Silktree Closed Form

I started turning this piece about 2 weeks ago. I had it roughed out and just started to hollow it when I had to set it aside. Put it into a paper bag packed in wet shavings. The log was cut last November and sat outside with the ends sealed until the end of May. The pith is not sound but I wanted to turn a whole log hollow form to show off the grain.

I applied super glue to the cracks around the pith before packing the partially turned piece in shavings.

When I put the roughed out piece into the alcohol there was no further cracking. I have successfully dried pieces with the pith in the sides using the alcohol soaking protocol. This is my first attempt with silktree.
I did not check the concentration of alcohol before putting the piece in the bucket. If the ending alcohol percentage is above 70% then I expect the piece to be dry in 5 to 7 days. Silktree is quite porous which allows it to lose moisture quickly.

Fresh out of the alcohol.

After drying for one hour the piece was wrapped, weighed, and put on a rack.

Even though the ending solution is below 70% I expect the piece to be dry in 5 to 7 days.

Silktree from Gresham. OR. Cut down 11 November 2005.
Diameter: 7.5"
Height: 7.5" including tenon
Wall thickness: 0.5"
Rim opening: 2.5"
Bowl into alcohol solution: 2145, 06/10/2006
Bowl out of soaking solution:
Alcohol percentage of solution:
Begin soak: Did not measure.
End soak: 65.5% *

Weight in grams
06/11 - 1100 - 1286
06/11 - 2145 - 1184
06/12 - 0905 - 1112
06/12 - 2115 - 1070
06/13 - 0815 - 1034
06/13 - 2130 - 1002
06/14 - 0930 - 979
06/14 - 2300 - 956
06/15 - 1330 - 937
06/16 - 1245 - 907
06/17 - 0715 - 883
06/18 - 0915 - 857
06/19 - 1400 - 840
06/20 - 1330 - 828
06/21 - 2015 - 812
06/22 - 1400 - 807
6/23 - 2200 - 795
6/24 - 1400 - 794
6/25 - 1530 - 793
6/26 - 1500 - 791
6/27 - 2000 - 790
6/28 - 1500 - 788
6/29 - 1530 - 790
7/16 - 1000 - 789

Silktree
Click on picture to enlarge
* - I have had success soaking bowls in solutions as low as 50% but after further research I don't recommend it. I will add dry alcohol to the solution to bring it to a concentration greater than 70%.

06/24/2006 - Looks as if I missed the drying time on this piece. A combination of low alcohol concentration and the small opening probably lead to the slower drying time. Still, 13 days to dry a closed form is not bad. The piece will probably not lose any significant weight from now on. I will continue to record data for a few more days then unwrap it. There are no indications of degradationon the inside and the pith is intact. Final pictures in a few days.

07/16/2006 - Unwrapped and started to finish the hollow form. Final weight take today is 789 grams. No change in over 2 weeks. Since the 24th of June when I called the piece dry enough for turning it lost a total of 5 grams which represents 1% of the total weight loss.

Data Cards

Bottom has very little distortion.

No degradation of the CA glue I applied to the cracks developing around the pith during rough out.

Top nearly flat with very little distortion of opening.

The final measurements at the widest diameter are 7 7/16" by 7 1/4". The piece remounted tightly in the chuck which indicates how little the foot distorted while drying.

Very little material was removed to reture the top opening and the bottom tenon.

After turning and power sanding to 150 the piece is ready for a coat of finish.

Since silktree is porous and soft. I apply a coat of finish before making any decorative cuts like rings I intend to turn around the opening. The CA glue has been turned away from one pith but is still visible in the other. The crack on the inside is barely visible so I could turn away more material to reduce the crack size visible on the outside.

At this point I haven't decided if I want to add a collar.

Finish brings out the contrast in the different layers of wood.
The finished piece is available for purchase in the Gift Shop at Wood n Heart.





Finished pictures added 12/22/06.

White Oak Bowl Drying Process

I turned this bowl from a tree I obtained the beginning of May 2006. About 11 1/4" in diameter.

Click on pictures to enlarge.

I turn bowls close to the pith as can be seen here. I have found that even if the pith area cracks it is going to be turned away when returing the rim. Even if I trimmed an inch from the pith when roughing out the blank, as most people suggest, the end grain edge will deform upward requiring further reduction in bowl height. I seldom ever have to trim the walls lower because of cracks extending from the pith.


The wall thickness is 3/4" and the rim is about 1" thick. The rule of thumb is to rough bowls to 10% of the diameter. Following that rule I would have turned the walls to 1 1/8". The rim is thicker because I plan to form a bead on the outside of the bowl to facilitate lifting it with one hand.


The bowl was placed in a 13 quart stainless steel bowl. No problem with green white oak it goes right to the bottom.


The cover I use is made by placing a heavy piece of plastic sheeting over the bowl then wrapping the rim with plastic shipping tape. By stretching the tape a reasonably tight fit is achieved. This is only the second cover I have made in five years.


After soaking about 20 hours the bowls was removed. The bowl could have been removed sooner but the longer soak time suited my schedule.


After allowing to dry for about one half hour it was ready for wrapping in a brown paper grocery bag.


After cutting the paper roughly to size it is helpful to tape down two sides to keep the paper in place while taping.

Gather the paper as you wrap tape around the rim.

Trim the paper to the in side edge of the rim.

Weigh the wrapped bowl and place it upside down on a rack to allow air to circulate inside the bowl.



A data card is not necessary but at least write the date, time , and initial weight on the paper. This will allow you to estimate when to start checking the bowl weight if you want to turn it as soon as possible. Most bowls are dry in about 2 weeks. I expect this white oak bowl to stop losing weight in 8 to 10 days.


My intent was to post this information the day the bowl was wrapped and set aside to dry. Then post the weight each day so turners could follow the progress. Life sometimes gets in the way of good intentions.

White oak from Red Lion Motel, Kelso, WA. Cut down 1 May 2006.
Diameter: 11.25"
Height: 3"
Wall thickness: 0.75"
Rim thickness: 1"
Recess cut in bottom for expanding grip with chuck jaws: 0.25" deep, 3.25" diameter
Bowl into alcohol solution: 1515, 06/01/2006
Bowl out of soaking solution: 1030, 06/02/2006
Alcohol percentage of solution:
Begin soak: 75.3%
End soak: 73.1%

Weight in grams.
06/02 - 1115 - 1490
06/03 - 0040 - 1366
06/03 - 0625 - 1324
06/03 - 1520 - 1250
06/04 - 1045 - 1198
06/04 - 2025 - 1176
06/05 - 0840 - 1144
06/06 - 0055 - 1112
06/06 - 0835 - 1106
06/06 - 2150 - 1082
06/07 - 0800 - 1072
06/07 - 2000 - 1058
06/08 - 0830 - 1048
06/08 - 2015 - 1038
06/09 - 0740 - 1026
06/09 - 2010 - 1016

Click on picture to enlarge.

The paper is very loose and the pith is hanging in there.

Picture taken 06/09/2030.

06/10 - 1015 - 1012
06/10 - 2145 - 1008
06/11 - 0905 - 1006
06/11 - 2145 - 1000
06/12 - 0905 - 997
06/12 - 2115 - 998
06/13 - 0815 - 995
06/13 - 2130 - 992
06/14 - 0930 - 991
06/14 - 2300 - 992
06/15 - 1330 - 991
06/16 - 1245 - 991
06/17 - 0715 - 989
06/18 - 0915 - 986
06/19 - 1400 - 985

White Oak bowl drying curve.
Click on the chart to enlarge.

The charted weight and time data yields a curve which is typical of an alcohol soaked piece. At this point the bowl weight will fluctuate with the shop humidity. I consider the piece dry and ready for turning. I will continue to record data for several days and up date the chart in a few days.

06/17/2006 - After 2 weeks the bowl weight is changing in relation to shop humidity. .

06/21/2006 - Removed the paper yesterday and took several pictures of the white oak bowl. There were three small cracks on one end of the bowl that do not go all the way through. My experience has been that the cracks will turn away.

The paper became very loose as the wood shrank.


Recess ovaled to 3 9/16" x 3 13/16"

Narrowest outside diameter is 10 5/8"

Widest outside diameter is 11 1/8"

Pith raised about 1/4"

Bottom distortion is less than 1/8"

Three small cracks on the outside wall of one end

My experience is that the cracks will be turned away.