Kiln Drying Cherry Lumber

Mike N · November 16, 2015, 05:51:24 PM

I just cut up some Native Central Minnesota Cherry logs.

The logs were dead on the stump for about 3 yrs. The bark had completely fallen off, but the interior is very solid. The wood was wet about 30%+ moisture content. I took it from the saw mill directly to my Kiln dryer. Now I am afraid the lumber will either warp, check or split if I dry it too fast. Most of the lumber I have dried in my kiln was air dried to about 15% first, mostly Black Ash, & Red Oak. I hope my boards turn out, I plan to make 4" Tongue & Groove paneling. Most of the boards are too nice for this project. But I will have a good looking office! I ended up with about 850 bd. ft all 5" wide & 6-12ft. long.

bkaimwood · November 16, 2015, 06:15:36 PM

If it was me, I'd slow the drying down a bit...lower temps, airflow, and dehumidification... And constantly monitor for sticker stain...but I'm a bit of a beginner on drying cherry...I'm sure someone with more experience will chime in...

beenthere · November 16, 2015, 06:34:10 PM

Mike
Look forward to some pics of your cherry.

Did retirement work out for you as planned?

hackberry jake · November 16, 2015, 07:34:46 PM

The main problem I would watch for would be end checks. Cherry is known for this. Did you seal the ends?

Mike N · November 16, 2015, 08:22:14 PM

Quote from: beenthere on November 16, 2015, 06:34:10 PM
Mike
Look forward to some pics of your cherry.

Did retirement work out for you as planned?
***********************
beenthere,

I am still on the job until Jan.-Feb We are trying to close a deal to sell the company.

I will have pics once we open up the Kiln.

Thanks

Mike N · November 16, 2015, 08:32:37 PM

Quote from: hackberry jake on November 16, 2015, 07:34:46 PM
The main problem I would watch for would be end checks. Cherry is known for this. Did you seal the ends?

No we did not seal the ends. I have about 25% more material than I need, so if the ends check in a few inches or less I will be Ok. The wood seemed to be aged (not green) however it is wet. The logs were dead & suspended from the ground but tipped over from a tornado about 3 years ago. The bark was all gone & some of the outer sapwood was rotten. I want to get it dried & milled so it is ready to use by Christmas Holiday break. I think it will take approx. 3 weeks in the Kiln. Some of the boards were completely clear, I will post pictures when they come out of the Kiln. Thanks

xlogger · November 17, 2015, 05:45:36 AM

I was told to put the cherry away (stickered) and forget about it for awhile before drying it.

GeneWengert-WoodDoc · November 17, 2015, 06:46:14 AM

Cherry is about medium in drying difficulty. So, it is easy to dry.

The color of cherry varies depending on the temperature and humidity used in drying. If cherry is partly air dried, you get a nice color in the shell. Then, if put into the kiln, when the core dries, you will get a different color, as the kiln is hotter and drier and so dries faster than air drying.

So, the best color is when we dry it 100% in the kiln, or air dry it down to 25% MC before going into the kiln.

Mike N · November 17, 2015, 11:39:46 AM

Quote from: GeneWengert-WoodDoc on November 17, 2015, 06:46:14 AM
Cherry is about medium in drying difficulty. So, it is easy to dry.

The color of cherry varies depending on the temperature and humidity used in drying. If cherry is partly air dried, you get a nice color in the shell. Then, if put into the kiln, when the core dries, you will get a different color, as the kiln is hotter and drier and so dries faster than air drying.

So, the best color is when we dry it 100% in the kiln, or air dry it down to 25% MC before going into the kiln.

The bds. had 30% MC when we loaded the Kiln. It will take about 3 weeks to dry in my small dryer. I built a 4' x 4' x 12' air tight box from 1 1/2" pink foam, 30 pint dehumidifier (set to run continuously), 20" fan set to high speed & a ceramic space heater with a thermo-coupler to allow 120F max. Once the unit gets working the dehumidifier keeps the heat up & ceramic heater shuts off. I hope it turns out. We have had great results on Walnut, Oak, Aspen, Basswood & Ash so far. This is the first time I went from the Woodmizer directly to the Kiln, we usually air dry first for at least 6 months before going into the Kiln.

hackberry jake · November 17, 2015, 05:39:46 PM

If aged wood gets a bacterial infection, it actually makes drying defects worse. I know some oaks are bad for this. Hopefully your cherry comes out ok.

samandothers · November 17, 2015, 07:57:20 PM

Mike do you have some pictures of you kiln? I would like to see it.

GeneWengert-WoodDoc · November 17, 2015, 09:45:08 PM

I would suggest that Jake's comment could be modified to start out

"If ANY wood has a bacterial infection (which develops only in soaking wet wood because the bacteria live in no-air conditions), it actually makes drying defects worse."

Trees on wet sites are worse, as they have the anaerobic conditions in the soil. Oak, eastern and western hemlock, willow, cottonwood and aspen seem especially prone.

Because of the high MC in infected logs, they often do not float. Those are the logs that we hear about being pulled up from a lake, River, pond, etc.

Mike N · December 01, 2015, 05:54:37 PM

Mike do you have some pictures of you kiln? I would like to see it.
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Quote from: samandothers on November 17, 2015, 07:57:20 PM

I will post more pics once the Kiln is emptied out.
The Cherry is 2 weeks in the Kiln & I remove approx. 5 gallons of water per day. It has slowed down a bit now. I opened the Kiln & the Cherry looks good so I closed it up again.

GeneWengert-WoodDoc · December 01, 2015, 10:37:46 PM

How do you get air flow past the lumber faces? It looks like there is not gap between the wall and the lumber.

Mike N · December 02, 2015, 11:04:03 AM

Quote from: GeneWengert-WoodDoc on December 01, 2015, 10:37:46 PM
How do you get air flow past the lumber faces? It looks like there is not gap between the wall and the lumber.

The Kiln is 12ft. long. I can dry approx. 800 bd. ft. per load.
There is a 20" box fan on the left hand side of the wood stack. (Set on High)
Small ceramic heater & dehumidifier on the right hand side of the enclosure.
Most of my lumber is cut to 100" long.
I can dry 10ft. lumber once the stack gets high enough to clear the fan.
There is a lot of air moving through out the stack from the end & between the boards.
Once the systems gets going the dehumidifier creates the heat & small heater does not even come on, it maintains approx. 115 degrees F.

It works really good!