Bowl drying, without cracks, is accomplished by slowing down the escaping moisture until moisture equilibrium (emc) between the bowl and the ambient air is achieved. As a turner, we can improve the odds of successful drying- regardless of the method used- by assuring the roughed out blank walls have a consistent thickness and round over sharp corners/edges before starting the drying process.

One of the earlier more successful methods of achieving slow drying was to surround the blank with a barrier to prevent the moisture from escaping too quickly. Various containers can be used as a barrier. Mostly we find paper grocery bags or cardboard boxes being used. In addition, the shavings from the blank turning process are packed around the rough blank to slow the drying and help absorb some of the escaping moisture.

Blanks should be checked for mold and moisture as the process takes place. When the blanks have released the majority of their moisture, they can be removed from their container and placed on a shelf to reach final equilibrium. The storage are should be free from a lot of air movement and out of the sunlight to allow the blanks to dry evenly.

Checking for moisture can be done with a moisture meter or with a kitchen/mailing scale. Using grams instead of ounces will provide a more accurate indication of moisture loss. If you are using a scale to check for moisture, when the weight of the blank remains constant, it is dry. For moisture meters, refer to the instructions to determine the moisture content.

There are some turners who use plastic bags for the barrier. These bags do not transfer the released moisture into the surrounding air. Every few days, the bag should be opened, turned inside out and the moisture shaken off and then put the blank back into the bag. Shavings can be used to help absorb moisture.

This video from Sam Angelo, WyomingWoodTurner, illustrates these methods-

Tim Yoder mentions using a garbage bag in this video. He said this particular method was from Ron Fleming. This is just the segment of the video that deals with drying-

One of the major drawback of this technique is the time involved. Depending on the size of the blanks, drying can take several months (or longer). Turners are inherently impatient people. Turning offers almost instant gratification for a project. Waiting for months to see a turning to fruition isn't something we enjoy. So, we will investigate other methods that promise faster, successful results and see how they stack up.

Some of the terminology used throughout this blog can be found at this link-

https://uwoodcraft.com/a-glossary-of-wood-drying-terms/