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air drying nested bowls

Joined
Mar 17, 2011
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Lake St Louis, MO
Cored out a few nest bowl sets. planning on doing some more. Can I air dry these stickered and stacked as a set with ~5/8 gap. Or am I better off separating and laying each bowl out on a shelf (unstacked). Not concerned with time to dry just with crack prevention.

Obviously stacked helps with space, but preventing cracking is priority.

Also, I put my 1st turned bowls (with a coat of anchorseal) on a wood shelf or on the floor. I set them on the tenon. Is that ok or do I need wire shelfing. And/or should they be top down. I assume that if stacked is ok for part one, then I can stack bowls to dry that aren't nested. Right/Wrong?

Thanks
 

odie

TOTW Team
Joined
Dec 22, 2006
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Panning for Montana gold, with Betsy, the mule!
Cored out a few nest bowl sets. planning on doing some more. Can I air dry these stickered and stacked as a set with ~5/8 gap. Or am I better off separating and laying each bowl out on a shelf (unstacked). Not concerned with time to dry just with crack prevention.

Obviously stacked helps with space, but preventing cracking is priority.

Also, I put my 1st turned bowls (with a coat of anchorseal) on a wood shelf or on the floor. I set them on the tenon. Is that ok or do I need wire shelfing. And/or should they be top down. I assume that if stacked is ok for part one, then I can stack bowls to dry that aren't nested. Right/Wrong?

Thanks

Brian.......It's difficult to give a definite answer to your stacking question, without knowing your exact circumstance. Heat and air circulation are the things you can control, and directly effect the rate at which moisture is eliminated. The bowls will dry if stacked within one another, but the air circulation is significantly reduced. By placing roughed bowls on the floor, the temperature will be cooler than higher up. Except for times when I'm physically present, the inside temperature of my shop stays around 40-50 degrees during winter months, and usually not over 65-70 degrees, even when it's hotter outside. My well insulated shop is cooler year around than someone in Texas, for example, and I've been putting my roughed bowls on top shelves.......but, this only fits my particular circumstances.

The key to preventing cracks is to lower the rate of moisture loss. The more time it takes, the better success rate you'll have. (Not withstanding that a certain small percentage of roughed bowls are going to crack, even when you do everything right!)

Moisture loss is greatest at the endgrain. You shouldn't have a worry to place the bowl directly on the tenon, because this is the place where the least amount of moisture loss will occur. The most moisture loss will be where the end grain is exposed along two strips of the sides and rim. I would think that wire mesh shelves would be a good thing......not because more surface area of the tenon is exposed, but because the overall air circulation around all of the bowls on the shelves would increase.

I have always used stickers between bowls for seasoning purposes, but I've now got so many seasoning bowls that I'm having space problems, too. Very soon, I'm going to be forced to deal with the space issues, and stacking one within the other is an alternative I'm going to seriously look into. I'm not completely sure how to do this, but my thoughts are that once the monthly weighings indicate that the MC loss is coming close to stabilization, that might be the time to start stacking these "almost stabilized" bowls.......anyone else have thoughts on this particular thing? I do know one thing for sure, though.....and, that is my seasoning process works very well with all bowls "stickered" during the entire process up to the point of stabilization. After that point, I've never been concerned with air movement......and, stack the MC stabilized bowls whatever way best gives me optimum use of space........

ooc
 
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OD is close. Anything that helps preserve high humidity around, or hold moisture in the wood can be regulated. If you nest the bowls, the air is quiet and the inner ones stay wetter. If you coated them to hold the water in, you have doubled the problem. If you store them where the RH is high, tripled. If the air exchange is also poor - well you get the idea. Black mildew - there's also a "hairy" mildew - can stain deeply, so allowing the water out, even encouraging the unbound water to leave with centrifugal force or compressed air will get you below the ~18 percent figure a bit faster is worth it. Or keep it below about 50 degrees while it does its first month, because mildew does not like low temps. Anchorseal and a basement at 65 per cent RH combined to ruin nice white maple for me, so I took up bare wood drying many years ago. I've played with a lot of fads, but the real answer is to keep the water from leaving too fast where the wood checks and cracks or too slow where it mildews.

Best equipment to buy to help damage-free curing is a hygrometer, best info to keep at hand the tables of RH to MC found in the Wood Handbook. If you like to play with your roughs, weigh them all you want. If you'd rather not, don't weigh them until they have a chance to be cured. You can figure that out by checking the shrink across the mortise or tenon. Get a diet scale for smaller work, or a postal scale for larger. The really big stuff goes up to the meat department scale. Once cured, they will continue to cycle, so storing them anyplace special just begs for trouble when they are taken to noplace special.
 
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