The Forestry Forum is sponsored in part by:

iDRY Vacuum Kilns


Forestry Forum
Sponsored by:


TimberKing Sawmills



Toll Free 1-800-582-0470

LogRite Tools



Norwood Industries Inc.




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

Michigan Firewood, your BRUTE FORCE Authorized Dealer

Baker Products

ECHO-Bearcat

iDRY Wood Lumber Vacuum Drying for everyon

Nyle Kiln Dry Systems

Chainsawr, The Worlds Largest Inventory of Chainsaw Parts

Smith Sawmill Service



Author Topic: Shrinkage  (Read 576 times)

0 Members and 1 Guest are viewing this topic.

Offline Crossroads

  • Senior Member x2
  • *****
  • Posts: 1559
  • Age: 51
  • Location: Plummer Idaho
  • Gender: Male
  • letís make some sawdust
    • Share Post
    • Kevin Bales faith family farm and portable sawmill
Shrinkage
« on: August 02, 2021, 12:08:57 AM »
I ran a bunch of 2x through the edger a few weeks ago and didnít measure any of it to verify that it was coming out at 7 1/4Ē wide. A couple days ago I was walking by and happened to throw a tape on it. To my surprise it ranges from 7Ē to 7 1/8Ē. The wood is Doug fir. Iím just now starting to mess around with drying and processing, is a 1/4Ē of shrinkage to be expected on a 2x8? Next time I set the edger up, Iíll definitely be checking whatís coming out of it.
2017 LT40 wide, Kubota l185dt, 2-036 stihl, 2001 Dodge 3500 5.9 Cummins, l8000 Ford dump truck, hr16 Terex excavator, Farmi logging winch, Valley je 2x24 edger, Gehl ctl65 skid steer

Offline customsawyer

  • Senior Member x2
  • *****
  • Posts: 5357
  • Age: 53
  • Location: Rentz, Ga.
  • Gender: Male
    • Share Post
    • The Custom Sawyer
Re: Shrinkage
« Reply #1 on: August 02, 2021, 06:33:27 AM »
I've never sawed Fir however that much and maybe a little more shrinkage would be in line with SYP. Might be a little quick but this time of year it can happen.
Two LT70s, Nyle L200 kiln, 4 head planer, 30" double surface planer, Lucus dedicated slaber, Slabmizer, and enough rolling stock and chainsaws to keep it all running.
www.thecustomsawyer.com

Offline scsmith42

  • Senior Member x2
  • *****
  • Posts: 5627
  • Age: 61
  • Location: New Hill, NC
  • Gender: Male
  • He who dies with the most toys... WINS!!!
    • Share Post
    • Whispering Pines Farm
Re: Shrinkage
« Reply #2 on: August 02, 2021, 06:50:33 AM »
Doug fir shrinks between .0015 (radial) to .0026 (tangential) per inch of width, per percent of moisture reduction.  So for structural use, it will lose around 14%MC  drying from 30% MC to 16% MC.

So a 7.25" wide board will shrink at most 7.25 x (.0015 or .0026) x 16, or between 3/16" to .300" in width as it dries.

So your results sound about right to me.
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 bannerd

  • Full Member x2
  • ***
  • Posts: 151
  • Location: Malone, NY
  • Gender: Male
  • Madman
    • Share Post
Re: Shrinkage
« Reply #3 on: August 02, 2021, 07:24:28 AM »
What about shrinkage end to end or does that not ever happen?

Offline Ianab

  • Administrator
  • *****
  • Posts: 15190
  • Age: 59
  • Location: Stratford , New Zealand
  • Gender: Male
  • Marmite on toast is a real breakfast
    • Share Post
Re: Shrinkage
« Reply #4 on: August 02, 2021, 07:37:46 AM »
What about shrinkage end to end or does that not ever happen?
Usually so small that it doesn't matter. 
There is some slight lengthwise shrinkage in wood as it dries, but it's about 100X less than the cross grain, so we tend to ignore it. 
Weekend warrior, Peterson JP test pilot, Dolmar 7900 and Stihl MS310 saws and  the usual collection of power tools :)

Offline Don P

  • Senior Member x2
  • *****
  • Posts: 9081
  • Location: Southwestern VA
  • Gender: Male
    • Share Post
    • Calculator Index
Re: Shrinkage
« Reply #5 on: August 02, 2021, 08:23:06 AM »
The exceptions to that are juvenile wood and reaction wood. Those fibers do shrink in length as they dry and are the force at work behind a number of drying warps.

The juvenile wood on the upper face of this board shrinks in length as it dries, bowing the piece. Enough length shrinkage that it sheared 2 deck screws.



The future is a foreign country, they will do things differently there - Simon Winchester

Offline Crossroads

  • Senior Member x2
  • *****
  • Posts: 1559
  • Age: 51
  • Location: Plummer Idaho
  • Gender: Male
  • letís make some sawdust
    • Share Post
    • Kevin Bales faith family farm and portable sawmill
Re: Shrinkage
« Reply #6 on: August 02, 2021, 08:57:27 AM »
Thank you, Iím actually pretty surprised that it would shrink that much. One more lesson from the school of hard knocks in the books. Fortunately I have a project at home that I can use it all up. I believe Iíll be spending a lot more time on this section of the forum. Thank you again!
2017 LT40 wide, Kubota l185dt, 2-036 stihl, 2001 Dodge 3500 5.9 Cummins, l8000 Ford dump truck, hr16 Terex excavator, Farmi logging winch, Valley je 2x24 edger, Gehl ctl65 skid steer

Online Southside

  • Administrator
  • *****
  • Posts: 10386
  • Age: 49
  • Location: Wilsons (Dinwiddie County), VA
  • Gender: Male
  • Have a plan to saw every log you meet.
    • Share Post
    • White Oak Meadows
Re: Shrinkage
« Reply #7 on: August 02, 2021, 09:18:57 AM »
The shrink sounds right  - but as you said, you don't know what you were actually set up to cut, so hard to say.  I know on my edger there are two brass wear rods that hold the adjustable blade in place for fine adjustment and weekly I need to bump them in ever so slightly due to the brass doing what is was designed to do.  Only takes a minute if that, but if I don't the adjustable blade would fall out of alignment with the the indicator and my output would not be what I thought it was going to be.  
Franklin buncher and skidder
JD Processor
Woodmizer LT Super 70 and LT35 sawmill, KD250 kiln, BMS 250 sharpener and setter
Riehl Edger
Woodmaster 725 and 4000 planner and moulder
Enough cows to ensure there is no spare time.
White Oak Meadows

Offline bannerd

  • Full Member x2
  • ***
  • Posts: 151
  • Location: Malone, NY
  • Gender: Male
  • Madman
    • Share Post
Re: Shrinkage
« Reply #8 on: August 02, 2021, 10:53:04 AM »
What about shrinkage end to end or does that not ever happen?
Usually so small that it doesn't matter.
There is some slight lengthwise shrinkage in wood as it dries, but it's about 100X less than the cross grain, so we tend to ignore it.
Good info here, Thanks!

Offline Crossroads

  • Senior Member x2
  • *****
  • Posts: 1559
  • Age: 51
  • Location: Plummer Idaho
  • Gender: Male
  • letís make some sawdust
    • Share Post
    • Kevin Bales faith family farm and portable sawmill
Re: Shrinkage
« Reply #9 on: August 02, 2021, 03:45:37 PM »
Sounds like I have been putting to much trust in my edger. I plan on swaps the blades out as soon as I get time. That should be an adventure 
2017 LT40 wide, Kubota l185dt, 2-036 stihl, 2001 Dodge 3500 5.9 Cummins, l8000 Ford dump truck, hr16 Terex excavator, Farmi logging winch, Valley je 2x24 edger, Gehl ctl65 skid steer

Online Southside

  • Administrator
  • *****
  • Posts: 10386
  • Age: 49
  • Location: Wilsons (Dinwiddie County), VA
  • Gender: Male
  • Have a plan to saw every log you meet.
    • Share Post
    • White Oak Meadows
Re: Shrinkage
« Reply #10 on: August 02, 2021, 04:13:22 PM »
Not really - it's a tool and now and then you need to calibrate and maintain it.  Just like the scale on the mill can get off. 
Franklin buncher and skidder
JD Processor
Woodmizer LT Super 70 and LT35 sawmill, KD250 kiln, BMS 250 sharpener and setter
Riehl Edger
Woodmaster 725 and 4000 planner and moulder
Enough cows to ensure there is no spare time.
White Oak Meadows

Online Magicman

  • Senior Member x2
  • *****
  • Posts: 42292
  • Age: 78
  • Location: Brookhaven, MS
  • Gender: Male
  • A "Traveling Man"
    • Share Post
    • Knothole Sawmill
Re: Shrinkage
« Reply #11 on: August 02, 2021, 04:21:37 PM »
Just round figures but when sawing framing lumber; on 4 & 6" I oversize 1/8", on 8 & 10" I oversize 1/4", and on 12" I oversize 1/2".   The key word is being consist.

Note that there can be a significant difference between sawing fresh felled and 'old' logs.  You can expect more shrinkage plus stress in fresh felled which is why I prefer to saw 'old' bark slipped SYP logs.
Knothole Sawmill, LLC     '98 Wood-Mizer LT40SuperHydraulic   WM Million BF Club Member   WM Pro Sawyer Network

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

Offline Crossroads

  • Senior Member x2
  • *****
  • Posts: 1559
  • Age: 51
  • Location: Plummer Idaho
  • Gender: Male
  • letís make some sawdust
    • Share Post
    • Kevin Bales faith family farm and portable sawmill
Re: Shrinkage
« Reply #12 on: August 02, 2021, 07:39:35 PM »
All good info, thank you! 
2017 LT40 wide, Kubota l185dt, 2-036 stihl, 2001 Dodge 3500 5.9 Cummins, l8000 Ford dump truck, hr16 Terex excavator, Farmi logging winch, Valley je 2x24 edger, Gehl ctl65 skid steer

Offline YellowHammer

  • Senior Member x2
  • *****
  • Posts: 6318
  • Age: 56
  • Location: New Market, Alabama
  • Gender: Male
  • Sawing is fun for the first couple million boards.
    • Share Post
    • Hobby Hardwood Alabama
Re: Shrinkage
« Reply #13 on: August 02, 2021, 09:26:02 PM »
There's enough shrinkage in wood that the Hardwood Market Report (the gold standard for wood prices) has different specs for "green off the mill" and "kiln dried" due to the amount of shrinkage and volume loss. 
YellowHammerisms:

Take steps to save steps.

If it wonít roll, its not a log; itís still a tree.  Sawmills cut logs, trees.

Kiln drying wood: When the cookies are burned, theyíre burned, and you canít fix them.  So donít burn the cookies.

Sawing is fun for the first couple hundred boards.

Offline Crossroads

  • Senior Member x2
  • *****
  • Posts: 1559
  • Age: 51
  • Location: Plummer Idaho
  • Gender: Male
  • letís make some sawdust
    • Share Post
    • Kevin Bales faith family farm and portable sawmill
Re: Shrinkage
« Reply #14 on: August 02, 2021, 11:49:26 PM »
I ran some 1x through the edger today and they were all 1/16th over, so Iím either looking at shrinkage or I done messed up on my edger settings. I guess 2x8ís will be getting an extra 1/4 from now on. 
2017 LT40 wide, Kubota l185dt, 2-036 stihl, 2001 Dodge 3500 5.9 Cummins, l8000 Ford dump truck, hr16 Terex excavator, Farmi logging winch, Valley je 2x24 edger, Gehl ctl65 skid steer


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

xx
Shrinkage...

Started by mrcaptainbob on Sawmills and Milling

21 Replies
4456 Views
Last post March 23, 2010, 04:50:52 AM
by SwampDonkey
xx
shrinkage

Started by vfauto on Sawmills and Milling

3 Replies
878 Views
Last post December 07, 2011, 07:46:32 PM
by red oaks lumber
xx
SYP shrinkage

Started by Jimbob on Sawmills and Milling

45 Replies
9390 Views
Last post November 27, 2008, 07:37:56 PM
by backwoods sawyer
xx
shrinkage

Started by fuzzybear on Drying and Processing

6 Replies
839 Views
Last post March 26, 2013, 10:57:59 PM
by Jay C. White Cloud
 


Powered by EzPortal