Drying rough turned bowls quickly.

Just about every wood you've mentioned!

Dominic Greco in Richboro, PA

>Gil,

Notice that Osage Orange platter I posted pics of a couple days ago? A month before it was a Cherry bowl along with a Maple bowl. And several months before that were bowls turned from Apple, Sassafras, Box Elder, Walnut, and Beech. All were alcohol soaked.

I was lucky enough to be in David's test group and I decided to REALLY give his technique a try. I've been using this technique ever since with a great deal of success.

See ya around,

Dominic

It works for pen and bottle stoppers blanks too

Dominic Greco in Richboro, PA

>Dave,

FINALLY, I can talk to people about this great discovery of yours! :>)

I gotta tell you people, Dave is on to something here. It really works! And not just for bowl blanks either!

I recently tried soaking a bunch of freshly cut (right off the log) apple, walnut, sycamore, osage orange, cherry, dogwood, and maple blanks in the alcohol bath. After a night they were allowed to drip off and were placed in a stack on my workbench and forgotten about for about 2 weeks.

When I finally remembered them, I took some preliminary moisture readings and found that they were dry enough to final turn!

BTW, I also tried this on hollow forms and found that it helps to minimize distortion after drying.

See ya around,

Dominic

Thanks for your help in testing the process.

Dave Smith, Longview, WA

>Hi Dominic,

I have been impressed with the range of wood and bowls sizes you turned over the last year. You and Bill Grumbine soaked and turned enough bowls to prove the process does work. In a couple of weeks I expect there will be a whole lot more believers.

Dave Smith

Should have bought stock in alcohol producers in Longview, WA.

Re: Methanol is dangerous stuff.

Bob Hackett

>Methanol is a POWERFUL carcinogen.There were better than 3 times more incidents of a number of cancers in folks who handled and transported it for use in the oilfields during the boom.

I stay as far away from that stuff as I can.Even with a respirator,It`s right up there with carbon tet in my book.

Mainely,Bob

Re: Drying rough turned bowls quickly.

Ray Johnson

>Congratulations Dave. Now that I am close to getting my lathe up and running, I can try this method.

Thanks for sharing.

RayJ

Another wood to add to the list

Mark Kauder. Phenix City, AL

>Dave,

Got an interesting addendum to add to the file.

Last month at our club meeting, I won a log section of what the guy who brought it said was Cherry. I had my doubts, but took it. When I got home and split it, I confirmed that it was not Cherry, but Chinaberry (Mahogany family).

Anyway, I have turned Chinaberry before, and it is nice wood. So I roughed it out, first with a screw chuck, and then glued on some waste blocks made from some very old, very dry Red Oak. This Oak had been drying in a barn for 13-15 years. I turned th waste blocks to about 5" in diameter and turned a tenon on them, and glued them to the Chinaberry.

After I finished roughing the bowls to about 10" diameter, and 5/8" wall thickness, I submerged them in alcohol.

Well, I forgot about them for the last month. I only found them today when I roughed out a nice piece of quilted Redwood that I won at this months club meeting. When I pulled the Chinaberry out, the bowls were still perfectly round. However, the waste blocks come off (I used CA glue to attach them). Not only had they come off, they had gone very oval. Basically they had re-hydrated themselves, presumably with some of the water that is in the alcohol.

I will keep you informed on how the long-soaked Chinaberry goes.

I also did some Walnut (that Joel Hunnicutt gave me) about 6 weeks ago, and they appear pretty dry, and have only gone slightly oval - maybe 3/8" across 12" diameter.

Mark

Re: Drying rough turned bowls quickly.

Dinyar Chavda

>Hi Dave (and other testers):

Very interesting process. I vaguely remember reading about the alcohol soak, but the wrapping on one side is a new twist.

Couple of questions for you re WHERE to do this. If one does not have a heated environment (I work in an unheated garage), is it ok to:

1. Do the soaking in the cold (currently fairly dry because of the weather) garage?

2. Do the drying in the same area?

3. Would it be better to do both or either of the above on a patio, which is colder, but has better air circulation?

4. Are you soaking for an hour or overnight---both are mentioned in the various postings?

5. Re the issue of discoloration--I have a ginko hollow vessel, where I want to preserve the color (almost white). Will this process darkent it appreciably?

Thanks

Dinyar

Good questions.

Dave Smith, Longview, WA

>Hi Dinyar,

I tried to answer each of your questions below.

> 1. Do the soaking in the cold (currently fairly dry because of the weather) garage?

I don't think the temperature will affect the ability of the alcohol to penetrate the wood. Remember that the bowl will dry to reach equalibrium with the suroundings.

> 2. Do the drying in the same area?

Lower temperature will slow the drying process but it should not make any difference on the final result.

> 3. Would it be better to do both or either of the above on a patio, which is colder, but has better air circulation?

It is important to allow air to freely access the inside of the bowls. Any time solvents are evaporating in a closed space one needs to make sure there is adequate ventilation. The most off gassing occurs when a piece is first removed for the alcohol and allowed to air dry for an hour. After that there is very little or no discernible odor from the bowls.

> 4. Are you soaking for an hour or overnight---both are mentioned in the various postings?

My original intent of the testing was to identify the shortest time to safely dry roughed out bowls. At one point I soaked similar bowls for different periods of time to see how short it could be. For small thin bowls one hour was all that was necessary for satisfactory results. To be safe I say a minimum of 2 hours. In reality I usually leave the bowls in the alcohol over night and some times several nights. There does not appear to be any detrimental effects of long soak times.

> 5. Re the issue of discoloration--I have a ginko hollow vessel, where I want to preserve the color (almost white). Will this process darkent it appreciably?

As I stated in an earlier response, one of the things I wanted to know was if light colored bowls would be discolored if soaked in a solution which previously had dark wood in it. My experience has been that there is no permanent discoloration. The surface darkens with oxidation when it drys but it is turned away when the bowl is finished. The surface of an alcohol soaked bowl looks similar to a boiled bowl when it drys. I have soaked holly and the surface does darken while drying but it is only on the surface.

Good luck.

Dave Smith

Mourning the Seahawk lose in Longview, WA.

Yes, I did comparative tests.

Dave Smith, Longview, WA

>Hi Andrew,

Sorry I missed answering your question earlier. I started out turning similar bowls from the same wood. I would soak one in alcohol and not the other then dried them in the same manner. In the most extreme case I set the bowls on a shelf in my heated, dehumidified shop. They dried very fast and while the alcohol soaked bowls had less distortion they were mostly firewood after drying. Putting the bowls in a paper bag produced better results as expected and the alcohol soaked bowls dried faster however there was still a high number of cracked bowls. The cracks appeared on the outside of a bowl and usually propagated through the wall. That is when I hit upon the idea of wrapping the out side of the bowl with heavy paper. Slowing down the evaporation of moisture on the outside allows the inside to dry quicker. The resulting contraction of the inner surface causes the outside of the bowl to under go compression. The compressive force keeps cracks from forming. Once I started wrapping the bowls on the outside the failure rate dropped to nearly zero.

Dave Smith

More finishing to do in Longview, WA.

Re: Yes, I did comparative tests.

Andrew Hilton

>I'm assuming you used an open-air rack like a wire rack of some kind so that there would be air circulation? Were the turnings stacked together? How close (side to side/space underneath/etc.)? Does it seem to make a difference? What moisture content were they when you considered them "dry"? How did that compare to the relative humidity of the room/environment? How long between the time you considered them "dry" to when you finish turned them? Did you leave any of the finished turnings unfinished? If not, why not? If so, what were the results of warping/cracking after a few weeks time?

Did you happen to keep notes on wood species, diameters, thicknesses, environmental conditions (humidity, temp, etc.), turning forms, and son on? Any pictures?

If not, would any of the others that confirmed your study have done that?

I'm very very interested in the numbers of this method. If you don't want to share this information right now, are you planning to in the future either online or in a published form?

Re: Methanol is dangerous stuff.

Shawn - in ID

>I'll jump into this now. I use grades of ethanol and methanol in my laboratory to dehydrate tissue. We only use the methanol at -20 C or lower because it turns the tissue white at warmer temps - no idea what it would do to wood. I'm jumping in to say don't play with methanol - it is a fixative, meaning that it cross-links proteins. I'll save you the chemistry/physiology; in short - stay away from it unless you have to use it. It sounds like you use it already - then, you shouldn't smell it, breath it, touch it directly to your skin, etc. Stick to straight ethanol!

Mechanism & cold (long)

Shawn - in ID

>There were a few questions about mechanism and one about soaking in the cold. I use ethanol to dehydrate tissue in my laboratory and I'll offer what I know. Ethanol is both water and lipid soluble. This means that it will penetrate tissue (and wood) cells freely. The ethanol replaces much of the water - if you kept moving the bowl over to fresh 100% ethanol, it would eventually replace all the water. Then, when you set the bowl in the air to dry, the ethanol evaporates very quickly, much faster than water (chemical properties not necessary here). Bottom line is, you are actually, 'drying' (i.e., lowering the water content of) the bowl when it is in the ethanol. Once, set out in the air, the ethanol evaporates quickly and you see the fruit of your soaking. There are many other chemicals that will do the same thing but ethanol will give the best combination of cost, speed, and it will leave you with a bowl that will soak up finish very well. Question about soaking in the cold came up...penetration of ethanol into the wood (if it is at all like tissue) will not be affecting by soaking in the cold - the benefit of soaking cold would be less evaporation of your ethanol. I would suggest that you might find cold soaking to be the best method.

Thanks for the info.

Dave Smith, Longview, WA

>Hi Shawn,

Thanks for the info on methanol and the dehydration effect of alcohol. It appears to me that ethanol penetrates the cell walls and replaces the cellular water. Then, as you said, it evaporates quicker than water to dry the bowl faster. Where were you when I was trying to figure out what was happening. I know, you were moving to Idaho. Where in Idaho? I owe you some turning wood for your help.

Dave Smith

Musing in Longview, WA over the depth of knowledge represented on Woodcentral.

If I may,.....

Dominic Greco in Richboro, PA

>

speak up in David's behalf at this time.

Andrew,

If anything, David's tests were very thorough and his attention to detail impeccable. I know from my conversations with him that he kept accurate track of the weight, diameter, wall thickness, and species (among other data). Much better than I did, in fact.

The test group (of which I was most fortunate to be a member) provided data on any of a number of troublesome species of wood on which we experimented. Over the past year (you see, this was no over-night affair) we pushed the limits and tried as many species, sizes, and shapes as we could. We reported back to Dave our findings so that he could compare results with what he had found.

Your battery of questions suggest that you have doubts as to the veracity of Dave's claims. In order to put these questions to the test, why not make a trail for yourself? I believe you enough of an explanation of the process to proceed on your own. After you've managed rough out as many bowls as Dave has over the past year (it was over 100 wasn't it Dave?), I'm sure you'll be able to provide us with some a veritable treasure trove of information.

Thank you.

Dominic Greco

Re: Yes, I did comparative tests.

Shawn - in ID

>I'm not sure I can bank on the inside contraction causing outside compression being the correct mechanism unless you actually have pressure measurements to back that up. Did you dry bowls rim up or down? If down, then the issue may more likely be evaporation rate of the ethanol - rim down would keep a higher percentage of ethanol vapor in the void and the outside would release ethanol and residual moisture faster = crack. See the mechanism post below. I bet that if the bowl were taken to complete dehydration by repeated refreshing of the 100% ethanol (to replace all water) and then let sit - it wouldn't matter how you wrapped or positioned it, it would never crack - just a hunch.

Re: Thanks for the info.

Shawn - in ID

>Hi Dave,

I'm in Pocatello. I'd be happy to discuss further and even help refine process via mechanism (i.e., mechanistically based testable hypotheses - yep, I'm a scientist). I also posted another querry above with an additional hypothesis/hunch. It's just a lot of fun when something like this comes up that I have a lot of experience with in other contexts.

Re: If I may,.....

Gil

>Hey Dominic,

I don't think Andrew doubted David's findings. Andrew may be a science minded type who likes to look at numbers. Numbers in studies like this are interesting. I'm actually composing an email to my friend who is a Material Scientist at a research university to see if he can come up with a scientific explanation for the findings of David's study.

I think there is an intrinsic problem with the Internet and tonality of conversation. Conversations are all one sided and we cannot read feedback from people as we could on the phone or in person. Therefore David's question, which may seem friendly and inquisitive in person, comes up as harsh and degrading when posed online in writing.

Have a great evening and wonderful week,

Gil

Gil...

Shawn - in ID

>see my post below "Mechanism and cold"

Re: Mechanism & cold (long)

Gil

>Shawn,

Thanks for the wonderful information. Do you know if denatured alcohol would completely evaporate from the wood leaving it non-toxic? This method could pose concerns if the wood is used in a food enviroment. I know when shellac is applied with denatured alcohol the ETOH evaporates and leaves a food safe finish. Just curious if you have a theroy on the wood.

-Gil

Re: Mechanism & cold (long)

Mark Davenport

>If the alcohol replaces the water in the wood cells, then where does the water end up? Does it build up within the alcohol bath? After using a batch of alcohol many times does its effectiveness change?

EtOH gone

John Trant (Baltimore/WashDC)

>Ethanol has much lower surface tension and thus moves through the wood and evaporates into the air much more readily than water. I would have very little concerns with residual solvent remaining in the wood.

John

Re: Mechanism & cold (long)

Dinyar Chavda

>Shawn:

If I may add more questions to the ones posed by Gill and Mark....if your theory is true, would it imply that it would take upto a week or more for the ethanol to "evaporate" from the wood? And would the absence of the paper wrapping cause the wood to crack as the ethanol leaves the wood?

While the approach is certainly appealing, we have been down this road before with LDD (no offence intended to the proponents of this method). Having a sound theory to back the results of individual turners gives one much more confidence in the approach, and may even help explain the "rare exceptions" that Dave has encountered.

Keep it simple.

Dave Smith, Longview, WA

>Hi Mark,

When I first started I considered the potential problem of alcohol dilution. I decided to first try using straight alcohol and see if it worked before worrying about concentrations. I wanted to keep the process simple. Having to purchase and use a hydrometer was just an other variable to track. It turns out that a small amount of solution is lost with each piece removed. So alcohol has to be added periodically to keep new pieces covered. I have not seen any difference in drying time from fresh solution to one that has had many bowls soaked in it. Relative to the cost of turning material and the time saved I believe the cost of the alcohol to be relatively cheap. Besides, I have always hated solution and dilution problems.

Dave Smith

Simple is better in Longview, WA.

Some thoughts (no data)

John Trant (Baltimore/WashDC)

>In theory, the ethanol would be most effective when it is dry (i.e., no water content) so that the water in the wood would combine with the ethanol to form an azeotrope (a mixture of 2 or more compounds that behave as a single compound with respect to many of its physical properties). This azeotrope moves into and out of the wood readily and evaporates rapidly. Even after the ethanol is completely consumed in the formation of the azeotrope, the addition of small quantities of excess water would have little effect on the benefits described by others. The excess water, diluted in the vat of ethanol, would have to have a greater content than the water content of wood at EMC. The evaporation of the azeotrope from the vat and subsequent refreshing the solution with "dry" ethanol will help depleat excess water. Again, this is a "perfect case scenerio. A more realistic situation is that once "dry ethanol" has remained opened to the air, it will primarily be in the form of its azeotrope fairly rapidly. My guess is that the ethanolic azeotrope is freeing up the bound water (solvation), diluting/displacing it, and then facilitating its capillary movement out of the wood via depressed surface tension. I voice in early discussions that I thought the mechanism of action of liquid dishwashing detergent (LDD) on rough turned bowls is essentially the same as I described for the ethanol soaks. I like this method better because the LDD method resulted in the wood ladened with residual soap (which is hydroscopic). Dave's ethanol method should have no residue.

Just my working hypothesis, but what do I know.

John

Remove 2 for email

LDD started me on this road.

Dave Smith, Longview, WA

>Hi Dinyar,

I tried LDD and did not find it very effective and kinda messy to boot. Many of the forum messages on the subject suggested that it was the surfactant in the soap that was allowing the cellular water to migrate out. I reasoned that if I used a solution of surfactant I wouldn't need the soap. So read the MSDS for several soaps and they all listed alcohol as the surfactant. What particular alcohol and the concentration is proprietary information. So I learned more about denatured alcohol than I ever wanted to know thinking I could bottle "Dave's Secrete Bowl Drying Solution" and make enough money to buy a big lathe. The easiest alcohol to get here in the States is denatured ethanol which turns out to be pretty cheap so there went my big lathe.

Wrapping the bowls was an attempt to stop the cracking which usually started on the outside. I am pretty sure that the out side went under tension and cracked as it dried faster than the inside. Slowing down the outside evaporation by wrapping the bowl took the bowl cracking to near zero. End of comparison testing for me. All that was left was to see how long to soak the bowls and how long they took to dry.

I actually had all the data I needed about two years ago but I figured that it would be dismissed out of hand if I suggested it so I just happily used the process. When I finally decided to stick my neck out I hedged my bet by asking several turners to try the process. I wanted to make sure I wasn't skewing the results and that it was indeed as simple as it appeared. It was important to me that the article was published so there would be no question where the idea came from. Also I had hoped I could garner a little compensation for all the time and materials I had expended perfecting the process. Had I not done that the information would have been released last Spring.

Dave Smith

More thinker than businessman in Longview, WA.