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First kiln drying experience a disaster. Please help!

Started by KenBala, September 15, 2015, 08:02:26 PM

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KenBala

Hi guys,

I think the title says it all.  This is my first post in the Forestry Forum and I would really appreciate your collective expertise!

Earlier this year I purchased a Sauno VT5 kiln.  As many on this site can attest to, the instructions leave a lot to be desired in regards to operating the kiln (one page) and there is NO customer support.

I constructed the kiln pretty much exactly as the instructions outlined.  I am one who figures if you are going to do something, do it right.  That being said, the kiln consists of a 2" thick walled polystyrene box with inside dimensions of 109" wide x 37" deep x 48" tall.  The Sauno unit is mounted against the side wall and sticks out about 5 inches.  My thoughts were that this leaves about 8' 8" - enough to stack 8' boards.  The instructions state that the kiln can be placed inside or outside.  I chose outside and built the box within a painstakingly constructed, well insulated lean-to shed that is painted and shingled to match my house.  (I was going to post a picture to this post, but can't figure out how.)

So, many weekends of construction later - show time!  I was ready to try my first load.  I cut down and milled a sugar maple tree (hard maple) to all 4/4.  The instructions state that you can put the wood in green, so that is what I did.  Basically, the unit is just a fan and heater.  There is a vent to the outside just above the unit, and one on the opposite end of the box toward the top.  There is also a drain at floor level.  The instructions state to first steam the wood for four days by placing a couple buckets of water on the bottom of the kiln (with the floor drain closed), close the vents and crank the heat to 160 degrees with the fan running to circulate air within the box.  This is supposed to open up all of the pores of the heartwood so that it gives up water easily.  So I did that.

After four days, as instructed, I adjusted the temperature down to around 104 degrees and opened the vents about 1/4" and waited.  The instructions stated to make sure there is always some condensation at the vent - this ensures there is enough humidity in the kiln to dry from the interior of the wood.  There always seemed to be humid air coming from the vent - not dripping, but enough to cause slight condensation.  I took the "no peek" approach since I have probes in one of the pieces to check the MEC remotely.  After 2 weeks the moisture finally fell below 50%.  I dropped pretty sharply at that point for the next week, but then leveled out at around 11% MEC.  At that point, I decided to take a look.  I was pretty upset to find mold all over the lumber with some moderate warping. 

I let the kiln run for another 4-5 days with no appreciable increase in mold, but no drop in MEC either.  Then I tried to put in a dehumidifier (25pint size) and got negligible moisture out of that.  I took one of the pieces into my shop and let it acclimate for a few days then did some tests on it only to find that, along with the mold, the wood is moderately case-hardened as well.  And I was so excited about this thing...

So, I am writing off this load as a learning experience, but need input from ANYONE who can help explain to me what you think the issue(s) might be!  Specifically:

1.  Why the mold?  I am wondering if it is because the kiln is outside and venting/drawing from the humid Pennsylvania air?  I reached out to another forum member who has the Sauno as well for some advice.  He apparently has been having no issues, but it is in his shop.  Would the conditioned air be making a difference?  I also read in another post that you can get mold if the water is not allowed to escape fast enough.  Perhaps the vents only being open 1/4" contributed?

2.  Why the case hardening?  It is my understanding that case hardening comes from drying lumber too quickly.  How could that be the case for my failed load if there is mold?  Doesn't that mean the humidity was too high?  That doesn't make sense that the lumber drying too quickly.

3.  Why did the humidity bottom out at 11%?  Is it because it reached equilibrium with the outside air?  Wouldn't the heat from the unit allow it to drop further?

4.  Why didn't the dehumidifier take out any more moisture?  I've read a bit about DH kilns and it is my understanding the you put air-dried lumber in those kilns to take the moisture down to your 6-8%.  I have some ash that has been air-drying for a year and it's MEC is right around 11% right now - same as the load in the kiln.  Does case-hardening prevent the unit from drawing out moisture?  Is the unit undersized?  Like I said, it's a 25 pint unit and I read that those guys use 70 pint units. 

It's not a total loss (well the maple is) - I do have a tight kiln that has good circulation from the sauno fan as well as the ability to safely get lumber to a temperature to sterilize the wood.  I was thinking of maybe just converting it to a DH unit, however a couple concerns about that.  With the DH running, the temp gets up to about 125 degrees - the high temp cutoff for these units are about 100 degrees.  At that point it cuts off the condenser.  I insulated the heck out of this kiln - did I do too good of a job?  How do you get around that, even with dedicated DH kilns?  Also, again, if I'm not drawing moisture from the lumber in the kiln that is at 11%, can I expect to draw it out of my stock that is air drying?  Time is essential at the moment.  The Hard maple I don't need, but the ash I do this winter to build my wife a kitchen!

So there you go, I would GREATLY appreciate any comments or input you may have!

Thanks,
Ken

beenthere

Welcome to the Forestry Forum.

Sorry to hear about your first experience and how it turned out.

Your pic is in your gallery, so just click the line below "click here to add photo to post" and go to "My Gallery" in the menu tab..  Click on your pic there, and SCROLL down a page or two to where it says "Insert image in post" , answer "yes" and should have a pic.
Click "preview" button to check it is done right.
south central Wisconsin
It may be that my sole purpose in life is simply to serve as a warning to others

plowboyswr

First I'll say welcome.  You might want to check out this thread https://forestryforum.com/board/index.php/topic,84939.0.html
It might give you the answers on the maple.
Just an ole farm boy takin one day at a time.
Steve

GeneWengert-WoodDoc

These answers might be too short, so ask more questions.

1.  Mold forms because drying is too slow...humidity is too high.  The humid PA air is ok, as when you heat it, the humidity drops quickly.  Heating 25 F goes from 100% RH to under 40% RH, for example.  Slow drying also accentuates warp.

2.  Casehardneing develops in all kilns using hot air, including this one.  It is normal.  It is caused when the shell tries to shrink but the core is still wet and does not.  So, there is a "stretched out" condition in the shell which is called casehardening.  Note that the casehardening sample prongs require no moisture gradient I order to get the correct reading.

3.  Do you mean 11% RH?  That is really dry.  If you mean 11% MC, that means that you have about 60% RH.  Or it means that the 11% MC reading is incorrect.

4.  Casehardening has no effect on drying speed.  I suspect there is a moisture content measurement error.  I am not familiar with your term MEC.
Gene - Author of articles in Sawmill & Woodlot and books: Drying Hardwood Lumber; VA Tech Solar Kiln; Sawing Edging & Trimming Hardwood Lumber. And more

Magicman

I do not dry, but Welcome to the Forestry Forum, KenBala.
Knothole Sawmill, LLC     '98 Wood-Mizer LT40SuperHydraulic   WM Million BF Club Member   WM Pro Sawyer Network

It's Weird being the Same Age as Old People

Never allow your "need" to make money to exceed your "desire" to provide quality service.....The Magicman

KenBala

 Thank you for the welcome and replies!  It seems I started with a tougher wood to dry.  I had a very informative discussion with Nathan from Michigan who has a similar (albeit larger) set up as I do.  I admittedly still have some confusion, but he helped clear some things up.  This is what I learned...

The instructions that came with the sauno unit stated to put the lumber in green (or air-dried, it didn't matter per the company) and immediately steam it for four days at 160 degrees.  I have read since in "Drying Hardwood" , and it was confirmed by Nathan, that that is a big no no.  And in fact, that likely contributed greatly to its warping (and possibly case-hardening?).  After that I was to drain the remaining water and open the vents and drop the temp to 104 degrees.  I think that is where the mold issue comes in.  There are only two passive vents - one above the fan unit and one on the opposite wall.  They are not power vented at all so I think the air in the unit stayed too moist for too long.  Does that sound correct?

Gene, I did mean 11% MC (I incorrectly wrote MEC instead of EMC - stupid newbie mistake!).  So as I read your reply, that equates to 60% RH.  If I had a powered vent, would that help that drop?  Nathan said that is what his units have to remove the moist air more effectively, however he only has them turn on for a certain amount of time every hour.  So my question is how do you determine how often and for how long your run the exhaust fan(s)?  Is there a published schedule for such things divided by wood species?

It appears that Nathan runs on a different schedule completely that what was suggested in the manual.  Per my understanding, he starts at a lower temp (around 90 degrees) and incrementally increases the temp to top out at 145 degrees which also disinfects the wood.  The last 24 hours he puts in a few buckets of water to condition the wood.  Species of wood and previously air-dried vs green all play a factor on how much air flow is ideal, controlled by fans and sticker height, what the RH should be within the kiln, temp selection and rate of increase, and amount of time needed to correctly dry the lumber.  Again, for those of us inexperienced in these nuances, is there a published schedule that can give guidance?  I've searched the web for conventional kiln schedules, but really didn't come up with anything useful.  I asked him specifically how he would dry the air-dried ash I have.  Nathan said that some guys would dry it within a week, but he would be more conservative.  He would put it in the kiln at 90-100 degrees for the first 3-4 days, then slowly ramp up the temperature maybe 5 degrees a day or so until the unit reaches 145 degrees.  He would then condition it for 24 hours, then remove the load the next day.  Sound about right?

I am trying to salvage my load the best I can.  I put in a few gallons of water and put the unit to 115 degrees to try and relieve some of the stresses.  I will elevate the temp 5 degrees a day after 48 hours until it reaches 145 degrees, then condition it one more time.

Please critique me and my thought process!  I was able to post a picture of the kiln as well (thanks beenthere).  You will notice the unit on the right hand side.  The fan blows under the stack of lumber and then returns through the lumber from the other side back to the intake at the top of the unit.  You will also notice a kind of duct work for the air to go through on the floor for the first few feet - that was suggested by the company for units more that 9' long.  I removed that after I discovered the mold thinking it may have contributed (there is a greater concentration of mold on the right side vs the left).

Thanks guys,
Ken



 

YellowHammer

You have a very nice kiln setup, obviously you are detail oriented.  I'm wish your first load had come out better, but I think everyone who has run a kiln has killed a few boards in their time.  It's a learning experience.  Kiln drying is both technical and intuitive.  The technical knowledge can be gained through this Forum and by reading some of the excellent material available on the web.  The intuition and feel come from just doing it, gaining experience and evaluating the results.  Get your hands, eyeballs and instruments on the wood during the process, it's the best way to truly understand what's going right or wrong.

There are a lot of good suggestions, and more to follow to help you, but one I would stress most strongly is, without fail, check on your wood every day and take corrective action immediatly if you see a problem, even if it means opening the doors, venting the heat and moisture, and letting things cool down, dry out and slow down.  It's not necessarily the best thing for the wood, and it causes additional time and a restart of the cycle, but it's better than turning it into potato chips or a couple hundred pounds of zebra striped moldy cheese. Good wood can get ruined in a short period of time, and it's makes for very bad day when it happens.
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

GeneWengert-WoodDoc

We do know that steaming and causing a moisture gain in air dried lumber will get the most warp of any drying method.

With AD lumber, the lumber has been used to approximately 12% EMC, so it makes sense to start the kiln a little bit drier, such as at 10% EMC for wood like ash.

The amount of venting is determined by the humidity in the kiln...too humid, then do more venting.  The desired humidity is given in a kiln schedule.  See DRYING HARDWOOD LUMBER for the details.  If the vents you have are not large enough, the make them powered vents or add more passive vents.
Gene - Author of articles in Sawmill & Woodlot and books: Drying Hardwood Lumber; VA Tech Solar Kiln; Sawing Edging & Trimming Hardwood Lumber. And more

Denny

When I dry SOFT maple my four non-powered vents stay open for the first few days. I was taught that high humidity in a maple kiln charge causes stains and a less than desirable shade of 'whiteness'.  My fan speed is adjustable and maples gets the high speed setting. On average my soft and hard maple goes into the kiln around 50% MC. With HARD maple, my humidity levels are higher, but the kiln is constantly venting because of how fast maples lose water.  On average it takes me 10 days to dry a charge of hard or soft maple and If we need it faster, I can get it out in 7 days. Soft maples are starting at 120 degrees while HM is started at 130 degrees. Maples are tough so checking & honeycomb never seem to be an issue. I move 10 degrees per day.  FYI I'm running a 'conventional' kiln.

GeneWengert-WoodDoc

Denny,
Great approach to maple drying indeed.

There is a lot of research showing that maple is even whiter when staying under 110 F until down t about 40% MC.

Some kilns need to keep the main doors open a crack the first few days to avoid the high humidities when the vents do not do a good job.  Just make sure the doors will not blow away or come lose in the wind.

Although this might not apply to your operation, when air drying first, we do get a nice white color on the outside when drying is fast.  Then when the lumber goes into the kiln, the core dries at 130 F , we get a different core color.
Gene - Author of articles in Sawmill & Woodlot and books: Drying Hardwood Lumber; VA Tech Solar Kiln; Sawing Edging & Trimming Hardwood Lumber. And more

Denny

"There is a lot of research showing that maple is even whiter when staying under 110 F until down t about 40% MC."

Yep about five years ago I switched up maple schedules to the 'low temp' schedule and I thought the lumber looked noticeably whiter. I just spent 15 minutes looking for my 'low temp' maple schedule but couldn't find it, but if I recall, I ran the 110 temp for as long as possible / until the vents closed, lowering the WB temp to keep the vents open... then I eventually ramped up the temp to finish her off. I think the reason I stopped with the low temp schedule and went back to the standard maple schedules is because the low temp charges took a day or three longer to finish and we really don't need a super-white color for the products made with our maple.

On six of my kilns the vents are on the roof and two of my kilns the vents are on the side of the kiln. The roof vents work "ok" but they're not the best design so they'll open up 3\4 of the way. When I have maples in these kilns, I'll take some 2x4's and prop open the vents so they are WFO (wide frickin' open).  I've never had a checking problem with maples, I have yet to find the breaking point on em ( i might have just jinxed myself).

I was surprised to hear the OP say that he closed the vents and put water on the floor for the first four days(at 160 degrees yet) and then after that he only cracked open the vents a quarter inch.  Is this a valid procedure for maples ? It seems to be the opposite from how I was taught.

bkaimwood

I am reasonably green with drying lumber, but not totally inexperienced... There have been responses here from plenty of guys that I could only hope to know as much as in my lifetime... But here it goes, just don't ream me a new pith, learn me....I can't understand, for the life of me, why in pith's name, you would take lumber, at its highest MC, just cut, and put it in a box, and ADD water to the situation, in attempt to add moisture to the lumber???!!! It only would make sense to me that it would be an instant recipe for mold...as soon as I cut, clean, and sticker pine or maple,  I get the fans on it asap to get the surface moisture off, and minimize the risk of mold and sticker stain...this by means is no attack on the original poster, he was just following instructions for the kiln he purchased...
bk

beenthere

bkaimwood

You have to coax the water out of the wood slowly.. wood shrinks when it is below about 30% mc. If you dry that surface wood below that, it shrinks only at the surface, but below the wood does not.
When that happens, the surface splits open and damage is done that will not "heal". However when the interior wood finally comes down below the 30% mc, it will shrink and because the surface as taken a "set", the interior wood splits open. So in effect, you have destroyed the wood.

If dried slowly, and wait for the interior to go along with the surface and you are lucky, then the surface wood remains intact.

Hope that helps.
south central Wisconsin
It may be that my sole purpose in life is simply to serve as a warning to others

bkaimwood

Thanks beenthere...I used to check to MC of stuff I just cut out of curiosity, but stopped that long ago...maybe I should start again...but I typically found that most stuff was 40-45% or better... So the question still remains, why add moisture to wood that wet? All I see is the potential for mold? I need to get that surface MC down fast to get away from mild and sticker stain, then slow way down??? Please continue to edumicate my green pith...and thank you!!!
bk

KenBala

For everyone's entertainment, I am attaching the comprehensive, one-size-fits-all, one page instruction manual from the company to dry all species of wood (disregard my chicken scratch on it).  I am more than a little embarrassed to say that those instructions were the limit of my investigation into kiln drying.  Tonight I really started studying Gene's DHL publication.  As I am reading through it I am just shaking my head.  The instructions provided by the company are nearly the polar opposite of all proven drying principles.  I am very happy, however, that it appears that I still have a good conventional kiln - I just need use the appropriate schedule (which I haven't gotten to yet in the book).  I have ordered a 4" duct fan to power my one vent to remove the humidity as needed.

Question:  This is a bit of a primitive set up and I do not have the classic dry bulb and wet bulb sensors.  I do have a temperature sensor with a probe in the unit that is my dry bulb.  Can I just get a RH sensor with a probe as well that will automatically just quantify the wet bulb/dry bulb differential?

Another question:  The publication talks of sample boards with sections cut out of them and oven-dried to determine the lumber's MC.  I am sure that is the most accurate way to do that, however is there major issue in just using a Lignomat mini with remote probes?

 

GeneWengert-WoodDoc

I think I see the problem...the title says that this is for drying kilns...it is a "kiln dryer" ...and not a lumber dryer.   But seriously,

There have been many postings about this kiln and its operation.  Let's look more closely at a few items.  First, it says that drying green lumber is best.  Indeed, if you will use their so-called "steaming" process, then this is good advice.  Then they say that oak must be air dried for at least six months.  This is a good idea, but then the steaming process should not be used, as moisture gain with air dried wood, especially oak, creates deep checks and increases warp.

As we probably all know, steam is formed at 212 F (100 C).  So, running this unit for four days or so at 158 F is really not steaming.  What is actually happening is that the unit begins at a low temperature and, being tightly sealed with water on the floor, slowly  increases the temperature to 158 F.  By doing this slowly, the interior environment is maintained at 100% relative humidity.  If the temperature goes up too fast, the humidity will not be 100%, and so the green wood will start to dry.  We all know that drying green oak at 120 F or hotter is not a good idea as it causes checks, so keeping the RH at 100% RH is critical.  But if we do not, the moisture from the floor or from wet lumber will increase the humidity to 100%.   Also, as we go over 120 F, it is too hot for mold, mildew, decay fungi, and other living things to grow, so the wood will be sanitized.   

The problem with this treatment is two fold.  First, for a white colored wood, like maple, ash, or pine, above 50% MC, this heat will darken the wood and will also be favorable for developing enzymatic oxidation stains, like sticker stain, pinking, coffee stain, etc.  actually, in Europe, this high humidity treatment is used for beech lumber before drying all the time to develop a pink color.  It is used for walnut and cherry to get a darker color.  The key is to use it on never-dried lumber.  Second, for air dried species prone to checking, like oak, this high humidity treatment will worsen checks.  For all species, it will increase warping.

The high humidity treatment at high temperatures before drying process is a patented process in the U.S.  It is not clear if this kiln has permission to use this process.  The patent holder is Danny Elder.  In his work, he found that hotter.temperatures developed  nice color enhancement in oak and, just as in walnut, darkened the sapwood.

The second part of the drying process in this kiln is similar to how wood is dried normally, although for many species, the humidity is much higher than we would use traditionally.  With very high humidity, because the vents are just cracked open 1/4", the conditions are ideal for mold and mildew.  It is likely that the 158 F temperatures deactivated the enzymes, so the enzymatic stains will not form or develop any more at this part of drying.  One might also ask why dry so slowly if the wood can withstand more severe drying?  The answer might be that faster drying means more drying stress (also called casehardening).  But air dried lumber doesn't have casehardening initially.

So, maybe this helps to understand the process and its application to our species in North America.
Gene - Author of articles in Sawmill & Woodlot and books: Drying Hardwood Lumber; VA Tech Solar Kiln; Sawing Edging & Trimming Hardwood Lumber. And more

KenBala

Very interesting analysis of the recommended drying schedule from Sauno Mr. Wengert.  I know that it has worked out well for some people who use it, but for me it's a case of "once bitten, twice shy"...

I've also been in contact with YellowHammer who has given me a much clearer insight on the process of drying (thank you!).  I have decided moving forward that I am going to air-dry my lumber first to a MC below 25% (since I am a hobbyist and not really in any rush), and then finish it off in the kiln.  This brings a few more questions that I would appreciate guidance with.

In looking through DHL, there are schedules for drying air-dried and partially air-dried lumber.  All of the schedules include an equalizing and conditioning component.  Why is this needed?  It was my understanding that lumber air-dried to 25% or below does not suffer case-hardening (that is one of the primary reasons I've decided to air-dry first).

Secondly, the schedules all suggest a dry bulb temp of 160 degrees once the moisture content falls below 15%.  I would really like to top out around 135 degrees.  If I adjust my RH in the kiln to an equivalent value as the suggested schedule (160 DB, 115 WB = approx 25%RH), will that bring my lumber down to the same MC eventually?  I am assuming the answer to that would be yes, but is that going to significantly increase my kiln time?  Also, if I have a powered vent will I be able to obtain that RH inside the kiln?  Will topping out the DB temp at 135 degrees be enough to sterilize the wood, or should I bump it to 145 degrees for 24 hours at the end of the cycle?

And a last question (for now, haha), once final MC is reached, do you let the lumber cool down in the kiln a few days before taking it out, or is it safe to take it out right away (that is, not stress the wood).  Thank you!

Ken

GeneWengert-WoodDoc

The kiln temperatures in the schedules are maximums.  Cooler temperatures do take longer.

Equalizing is needed to assure uniform final MC.  Well air dried lumber has very little stress, so conditioning is not needed in most cases.  (Remember that the prong test requires no moisture gradient to get a valid answer.)

If the kiln is 135 F, it is likely that the core of the wood is a bit cooler... perhaps 10 F.  The bit warmer temperature for a day is better.



You can empty the kiln when done promptly.  However, you should wait a few days after unloading before using the lumber to allow the moisture to move a little bit, if needed, throughout the piece.  Although called cooling, it is all about uniform MC.
Gene - Author of articles in Sawmill & Woodlot and books: Drying Hardwood Lumber; VA Tech Solar Kiln; Sawing Edging & Trimming Hardwood Lumber. And more

KenBala

So please tell me if I am on the right track here moving forward.  As I look at DHL, it appears that all hardwood species up to 6/4, once they are under 15% MC, have a DB temp of 160 and WB temp of 115 across the board on the schedules.  That equates to a 26% RH in the kiln.  As I've previously noted, I have some ash that has been air drying and is around 12%MC now.  I was thinking of topping out my DB temp at 135 degrees (knowing it is going to take a bit longer to dry).  So, is this an appropriate schedule?...

Day 1 and 2 - DB temp 110
Day 3 - DB temp 115
Day 4 - DB temp 120
Day 5 - DB temp 125
Day 6 - DB temp 130
Day 7 - DB temp 135
I would then keep the temp at 135 until the MC reaches 6% (if it hasn't already by then).  I just added an exhaust fan to my vent.  I do not have a wet bulb, but do have a humidistat that can turn on the fan whenever humidity exceeds 26% from Day 1.

Once my target MC is reached, I would bump the DB to 145 for 24 hours for sterilization.

I will not have to condition the lumber because all of the stresses have already been released during air drying.

So, will this work?  Am I "babying it" too much by only moving up 5 degrees/day?  As I look at DHL, it seems that I could actually bring the DB up to my final desired DB temp right away instead of incrementally stepping it - is that true as well?  Any advantage one way over the other?

And lastly, if this schedule is good for ash, I assume it would be good for any hardwood lumber that has been air-dried below 15%, correct?

I'm just being extra cautious - this is the wood I am using for my kitchen project this summer and I don't want to mess it up!  Thanks.

GeneWengert-WoodDoc

This is an ok schedule for any species at low MCs. 

This is indeed unnecessarily slow...you are gaining no increase in quality by being slow and cool at this point.  In any case remember to avoid rewetting...the kiln conditions must always start and continue at humidities less than outside, which means under about 10% MC.

There should be no stress.  Remember that the prong test requires no gradient in moisture to read correctly...a gradient will show stress even though there is none.
Gene - Author of articles in Sawmill & Woodlot and books: Drying Hardwood Lumber; VA Tech Solar Kiln; Sawing Edging & Trimming Hardwood Lumber. And more

KenBala

So I can load the kiln with AD lumber below 15% MC and take the DB temperature right to 160 (or anywhere below that) and set the RH TO 26% and this would be safe for the lumber while drying it faster at the same time?

GeneWengert-WoodDoc

Yes. 

To control the humidity during the heating cycle to 160 F, many kilns will need to be heated in steps over several hours.  Otherwise, with quick heating, it is possible that the heat will reach temperature ahead of the wet-bulb (or humidity), so you will have conditions out of range for a while.

Further, kiln start up procedures suggest 2% EMC below surface MC, which will often mean 10% EMC.  If you get to 160 F, the lumber surface might still be cooler, so the indicated EMC of the air would not be the surface MC because the wood is still cooler, which means higher surface MC compared to the EMC.  With slower heating, this effect will be small.

Gene - Author of articles in Sawmill & Woodlot and books: Drying Hardwood Lumber; VA Tech Solar Kiln; Sawing Edging & Trimming Hardwood Lumber. And more

KenBala


KenBala

Quick question.  I have successfully dried my load of previously AD ash to 6.5%.  My top temp was 135 degrees at around 26%RH.  I just closed the vents and put the temp to 145 degrees for sterilization over the next 24 hours.  After this is done and I bring it into my shop, do I have to sticker it in my shop?  I don't plan on using it for at least 2 weeks - will it reach EMC with the shop by just being stacked?  Thank you.

beenthere

For best results, I'd say sticker.

But that is up to you, as just the outside of the solid stack will work to reach equilibrium first and you may see some movement.

Click on your forum name, and it will take you to where you can update your profile with a location as well as other good info.
Helps to have that info when answering questions such as you asked this time.
south central Wisconsin
It may be that my sole purpose in life is simply to serve as a warning to others

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