Drying Walnut Crotch Slabs

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A light coat of sealant? Or a slow, careful spell in the kiln? February 26, 2005

I have some awesome black walnut crotch slabs ranging from 2 to 3.5 inches thick. They are currently on sticks and are very green. I've endcoated them very well with Anchorseal. I want to be sure they dry with minimal (no) degrade and am looking for suggestions on successfully drying such stock. I have a Northland Kiln that runs 24/7, but am wary to put them in until at least all the free water is gone.

I searched the forum and someone wrote: "...after sealing the ends with wax end sealer, apply pentacryl generously over the entire crotch...". I would like to hear more about this.

Can anyone help? I have a lot of this material and need to be sure it's handled correctly.

Forum Responses
From contributor S:
I'd slap some wax on the face of those crotches immediately.

Even then, they may check a little, but not to worry - a little color matched epoxy will bring it back together when you get around to working with them.

From the original questioner:
If the ends are sealed and you wax the faces of the material, how does drying take place?

From Gene Wengert, forum technical advisor:

It is critical to dry such pieces very slowly. The light coating of the faces with a moisture resistant coating (but not real heavy) will help prevent rapid drying.

I have tried to get more technical information about pentacryl, but I have not seen any independent studies concerning the use of such a material. Everything I have seen with technical info comes from the manufacturer.

From the original questioner:
I talked to the folks at Preservation Solutions. They suggested their Wood Juice product to help slow drying and stabilize the material.

Would giving the faces a thin coat of watered down Anchorseal be appropriate? Also, it is stickered and covered in a typical fashion. It is shaded all day, but gets later afternoon sun for a few hours. Should I consider Shade-dri curtains or such?

From contributor S:
I Anchorseal the logs when bucking or just after I've cleaned them up 6" or so on the mill.

When I find a nice crotch - the spinal looking figure that's prone to checking - I rub the face with a thin coat of carnauba wax. It slows the end grain drying just enough to avoid checking, but not so much as to make a problem in terms of uneven drying.

I always carefully shade dry crotches before, if any, kiln drying.

From Gene Wengert, forum technical advisor:
If you use Anchorseal full strength, it will almost stop drying, which is too slow. A light coating or the wax idea mentioned should be great.

Shade-Dri is probably a good idea, so long as some drying still occurs. Maybe 100% coverage with Shade-Dri is too much, especially if you wax the faces.

From the original questioner:
Thanks for all the responses. I intended to air dry the material until at least all of the free water is gone. Would that be advisable or should I just get it in the kiln and pay close attention? I figure 2% MC loss per day would be a safe bet.

I have not done any oven sampling yet, but I suspect it to be in the 60-80% range.

From contributor K:
I've sold crotches for a couple of years now. Recently, I needed more crotches than I had. I bought them from another sawmiller in the area, who dried them to 9% in his slow solar kiln (except he waxed the figured area). I needed to use them and sure enough, the crotches hadn't dried at all in the figured areas, and the rest of the wood was 9%.

So, concerning your pieces of wood, the only way I know of to dry them without surface checks is to put them in the kiln right away with a s-l-o-w schedule (Gene could certainly fill us in on the schedule for 8-12 quarter walnut). What I do all the time is let them air dry (yes, with small surface checks in the figured area, which I don't consider a defect in the crotch area anyway) until my kiln is ready for an 8/4 wood load, and then I put them in with it.

From the original questioner:
I agree - the kiln is the best place to control the environment for drying these valuable yet troublesome treasures. However, it requires almost constant attention and locks up the kiln for a long time. But, I am willing to do it if it's required for maximum success.