• Processing a Bowl Blank

    by
    Dennis Peacock
    Published on 01-02-2011 6:32 PM  Number of Views: 29807  
    20 Comments Comments
    With all the newcomers here on SMC with questions about bowl turning and drying roughed out blanks, I figured it was time to post something about how I go through the process. I may not be "right" about my process, but it's the way I do it anyway. Ask 10 turners about turning a bowl and you'll get 15 different answers.
    So here goes......



    1st Pic - This is a Pecan bowl blank that I needed to get roughed out and thought I'd use it for this article/process of showing how I go through the process. It's just over 19" in diameter and weighs around 40 pounds since it's wet wood. It's mounted to a 3" faceplate with good steel screws and I also slide up the tailstock to provide that "captured" security while spinning a heavy bowl blank on the lathe. I used my 5/8" bowl gouge to rough it out on the outside and worked on getting my rough form of the bowl.



    2nd Pic - This is what I've finished roughing out the outside and bottom of the bowl. I've also since moved the tailstock out of the way and turned off the small nub left where the tailstock was holding the bowl blank. I've also turned the tenon on the bottom so I can mount it to my Super Nova Chuck. I use a tenon as it's difficult to crush a tenon. I used to mount via a recess and expanded the chuck jaws into the recess, but I began cracking bowl blanks that way, so I went back to the tenon process and haven't had a problem since. You CAN apply too much pressure on the tenon and it will snap the tenon off if you get a catch while turning. So apply clamping pressure but not so much to where you start really crimping the wood. That's too tight....back it off just a tad.



    3rd Pic - This is after I've removed the bowl and reverse mounted it on the Super Nova Chuck and hollowed out the inside of the bowl. Now...I do use the tailstock while working the inside of the bowl as well. I then slide the tailstock out of the way and turn away the "spindle" that's left from where the tailstock was. I then use my 3/8" bowl scraper to flush and smooth everything out on the insde of the bowl.



    4th Pic - Shows the bowl all roughed out on the outside and the inside and still mounted to the Super Nova Chuck. It's now ready to be removed from the chuck.



    5th Pic - Here's the freshly turned bowl blank now setting in it's 24 hour home of an alky bath (Developed by Dave Smith). Notice that it's not fresh alky. Black Walnut and other dark woods will turn the Alky dark like that....so I call it my Alky Tea.



    6th Pic - Here's the bowl getting ready to come out of the alky bath at about 24 hours later. Don't pay any attention to the color of the outside of the wood. It all turns away when finish turning the bowl.



    7th Pic - I have a piece of 6" metal ducting that I now place my alky wet bowls on the air dry for about 20 minutes or so before wrapping in newspaper. You can speed this process up a great deal if you will take a rag and dry the outside of the wet bowl blank and wait about 1 minute before you start wrapping it in newspaper.



    8th Pic - Here's the bowl turned upside down on top of 2 sheets of newpaper ready for the wrapping process. I use 1" wide masking tape for the tape of choice. It's cheap and works well.



    9th Pic - This is the bowl wrapped up as far as the newspaper would reach. I just fold it up around the bowl snuggly and tape it all in place.



    10th Pic - Here's the bowl all wrapped up and labeled as "Pecan 4-6-06". I always write the wood type on the outside so I know what TYPE of wood I have drying as well as the date I took it out of the Alky bath. You see, I don't weigh any of my blanks. I just leave them on the drying rack, unwrap and finish turn. I'm not in such a hurry that I need to weigh it before I know I can turn it. Leaves me more time to spend at the lathe that way.



    11th Pic, and Yes....the final pic - I then flip the wrapped up bowl over and use a nice sharp knife and cut out the center section of the newspaper so air can get to the insdie of the bowl and allow it to dry and let the rest of the bowl to dry through that "port" more slowly.

    I then place the bowl Upside-Down on my drying rack so sits there and behaves itsself for 21 or more days before I unwrap it. If I'm not going to finish turn it right away, I then stack it upside down on top of two other bowls so air can continue to circulate around it. That way it can dry more if it wants to and later down the road? I have a big stack of dry, roughed out bowl blanks to choose from. This way, the bowl will keep for YEARS since it's dry now and ready for finish turning. Keeping green or wet wood for long periods of time can prove to be wasteful as it will sooner become firewood than a chosen bowl blank. So...my choice is to rough it, dry it, and stack it until I'm ready for the final turning of my bowls.

    I hope that this explains things a little better and provides you with ideas about your own process of rouging out, drying, and storing your own bowl blanks.

    Thanks for reading!
    Comments 20 Comments
    1. Paul Brinkmeyer's Avatar
      Paul Brinkmeyer - 01-03-2011, 4:43 PM
      I have never turned a bowl, but have thought about it.

      NOW I have many more questions than before.
      I think this might be why some others I know always work from bowls that were roughed out.

      Thanks for the great article.
    1. Dave Wagner's Avatar
      Dave Wagner - 01-03-2011, 5:44 PM
      Nice article. I did my first bowl today, had a piece of 2x8 and thought I would experiment. Turned out pretty good for my first try.
    1. Chuck Wintle's Avatar
      Chuck Wintle - 01-04-2011, 7:54 AM
      Why is it necessary to soak the bowl in the alky bath?
    1. Ken Fitzgerald's Avatar
      Ken Fitzgerald - 01-04-2011, 8:09 AM
      Chuck,

      The alky bath is supposed to aid in a check-free, crack free drying of green wood.
    1. James K Peterson's Avatar
      James K Peterson - 01-04-2011, 8:30 AM
      Is there some ingrediant list for the "alky bath" ? I thougth about using it, but never found a good list.

      Thanks for the great tutorial.
    1. john davey's Avatar
      john davey - 01-04-2011, 12:12 PM
      So 3 weeks is all you need to let it dry? Somehow I though most people believe a much longer drying time is in order. I don't know but really am interested in this. Thanks, John
    1. Dennis Peacock's Avatar
      Dennis Peacock - 01-04-2011, 3:40 PM
      James,
      No special ingredients needed, just Denatured Alcohol.

      John Davey,
      21 to 28 days is the basic rule I've always used. I've even left bowl blanks in the alky bath for over 3 months before and then still dried them for 21 to 28 days (or longer) with great success. Allowing them to dry longer is fine as well, it's really up to the turner as to how long he wants his own bowl blanks to dry on the rack.

      I have found that less than 21 days doesn't work as well for me as 21+ days on the drying rack. Of course, my shop is heated and before my A/C units broke, I had running A/C in my shop which also help the drying process.

      Just use a time that is acceptable for you. But in my humble opinion, 30 to 45 days on the drying rack is plenty.
    1. Jack Camillo's Avatar
      Jack Camillo - 01-04-2011, 8:26 PM
      Thanks for the article - valuable nformation I need to know when I begin turning, which will hopefully be soon.
    1. Jim Colombo's Avatar
      Jim Colombo - 01-05-2011, 5:51 AM
      Do you have or know of a formula that tells you how long to leave a certain sized bowl in the alky bath? I imagine the soak time depends on the size of the bowl as well as the wood type.
    1. Dennis Peacock's Avatar
      Dennis Peacock - 01-05-2011, 3:54 PM
      Jim,
      I've treated every size bowl the exact same. I've soaked 6" bowls in with 15" bowls, took them all out at the same time, wrapped them, and put them on the drying rack. All came out exactly the same...unchecked and uncracked.

      The alcohol encapsulates the water molecules in the wood and helps with getting the water out of the wood faster (as per Dave's research). I've been using this alky method since before it was published in public.
    1. Skip Spaulding's Avatar
      Skip Spaulding - 02-05-2011, 9:04 AM
      Nice article Dennis, I've been using the same method since I found it here on" SMC" a few years ago. I do use the McNaughton system on larger blanks and like you, I have found the drying time for small to large blanks about the same.
      Thanks again for a nice pictorial.
      Skip
    1. Allen Linton's Avatar
      Allen Linton - 05-16-2011, 12:23 AM
      My biggest issue with turning is with drying the wood. I have tried Anchor Seal with poor results. I have buried rough turns in sawdust, I have also tried the Alky bath and drying with out a paper wrap; no real success. I have just aquired some Cherry from a good friend and will try this method. Wish me luck, I would hate to lose this fantastic aquisition.
    1. Primvs Aebvtivs's Avatar
      Primvs Aebvtivs - 09-17-2011, 4:41 PM
      I have acquired, through a fire, some silver birch, suitable for bowl turning, it's been outside for a year "aging / drying", and some walnut, which was a standing dead tree at work. I'm going to see where I can get denatured alcohol from in the U.K. This alky bath works on rough turned bowls, so does it work on tree branches also? I've a few bits put aside, but am worried about them cracking as they dry out.Any help would br gratufully received!'Bvt
    1. Melissa Messick's Avatar
      Melissa Messick - 02-29-2012, 5:48 PM
      I too have been given some wood holly wood still with the bark on. I'm wondering if this will work on it?
    1. John Meade's Avatar
      John Meade - 04-28-2012, 11:08 AM
      Thanks for the article. I have a few questions:

      1. So the alky bath is nothing but denatured alcohol, correct?

      2. Starting at an earlier point in the process...when I cut the log in half and remove the pith, I have been told to "paint" the exposed grain with anchor seal. Do you do that before turning your rough bowl? Then you do the alky bath after you turn the rough bowl blank? Is this right?

      3. Can you show a picture of your drying rack?

      Thanks for your help.

      John
    1. ted huminski's Avatar
      ted huminski - 04-30-2012, 3:11 PM
      Quote Originally Posted by John Meade View Post
      Thanks for the article. I have a few questions:

      1. So the alky bath is nothing but denatured alcohol, correct?

      2. Starting at an earlier point in the process...when I cut the log in half and remove the pith, I have been told to "paint" the exposed grain with anchor seal. Do you do that before turning your rough bowl? Then you do the alky bath after you turn the rough bowl blank? Is this right?

      3. Can you show a picture of your drying rack?

      Thanks for your help.

      John
      John,
      I had to alchi dry a number of bowls when i started. It is just denatured alcohol.

      Once you cut the blank from the log, you need to seal it if you aren't going to rough it immediately. If you walk away from it while turning, cover it with a plastic bag to prevent cracking. Rough it to a thickness of 1 inch per 12 inch of diameter. Some say 10% of diameter to be safe. After roughing, submerge in the alcohol bath for a good 24 hours, remove, and wrap in brown paper. I cut a 2" to 3" hole in the top of the wrapping and store it upside down. 3-4 weeks should do it and it's ready to turn. You can weigh it on a postal scale or kitchen scale every day or so until the weight levels out to be sure.

      I have had great success with that process. Once you build up an inventory, you can get rid of the alchi bath. It can be expensive because you may need several gallons to soak a big bowl and it needs replenished and replaced after a while.

      Ted
    1. Frank Hasty's Avatar
      Frank Hasty - 05-22-2012, 1:04 AM
      I live within 200yds of a salt marsh on the Georgia coast. Relative humidity is usually well above 50% and we have only a couple of months when freezing may occur. Therefore I have had good luck drying (and spalting), local wood both by placing the log in paper bags under a shed and also using a wax emulsion. I apply the emulsion to the raw end and immediately imbed a sheet of wax paper or parchment (baking) paper in it and set it aside.
      The drawback is that this takes a long time, but I have accumulated a fairly good backlog from a local tree cutter and can usually wait a yearor more. So my blanks are dry and bowls can be turned to completion right from the start.
      However: The "alky bath" interests me and I am wondering, regarding what happens to the bath after a blank has been soaked. I recall that "alcohol" has an affinity for water. I imagine that there is a transfer of alcohol into the wood with a corresponding dilution of the alcohol.
      Seems that additional "soaks" would eventually reduce the alcohol concentration.
      I just happen to have some fairly "green" River Birch so I may try weighing the wood and alcohol before and after soaking to see if I can learn anything.
    1. Raymond Thomas's Avatar
      Raymond Thomas - 08-25-2012, 10:08 AM
      Thanks for the great article - I will definitely have to give this a try.
    1. Joe romano's Avatar
      Joe romano - 12-26-2014, 10:13 AM
      Great article!
      How do you when your "ally bath" has reached exhaustion?
    1. Joe Frank Porter's Avatar
      Joe Frank Porter - 06-10-2016, 1:06 PM
      I guess the alcohol mixes with the water in the wood. Then the water /alcohol mix evaporates much quicker than plain water. Alcohol evaporates at a much, much faster rate than water.