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  • drying wood using boiling method...data and charts

    I finally got around to trying the boiling method of greenwood drying and decided to chart the process and share the data with you. I like seeing hard data, and thought some of you might enjoy seeing this.

    I used the technique described here by Steve Russell: http://www.woodturningvideosplus.com...reen-wood.html
    He seems credible, and gives more technical details as to the benefits of this method. It’s a very interesting read.

    Essentially, you turn your bowl oversize (i.e. wall thickness should be 1/10 the diameter of the bowl… this gives you something to work with, if the bowl warps). The next step is to immerse your greenwood bowl into boiling water ASAP after turning. Keep it there for at least 1 hour per inch of wood thickness, weigh it down with a stone if needed. Remove the bowl from water and cover with several old bath towels, and let it cool down overnight. Finally, place the bowl in a sealed paper bag, wait a few weeks, and start weighing the bowl. When the weight is stable, then the bowl has finished drying.

    The wood used in this case, came from a diseased poplar a neighbor had cut down last summer (2007). The initial blanks were 10.5” in diameter and 5.5” thick. One weighed 8.75 lbs (bowl “A”), the other 12.25 lbs (bowl “B”).

    Bowl “A” was rough-turned and boiled on October 23, 2007, and bowl “B” on October 24, 2007.

    Each morning onwards, at 7 AM, I removed the bowls from their bags and weighed them. A few days into it, I also decided to start recording the room temperature and air humidity (could prove useful for someone).

    As you can see in the “Bowl Weight” and “Bowl Weight-Loss” charts below, both bowls had pretty much reached equilibrium after 3.5 to 4 weeks. I continued recording the data until I was ready to finish-turn the bowls.

    Everything went very well, the bowls dried thoroughly, and neither had any checking or cracking. Bowl “B” did warp pretty badly, but since its walls were roughed-out oversized, it was a non-issue.

    Two things really surprised me. The first was how quickly the bowls dried, especially considering the large amount of water they absorbed during the boil (bowl “A” almost doubled its initial weight). At first, they were evaporating up to 65 ml of water a day (13 teaspoons)…through a sealed paper bag! The second thing that surprised me was the smell. During the first few days, the smell was that of walking in the woods in the springtime after a rainfall. Latter, bowl “A” developed a lot of mold and its smell became very sweet…almost tasty. But both smells completely disappeared after 12 days.

    In conclusion, I would like to say that I don’t have enough experience to claim that this is the best drying method, but it works very well, it’s cheap, it’s easy, and uses no chemicals.

    I’m happy I finally tried it, and yes, I will use it again.
    Attached Files
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  • #2

    Re: drying wood using boiling method...data and charts

    I am very sceptical of the boiling process and also DNA and LDD and although I applaud the effort you made collecting this data it is seriously flawed.
    To be able to draw any conclusions from any such data you have to set up a blind. That is an identical sized rough bowl and not boil it. The test bowls would have to be sized very accurately and preferably turned from adjacent pieces of wood within the tree. Also to get accurate results more bowls would have to be done, then the the use of identical pieces of wood really becomes a problem.
    Also how much time elapsed from the tree being cut and the bowls being turned. Wood looses most of it's moisture within a few weeks of it being felled. You also mention the tree was in bad shape so the chances are it was already dead and starting to dry out before it was felled.
    I have tried all 3 drying methods and quite honestly really didn't notice any gains in drying times or lack of cracking that made it worth the time and effort. It is still a lot easier to rough turn within a few days of felling and then coat with wax and set aside until nature takes it's course. Once you get into this kind of a cyclical rhythm then you always have a supply of rough turned bowls to finish. Even when allowing the logs to dry somewhat before any turning is done you can cut down the chances of serious cracking by splitting the log down the middle and removing the pith. This releases all sorts of tension in the wood and waste is reduced.
    But I am glad to see there are turners who are willing to do data collecting, and who knows some day we might get to the bottom of all these voodoo drying techniques.
    Thanks

    Comment


    • #3

      Re: drying wood using boiling method...data and charts

      Joseph,
      Thanks very much for all the data. Can you post a picture of the bowls? The reason I ask is that I find the main problem with poplar as it dries occurs at knots, where there have been side branches. Unfortunately these are also the areas which add colour and character to the turnings. If the boiling method diminished the chance of cracks emanting from these spots it would be very helpful.
      Glenn

      Comment


      • #4

        Re: drying wood using boiling method...data and charts

        Hi Joseph
        Why would you boil the Poplar blanks ???
        Poplar and Willow are some of the most foolproof woods to dry without checking/spitting, as it is cross-linked grain wood and like Elm and others they do not split easily.
        If you had done this for say Arbutus or Plum or the like, I can see doing that, but only for trying to lessen the splitting of the wood.
        Wood lignin is what keeps the wood bundles (just to make it easy) together, and at boiling point it gets liquified, so stresses can release, or we are able to bend planks etc., as boiling/steaming is done for all kinds of uses.
        You do however have to let the wood/lignin cool before releasing these things, and I would say that's what you should also do with the bowl blanks, (leave them in the water until all is cooled down).
        You did keep them wrapped in this case, and of course it worked fine (Poplar would not split anyway), to come back to the stress release, as the wood dries the stresses from drying will inevitable occur/recur, though the initial before boiling stress has been diminished, and it seems to help in lowering the splitting rate, not eliminate !!
        I have for years already dried my rough turned bowls, with good success, without any alcohol, soap or boiling, yes I tried the soap and the boiling, the alky ??, WELL CHEERS ;-)))
        You might have seen my pictures of the rough turned bowl in my drying "Chalet" ?? , if not just have a look, and see how many splits you can find on those bowls, and no I didn't position them so you couldn't see them.
        And there are lots of Apple and Cherry and Oak and Mulberry wood bowls in there, that according others are so hard to dry without splitting.

        http://homepage.mac.com/l.vanderloo/PhotoAlbum26.html

        Have fun and take care
        Leo Van Der Loo
        Last edited by Leo Van Der Loo; 02-03-2008, 01:46 AM.

        Have fun and take care
        Leo Van Der Loo

        Comment


        • #5

          Re: drying wood using boiling method...data and charts

          Thanks Joseph. I am new to turning and I really appreciate learning new things. I will investigate more.

          Leo. Is your drying shed heated? Also, do you seal the end grain before putting on the shelf?

          Don
          Don McFarland
          ​Member - Durham Woodworking Club
          http://www.durhamwoodworkingclub.com/

          Comment


          • #6

            Re: drying wood using boiling method...data and charts

            A lot of good info and thanks for providing but I too must agree with Pete as it is a slanted stack of data. You need at the least a test piece that is left to cure on it's own. All of what
            Pete said holds water (so to speak... pun intended) but a simple test using a controled group as well as the theory group, etc would provide more plausable info.

            I do not agree with Pete on his idea about mass producing blanks and setting them aside, for a production turner, maybe that would be the best method but for a hobby guy who gets the urge to turn a bowl and doesn't have a stockpile of bowl blanks in waiting, any of the three major (and now 4) methods are handy. I prefer the DNA as it is cleaner and quicker, in my opinion. I tried Microwave but not successful, never tried soap but invision it is rather messy and a waste of soap. Boiling ,In my opinion, is best left to potatoes. but it is another method to consider if you are fresh out of alcohol or soap. (or not ready to wait a couple months to play with your lathe)

            Thanks for the hard work and the tabulations, most don't realize how much effort went into compiling and sorting the info. I do, and appreciate your efforts to relate to us undeserving woodbutchers.
            Bill "Hickory" Simpson

            Comment

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            • #7

              Re: drying wood using boiling method...data and charts

              Thank you all for your comments.

              But please understand that this was in no way meant to be a definitive, exhaustive scientific study to prove or disprove the method.

              It was only a data gathering exercise for curiosity’s sake.

              ---

              Hi Pete,

              What would be flawed, would be deriving definitive conclusions from such a small sample size. The data is sound.

              I was a little bummed because the original plan was to boil one and just bag-dry the other, and see if there were any differences. But when I saw the huge weight difference there was between the two 10.5”x5.5” blanks (i.e. 8 VS 12 lbs), I just decided to boil them both.

              ---

              Hi Glenn,

              If you do try it, please read the instructions from Russell’s link, they are much more complete. Whatever the outcome, please let us know your findings.

              Here is a link to some pictures you requested:
              http://www.canadianwoodworking.com/f...ad.php?t=20222

              ---

              Hi Leo,

              Sorry, my arbutus and pear supply was a little low ;)

              I used poplar because it was free, not out of choice.

              ---

              Hi Don,

              I’m still as green as they come myself.

              Comment


              • #8

                Re: drying wood using boiling method...data and charts

                Hi Joseph
                Here's some more info that also reflects my believe and experience, pertaining the fast wood drying, and the persistent tales surrounding this.

                Have fun and take care
                Leo Van Der Loo
                Attached Files

                Have fun and take care
                Leo Van Der Loo

                Comment


                • #9

                  Re: drying wood using boiling method...data and charts

                  Thanks for all the kind words Bill,

                  your response came in while I was typing up the answers to the other people.

                  Concerning control groups, as I said to Pete above, the initial blanks were too different to be of any use in a comparison. I really wanted to do so, just couldn't.

                  Leaving the boiling to the potatoes :lol: :lol: :lol:
                  that was funny.

                  Comment


                  • #10

                    Re: drying wood using boiling method...data and charts

                    Joseph
                    You did lottsa work on your data collecting and right or wrong, this is how we all learn. I didn't do very much drying myself, one reason being that is in this town you can not buy anything such as DNA or wax emulsion or much else. ( so now maybe lucky for me)
                    They sure pounce on you in here:lol: , but that is a good thing as these guys have been through it all and have the knowledge and are not scared to keep us on the straight and narrow. Anyway, boiled or not, your bowls look great.
                    Murray

                    Comment


                    • #11

                      Re: drying wood using boiling method...data and charts

                      Hi Don
                      Sorry for the delay, hadn't seen your post/question.
                      You won't get a yes or no as an answer, as it all depends on what I turned and when, for instance if I turned a Willow bowl right now, it probably go just on the shelf, if it was Apple, it would go in a closed paper bag and on the floor.
                      If this was summer, the Apple bowl would still go in the closed paper bag, but would go down into the basement for a few weeks, then into the shed still in the bag.
                      There are very few bowls I wax, but Beech is one of them if I didn't finish turn it thin to let it dry and warp, they still do go into the brown paper bag though, also summertime is when I might wax earlier than in the wintertime, as high temps are more likely to increase the drying speed, and that is exactly what you don't want, wood needs time, dry wood will not split, and wet wood does not split, it's when there is to much of a difference in the wood, between one area and another or between inside and outside, so slowing down the drying and giving the wood moisture time to move in or out, out mostly as we want to get it dry, but yes making the outside wet while the inside is less so might split the wood also.
                      There are also a couple of important things to watch out for, first is to start with wood that does not have splits in it already, very often hard to detect, but sawing a thin slice off the end, and then bending it will show if there are any splits in it already, the pith area is prone to split, and cutting that off is a good idea.
                      The other thing is if you start turning, finish it, and don't go away for a coffee break and let the partially turned piece just sit there, spray a little water on the block and then slip a plastic gag over it, turn off the light that's shining on it also.
                      Turn the walls evenly or go a little thinner as you get closer to the foot, also try to keep the foot no thicker than needed, one reason I very often use a recess to hold my bowls, rather than a tenon.
                      The problems that arise is that wood is always different, and the wild grains occur in stressed areas and by knots etc, it is very often just taking a good guess and extra precaution by making sure the drying goes slow, especially the first week or two, and keep an eye on the bowl, look it over good, and if anything shows, put some CA on it, just to increase the strength in that area, I often do this as soon as I'm finished turning if I don't trust something to stay together, like a knot, as it is all end-grain and will dry quick and split, they like to do that even if you could slow it down to the same speed as the rest of the wood, so I let some CA soak into it, keeps it from splitting very often, but not always.
                      I try to visualize how the wood is going to chance shape as it dries, and where it will dry faster or slower, and always keep in mind what species of wood it is, even then there is a difference where a tree grew, like in the case with fruit wood, apple tree growing just wild somewhere, will be easier to dry than a heavily fertilized tree that has been trimmed to a open form with heavy loads of apples on them at times, the stresses in that wood will make it much more prone to excess warping and twisting, and splitting.
                      Same with a big long branch that grows out horizontally, they have more stress in them and are more likely to warp and split.

                      My shed is pretty near airtight, well not really, but close, the whole thing is fully insulated, floor walls and ceiling and doors (4" thick), all seams are caulked, and all the wood surfaces are left without any finish on it, so the wood that's in there and the shed itself take up and release moisture, because there is no draft and with the insulation the temperature swings are much slower and the peak high and lows during the days are less so, temp and humidity are so more equalized, that's the whole principle of my drying shed, and it has worked well for me, If it feels like it's damp in there (very seldom) I turn on the heat-lamps for a few hours so the temp goes up and it gets a little drier, but normally there's no heat in there.
                      Well that's about it I think.
                      Have fun and take care
                      Leo Van Der Loo

                      Have fun and take care
                      Leo Van Der Loo

                      Comment

                      • Thread Continues Below...

                      • #12

                        Re: drying wood using boiling method...data and charts

                        When I got back into turning around 2000 and all the new stuff the internet brought to light, I got excited by Steve Russels' stuff on boiling and similarly when the alcohol craze started a couple of years ago. I wholeheartedly agree with Leo. Even as a hobbiest turner, the easiest way is to just keep plugging away, don't get anxious for quick results, turning a green bowl now and then and building up a reserve of dried blanks. I did try boiling a small plum bowl a couple of years ago and it did crack somewhat in the middle of the wood. The one I didn't boil, cracked a little more. Have to admit I have tried microwaving a few things and they did work out. Over the past few months I have been using up dried roughouts and in a couple of hours have a finished nice bowl, forgetting the initial work. This is a 10" Norway Maple from a batch cored out in August of '06. Picture is a bit fuzzy. My wife had been using the camera and I hadn't noticed the setting on Face Mode! My outdoor studio is a bit snowbound these days so haven't reshot.
                        Attached Files
                        Mike

                        Comment


                        • #13

                          Re: drying wood using boiling method...data and charts

                          Hi Mike
                          Just butting in here, that's a sharp looking bowl Mike, love the color also, nice.
                          Have fun and take care
                          Leo Van Der Loo

                          Have fun and take care
                          Leo Van Der Loo

                          Comment


                          • #14

                            Re: drying wood using boiling method...data and charts

                            Hi Leo,

                            thank-you for all the information.

                            I am certain that your objective is to guide us newbies, and protect us from ourselves.

                            For that I am truly grateful.

                            But sometimes, I'm sure you understand, we just got to try things out for ourselves.

                            Something which should be encouraged.

                            Cheers,
                            Joseph

                            Comment


                            • #15

                              Re: drying wood using boiling method...data and charts

                              Hi Joseph
                              No sheep herding here at all Joseph, but people usually like to know if things have already been tried and/or studied, rather than trying to reinvent the wheel again, and it is with that in mind that I try to bring answers here to the forum, and no I don't have all the answers by far, just tried and heard and seen things for a longer time maybe, and I also will go to try and find info/answers if I can.
                              I certainly would not want to try to stop anyone from trying new ways or even old ways if that's what they like to do, we do after all have to figure a lot of things out for ourselves, right ??
                              Have fun and take care
                              Leo Van Der Loo

                              Have fun and take care
                              Leo Van Der Loo

                              Comment

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