The Forestry Forum is sponsored in part by:

KNOW WHAT?
Between February 12, 2018 and June 18, 2018, this space displayed 13 Million, 871 Thousand and 87 times.



Forestry Forum
Sponsored by:


TimberKing Sawmills



Toll Free 1-800-582-0470

LogRite Tools



Norwood Industries Inc.


Sawmill & Woodlot Magazine



Your source for Portable Sawmills, Edgers, Resaws, Sharpeners, Setters, Bandsaw Blades and Sawmill Parts

EZ Boardwalk Sawmills. More Saw For Less Money!

STIHLDealers.com sponsored by Northeast STIHL


Woodland Sawmills

Peterson Swingmills

 KASCO SharpTech WoodMaxx Blades

Turbosawmill

Sawmill Exchange

BRUTE FORCE Authorized Dealer

Woodshax Outdoor Vending Solutions

FARMA


Council Tool

Baker Products

ECHO-Bearcat



Author Topic: The need to get to 7%  (Read 710 times)

0 Members and 1 Guest are viewing this topic.

Offline Clevelander

  • Full Member
  • **
  • Posts: 53
  • Age: 58
  • Location: North Olmsted, Ohio (just west of Cleveland)
  • Gender: Male
  • Livin the dream
    • Share Post
The need to get to 7%
« on: April 23, 2018, 09:24:08 PM »
I specialize in live edge slabs over 36" wide. I bring them down to between 7-9% moisture content in my dehumidification kiln. I store them in a non-humidity controlled environment. Within just a few days the outer slabs are back to 15% +-. I have had zero callbacks or issues selling and using them at this percentage. If they are going to go back up to 15% is there a need, if so, what is the need to take them to 7% to begin with?

Thanks
Live your truth and your truth will find you

Offline firefighter ontheside

  • Senior Member
  • ****
  • Posts: 327
  • Age: 44
  • Location: DeSoto MO
  • Gender: Male
  • I like trees.
    • Share Post
Re: The need to get to 7%
« Reply #1 on: April 24, 2018, 07:25:36 AM »
I would find it hard to believe that the MC content of the center of a 8/4 slab would go back to 15% in such a short time if it truly was down to 7% at the center.  

I think the projects that people are making with large live edge slabs are not prone to wood movement problems.  If I make a breakfast bar with a big slab, it shrinking a small amount isn稚 gonna be noticed.  Nobody is building a cabinet with large slabs.

I知 in the same boat with you.  Currently I知 air drying down to similar as you in MO.  I知 going to build a kiln, but I don稚 have a controlled enviro to store in afterward, so wood will begin to take in moisture again. I値l have to try and sell stuff soon after drying.  Maybe sell in units, but that usually means giving a discount per bf.  

I知 interested what others will have to say.
Woodmizer LT15
Kubota Grand L4200
Stihl 025 and MS291
2017 F350 Diesel 4WD

Offline GeneWengert-WoodDoc

  • Senior Member x2
  • *****
  • Posts: 2257
  • Location: Bishop, GA
  • Gender: Male
  • Author of "Sawing Hardwood Lumber"
    • Share Post
    • Book on Sawing hardwood Lumber
Re: The need to get to 7%
« Reply #2 on: April 25, 2018, 06:29:17 AM »
If dry wood could gain moisture that fast, it would also lose moisture that quickly, but we know it does not.  Also, to achieve 15% MC, after being at 7% MC would require exposure to humidities well over 80% RH, but the average outdoor humidity is 65% RH or 12% EMC.  Even if the wood is exposed to really high humidity, it does take many weeks or months for the core MC to change.  So, it would seem that there is some sort of moisture measurement problem.

Are you using a pin meter?  Are the needles insulated?  Does the meter read a low MC when you check some dry wood in your house within a minute of your 15% MC readings?  The house we know will be around 7% MC?  Is there perhaps some condensation on the meter that is shorting out the meter?

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

Offline YellowHammer

  • Senior Member x2
  • *****
  • Posts: 3046
  • Age: 53
  • Location: New Market, Alabama
  • Gender: Male
  • Always taking steps to save steps
    • Share Post
    • Hobby Hardwood Alabama
Re: The need to get to 7%
« Reply #3 on: April 25, 2018, 09:37:02 AM »
Among other things, I like to dry down to past what a customer may reasonably subject any of my wood. I consider it a stress test. If a board has been to 7% with no defects then goes up higher I can reasonably assume the board can again go down and will behave. I would have seen any poor behavior, cracks and already corrected it or culled it when subjected to low moisture values.

I never want a board to go down lower for a customer than I have taken it myself.  Bad phone calls happen.
HobbyHardwoodAlabama.com

Offline GeneWengert-WoodDoc

  • Senior Member x2
  • *****
  • Posts: 2257
  • Location: Bishop, GA
  • Gender: Male
  • Author of "Sawing Hardwood Lumber"
    • Share Post
    • Book on Sawing hardwood Lumber
Re: The need to get to 7%
« Reply #4 on: April 25, 2018, 11:31:47 PM »
Y-H is right on target.

One reason this works is that shrinkage causes splitting or cracking, while swelling does little to the appearance.  Second, when we reverse direction, going from losing moisture to gaining moisture, there is a lag, called the hysteresis effect, which essentially says that there is about a 1% MC lag or delay when you reverse.
Gene - Author of articles in Sawmill & Woodlot and books: Drying Hardwood Lumber; VA Tech Solar Kiln; Sawing Edging & Trimming Hardwood Lumber. And more

Offline scsmith42

  • Senior Member x2
  • *****
  • Posts: 4559
  • Age: 58
  • Location: New Hill, NC
  • Gender: Male
  • He who dies with the most toys... WINS!!!
    • Share Post
    • Whispering Pines Farm
Re: The need to get to 7%
« Reply #5 on: April 27, 2018, 05:50:09 PM »
Among other things, I like to dry down to past what a customer may reasonably subject any of my wood. I consider it a stress test. If a board has been to 7% with no defects then goes up higher I can reasonably assume the board can again go down and will behave. I would have seen any poor behavior, cracks and already corrected it or culled it when subjected to low moisture values.

I never want a board to go down lower for a customer than I have taken it myself.  Bad phone calls happen.
I do the same.  It eliminates a lot of problems.
Peterson 10" WPF with 65' of track
Smith - Gallagher dedicated slabber
Tom's 3638D Baker band mill
and a mix of log handling heavy equipment.

Offline moodnacreek

  • Senior Member
  • ****
  • Posts: 514
  • Location: Orange County NY
  • Gender: Male
  • Sawin by the notches
    • Share Post
Re: The need to get to 7%
« Reply #6 on: April 27, 2018, 06:46:08 PM »
Due to the demand, I keep more than 10 m of thick/wide un edged stuff on sticks. I do not have a kiln or time to do anymore expanding.  These planks are 2 1/4" thick and as wide as 22". I will not do; oak or ash and do all the cedar, soft maple, cherry, walnut and sassafras I can get. It is important that the user 'paints' the top surface first with the end grain and the bottom leaving a strip bare in the center. This will allow moisture to escape and reverse the cup that could happen. Also the 'bread board' on the ends is a no no.

Offline logboy

  • Senior Member
  • ****
  • Posts: 673
  • Location: Wisconsin
    • Share Post
Re: The need to get to 7%
« Reply #7 on: May 01, 2018, 01:11:06 AM »
I specialize in live edge slabs over 36" wide. I bring them down to between 7-9% moisture content in my dehumidification kiln. I store them in a non-humidity controlled environment. Within just a few days the outer slabs are back to 15% +-. I have had zero callbacks or issues selling and using them at this percentage. If they are going to go back up to 15% is there a need, if so, what is the need to take them to 7% to begin with?

Thanks
Let me guess: youre using a Mini-Ligno moisture meter, and even with the temperature correction chart its saying they're 7-9% in the kiln at 120F, but 15% at 70F?  I ask because I had the same problem many years ago before I upgraded to a proper moisture meter. Your slabs aren't gaining moisture, they're just not dry yet when you're yanking them out of the kiln. If youre using a cheap meter, junk it and spend the money on a proper one with deep probes for slabs. It will be expensive, but still cheaper than a ruined reputation and lost sales from selling wet slabs. After handling thousands of slabs, I use a two part method to check moisture. First, I lift one end. I can tell just by lifting a slab whether its close to dry or not. Dry slabs are light, wet slabs aren't. Then I use my meter to verify.
I like Lucas Mills and big wood.  www.logboy.com


Share via delicious Share via digg Share via facebook Share via linkedin Share via pinterest Share via reddit Share via stumble Share via tumblr Share via twitter
 


Powered by EzPortal