll use beer next time?

[John Hart]

Bit of a misleading title there, John... not everyone is wrong (some are), they're just not looking at the entire picture. I'm happy to ignore differences in soak time between species, figure, etc. by soaking extra long for all woods. From an academic standpoint it would be great to have a better grasp on how they all affect soak time, but spending an extra couple of days in the bath is much easier than running a five-year study (or waiting for someone else to). I don't much care what the electrical resistance of the wood is, either, unless it tells me something that drastically changes my steps... a higher resistance means I have to soak for 10% longer means diddly if I always soak 25% longer than needed on every blank. A lower resistance may mean more water, or it may mean more mineral content... I don't care, unless it affects my time drastically.

That said, from an academic view your point is well taken. It would be lovely to have a huge study run to determine what affect, if any, these different variables have on things. But again, only the high-throughput wood processors (kilns, etc.) will care about shaving 15% off of their working time. So we work with extended values and be relatively happy with them.


I've often wondered about the interaction of the alcohol and the cell wall itself (i.e., is is strictly mechanical by removing water from the cellular structure, or is there also a low-level chemical reaction), so you can bet I'll be raising this issue with some of our microbiologists and see what kind of a discussion I can get going on it... I'm guessing they'll have an interesting view.

Yes...Dan...please don't get me wrong, I am not saying that everyone should take all this stuff into consideration before they attempt drying their wood. Your approach to soak longer than the accepted period of time seems like the right thing to do, in my opinion. My purpose for writing this was to clarify that folks tend to argue about the subject....but do not argue apples to apples.

Also...your other point about the cell wall. The alcohol replaces the water inside the cell. I am having trouble nailing down that mechanism from out molecular biologists here. They do agree that there is an energy exchange, but don't agree completely on what causes the alcohol to have a dominant ability to enter the cell and kick the water out. However, they all agree that the alcohol in the cell, kills it, and allows it to harden, while maintaining the cell structure.....Whereas water leaving, due to normal evaporative drying, causes a pressure differential between the inside and outside of the cell.....then implosion.

[Gene Hintze]

I have tried DNA soaking two different ways.

1. The "normal method" that has been discussed here frequently.

2. The "normal method" followed by waving a dead chicken around the top of the bowl after the DNA bath.

Method 2 always results in faster drying, no warping, no checks and hair growing back on my bald spot. I believe that the dead chicken is the key.

[John Hart]

Well, someone had some time on their hands today!!! .....

Ain't that the truth.
But I enjoyed my idle time. It was better than playing solitaire...and there's no lathe here..so...:)

[John Hart]

Very good John, but I tend to agree with Dan. If you soak long enough, with pure enough alcohol it *will* dry faster, and with less warping - in theory. As to whether the total time decreases - as you said - it just depends!
FWIW, I've had mixed results.

Personally Thom, it got me to thinking that maybe I oughta just put everything in alcohol for 2 weeks. I'm with Dan though....I ain't running no experiments to find out. I just wanna turn stuff.

[John Hart]

In all truth, if folks read what I think is the bottom line here, it's that you can't generalize what will work for one and not another and expect same results for someone else, let alone yourself unless you have a 'control' group of the same identical wood.

Great job of spelling out so many of the variables and shedding some light to those who have unsuccessful attempts at DNA or dishwashing liquid, etc.

Back to the microwave!:D

Thanks Tim....Yes....That was my point exactly.

[Erik Johanson]

John I am not a science person but could this process be something as simple as osmosis. there is a greater amount of alcohol out side of the cell so it takes it in and releases the water. Is that not the process by which a board naturally looses water and also expands and contracts due to season changes?

[Dan Forman]

John--- A very well thought out treatise. I think my bowl is dry now, gotta go.

Dan

[David DeCristoforo]

Whew!

You are either:
A) Completely correct
B) Completely incorrect
C) Partly correct but mostly incorrect
D) Partly incorrect but mostly correct
E) Trying to start a fight
F) Bored out of your gourd
G) All of the above
H) None of the above

[Tim Rinehart]

John I am not a science person but could this process be something as simple as osmosis. there is a greater amount of alcohol out side of the cell so it takes it in and releases the water. Is that not the process by which a board naturally looses water and also expands and contracts due to season changes?
Erik...you're pretty close. http://www.chemistryexplained.com/Ru-Sp/Solution-Chemistry.html Actually, it's more like the water and alcohol are trying to reach a state of equilibrium. Also explains why the solution needs to be refreshed after a while.

[Ken Fitzgerald]

Excellent paper Dr. Hart!


Gene....rolling chicken bones on the ground near the bucket with the DNA will get the same results and you get to eat the dead chicken first. BTW...I recommend cooking the dead chicken before eating. Cooking doesn't seem to effect the bones interactions with the DNA in the bucket.

[John Hart]

I like dead chickens :)

[Lee Koepke]

I think DD is correct !!!!

(or maybe he's wrong ... )

[Ken Fitzgerald]

I like dead chickens :)


Cooked or uncooked? Curious minds wanna know.

[John Hart]

Cooked or uncooked? Curious minds wanna know.

There's a difference?:confused:

[Roger Chandler]

That is why we call him "Professor Hart!" Because he acts like he knows what he is doing.............only the lacquer fumes may be what gives him his inspiration?? :p

Nice thesis, professor!

[David E Keller]

Well, I read the post and subsequent responses, but I'm gonna forget all of it. This whole 'scientific approach' to woodturning sounds a lot like witchery to me! Also, it seems to involve thinking which is something that I prefer not to do in my free time. I have to think at work occasionally, and I find it makes me tired and somewhat irritable. Now the chicken thing has got promise...

[John Hart]

Ok...it's settled. Let's all have some lacquer and talk about chickens.

[Gary Max]

Why did the chicken cross the road----------------------so he could buy more DNA.

[Roger Chandler]

Professor Hart and Alfred E. Newman taught at the same institution........ He knows what of he speaks!:rolleyes:;)

[Steve Schlumpf]

Man... turned a hollow form and when I come back I find the Reader's Digest version of the DNA argument! Should make this thread into a sticky so the next time someone asks about DNA and asks if it works - we can just point them to the sticky and get back to turning!

Very interesting read John! Have you given any thought to the liquid dish soap method?

[Scott Hackler]

Very nice write up John (laquer induced, I'm sure). It is nice to see someone scientifically explain the process. I believe the biggest variables in the Dna process are relative humidity, relative temparature and soak times for different woods. That would explain why some people dont have success with it (or have just as much luck with air drying) where as I have excellent luck using Dna ...here in Kansas. I have tried several different ways and the Dna method works almost everytime with little warpage and dry in 3-4 weeks (for most species).

Now put down the laquer and go outside.... :)

[Roland Martin]

Wow, Steve! Don't get John going on dish soap now, he may overdose on lacquer:eek::) You know, a sticky is actually a great idea, this subject can get quite lenghthy and repetative, why not a sticky:confused::).
BTW John, this was a very well done piece of work, thanx

[Nate Davey]

+1 for making this a sticky. Sitting in LAX waiting for a flight to the Phippines and this took smoetime to digest. Great write up.

[Kevin Stanbary]

Outstanding! Thanks for this. As I've read (and participated in) the many debates about DNA and other drying methods here and elsewhere on the web, I kept thinking that perhaps we were trying to over-generalize the results.. I think "It depends" sums it up nicely. Well done!

[David E Keller]

... I think "It depends" sums it up nicely. Well done!

You mean that John could have just typed, "It depends"? I hope he doesn't find out...

[John Hart]

You mean that John could have just typed, "It depends"? I hope he doesn't find out...

:D:D I am actually laughing out loud :D

[Jim Heikes]

Water does not react with water. You start out with C2H5OH when you start soaking the wood and you end up with C2H5OH at the end. The only difference is that the DNA is now diluted with water. The process becomes less effective as the water concentration increases. As far as boiling points, ethanol forms azeotropes which boil lower than either component.

[David E Keller]

Water does not react with water. You start out with C2H5OH when you start soaking the wood and you end up with C2H5OH at the end. The only difference is that the DNA is now diluted with water. The process becomes less effective as the water concentration increases. As far as boiling points, ethanol forms azeotropes which boil lower than either component.

Let's keep the language clean here... This is a family site.

[John Hart]

Yes Jim...thanks...and despite your profanity, I agree. When I originally typed this up, I stated that the alcohol bonds with the water, and that is not exactly what I meant. I was trying to figure out a way to word it....because the alcohol moves into the cell, and the water departs, the two interact, and supposedly, there is some interaction with the carbon in the alcohol...that frankly, I don't understand.....And I don't think I want to.:eek:

[Alan Schwabacher]

I don't pretend to have expertise in turning, but I do understand the chemistry.

There is no chemical reaction between the water and alcohol, and little reaction with the wood. But they all stick to one another, and when water is present wood swells. The reason you normally want wood to dry slowly is simply that the water is lost from the outside of the wood; if the outside dries first while the inside is still swollen, the wood develops a lot of stress and can warp or crack. What you want is for the water content to decrease evenly throughout the wood, even though it can take a while for water to travel within the wood. If the water moves around within the wood faster than it leaves the wood, that will minimize stresses caused by drying. This can be done either by speeding up water movement, or slowing down water loss. Drying slowly can provide time for movement, while heating to speed up water movement while exposing the outside to moisture (to keep it from drying too quickly) at a gradually decreasing level, as in a kiln, can keep the moisture levels more similar inside to out.

So what happens with alcohol? It also sticks to the wood, though not so tightly as water. It can diffuse in and replace water simply by chance. The reason to change the alcohol is simply that the water needs to go somewhere, and it slowly comes out of the wood into the alcohol, so you are changing the alcohol to get rid of that water. Because water sticks better to wood than does alcohol, you may need to get the water content of the alcohol fairly low to get most of the water out of the wood. Because the lost water is being replaced by alcohol, the wood does not shrink much. But because the alcohol evaporates more easily than water and does not stick to the wood as well, when you do take it out of the bath and let it dry, the alcohol can travel faster in the wood, so it can dry more evenly. If it dries evenly enough, the wood will not warp or crack.

I don't know to what extent the alcohol might damage the cells and provide a freer path for water and alcohol to travel within the wood, or if exchange of water for alcohol allows partial shrinkage of the wood so that when the alcohol goes away there is less shrinkage left to do, thus dividing the stress of drying between the two stages of shrinkage. I suspect this does happen because alcohol based stains are called non grain raising (NGR), and raising of the grain likely depends on swelling the wood. They probably should be called LGR (less grain raising.)

Your title is deceptive: to me, DNA refers to something completely different. But since you describe isopropyl alcohol, you are not talking about denatured alcohol anyway. The nature of isopropyl alcohol is to be poisonous. Denatured alcohol is ethyl alcohol (the kind in alcoholic drinks) with something added to change its nature by becoming poisonous to keep people from drinking it. This is done to avoid liquor taxes, allowing it to be sold at a lower price.

Edit: It looks as though Jim Heikes made my main point more succinctly as I was typing.

[Grant Wilkinson]

Fun and fascinating discussion. Just to add to the general confusion, all the talk about DNA could lead the reader to believe that everyone is talking about the same substance. When I first heard using DNA for drying wood, I tried to find out just which DNA product was being discussed. In Canada, we have, by law, over 50 formulae for DNA. All they have in common is that they all have some percentage of ethyl alcohol in them. As Alan said, what all these grades also have in common is that the alcohol in them has been rendered non-potable by adding something to it. This relieves the tax that would ordinarily apply to it.

[J.D.Redwine]

Would dry wood absorb the water from my used DNA?

[Jim Burr]

Sorry John...Mod and all, about 10 of your original criteria don't matter...it's just organic chemistry and Microbiology. The bottom line is that for some it will work, for some it won't. I did one by the book and it came out great..I did one badly and the final result showed. Perhaps a better use of bandwidth would be to offer a proven, without a doubt, can't miss, only do it this way, never fails soultion rather than trying to disprove what can work. Diffusion has no choice but to work unless it's mechanically changed. This subject is so dead...let's move on...please!!!!!

[John Hart]

Well, I'm not arguing with any of these guys. I work at a chemical manufacturer, but I do not pretend to understand it. I'm just an electronic engineer and the computer guy. I ask questions of our chemists and they explain to me as best as I can understand. If I have it wrong, it is probably my misinterpretation as to what they told me.

But I'll listen carefully to what others have to say....including Mr Burr who thinks I might want to just drop it. :)

As I said in the beginning, I usually don't get involved in these discussions because they generally go no where. But I thought I'd offer a description of how many variables are involved and that they come into play. I apologize for any ruffled feathers. That was not my intent.

[John Keeton]

That’s why, if you step into a bath tub filled with pure water, and drop a toaster in it, you will not be electrocuted. But, if you’ve been bathing a while and your bath water is dirty…..dropping a toaster in there, results in your immediate demise. (If it’s plugged in)
I have studied your hypothesis at length, Professor Hart, and I think I can accept all of it except this particular statement. I will need to see proof of this - not "hands on" mind you, but "eye witness" will work - preferably at some distance, and standing on dry ground with rubber tennis shoes!:D

[Ken Hill]

From DNA to a guy in the shower......full circle me thinks.

[Bernie Weishapl]

Really a great write up John. I use DNA to dry wood and like Scott H. it has worked extremely well for me also here in Kansas. I agree with temp, humidity, and soak time. I soak fruit wood longer than others. Most times I forget and most of the wood gets soaked 3 to 5 days anyway. In about 3 weeks I can return to the lathe to finish. I also use anchorseal painted on the whole bowl. It works great but takes 6 months to a year to dry. It really doesn't bother me because I am not in a big hurry. I think there are many methods to dry wood and if it works I say use it.

[Mark Hubl]

I find if I drink alcohol a bit, sometimes I become more patient and the wood drys at about the desired rate. But, other times if I drink alcohol I become less patient and the wood is drying way too slowly. So, I guess that Professor Hart's Thesis is indeed correct. It depends!! Now I am a believer.

The other thing I noticed is Mr. 10K Dry Turning Keeton has not posed an opinion on the matter. I figure even with that big shiny new lathe he is not going to want to get those ways wet!

Whoops, my bad. I see Mr. K has chimed in. Silly me.

[Baxter Smith]

I only question one thing. How could we "all have been wrong" if I didn't have an opinion about it? When I decide I want one, I will make sure I come back and reread this.:)

[Jeff Nicol]

Thus all of John's elloquent words of wisdom are why I don't use DNA and most likely never will, except to dillute shellac. What I have learned over the years is if I turn enough things and have lots of them drying all the time each type of wood, shape of turning, time of year, and if I am in a hurry will be what makes or breaks the piece. The only things I have crack on me are the ones I rough out and forget to put some anchorseal or toss them in a bag or in the shavings or wrap them in plastic or use my floor dry method to dry them. But when I come back in the shop a day or 2 later and see the big cracks in the blank, well I chalk it up to my addled brain and move on to something else.

To me DNA is more danger to add to my shop and it is dangerous enough with me and the tools in it, and I would spill it for sure, it is just my luck!

Have fun and no matter how we dry things, it is the end result that matters most!

Have a great weekend all,

Jeff

[John Hart]

I have studied your hypothesis at length, Professor Hart, and I think I can accept all of it except this particular statement. I will need to see proof of this - not "hands on" mind you, but "eye witness" will work - preferably at some distance, and standing on dry ground with rubber tennis shoes!:D

Given the many comments in this thread and weighing them equally, I'm thinking this experiment must be conducted with a chicken. It seems logical to me.

[Roger Chandler]

4:45 a.m...........Hart, don't you ever sleep?

[John Hart]

Heh heh...didn't think anyone would notice. Just woke up early...made coffee...enjoying a little quiet time Roger. :)

[Roger Chandler]

Heh heh...didn't think anyone would notice. Just woke up early...made coffee...enjoying a little quiet time Roger. :)

Quiet time is nice. My mother in law has a small dog, and it awakened me at 3:00 am, and that was it for sleeping any during the night......a lot to do today, so I am getting an early start myself!

[Cathy Schaewe]

Well, I read the post and subsequent responses, but I'm gonna forget all of it. This whole 'scientific approach' to woodturning sounds a lot like witchery to me! Also, it seems to involve thinking which is something that I prefer not to do in my free time. I have to think at work occasionally, and I find it makes me tired and somewhat irritable. Now the chicken thing has got promise...
I'm with you - I do woodturning as a process to get away from thinking! But I do like chickens ...

[Dan Hintz]

If you purchase enough chickens, the shop even gives you a nice red and white striped bucket to put all of the pieces in.

Do you need to order extra crispy to keep natural edges from warping?

[Leo Van Der Loo]

John, the lumber industry and government did al kinds of testing years ago, and the industry uses Kilns, Vacuum drying with Microwaves for special valuable logs, Air-drying and a few more ways, but not DNA or LDD or Mumbo Jumbo, dancing in the rain etc. :eek: :p.

And I will continue to use my Brown Paper Bag kilns, as I have done for years, it works for me and many others :).

Of course when you get true believers, the blind can see again and the lame walk, it is why placebos are needed to try to get a more believable outcome when we do experiments or trials, so for what it is worth, you don't have to believe a word of what I or others have been saying, do whatever you're happy with, I do know what does work for me and my bowls :D :D :)

[John Hart]

John, the lumber industry and government did al kinds of testing years ago, and the industry uses Kilns, Vacuum drying with Microwaves for special valuable logs, Air-drying and a few more ways, but not DNA or LDD or Mumbo Jumbo, dancing in the rain etc. :eek: :p.

And I will continue to use my Brown Paper Bag kilns, as I have done for years, it works for me and many others :).

Of course when you get true believers, the blind can see again and the lame walk, it is why placebos are needed to try to get a more believable outcome when we do experiments or trials, so for what it is worth, you don't have to believe a word of what I or others have been saying, do whatever you're happy with, I do know what does work for me and my bowls :D :D :)

Well...for what it's worth Leo....I don't to the DNA thing either. I'm just interested in the many variables that are involved and noticed that there is a certain amount of vagueness when people describe their failures and successes, with regard to the conditions and materials.

Many people don't like the subject. Many people do.

I like the quote from the movie "Heaven Can Wait"....goes something like, "The probability of one person being right, increases with the intensity at which others are trying to prove him wrong"

But I am interested in that "Dancing In The Rain" technique you referred to. Can it be done with a chicken? :)

[Reed Gray]

I dried maybe 500 or so bowls with the DNA method, soaking anywhere from 1 day to weeks on pieces I forgot about. I do turn green to final thickness, and let them dry and warp. I now use the LDD method on several thousands of bowls, and will continue to use it. As far as the DNA on my thin bowls, there was no noticeable difference in drying time, distortion, or cracking. The wood was harder to sand out. I tried the LDD method and will stick with it. The only difference I have noticed with it is the woods are a lot easier to sand out. Especially on woods like maple that like to burnish and glaze over even with fresh abrasives. It makes a difference on woods like cherry which also are more prone to burning. Hard woods like Myrtle are a lot easier to sand out. The LDD method was developed by Ron Kent to help sand out Norfolk Island Pine. I don't know exactly what it does, but it does make a lot of difference.

I am curious about how the soaks might effect the water in woods. There are two types, the free water which is what gets you wet when turning, and the bound water which is on the cellular level. Interesting to think about the cell walls remaining rigid or collapsing. Kiln/kill dried wood works. Wood from a vacuum kiln or a solar kiln, or air dried lumber are very similar in workability, but radically different from kd lumber. If you rip a board on your table saw, the kd wood gives you dust. If you rip boards from the other drying methods, you get shavings. Any one know why?????

robo hippy

[Dan Hintz]

John, the lumber industry and government did al kinds of testing years ago, and the industry uses Kilns, Vacuum drying with Microwaves for special valuable logs, Air-drying and a few more ways, but not DNA or LDD or Mumbo Jumbo, dancing in the rain etc.
Did those test reports specify why DNA is not used? We don't use plutonium to run our vehicles, even though we would never have to fill up again in our lifetime... but the reasons for not doing so are obvious (huge engine, nasty disposal, etc.).

If the only reason someone can give is "industry doesn't use it", it's hardly a strong argument. So far, I haven't seen any of these threads answer why, just the occasional "It's not done that way with the big boys, and they can't be wrong." Maybe it's a matter of scale... 5 gallons of alcohol that gets replaced every year or two is vastly different than 30,000 gallons that must be replaced every month or two.

Note I'm not saying the conclusion is incorrect, only the supporting argument. And without a good supporting argument, the conclusion is suspect, at best.

Something has to be said for the many many woodworkers out there that can rough a huge green bowl, soak it, and final turn without cracks less than a month later... either the alcohol is doing something useful, or the people waiting for a year to final turn are waiting 11 months too long. Don't consider just one bowl, consider hundreds. (and before someone jumps in with "Reed just said he did 500 bowels...", I notice he turns green bowls to final thickness before soaking).

[John Hart]

If you rip a board on your table saw, the kd wood gives you dust. If you rip boards from the other drying methods, you get shavings. Any one know why?????

robo hippy

Case Hardening? Just guessin'.

[Leo Van Der Loo]

Did those test reports specify why DNA is not used? We don't use plutonium to run our vehicles, even though we would never have to fill up again in our lifetime... but the reasons for not doing so are obvious (huge engine, nasty disposal, etc.).

If the only reason someone can give is "industry doesn't use it", it's hardly a strong argument. So far, I haven't seen any of these threads answer why, just the occasional "It's not done that way with the big boys, and they can't be wrong." Maybe it's a matter of scale... 5 gallons of alcohol that gets replaced every year or two is vastly different than 30,000 gallons that must be replaced every month or two.

Note I'm not saying the conclusion is incorrect, only the supporting argument. And without a good supporting argument, the conclusion is suspect, at best.

Something has to be said for the many many woodworkers out there that can rough a huge green bowl, soak it, and final turn without cracks less than a month later... either the alcohol is doing something useful, or the people waiting for a year to final turn are waiting 11 months too long. Don't consider just one bowl, consider hundreds. (and before someone jumps in with "Reed just said he did 500 bowels...", I notice he turns green bowls to final thickness before soaking).

Russ Fairfield (Rest in peace) who was in the team when Weyerhaeuser did their trials (alcohol not DNA I think) said something to the effect of "they could not control it" as it didn't work with any consistency, and found with all their testing that they could control the kiln drying without the use of chemicals. (alcohol is poisonous after all)

Oh and Reed doesn't soak his bowls (Hope they are not bowels :rolleyes:) in DNA, just the soap so it sands nicer according to him.

The DNA soak does rest on this conclusion from Dave Smith and with the help of a handful turners some of who were brand new turners at that time, as I remember. (True believers ??)

[Dennis Simmons]

It would take me 2 weeks to type what you have posted. You have many good points, it simply comes down to "what works for ME" (I still like oil dry) :)

[Russell Eaton]

After reading this whole thread, I just want to know, anybody ever TURNED a chicken? OK bad joke but thanks for the info.