Drying Rough-Turned Bowls

Experienced wood-turners discuss how to dry and finish turned bowls without cracking them. August 23, 2005

I can't find anyone where I live who uses an Ebac kiln to dry rough-turned bowls, turned on a lathe. I use a lot of madrone, black locust, maple, and cherry. Obviously, the madrone and cherry are hardest to keep from cracking. I spray them every day, and that inhibits cracking; however, I'm going by the seat of my pants, not science. I don't have a vent to expel humidity. Opening the door every day may do that. Does anyone have any suggestions?

Forum Responses
(Sawing and Drying Forum)
From contributor T:
I turn a fair number of bowls and have owned a Ebac lt 800 for three years. I have an 8 ft by 4 ft chamber made out of two in styrofoam. I can dry about 100 mid to large bowls in 19-25 days at mid to mid-high temperature settings.

From contributor P:
As a professional woodturner, I suggest you seal your rough turned bowls with Anchorseal. If you're in a humid climate, just seal the end-grain. Otherwise seal the whole thing inside and out. Put it away somewhere out of drafts and direct light/heat for a year. By then, they should be ready to turn to final thickness.

From contributor W:
To contributor P: What do you do if you turn a finished bowl from a green blank to keep it from cracking. I have a number of anchor sealed bowl blanks of walnut and osage orange that I have been reluctant to turn for fear the final bowl would crack.

From contributor P:
Actually, 90% of my work is natural edge bowls that are cut, blanked, turned, sanded, and finished on the same day. The bowl is turned to less than 1/4" thick throughout. This is important. If you have a thick bottom, it'll crack. After its turned inside and out, I will use a heat gun to dry just the surface, then I start power sanding.

The friction of the sanding will keep the surface dry enough to prevent the paper from clogging. Then I do the same on the outside. Once finished, it usually sits around for a couple hours while I finish a few more. Then I finish them with urethane oil. I put a heavy coat on, wait a few minutes then wipe it off thoroughly. Let it dry overnight, lightly sand with 800 grit, and repeat. Usually I use five coats (five days) then a three step buffing process to give it a high gloss shine. If I have cracks its because I didn't turn the bowl to a truly consistent thickness throughout.

From contributor D:
To contributor P: I can appreciate your work, and here is the reverse, sweet gum with a bark base.

Click here for full size image

From contributor R:
To contributor D: I'm a little confused. You mention doing it all in one day, and then the description you give takes five days?

From contributor P:
Yes, its all done in one day including the first coat of finish. Since I use four or five coats of finish and it takes a day for each coat to dry, it takes five days to complete. But everything up to the first coat is done in one day.