think i might have damaged my load of QSRO, what do you think?

Kelvin · March 09, 2010, 08:52:36 PM

Howdy all,
Well i set my Nyle kiln at the conservative setting for my green QSRO load, and turned it on. For some reason my life got hectic and i couldn't get around to oven drying my samples and getting things checked to see how my drying was going. Well after 4 days i checked and the lumber samples were surface checked badly already and my samples were down to 30% MC from 61% start so i lost 29% in 4 days or roughly 7% per day instead of my target of 3%.

Man my kiln must have been leaking the moisture out as it was at 90 degrees and 20%compressor cycle, which i thought was hardly anything. I turned off the compressor when i discovered what was happening and now with the compressor off the samples are loosing 3% MC per day just through the leaky chamber. though i checked the main stack and its nowhere near as dry as my samples. I think they were more in direct wind area, so dried much faster. I'm still very worried about surface checking in my main stack, i can't see much, but they say you can't see all the damage that might have occured until you get till final MC range and they open up. I can't see the surfaces very well either, but i'll cross my fingers.

My samples are now about 5 days older than when i stopped the compressor and read 20%MC. I cut new samples however from some bigger pieces i had left over from the samples and they are reading 32% MC. I end coated the sample pieces so i don't know why there is such a difference in the dry rate on the samples, but man this is not an easy thing to do with oak. I really need this stuff to turn out as i don't have the time or the money to wreck 800 bd ft that i'm using for a project i promised and is waiting on me. I guess i can't tell how dry the main stack really is, i hope the samples are out of whack and its not that dry really. Sweating bullets!
KP

Kansas · March 10, 2010, 06:44:15 AM

Long as what your drying is 1" lumber, even with a leaky kiln you should be fine. 90 isn't that warm. I'm actually suprised you don't have water standing in the kiln. I would think the humidity of the kiln would be high.

DR Buck · March 10, 2010, 07:25:31 AM

I use the Wood-Mizer controller (DH4000) on my Nyle and don't set compressor run time. I just set RH and let it go.

I think the most important thing you can do is get the chamber air tight. If you can't control a stable RH you're headed for trouble. I lost the bottom gasket off one of my doors and didn't realize it until I ran into a way to rapid drop in RH. Luckily I found the issues before I damaged the 1800 bf load of Walnut.

jim king · March 10, 2010, 11:54:10 AM

Take a peice out and plane it. It will either make ypu feel better or worse to know but at least you will know.

OneWithWood · March 10, 2010, 12:29:44 PM

Let me echo what DR said.

When you are finished with this charge take the time to totally seal your chamber. You cannot control the variables in a leaky chamber well enough to assure quality.

How long did the stack sit from the time it came off the mill until you fired up the kiln?

Kansas · March 10, 2010, 01:30:38 PM

I just can't see damage at 90 degrees, set at 20% on the compressor. The only way I could imagine is if you had a very high volume of air moving, coupled with not just a leaky kiln, but a well ventilated one. Not with 4/4 lumber.
Now, if its 8/4, thats a whole different story.

Kelvin · March 10, 2010, 06:38:40 PM

Howdy all,
Yeah, i was hoping i couldn't wreck the 4/4 but the samples have me worried. Has anyone had oak dry at over 7% MC per day? I wonder if its easier to wreck it from 60-40%MC or 40-30%MC? The lumber is still over 30% MC so i don't think i will see the damage until its down to 7%.