The Tri-Cities Woodturners Association is a member of the American Association of Woodturners.
The Tri-Cities Woodturners Association is a member of the American Association of Woodturners.
Article and photos by: Jim Ketron
This method can save a lot of drying time and wood from checking under normal drying methods. Warping and distortion is reduced and loss from checks is greatly improved! It can take months and upwards of a year for other drying methods, as this one takes only weeks!
Here is the DNA method I use to dry my green bowls. Dave Smith come up with this method and I have modified it somewhat from what he uses.
REMINDER: This is Flammable so take caution and use appropriate measures to protect your shop and home!
You need to get Denatured Alcohol it can be found at most hardware stores, Home Depot and Lowes. I was buying the 1 gal cans but you can go to most Mom and Pop Hardware stores and they can order it in a 5 gal bucket. It’s like getting 1 gal for free when buying it this way.
You will need a good container to store and soak your bowls in. for most bowls less than 10" a 5 gal bucket will work. I also have a large food service tub that has a good seal and a locking ring. Just make sure whatever you use has a good seal like a rubber o-ring in the lid, they will prevent loss of the DNA from evaporation. As you will find you will need to keep adding to your batch to keep the level of DNA to completely cover your bowls.
I like my bowls a little thicker than most. I like a heftier feeling bowl and one that can take some abuse. So I rough turn my bowls 6" and under at least 1/2" thick, 7" to 12" to about 3/4" thick, 13" and above at least 1" thick and above. I roughed turned a 16" and an 18" bowl to 1 1/2" thick and had good success.
I always soak my bowls at least 18 hrs or overnight. For the larger thicker bowls I soak them 24 to 48 hrs. And have accidentally forgot about a bowl or two and left them in for days. It does not hurt them if you forget for a few days. As you will notice the DNA will get color from the wood that you soak Cherry will turn it pink looking and Walnut will turn it very dark. The color will not hurt your lighter wood bowls unless you leave them in the soak for days on end. I like to completely cover my bowls and if you have a floater you might need to add some weight with something to keep it submerged.
After your bowl has soaked take it out of the DNA (don't forget to use latex gloves) and set a wire rack or something similar over your bucket to let the DNA drip back into your bucket. I let the DNA flash off the outside of the bowl then wrap the outside and the top of the rim with a paper grocery bag, use masking tape to hold the paper on tightly around the bowl and on the rim. Cut away any paper that overhangs the rim, this will help to get good airflow inside the bowl when drying. Place on a wire shelf or something similar rim down, bottom up. The wire shelf lets air flow easily to help dry the bowl.
A lot depends on how thick you roughed the bowl, most bowls that are rouged out around 3/4" thick will be dry in three weeks for a thicker roughed out bowl you will need to wait a bit longer. You can weigh the bowl each day and when it stops losing weight for 4 days it should be ready.
I did that for a while but it is time consuming to do that and I don't always go into my shop each day. So this is what I do now. For a bowl that is rouged out to 3/4" thick I let it dry for two weeks with the paper on then let it dry for one week with the paper off and I have has good success doing it this way. For thicker and larger bowls you will need to add some more drying time to be safe! My shop is only heated and cooled while Im in there, in the winter months after the 2 week drying period and I take the paper off I bring the bowl inside the house to finish drying for the last week.
If you have any questions just e-mail me or ask on our turning forum!
Jim Ketron