New way to quickly dry green bowls

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gritz

New User
Robert
I chanced to watch a yall-tube turning video by a novice turner and found this idea. I tried it Friday afternoon on a 10" maple bowl which I took from fresh cut tree to the lathe within an hour. I roughed it and left only a 5/8" wall thickness.
This method reduced the % moisture meter readings from 38 heartwood / 45 sapwood down to 6 heartwood / 15 sapwood after 24 hours. Distortion was within turnable limits and no cracks appeared.
Since I'm way behind on roughing and drying for Christmas gifts, I plan to use this idea for a load of cherry I picked up last spring. Those bowls will be 12" to 16" and I plan to leave the walls thicker than recommended.
I don't necessarily agree with his turning or finishing tools and methods. If you want go right to the drying method, start watching the video at 15:00 and continue until about 20:00. Give it a try with your next green utility bowl. I think you will find the results pretty interesting.

https://www.youtube.com/watch?v=-6quzSzrMs8
 

jerrye

New User
Jerry
Is it just me, or does he sound a lot like the actor William Sanderson? I can easily hear this man saying, "Hi. I'm Larry. This is my brother Darrell, this is my other brother Darrell."
 

Roy G

Roy
Senior User
Did he put some sealer on the outside of the bowl before he put the fan on the inside?

Roy G
 

gritz

New User
Robert
He does use a sanding sealer on the outside of the piece. That's the only "traditional" thing he does.
I just found it interesting because the piece stays in the chuck. and can be finish turned in 24 hours. I will have a couple of finished examples in a few days.
 

Gilley23

New User
Bryan
Is it just me, or does he sound a lot like the actor William Sanderson? I can easily hear this man saying, "Hi. I'm Larry. This is my brother Darrell, this is my other brother Darrell."

True story: I work on the same building as he does. I'm always amazed at the people who have never heard of Newheart!
 

gritz

New User
Robert
Stuart,
I browsed his videos and found another example. While his shapes and finishes are still just giveaway quality, you do have to give him credit for thinking outside the bowl...
 

chris_goris

Chris
Senior User
It looks like hes finishing his bowls with a very heavy wall thickness, I doubt its really dry much past the surface hes measuring.
 

William Roscoe

New User
William
wonder if it might be even better to let it dry with the fan for 2 days?? Or even 3. I'd like it to be below 10% at least
 

Jeff

New User
Jeff
I'm not a "turner" but I often see green wood turning of a rough bowl and then it's stored away in shavings for months, etc for slow drying before the final turning/shaping.

I'm curious though. What do you folks consider to be adequate drying before the final turning (%MC) so that the bowl doesn't crack and blow apart? Is this guy rushing the process and will his bowls will be doomed in another year?
 

Hmerkle

Board of Directors, Development Director
Hank
Staff member
Corporate Member
Stuart,
I browsed his videos and found another example. While his shapes and finishes are still just giveaway quality, you do have to give him credit for thinking outside the bowl...
I can't wait to see what level of success you have when you try it.
It would also be interesting to see if Chris G is correct (the core of the bowl is still high moisture content.)

Also, I am thinking (just thinking) I had some wet (not green) ambrosia maple and turned a hollow vessel in a class at Woodcraft. I questioned the teacher and he said just try it!
He said, turn it to a finished shape, sand and finish. Years later, no cracks, little out of round!

So based on that, if we can get the surface (to some unknown depth) down to an acceptable moisture content without the blank checking or cracking, then finish turn, maybe this works...

Again proof is in the pudding, let's see what success Robert (Gritz)has.
 

gritz

New User
Robert
The second bowl is roughed and sitting under the fan now. It is 9 1/2" in diameter and I left the walls a little thicker, but plan to check it at 24 hours. At that point I will decide whether to leave the fan on for a longer time period.
attachment.php

Here is a photo of the first bowl. I finish turned it today, but only because I was busy all day Monday and Tuesday. The fan was on for 24 hours, then it sat in the chuck on the lathe in the basement. Today the highest reading was 8% in one small section of the sapwood where I just barely shaved off the bark. The walls are 3/16" and the finish is walnut oil and wax.

attachment.php

If we use the soda straw conceptualization of wood fibers, I clearly see what transpired during drying and why the sapwood had a higher moisture reading. That is where the unexposed fibers were longest on this piece. The short fibers in the heartwood gave up their moisture load pretty quickly through evaporation and capillary action. The fibers in the sapwood portions were longer and would obviously hold moisture for a longer period in any drying scenario...given equal everything else. It did dry out sufficiently for final turning with the total elapsed time of 5 days.

To answer the question about surface drying...I have to say perhaps. Perhaps, because the piece went out of round during the turning and finishing process by less than 1/8".

I am convinced this method has value and I plan to pursue it further while tweaking the variables. One variable I plan to try is using a denatured alcohol soak with enough air drying to allow me to seal the outside before beginning the fan drying process. I am sure the result will vary with different wood species.
 

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cyclopentadiene

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If you are new to turning, I understand the desire to have a bowl dried relatively quickly so you can actually have a finished product soon. I was the same way when I first started turning. I then realized I could rough turn a green bowl and have it stored in a bag of shavings in 20-30 minutes. I completed several hundred in a short time period. After these were all dry, I selected the most unique ones and finished about 100 bowls.

After you give one to all of your friends and family and have a dozen or so special ones sitting around the house, what do you do with them? I placed a few in a gallery and sold a dozen or so but sales are really slow as the market is saturated and I hate providing 30-50% to a gallery that does very little.

I have about 200 dried bowl blanks of different species sitting in the rafters of my shop that are leftovers after I was booed with completing them and had bowls everywhere.
 

Willemjm

Willem
Corporate Member
Turning Walnut wet is pretty forgiving, Cherry and Maple not so much.

Have you tried taking the moisture readings a day or so after the piece rested again?
 

nn4jw

New User
Jim
Based on something I saw on tv yesterday about air drying beef jerky (yep), I'm wondering if this technique would work differently (better) in a cold shop during the low humidity days of winter than it does in summer heat and humidity?
 

Willemjm

Willem
Corporate Member
Based on something I saw on tv yesterday about air drying beef jerky (yep), I'm wondering if this technique would work differently (better) in a cold shop during the low humidity days of winter than it does in summer heat and humidity?

I have done a lot of experimentation with fast drying in a dehydrator.

Some woods are very forgiving such as Walnut, drying thinner pieces 3/4" to below 6% overnight. Most are not. I find Pecan develops cracks even if dried slowly over a week or so. It also depends on the starting moisture content. If you start below 15% the chances of checking is much less. Starting above 25%, most woods will develop checking.
 

nn4jw

New User
Jim
I wasn't suggesting a dehydrator at all, just the fan and airflow this thread started with, but in the winter cold and low humidity. And just to be clearer, in an unheated shop or shed, not outside. Sorry if I wasn't clear enough. The tv show I referenced didn't use a dehydrator either for drying the jerky. (But I do.)
 

gritz

New User
Robert
Based on something I saw on tv yesterday about air drying beef jerky (yep), I'm wondering if this technique would work differently (better) in a cold shop during the low humidity days of winter than it does in summer heat and humidity?

I agree with that hypothesis.
I'm in Hickory visiting our kids this weekend so I just left the fan on. It will be 5 days when I get back.
 
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