Drying thick Red Oak in DH4000 (L-200)

[DR Buck]

I have a potential customer that will be bringing large amounts of thick red oak several times a year for kiln drying.   His company provides "low budget" fireplace mantles to builders.  They are milled from red oak and are 5" x 9" thick and just over 7 feet in length.   In the past the mantles were installed regardless of moisture content and they have had about 25% that have to be replaced because of checking.   He would like to have them kiln dried to reduce his loss on replacements.    

I'm running the Woodmizer DH-4000, same as Nyle 200 with a different controller.    I typically avoid drying stuff over 4" thick, but this could be a great income maker for me.   The customer usually acquires 60 at a time from the sawmill he deals with.    My questions are :

1- What sort of schedule should I dry at?   I assume this will be longer than my normal 3 to 4 weeks for 5/4 and 6/4 boards.

2- I don't think pulling them down to 6 or 7% MC is going to be cost effective, so I thought that a target MC under 10% would be sufficient.    

3-  Is this even feasible and can it be done in a 6 week timeframe?

[GeneWengert-WoodDoc]

We can dry 4/4 in 5 weeks, but 6/4 is likely 8 to 9 weeks.

6/4 is dried using the 8/4 schedule that is in Drying Hardwood Lumber.

Because you tie up the kiln so long, you would find proper air drying would be more reasonable, cost wise.

[Ianab]

3-  Is this even feasible and can it be done in a 6 week timeframe?

I suspect not for that thickness. If they were air dry (for a year or so?) then maybe you could finish them in that time frame. Otherwise you are in vacuum kiln territory.  Either way isn't going to be "budget".  Air drying for a year or two has a cost as well. 

[K-Guy]

I would air dry to 25-30% before putting them in the kiln. If they are cut to shorter pieces(3 ft) it may reduce the drying time with less defects but I would bow to Gene's experience on that.

[Stephen1]

I would expect them in my Vacuum kiln for 4-6 weeks at least. 
Just following along 

[YellowHammer]

I agree 5" thick red oak has a high defect rate either in a dh kiln or air drying.  

Both will take many months at best.   

  

[boonesyard]

Recently we dried a 6x9x12' red oak mantel in our vac kiln. It had air dried for about 6 months, and was in the kiln for 7 weeks. We dried it down to 7%, but there as still a substantial amount of checking. Most like that look when going that large.