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Turning green bowls to finished state in one day

14K views 27 replies 19 participants last post by  HalDougherty 
#1 · (Edited by Moderator)
Looking for ANY info on this. I know that as a woodworker I'm supposed to be patient, but I need at least SOME instant gratification. I have been turning bowls for a little while, and most of the wisdom I've garnered from folks on this site and others tells me I should rough turn the bowl to a thickness that's 1/10 of the diameter, seal the bowl with anchor seal, and then say goodbye to it for 3 - 6 months. After that time, I'm supposed to rechuck my now much drier and somewhat warped bowl for final turning and finishing.
I'm ok with that, I suppose…....... but I've read about folks who take green wood, turn it down to the final thickness, somehow sand it (not sure how - when I try to sand green wood the sandpaper lasts about 30 seconds before clogging) then seal and finish it with some sort of coating. Then over the course of several days, they lightly sand and reapply to build up a finish.
Anyone ever heard of doing this and if so, what are the specifics? how thick are the bowls? how large? how do you sand them? what do you finish them with?

Thanks,
Mike
 
#2 ·
I have read something about drying the wood with a heat gun and competing the sanding before the woods internal moisture rises to the surface.
This may not work on some woods though; they may surface crack.
Im also not sure how much a heat gun would cost if you dont have one. Probobely expensive
 
#4 ·
Another option is to rough turn your bowls as you have described and then soak them in denatured alcohol for 24 hours. After the soak, wrap it in a brown paper bag for 1 to 2 weeks and it should be dry. Then you can remount and do your final turn.

Check out my project page, the majority of my hollow forms where turned from green wood. Some of them do move a little, but I think it adds to the organic feel to the piece. On some of the really wet pieces I wet the exterior when the piece is finished and wrap it in a brown paper bag for a few days.
 
#5 ·
i read an article about a method that turned a bowl in a single trip to the shop. starting from green stock he turned the complete bowl less then 1/4 of an inch thick.. because the bowl was so thin, the heat from the turnning did the rest…

i can not turn one that perfect, he used an internal light source to get it uniform.. i turn one blank every week or two.. so i've got 30 blanks roughed out drying.. i started one today from walnut burl that i roughed out maybe a year ago.. the instant gratfication happens after you have a six month supply of blanks..
 
#8 ·
trifern's approach with replacing the water with alcohol is the only way I have ever had any success.

You could borrow from the hat turners technique. A turned hat starts out with wet wood that is turned to final thickness (plus a little sanding room) and using a light to determine the even-ness of the wall. The somewhat pliable and wet-like turning is then secured over a drying form and placed in an environment that will allow it to SLOWLY dry. Because of the wall thickness this doesn't take very long.
To turn bowls I guess you could take the same approach and then just strap/rubber band the turning over a ball or some other pre-formed object to let the wood dry and thereby take the shape of the form. My guess would be that tighter grained woods would have more success with this approach while "grainer" woods have good luck with the water replaced with alcohol approach.
 
#9 ·
For sanding wet wood, us 3M silicon carbide (the black stuff).
It is totally waterproof.
For some fun, try this:
Turn a small bowl or hollow form from very wet wood. Make it as thin as you possibly can - less than 1/8 inch is best. Immediately, put it in a microwave overn for a minute and watch the action.
 
#12 ·
I have heard of using a microwave to dry wood. You have to be very careful as not to fry it to a crisp.

FYI: They also use very low wattage microwave to keep piglets warm. Pigs in a microwave, no blanket.
 
#13 ·
Microwave the finished bowl for a few minutes - but be warned it will warp and twist. The base will become an oval shape - it can be very pleasing to the eye.

There is no short term solution to a good symmetrical bowl without any cracks - I rough out my bowls, wrap them in news paper and stack them in a cool dry place. I check them after about 2 months, depending upon the thickness and type of wood, some blanks stay there for a year or more.

Once you have a stack of green blanks turned, you just keep adding to them and rotating the stock. soon you will have more blanks than you know what to do with.

Note: even drying these blanks slowly will produce a few blanks that can straight to the fire, because of large splits and cracks.
 
#14 ·
Rough turn your bowl then place in the freezer at least 24 hours. Take it out of the freezer and let it sit until it thaws out Then finish turn. There may be some moisture left at that point so let it sit somemore and try again. I have not found this method anywhere on the internet-I learned it from a woodturning group I attend. (This method works by the water expanding and breaking up the wood cells thus releaseing the water.) I have had great success with this method.
 
#16 ·
I'll bet if you just put your turning in a frost free refrigerator, it would work.

It may take longer though.

Did you ever notice that if you put a piece of fruit, or an open dish of something, it will dry up.
 
#17 ·
The wood will continue to dry. However after its dry enough to sand I go ahead and finish the work . As to warpage it depends on the species of wood. I have experlenced only minor warpage so far. I've only been using this process for several months-so far so good. (Some of the species I have turned are birch, black acacia, pear, plum, black walnut,)
 
#18 ·
Jim (jlb) - Thanks for this tip, I have not heard of this either, but it is worth trying. If it works, then I will turn my blanks in the late autumn and leave them outside over the winter to have a long freeze (4 -5 months), this will keep the wife happy not having her freezer filled with bowls.

This would also explain why my freshly cut lumber dries so well out side during the winter.
 
#20 ·
I think a frost free freezer would work the best.

There should be some way of putting your turning in a vacuum bag, or chamber.

& suck the moisture out, while it's in the freezer. That's how they freeze dry food.
 
#22 ·
We hardly ever use ice cubes, they dry up into flakes of mineral from the water.

We quit making ice cubes.
 
#26 · (Edited by Moderator)
I have done this both with large and small bowls. What I do is get the best surface I can with the Kelton Multi Axis scraper. After I complete the bowl I put it aside for several days in my unheated shop. After the surface has dried some, I sand with Abranet ( I think I spelled it correctly). A number of suppliers carry it; I buy from The Sanding Glove. The Abranet is made to sand wood that is not completely dry.
After sanding I put it aside until dry before putting a finish on it.
 
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