DNA Testing

After turning a bowl from green (wet) wood, one must dry the bowl.  Usually this drying process is slowed by the application of waxes, sealants, or drying in a humid environment (like a paper bag).  This can take 3-6 months or more, depending on many factors.

There are dozens of different methods out there that allegedly speed up this process.  They range from kilns, to microwaving, boiling, soaking in soap, and soaking in Denatured Alcohol (or DNA for short).

Being of a scientific mind, I was suspicious of the science behind these methods.  I set out to test the DNA method here, and plan to test others in the future.

I will be comparing air drying with no sealer against the DNA soaking procedure found at David Smith's site, found at this link. 

I'm carrying out two tests.

A test comparing two bowls.

A test comparing two end-grain slabs.

BOWL TEST:

Weight Chart

Date	Bowl	Weight (oz)	Weight Loss (oz)	% Weight Loss	Total Weight Loss (oz)	Total % Weight Loss
26-Jun	1 DNA	25.875
	2 AIR	21.125
27-Jun	1 DNA	22.875	3.000	11.6%	3.000	11.6%
	2 AIR	20.500	0.625	3.0%	0.625	3.0%
28-Jun	1 DNA	21.875	1.000	4.4%	4.000	15.5%
	2 AIR	20.125	0.375	1.8%	1.000	4.7%
29-Jun	1 DNA	21.500	0.375	1.7%	4.375	16.9%
	2 AIR	19.875	0.250	1.2%	1.250	5.9%
30-Jun	1 DNA
	2 AIR
1-Jul	1 DNA
	2 AIR
2-Jul	1 DNA	20.875	0.625	2.9%	5.000	19.3%
	2 AIR	19.500	0.375	1.9%	1.625	7.7%
3-Jul	1 DNA
	2 AIR
4-Jul	1 DNA	20.500	0.375	1.8%	5.375	20.8%
	2 AIR	19.125	0.375	1.9%	2.000	9.5%
5-Jul	1 DNA	20.375	0.125	0.6%	5.500	21.3%
	2 AIR	18.875	0.250	1.3%	2.250	10.7%
6-Jul	1 DNA
	2 AIR
7-Jul	1 DNA	20.250	0.125	0.6%	5.625	21.7%
	2 AIR	18.625	0.250	1.3%	2.500	11.8%
8-Jul	1 DNA	20.125	0.125	0.6%	5.750	22.2%
	2 AIR	18.500	0.125	0.7%	2.625	12.4%
9-Jul	1 DNA	20.000	0.125	0.6%	5.875	22.7%
	2 AIR	18.375	0.125	0.7%	2.750	13.0%
10-Jul	1 DNA	19.875	0.125	0.6%	6.000	23.2%
	2 AIR	18.250	0.125	0.7%	2.875	13.6%
11-Jul	1 DNA	19.875	0.000	0.0%	6.000	23.2%
	2 AIR	18.250	0.000	0.0%	2.875	13.6%
12-Jul	1 DNA	19.625	0.250	1.3%	6.250	24.2%
	2 AIR	18.125	0.125	0.7%	3.000	14.2%
13-Jul	1 DNA	19.625	0.000	0.0%	6.250	24.2%
	2 AIR	18.125	0.000	0.0%	3.000	14.2%
14-Jul	1 DNA	19.500	0.125	0.6%	6.375	24.6%
	2 AIR	18.125	0.000	0.0%	3.000	14.2%

After removing paper:

Date	Bowl	Weight (oz)	Weight Loss (oz)	% Weight Loss	Total Weight Loss (oz)	Total % Weight Loss
26-Jun	1 DNA	22.75
	2 AIR	20.25
14-Jul	1 DNA	19.000	3.750	16.5%	3.750	16.5%
	2 AIR	17.500	2.750	13.6%	2.750	13.6%

I wanted the two bowls to be as similar as possible, so I turned them from two halves of the same log.  They are both 7.5" in diameter, and about 4" tall.  The walls were turned to about 3/4" thickness.  They were checked for similarity with a caliper.

The bowls will be treated in the same manner, with the exception of the DNA soak.

06/25/2006

Both bowls were turned, then weighed.  Here are our test subjects:

Note how scared they look.  Bowl 2 will be air dried, bowl 1 will be receiving the alcohol soak.

Bowl #1: 1 lb 6.75 oz

Bowl #2: 1 lb 4.25 oz

Hey, not bad!  So, marked and weighed, bowl 1 meets its fate in the DNA bath, weighed down with an old hammer head.

Be brave, my little friend.  Be brave.  After seeing bowl 1 sleep with the fishes, bowl 2 retreated to a paper bag filled with its own shavings.  I thought this would be the fairest way for it to spend the first day of the test.

More tomorrow!

06/26/06

I pulled the bowl from the DNA and set it on a rack to dry.  In the meantime, I took the other bowl out of the damp shavings and wrapped the outside in a paper grocery bag, per the directions at Mr. Smith's site.

After almost an hour of drying, I wrapped the DNA bowl in the same paper.  Both bowls were weighed and put in my dehumidified basement to dry on a wire rack.

Note the extra wrapped thing on the left.  See the slab test for more info on that.

06/27/06

Like my new weight chart?  It appears that the DNA bowl has lost a much larger percentage of its weight the first day.  That may be attributable to the leftover DNA evaporating.  We'll see what future days bring!

07/02/06

Just back from a weekend trip.  The DNA bowl continues to lose moisture at a faster rate than the air dried bowl.  Very interesting.  Is could be that wood soaked up extra alcohol during the DNA bath, and is now giving it off.  Notice that the DNA bowl started out 2.5oz heavier, but was 4.65oz heavier after the DNA bath.  This doesn't necessarily mean the DNA process doesn't work, as the DNA could have displaced the water in the wood.  Since the DNA evaporates faster than water, it explains why it's losing weight at a faster rate.

07/14/06

The paper was removed from the blanks, and they were brought upstairs to dry in my living room.  There was similar distortion noted in both bowls, and no new checks in either bowl were noted at the piths.

SLAB TEST:

Weight Chart:

Date	Slab	Weight (oz)	Weight Loss (oz)	% Weight Loss	Total Weight Loss (oz)	Total % Weight Loss
27-Jun	1 DNA	19.250
	2 AIR	16.375
	3 Water	20.625
28-Jun	1 DNA	18.125	1.125	5.8%	1.125	5.8%
	2 AIR	16.125	0.250	1.5%	0.250	1.5%
	3 Water	20.125	0.500	2.4%	0.500	2.4%
29-Jun	1 DNA	17.750	0.375	2.1%	1.500	7.8%
	2 AIR	16.000	0.125	0.8%	0.375	2.3%
	3 Water	19.625	0.500	2.5%	1.000	4.8%
30-Jun	1 DNA
	2 AIR
	3 Water
1-Jul	1 DNA
	2 AIR
	3 Water
2-Jul	1 DNA	17.250	0.500	2.8%	2.000	10.4%
	2 AIR	15.875	0.125	0.8%	0.500	3.1%
	3 Water	18.875	0.750	3.8%	1.750	8.5%
3-Jul	1 DNA
	2 AIR
	3 Water
4-Jul	1 DNA	16.875	0.375	2.2%	2.375	12.3%
	2 AIR	15.750	0.125	0.8%	0.625	3.8%
	3 Water	18.500	0.375	2.0%	2.125	10.3%
5-Jul	1 DNA	16.500	0.375	2.2%	2.750	14.3%
	2 AIR	15.375	0.375	2.4%	1.000	6.1%
	3 Water	18.125	0.375	2.0%	2.500	12.1%
6-Jul	1 DNA
	2 AIR
	3 Water
7-Jul	1 DNA	16.250	0.250	1.5%	3.000	15.6%
	2 AIR	15.250	0.125	0.8%	1.125	6.9%
	3 Water	17.875	0.250	1.4%	2.750	13.3%
8-Jul	1 DNA	16.125	0.125	0.8%	3.125	16.2%
	2 AIR	15.125	0.125	0.8%	1.250	7.6%
	3 Water	17.625	0.250	1.4%	3.000	14.5%
9-Jul	1 DNA	16.000	0.125	0.8%	3.250	16.9%
	2 AIR	15.000	0.125	0.8%	1.375	8.4%
	3 Water	17.500	0.125	0.7%	3.125	15.2%
10-Jul	1 DNA	15.875	0.125	0.8%	3.375	17.5%
	2 AIR	14.875	0.125	0.8%	1.500	9.2%
	3 Water	17.375	0.125	0.7%	3.250	15.8%
11-Jul	1 DNA	15.875	0.000	0.0%	3.375	17.5%
	2 AIR	14.750	0.125	0.8%	1.625	9.9%
	3 Water	17.250	0.125	0.7%	3.375	16.4%
12-Jul	1 DNA	15.625	0.250	1.6%	3.625	18.8%
	2 AIR	14.625	0.125	0.8%	1.750	10.7%
	3 Water	17.000	0.250	1.4%	3.625	17.6%
13-Jul	1 DNA	15.625	0.000	0.0%	3.625	18.8%
	2 AIR	14.625	0.000	0.0%	1.750	10.7%
	3 Water	16.875	0.125	0.7%	3.750	18.2%
14-Jul	1 DNA	15.500	0.125	0.8%	3.750	19.5%
	2 AIR	14.375	0.250	1.7%	2.000	12.2%
	3 Water	16.625	0.250	1.5%	4.000	19.4%

After removing paper:

Date	Slab	Weight (oz)	Weight Loss (oz)	% Weight Loss	Total Weight Loss (oz)	Total % Weight Loss
27-Jun	1 DNA	19.250
	2 AIR	16.375
	3 Water	20.625
14-Jul	1 DNA	14.875	4.375	22.7%	4.375	22.7%
	2 AIR	13.625	2.750	16.8%	2.750	16.8%
	3 Water	16.000	4.625	22.4%	4.625	22.4%

This test uses three slabs of wet hickory, which has been very prone to splitting.  The slabs were cut consecutively from the same log.  Care was taken to make sure none of the three slabs had any visible checks to begin with.

Slab #1: Will be soaked in DNA for 24 hours, then wrapped in paper.

Slab #2: Will be immediately wrapped in paper.

Slab #3: Will be soaked in water for 24 hours, then wrapped in paper.

06/26/06

The slabs were cut and put in their respective mediums.  Slab #1 went right in the DNA, slab #2 was wrapped with paper, slab #3 was dunked in a bucket of water.  Interestingly, the hickory sunk in the DNA but floated in the water.

Weights:

Slab #1: Still in DNA

Slab #2: 1lb 0 5/8oz

Slab #3: Still in water

07/02/06

Amusingly, the slab soaked in water lost more weight this time than the DNA slab.  It does correlate my hypothesis about extra weight absorbed during the soaking step for the DNA bowl.  Again, time will tell.

07/14/06

The paper was removed from the blanks, and they were brought upstairs to dry in my living room.  The DNA slab has 3 noticeable checks radiating from the pith.  The other two slabs have no noticeable checks.