The Forestry Forum

General Forestry => Drying and Processing => Topic started by: Jtd83 on October 08, 2018, 07:08:42 AM

Title: Final Drying Thick Slabs 16/4
Post by: Jtd83 on October 08, 2018, 07:08:42 AM
Hi everyone,
I have acquired a number of Maple slabs that are 12/4 to 16/4. Most 11-13" wide and 8 feet long. They have been air drying for over 10 years and have a moisture content of approx. 12 percent.
Based on my Reading, it seams it is very difficult to dry slabs this thick. All I really have access to is a homeade DH kiln that I made in my basement.
Any advice as to how I may be able to make this work?
Thanks!
Title: Re: Final Drying Thick Slabs 16/4
Post by: GeneWengert-WoodDoc on October 08, 2018, 01:44:14 PM
They do indeed dry slowly, very slowly at 80 F.  Heat speeds it up.  To get such thick pieces dry in a month or so, in the kiln, you need no less than 150 F and around 44% RH or 6.5% EMC.  Even then, the shell will be drier than the core unless you wait a bit longer.

Do you have an attic?  If so, storing (drying) a few pieces in the attic will work if they are not to heavy for the roof trusses.

To check the MC, use a moisture meter with insulated 2" pins, such as a Delmhorst with the 26ES electrode.  I prefer a digital meter.
Title: Re: Final Drying Thick Slabs 16/4
Post by: Jtd83 on October 08, 2018, 06:58:26 PM
Thanks. 
Why not a lower RH? Would that dry the surface even further and leave the core wet?
Title: Re: Final Drying Thick Slabs 16/4
Post by: GeneWengert-WoodDoc on October 08, 2018, 10:01:06 PM
The lower the EMC, the harder it will be to machine the surface and get high quality.