Large Beams

[boonesyard]

 A local historical society is working on a large scale project and contacted us about cutting some large beams, 6"x12"x10' out of white pine. They requested them kiln dried, I told them kiln drying green pine that big and fast isn't realistic and would have a lot of degrade in them. I said I could sterilize, set the pitch and then they could install. My question, how long would it take to sterilize and set the pitch on large beams like that? Also, should I ramp it up to 160 right away, or slowly work my way up? I was thinking if I just set it at 160 right away, 6 days should get it done? Any advice would be greatly appreciated.  

[Don P]

Can you set pitch in a green timber?

[Southside]

@scsmith42 has dried large beams, perhaps he can offer some advice. 

[boonesyard]

Can you set pitch in a green timber?

Well that was silly of me, timber would have to be dry to set the pitch. Then I guess the question is, how dry before the pitch can be set? And what's the best way to go about that?

[scsmith42]

We dried several thousand bd ft of 7" x 14" x34' SYP beams from green in an L200. It was a three month kiln run, but they dried down to 16% and passed grading by SPIB.

They had a couple of weeks of air drying first so as to minimize mold development during the first part of the kiln run.

[boonesyard]

How did you handle your kiln run? 

[scsmith42]

How did you handle your kiln run?

I'm not sure what you're asking....

[boonesyard]

What kind of temp for how long? when and how much do you turn it up and for how long? I know you said it was about a 3 month kiln charge, was a low temp run for 3 months?

Thanks

[scsmith42]

I started the kiln run at 90F and 95% RH. Kept it there for around 2 weeks, then dropped to 90% RH for four weeks.  After that I started following Nyle's schedule for Group 4 hardwoods based upon MC% readings taken 2/3 of the way from the core to the shell with a slide hammer.

The beams were treated with Premier fungicide to retard mold development.

[Stephen1]

I dry beams all the time, pine 4x4 up to 8x8 10x10, 
The 4x4 took 4 weeks and came out at 7%
The 8x8 and larger never really dried, (4 week) The pine will show 10% on the surface 2" in with the probe. but when you cut them open they still 30%+ in the core. 

 hardwood and pine mantles ( fireplace mantles) I mainly do it for sterilization. My customers like it, it also starts the drying process in that checking develops, especially in the pine. I just dried some 4" cherry FP mantles and they came out looking great. Still 20% with a full probe. I'll leave them in the shop to sell this fall/winter. 
I only run them  1 cycle (2 weeks) at full power and most of my customers are happy with it. 
They like that I sterilze them. NO BUGS

[boonesyard]

Thanks guys, I've been doing some large hardwood beams for mantles as well. Everything I've done had air dried for a good time, although a 6x9 mantle doesn't dry much in the core. We just finished a large black walnut mantle that turned out well, was in the kiln for 3 weeks but was still 25% when it was finished, owner was happy. Almost all of the big heavy stuff ends up with cracks/checks. I've tried low power for a couple weeks (125-130 deg) and then run it at 155-160 deg for a week and still get checking. I've decided that's just the nature of the beast when dealing with the heavy stuff, 4"+. The good thing is the customers I have looking for the heavy stuff are also looking for weathered, natural, and high contrast, so it works. Every day is like a big giant science project, love this stuff.