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Red oak air drying

Started by Joey Grimes, June 28, 2016, 08:24:20 PM

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Joey Grimes

I recently cut some nice red oak it was stacked on sticks under my sawmill shed it's closed on one side I didn't think it would get to much air but after a week it started checking severely. Should I be wraping bundles with burlap or something similar to slow airflow? 

 
94 woodmizer lt40 HD kabota 5200 ford 4000 94 international 4700 flatbed and lots of woodworking tools.

WDH

Are the boards checking on the ends?  Did you seal the end of the logs before sawing?  Are just the top boards in the stack checking?
Woodmizer LT40HDD35, John Deere 2155, Kubota M5-111, Kubota L2501, Nyle L53 Dehumidification Kiln, and a passion for all things with leafs, twigs, and bark.  hamsleyhardwood.com

GeneWengert-WoodDoc

Where are the checks...face or ends? How does the lumber smell...normal or a bit different, maybe even a little foul smell?

Wood checks becuase the stress created by shrinking is greater than the strength of the wood.  So, we first need to find out if the wood is weaker than normal.  Hence my questions.  Next, if the wood is strong, then there is excessive shrinkage, which is not unusual for a wide piece and with the 30% RH or 6% EMC we had the previous week's here in the South.  Today, we have 65% RH or 12% EMC which is much more reasonable for oak drying.

So, my guess is that the low relative humidity we had was too dry for freshly sawn oak.  Using plastic burlap (Shade-Dri) would have certainly helped in this case, but it would not be needed this week.
Gene - Author of articles in Sawmill & Woodlot and books: Drying Hardwood Lumber; VA Tech Solar Kiln; Sawing Edging & Trimming Hardwood Lumber. And more

Cazzhrdwd

Simple answer is Joey, yes wrap it with burlap or shade dry every time. Also best to put it in a shed and block one side. It may dry slower than it has to but if you get some wind one night or day, that's all it takes to ruin it.
96 Woodmizer LT40Super  Woodmizer 5 head moulder

Joey Grimes

What kind of results would I have gotten if I had gone directly into solar kiln?
94 woodmizer lt40 HD kabota 5200 ford 4000 94 international 4700 flatbed and lots of woodworking tools.

GeneWengert-WoodDoc

A solar kiln, IF RUN PROPERLY, can dry very high in quality...but so can air drying if done properly. There is no 100% foolproof drying option; all require some monitoring and intervention when conditions are not acceptable.  Basically, we monitor the daily drying rate of the lumber using samples to determine what is going on.
Gene - Author of articles in Sawmill & Woodlot and books: Drying Hardwood Lumber; VA Tech Solar Kiln; Sawing Edging & Trimming Hardwood Lumber. And more

Joey Grimes

What I was asking was being the solar kiln is a semi sealed environment with the vents closed would the high humidity due to the green lumber with high temperature dry slower than air drying?
94 woodmizer lt40 HD kabota 5200 ford 4000 94 international 4700 flatbed and lots of woodworking tools.

Ianab

Quote from: Joey Grimes on June 30, 2016, 10:01:55 PM
What I was asking was being the solar kiln is a semi sealed environment with the vents closed would the high humidity due to the green lumber with high temperature dry slower than air drying?

It could be slower than air drying.  Because you have some control over the drying (collector size and vents) you can ensure you dry at the correct rate. This is offset by the fans and solar heat that will speed up the drying (But still at a safe rate) on a cool / calm / humid day. With air drying you are more at the mercy of the weather, and a couple of hot dry and windy days can dry some woods (like oak) too fast. Other woods you get issues where the wood dries too Slow, and then you get mold and fungus. The kiln helps avoid that as well.

It's possible to slow down air drying to a safe rate too with the shade cloth or a partly enclosed building, but harder to get ideal conditions.   
Weekend warrior, Peterson JP test pilot, Dolmar 7900 and Stihl MS310 saws and  the usual collection of power tools :)

YellowHammer

Quote from: Joey Grimes on June 29, 2016, 09:12:54 PM
What kind of results would I have gotten if I had gone directly into solar kiln?
You could have simply closed the vents some to keep the moisture in the kiln if you felt the wood as dying too fast. 
You can also decrease the heat, and run the solar kiln cooler, by reducing some of the the black absorber area, the black painted sheet metal, sitting on top of the wood stack.  I use two pieces in my solar kiln, and when I put fresh white oak in, or thicker slabs, which is even worse than red oak in the summer, I may only use about half my absorber area until I see how the wood is behaving.
Thing about a solar kiln, it's very easy to slow it down, just can't go so slow you start to see sticker stain or begin have other problems. 

YellowHammerisms:

Take steps to save steps.

If it won't roll, its not a log; it's still a tree.  Sawmills cut logs, not trees.

Kiln drying wood: When the cookies are burned, they're burned, and you can't fix them.

Sawing is fun for the first couple million boards.

Be smarter than the sawdust

Denny

Page 12 of Drying Hardwood Lumber discusses the three environmental variables that control the rate and quality of lumber drying. They are temperature, relative humidity and air velocity.  Which of these variables do you think is causing your checks ?

Page 26 of Drying Hardwood Lumber under the title of "Protection of Green Lumber" states... "The sooner that controlled drying can begin, using the appropriate temperature, humidity and air velocity, the better the quality of the dried lumber."

Red oak is 75% of my business.  We buy it 70% MC and up, and as soon as we get it stickered it goes into my pre-dryer. Sometimes the green RO goes straight to the kiln, but I'd much rather have it in my pre-dryer for 2 or 3 weeks.  I don't like to see any RO air drying. Im lucky enough to have a pre-dryer to work with. I'd rather see it go into a kiln or pre-dryer ASAP where I can control the three drying variables.

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