Rough Blanks. DNA or Boil? Which is faster?

[dirk martin]

If I rough bowl blanks to 1" thick, which method will dry them faster? Boiling or DNA soaking?

[Jim Burr]

You really know how to start and argument Dirk!!

[Bernie Weishapl]

DNA can take anywhere from 10 days to a month depending on the wood is what I have found in 3 yrs of use. Never used the boiling method.

[Josh Bowman]

Jim, that's funny :D:D
And oh so true.

[steven carter]

My experience is the same as Bernie's. Average around 3 weeks.

Steve

[Barry Elder]

Definitely boiling!....er.....DNA?.....Yeah, maybe! There are as many opinions as there are body parts as to how to dry rough outs.:D

[Gary Max]

How much money you got to spend on DNA?????????
How wet is the wood and what flavor is it????

[Dennis Ford]

What is the rush? Roughin out blanks goes much faster than finishing so it should be easy to build up enough stock that you don't have to wait for something to dry.

[David Epperson]

DNA draws out the water faster replacing the fluid with alcohol which dries faster, boiling changes the sugars in the wood so that it doesn't crack so easily (we hope :D). I have no idea which is "best" for keeping the wood from cracking in the drying process. I've even wondered if adding shellac to the DNA (say 1/2 lb cut) might soak some shellac into the wood and help it stay together. Never tried it, just wondering.

[Dan Hintz]

Maybe boil in DNA, best of both worlds? :D

[Michael James]

Maybe boil in DNA, best of both worlds? :D

That sounds like a disaster of the fry the frozen turkey variety, albeit a smaller scale. Seriously....I would not personally try that.

[David Epperson]

Also Alcohol boils at a much lower temp than water, so the sugars would probably not be converted as in boiling water, and with the resulting vapors being very flammable - well the resulting firewood would be dry...unusable, but dry.

[Dan Hintz]

Guess I need to make my smiley face grin a bit wider next time...

[David Epperson]

Guess I need to make my smiley face grin a bit wider next time...
I had it figured as a tongue in cheek thing, but you never know. :D

[Bill Bulloch]

I put mine in my little ole bowl kiln takes 14 to 30 days depending. For around $100.00 you to can resolve the problem of "which is best: Boil, DNA, Paper Bag, Micro Wave or PEG?

[dirk martin]

Gentlemen....I'm not asking which is "better". That indeed is personal opinion.

I'm asking which will result in FASTER drying.

I'm being asked to turn dozens and dozens of bowls, and don't have the room for that quantity sitting for months and months.

Maple and Walnut.
Cost of DNA is not a factor for me.
Fully fresh, green, wet wood.

[Ben Martin]

I put mine in my little ole bowl kiln takes 14 to 30 days depending. For around $100.00 you to can resolve the problem of "which is best: Boil, DNA, Paper Bag, Micro Wave or PEG?

You got a link with some information about said bowl kiln?

[dirk martin]

I put mine in my little ole bowl kiln takes 14 to 30 days depending. For around $100.00 you to can resolve the problem of "which is best: Boil, DNA, Paper Bag, Micro Wave or PEG?

I'm sure I could, but was hoping someone else had already made this determiination, and thus not reinvent the wheel.

[Bernie Weishapl]

Either the DNA or the Kiln will be your fastest option IMHO. With DNA I soak the maple or walnut rough outs for at least 5 days and dry for 14 to 30 days depending on the wood. Walnut and Elm will probably take the longest which could be 30 to 40 days. I don't think you are going to get much faster than that.

[Bill Bulloch]

You got a link with some information about said bowl kiln?

Check out this thread: http://www.sawmillcreek.org/showthread.php?t=131269 It tells about the making of mine and gives the web site that I patterned my after.

[Don Alexander]

speed kills :eek:

[Reed Gray]

The best reason I can think of to boil would be for woods that are very difficult to dry, in that they want to crack when you fire up the chainsaw, and warp insanely. The boiling will stabilize those woods. Walnut and maple are fairly stable. You might want to do the maple in one crock of DNA, and the Walnut in the other. With my LDD (liquid dish washing degergent which makes my thin turned bowl easier to sand) the solution will pull out some color. Walnut will stain the other woods. I would expect the DNA to do the same thing.

robo hippy

[Jim Burr]

and the argument goes on and on...:D:D

[Reed Gray]

Actually, I think the vacuum kiln would work best. No alcohol, and the boards I have worked with that were dried that way worked like air dried lumber. A load of wood took about 7 to 8 days.

robo hippy

[Thomas Bennett]

I know boiling is considered a great way to process bowls. The one time I tried it I found the blanks (soft curly maple) more than doubled their weight after a 90 minute boil. Then I brown bagged the blanks and they all molded. Some developed checks in the end grain. I lost half of them. I waited about 6 weeks. The other half turned beautifully but were still a little wet. I could definitely tell the difference from turning air dried curly maple. Maybe i didn't do it correctly.I thought the experience was not worth the work involved.

[Barry Elder]

I think that if you were to read what Stephen Russell has written about boiling and drying, you would be able to make a decision. There is also a lot of information available about using DNA but I don't remember the man's name that did all of the research. No instant gratification, but an informed decision is available.

[Bernie Weishapl]

The best reason I can think of to boil would be for woods that are very difficult to dry, in that they want to crack when you fire up the chainsaw, and warp insanely. The boiling will stabilize those woods. Walnut and maple are fairly stable. You might want to do the maple in one crock of DNA, and the Walnut in the other. With my LDD (liquid dish washing degergent which makes my thin turned bowl easier to sand) the solution will pull out some color. Walnut will stain the other woods. I would expect the DNA to do the same thing.

robo hippy


Reed I used to soak walnut to the point the DNA was a dark brown/black color. It never bothered maple or holly that I soaked in it. Don't know why but it didn't.

[Dan Hintz]

Thomas,

I'm willing to bet you didn't let the blanks air dry for a day after you boiled them. Boil for 1 hour per inch of thickness, let air dry for 1 day, then bag 'em. Let sit for about 3 months, and they should be ready...

[Reed Gray]

Part of the reason I turn to final thickness and let them warp is the other drying methods take too much time and extra stuff around the shop. Kind of like sanding wet wood. Least amount of work way is to let them air dry. Instead of doing all the extra work, turn more blanks.

Efficiency is intelligent laziness. Author unknown.

robo hippy

[Clark Harbaugh]

I'll chime in and give my opinion. I prefer the kiln drying method. I built one last year that has worked out well all year. On average it takes me 10-14 days to dry a rouched out blank here in Texas, depending on the time of year and relative weather conditions. The time it takes will depend on your location and the relative temperature and humidity.

One trick I learned quickly is that if it starts drying too quickly (humidity inside the kiln drops too fast), which has happened with this rig, I simply added a soaking wet towel in the bottom to create a little extra humidity in the kiln.

Here is a link to my thread on the kiln. In that thread, there are some a couple of links worth reading about drying wood.

http://www.sawmillcreek.org/showthread.php?t=132904

[dirk martin]

Either the DNA or the Kiln will be your fastest option IMHO. With DNA I soak the maple or walnut rough outs for at least 5 days and dry for 14 to 30 days depending on the wood. Walnut and Elm will probably take the longest which could be 30 to 40 days. I don't think you are going to get much faster than that.

Bernie, why a 5 day soak? I've found no research on the web that suggests such a long soak time is needed. Most all documents I'm finding, state 24 hours per inch of wall thickness, is the rule.

And, your length of drying seems huge, also. According to David Marks, bowls with 1/2" walls dry in 5 to 6 days, and 1" walled bowls dry in "about 10".

How do you determine dryness? Do you weigh your bowls? And, if so, are you saying that some will still be losing weight after 20 days?

David Marks article:
http://www.djmarks.com/stories/djm/alternative_ways_to_dry_wood_turnings_91744.asp

[dirk martin]

Actually, I think the vacuum kiln would work best. No alcohol, and the boards I have worked with that were dried that way worked like air dried lumber. A load of wood took about 7 to 8 days.

robo hippy

How are you going to pull over 29.5 inches of vacuum?
Without air to carry the heat to the wood, how will heat transfer to the wood? Also, even in a vacuum, you still need 1,000 BTU per pound of water evaporated.....that's some serious energy.

[dirk martin]

Thomas,

I'm willing to bet you didn't let the blanks air dry for a day after you boiled them. Boil for 1 hour per inch of thickness, let air dry for 1 day, then bag 'em. Let sit for about 3 months, and they should be ready...

3 months ??!!
DNA is certainly much faster than that.

David Smith:
http://alcoholsoaking.blogspot.com/2005/12/alcohol-soaking-q-and.html

[David Epperson]

How are you going to pull over 29.5 inches of vacuum?
Without air to carry the heat to the wood, how will heat transfer to the wood? Also, even in a vacuum, you still need 1,000 BTU per pound of water evaporated.....that's some serious energy.
You don't need an Absolute vacuum to cause evaporation to increase, just a sharp decrease in water vapor partial pressure. And water "boils" at a much lower temperature as pressure drops. To illustrate that, I've seen the experiment that exposed a glass of water rapidly to a very low pressure vacuum - it was amazing to watch water boil and freeze at the same time.

[Bernie Weishapl]

Bernie, why a 5 day soak? I've found no research on the web that suggests such a long soak time is needed. Most all documents I'm finding, state 24 hours per inch of wall thickness, is the rule.

And, your length of drying seems huge, also. According to David Marks, bowls with 1/2" walls dry in 5 to 6 days, and 1" walled bowls dry in "about 10".

How do you determine dryness? Do you weigh your bowls? And, if so, are you saying that some will still be losing weight after 20 days?

David Marks article:
http://www.djmarks.com/stories/djm/alternative_ways_to_dry_wood_turnings_91744.asp

Dirk I have found here at least that fruit and nut woods need to soak longer. I have been using the DNA method for about 4 to 5 yrs now. When I would soak walnut, apple, cherry, etc for 24 hrs they would still crack a lot. I forgot one time that I had put a couple of maple, a walnut, and Elm roughed out blanks in the DNA. 5 days passed and I thought oh no I ruined them but went ahead with the rest of the drying process. Those bowls came out with not one crack and seem to dry the fastest of the roughed stock that had soaked a shorter time (24 to 48 hrs). Again just my obsevation here in my location.

I bought a postal style scale that weighs from .1 oz to 55 lb and will also weigh in metric at the big auction house for $17. I keep weighing them till they haven't lost any more weight for 3 days in a row. They are ready to finish. Yes I have had some bowls still losing weight after 21 days especially the ones that only soaked for 24 hrs.

[dirk martin]

I feel confident in saying none of us reading this will be able to pull an absolute vacuum. But, to boil water at 70 degrees F. you will need to pull 29.18 inches. Since ~30 inches of vacuum is the maximum that can be pulled here on earth, good luck on achieving 29.18.

Bottom line is, heat needs to be introduced, along with the vacuum....and that poses a host of additional problems.

[dirk martin]

Dirk I have found here at least that fruit and nut woods need to soak longer. I have been using the DNA method for about 4 to 5 yrs now. When I would soak walnut, apple, cherry, etc for 24 hrs they would still crack a lot. I forgot one time that I had put a couple of maple, a walnut, and Elm roughed out blanks in the DNA. 5 days passed and I thought oh no I ruined them but went ahead with the rest of the drying process. Those bowls came out with not one crack and seem to dry the fastest of the roughed stock that had soaked a shorter time (24 to 48 hrs). Again just my obsevation here in my location.

I bought a postal style scale that weighs from .1 oz to 55 lb and will also weigh in metric at the big auction house for $17. I keep weighing them till they haven't lost any more weight for 3 days in a row. They are ready to finish. Yes I have had some bowls still losing weight after 21 days especially the ones that only soaked for 24 hrs.

Well, something doesn't seem right, Bernie.
From the information you are giving, I'm guessing that either your DNA has lost a lot of its effectiveness (a lot of water is in it), or it's wasn't pure DNA when purchased.

Have you measured its specific gravity?

[dirk martin]

Reed I used to soak walnut to the point the DNA was a dark brown/black color. It never bothered maple or holly that I soaked in it. Don't know why but it didn't.

According to David Smith, Bernie's findings are the typical.

David Smith on Alcohol Drying
http://alcoholsoaking.blogspot.com/2005/12/alcohol-soaking-q-and.html

[Rich Aldrich]

I have soaked 1" thick x 14" diameter cherry bowls for 4 hours and had success. It doesnt hurt to leave them in longer. I have also finish turned bowls after 7 days with no issues - I have only done this twice because I thought they were drying for 5 weeks, not 1 week - forgot which month it was.

It doesnt seem like anyone has done both methods and compared them as scientifically as you would like.

Either method makes the cells release water and both methods work well.

Probably the best way is to try both methods and see what happens.

[Christopher K. Hartley]

I had intended to stay away from this one but it keeps coming up. Dirk my suggestion is to talk to Steve Russell. Steve is a production turner having much experience in this matter. He has written a protocol regarding boiling. Here is his web site but I do suggest you talk to him. He has studied various methods due to the fact he had to be efficient to be productive and profitable.

www.woodturningvideosplus.com (http://www.woodturningvideosplus.com)

[David Epperson]

I had intended to stay away from this one but it keeps coming up. Dirk my suggestion is to talk to Steve Russell. Steve is a production turner having much experience in this matter. He has written a protocol regarding boiling. Here is his web site but I do suggest you talk to him. He has studied various methods due to the fact he had to be efficient to be productive and profitable.

www.woodturningvideosplus.com (http://www.woodturningvideosplus.com)

I have to wonder...Has steaming been tried? Seems it would convert the sugars in the same way that boiling does, but rather than allow the soak water to enter into the wood it would be more likely to drive moisture out, in much the same way that a kiln would. And should allow some stress relief of the internal stresses - in much the same way as it allows flatwood to be bent.

[Christopher K. Hartley]

I have to wonder...Has steaming been tried? Seems it would convert the sugars in the same way that boiling does, but rather than allow the soak water to enter into the wood it would be more likely to drive moisture out, in much the same way that a kiln would. And should allow some stress relief of the internal stresses - in much the same way as it allows flatwood to be bent.Makes sense to me but I am no expert on steam. This would be good to know.:)

[Bill Bulloch]

I posted a link to pictures of my homemade kiln in another reply above. I just took three 15" diameter Ambrosia Maple bowls out of the kiln and thought I would share the results with you. These were roughed to about 1 1/2", waxed and put in the kiln on Nov 1. They were removed from the kiln after 28 days. I was going to take them out last Wednesday (21 days), but got cautht up with Thanksgiven. The mositure content is less than 7%, and there are no cracks and very little warping. The one that did warp some was on the bottom shelf of the kiln making me think that perhaps the air does not circulate as well down there.

This is just another way to dry them bowls..

[Scott Hackler]

Dirk, a lot of the responses you are getting are not generally based on scientific research but rather our own personal experience. Soak a fruitwood for a few hours to a day and I can give you pretty good odds that its gonna crack. Soak it for a few days to a week and your odds are a heck of a lot better on not getting any cracks. I don't question why this works better....it just does.

I do not weigh my soaked roughouts but, for me, if it still smells of alcohol through the breather hole.....its not fully dry. For most woods, in my climate (KS) that equals 3-4 weeks. Some varieties take longer, like black walnut and hackberry, but others such as maple seem to be ready in 3 weeks.

I wood say that through my own experience, the Dna method works the best and is the fastest. Frankly speaking, 3-4 weeks is a very short time to go from tree to dried roughout. Any faster and your really pushing the physics of drying vs cracking, IMO.