The Forestry Forum

General Forestry => Drying and Processing => Topic started by: west penn on March 28, 2010, 11:20:33 AM

Title: need some advice
Post by: west penn on March 28, 2010, 11:20:33 AM


  Hi Folks,  fairly new to this forum but have been drying lumber for a number of years in a small dehumidifier kiln.   Have run across this situation before where part of my load (poplar and oak) is at 8% but there is still some oak that is at 15%.  Normaly I will shut off the compressor and just leave the fans run with the temp. at 120 deg.  Was wondering what the proper steps would be in this case?Am I taking a chance on case hardening the drier part of the load?  Thanks in advance for any help.
Title: Re: need some advice
Post by: logwalker on March 28, 2010, 12:03:54 PM
I assume that is the risk when drying multiple species of wood. I think you will be ok letting it equalize and then going again. But my real world experience is limited.

Joe
Title: Re: need some advice
Post by: Den Socling on March 30, 2010, 10:35:38 AM
Is the oak quartersawn by any chance?
Title: Re: need some advice
Post by: OneWithWood on March 30, 2010, 12:12:38 PM
Poplar gives up moisture at a much faster rate than oak.  So much faster that it is recommended when drying poplar you load only half the capacity of the kiln.
I would unload the poplar and dry the wet oak by itself.
Title: Re: need some advice
Post by: Den Socling on March 30, 2010, 02:44:57 PM
west penn said "some" of the oak was 15% while some was dry. If you flatsaw through the pith and end up with some quartersawn and mix it all together, this is just what you get. It takes the quartersawn a lot longer to dry because the rays are not at an exposed face.
Title: Re: need some advice
Post by: scsmith42 on March 30, 2010, 04:05:34 PM
Quote from: Den Socling on March 30, 2010, 02:44:57 PM
west penn said "some" of the oak was 15% while some was dry. If you flatsaw through the pith and end up with some quartersawn and mix it all together, this is just what you get. It takes the quartersawn a lot longer to dry because the rays are not at an exposed face.

+1.
Title: Re: need some advice
Post by: west penn on March 30, 2010, 04:33:24 PM
   
  All of the load is flatsawn and has been air dried.  However, I didn't have enough of the same batch of oak to fill the order so I put some in that wasn't air dried as long.  Poplar was 24% and oak was 22 and 28%.   I've been running fans only at 118*  and it is now at 9 and 13. I just wondering what the poplar will be like when I get it out.  Luckily its on the bottom of the load.
Title: Re: need some advice
Post by: Den Socling on March 31, 2010, 10:35:41 AM
With 118', if the humidity is 40% or more, the poplar won't go below 7%.
Title: Re: need some advice
Post by: west penn on March 31, 2010, 10:21:19 PM

  Thanks for all the input.  I use only probes in my kiln - no wet bulb or humidistat. Mostly just monitor the water output and temp. a full load would be 1000 bd. ft.  I am getting close to putting an L200 to use and am wondering if I'll get by using the same procedures I use on the smaller kiln. Any reccomendations?   Was considering a humidistat but the factory rep said I really shouldn't need one.  Any thoughts?