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General Forestry => Drying and Processing => Topic started by: forrestM on February 16, 2020, 09:46:20 AM

Title: Kiln drying GREEN 10/4 white oak?
Post by: forrestM on February 16, 2020, 09:46:20 AM
Hello, 

Can someone give me an idea of how long it would take to kiln dry 2.5"x12"x14' green white oak slabs in a NYLE L200M?

I am still getting the kiln set up for this project and it is going to be the first load for the kiln. The customer wants the dried wood by april or may, and I just want to know how long it would take to dry something like that... so I can tell them it is possible or if they are just going to have to wait. 

Thank You,
Forrest
Title: Re: Kiln drying GREEN 10/4 white oak?
Post by: WDH on February 16, 2020, 08:21:59 PM
Months. 
Title: Re: Kiln drying GREEN 10/4 white oak?
Post by: Southside on February 16, 2020, 08:26:09 PM
And that's after you wreck the first load.  
Title: Re: Kiln drying GREEN 10/4 white oak?
Post by: forrestM on February 16, 2020, 08:47:45 PM
So not really possible? and is it a given that the first load doesn't go well?

Thanks,
Forrest

Title: Re: Kiln drying GREEN 10/4 white oak?
Post by: YellowHammer on February 16, 2020, 09:11:00 PM
At that thickness, you'd need to dial things back to about 1% moisture removal per day, to be safe, and make sure your air velocity in the kiln is down in the 150 fpm range.  So at that rate, yes, months tying up your kiln at least.

It is generally just as fast (or slow) to air dry it, and even in the summer, 10/4 white oak will air dry too fast and surface check (he in Alabama, anyway).  So now, early spring is a good time to do it.  Depending on how things go, you may be able to load and finish it in the kiln in May or so, although most likely I'd expect about June or July, then at least two weeks in the kiln at high temperature to finish.

 

 
Title: Re: Kiln drying GREEN 10/4 white oak?
Post by: Southside on February 16, 2020, 09:26:47 PM
Trying to dry green, 10/4, white oak in a new kiln, with a new operator, would be like renting an F-18 from a carrier with your total flight experience consisting of watching a 5 minute youtube video on how to fly a plane.  Yea - maybe you would get it off the deck, but it's the landing that really matters.  :D 
Title: Re: Kiln drying GREEN 10/4 white oak?
Post by: GeneWengert-WoodDoc on February 16, 2020, 09:46:19 PM
I agree that anything thicker than 8/4 northern or Appalachian white ok is extremely difficult to dry in a kiln, starting green from the saw MC.  Probably impossible for Southern white oak.  Drying time For green 8/4 is around 90-100 days, so 10/4 might add another month.

Compared to the profit if you rAn the kiln on a Two week cycle for 4/4 air dried of $300 or more profit, the charge for 10/4 green taking 140 days, would need to be around $3000 or more.




Title: Re: Kiln drying GREEN 10/4 white oak?
Post by: offrink on March 06, 2020, 10:28:18 PM
I have run oak like that in that kiln but the slabs sat for a couple of months first. Still took 2+ months. It is worth it if you can sell the finished product for the going rate.
Title: Re: Kiln drying GREEN 10/4 white oak?
Post by: scsmith42 on March 07, 2020, 10:20:06 PM
10/4 oak is about a 4-5 month kiln run in an L200.  The only way that Iíve been able to do it successfully is by injecting water fog into the kiln for around the first 2 months in order to keep the RH% high.

RH% needs to be kept in the mid 90% range, which is prime for developing mold on the lumber.

So, you also need to treat the lumber green with a fungicide such as Premier.

Ever since I set up my solar kilns I no longer go into the Nyle with green 8/4 or thicker oak.  Even using solar kilns I still air dry for a few months or risk honeycomb in the lumber.