Drying & Sealing Cookies

[Christopher Valois]

Hello all.

I am wondering if anyone has any experiences to share in terms of creating 14-20" diameter 2" thick cookies from oak or hardwood in general to be used for end tables, etc. ?

The main issue bring prevention of checking ...

I have researched using PEG or Pentacryl to displace the cellular water while the color is still green.

And was just thinking of additionally sealing both the top and bottom with a Bar Top epoxy to further reduce/prevent checking.

Thanks for any input or shared experiences !

-Chris in Boston

[Kevin Jenness]

I successfully treated a couple of oak discs approx. 18" d. x 2" thick with numerous applications of Pentacryl over a month or so. I kept them in a cool, dry barn space and slowed the drying down by sandwiching them between cardboard. I did get some superficial mildew, so doing it again I would use a looser kraft paper wrapping. The finish was wiping varnish. The unfinished sample is still crack-free 8 years later, and I know the finished piece was also at least a year after installation.

[Christopher Valois]

Thanks very much for the feedback !

About how long did you let the one that you finished dry for ?

[Kevin Jenness]

I don't remember exactly as it was so long ago, but at least a month. The challenge is to dry as slowly as possible while replacing the water with Pentacryl. If you are doing quantities perhaps you could buy in bulk and submerge the blanks to speed things up.

[Peter Christensen]

Joshua Salesin wrote a little book on making vacuum kilns for drying wood. Vacuum drying generally results in fewer defects like cracking. After it is dry you can then consider stabilizing the wood with something like Cactus Juice.

https://www.amazon.com/Vacuum-Kiln-Drying-Woodworkers-Build/dp/1546686126/ref=dp_ob_title_bk

https://www.turntex.com

[John K Jordan]

Another thing you might consider is boiling the wood. Boiling used to be fairly common for roughed out bowls and blanks to prevent cracking when drying, especially for difficult woods. I'd consider oak in rounds difficult since the T/R ratio is high and the wood really wants develop radial cracks. I understand the heat from boiling softens the lignum in the wood. These articles by Stephen Russell describes the process.

https://web.archive.org/web/20170829181812/http://www.woodturningvideosplus.com:80/boiling-green-wood.html

https://web.archive.org/web/20170816165325/http://www.woodturningvideosplus.com:80/boiling-protocol.html

[Kevin Jenness]

John K., thank you for the links.

I am skeptical about boiling or vacuum drying preventing cracks in oak discs the size Chris is talking about, but if someone has tried it successfully that would be welcome information. I was skeptical about the Polycryl treatment too before I used it.