Stabilizing green bowl blanks

[Herebrooks]

Hey, I've begun experimenting with the alcohol bath to help speed up the drying process of green bowl blanks. I'd love to hear from anyone who has tried it.
I have begun by turning thin(1/4 to 1/8" bowl sides). The first bowl was small, 5"x 3"high. It hasn't cracked yet. I am following the process of soaking the bowl for a few hours in DNA then letting the DNA dry off and wrapping the outside in a rag. Actually, I'm filling the bowl with alcohol and letting it bleed thru. I'm thinking of then sealing the outside with sanding sealer rather than wrapping it.
I'll be trying a thicker bowl side today.
I would rather turn thin and not have to return, we'll see.
Any input would be appreciated.
Bill

[robo hippy]

There are many who swear by it for the twice turned bowls. I green turn to final thickness. I soaked several hundred of them in the DNA, and the only thing I could notice was that they were more difficult to sand out than air dried ones. I did one test with some madrone pieces all cut from the same log. 2 were air dried, 2 were soaked in LDD (liquid hand dishwashing degergent), and 2 were DNA soaked. No measurable difference in drying time, warping, or cracking. I continue the LDD (1/2 tan or clear hand dish soap, 1/2 or more water, soak for 24 or more hours) soak because it really makes pieces easier to sand out than air dried pieces. I do make sure to round over the rims, and use plastic stretch film over the rim to dry them. Some maple will mold under the stretch film, but since maple is pretty easy to dry, I generally won't wrap it. Madrone on the other hand is difficult. I have found with it, I get much better success if I get early spring harvest trees rather than summer or fall harvest.

robo hippy

[Steve K]

I let everything air dry after sealing with anchor seal. That is, at least with twice turned bowls. I have only to begun to experiment with turning to finish green. As it is right now I have probably 75-100 bowls at various stages of drying with some always ready to finish. Can't really see the need to speed anything up.

[Herebrooks]

From what I know, moisture content can be variable depending on drying method, ie super drying tenons for chair work thus allowing them to expand when put together to ambient MC. When a bowl distorts terribly or cracks, it seems a function of grain direction, but also the speed in which it dries. Certainly reducing speed by either sealing the endgrain(usually the culprit) or wrapping in brown paper or a rag. make it less likely to crack. My question is at what point is the wood dry enough to safely return it or allow it to dry in the open air. For me, the process is as important as the product.

[Arlin Eastman]

I can see why you would want to do a lot of bowls like that since you are a school and many students trying their hand at bowls.

Someday I will afford to go there for some intermediate to advanced turning classes. Someday.

Arlin

[Herebrooks]

I hope you do Arlin!
All the best,
Bill

[Ruler2112]

Herebrooks said:

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Hey, I've begun experimenting with the alcohol bath to help speed up the drying process of green bowl blanks. I'd love to hear from anyone who has tried it.
I have begun by turning thin(1/4 to 1/8" bowl sides). The first bowl was small, 5"x 3"high. It hasn't cracked yet. I am following the process of soaking the bowl for a few hours in DNA then letting the DNA dry off and wrapping the outside in a rag. Actually, I'm filling the bowl with alcohol and letting it bleed thru. I'm thinking of then sealing the outside with sanding sealer rather than wrapping it.
I'll be trying a thicker bowl side today.
I would rather turn thin and not have to return, we'll see.
Any input would be appreciated.
Bill

---

I soak most of my bowls in DNA & find that the drying time goes from 6 months to 3 weeks to reach 8-9%. I turn most thick and then re-turn so that they're round when I get done. Wrap the outside in brown grocery bag paper & label with the date/species. From my experience, DNA does not stabilize it at all, only speeds drying. Wrapping only the outside is supposed to put a compressive stress on teh bowl and prevent cracking; works from what I've experienced.

Never tried sealing the outside with finish after soaking. You'll have to make sure ALL the alcohol has evaporated, as most sanding sealers are shellac-based. (Alcohol dissolves shellac.)