Dealing with wood movement - Woodworking Talk - Woodworkers Forum
 10Likes
  • 2 Post By NoThankyou
  • 2 Post By difalkner
  • 2 Post By FrankC
  • 1 Post By epicfail48
  • 2 Post By difalkner
  • 1 Post By FrankC
 
Thread Tools Display Modes
post #1 of 14 Old 12-08-2018, 11:41 PM Thread Starter
Ancient Termite
 
Join Date: Mar 2018
Location: Huntington Beach, California
Posts: 453
View NoThankyou's Photo Album My Photos
Dealing with wood movement

Wood moves, period. If your shop is in the Arizona desert and the piece is going to be used in Seattle, wood is going to move a lot. The trick is to first acclimatize your wood in your shop before use. This will normally take a few weeks of just sitting in your shop. Then as you build anticipate and build for wood movement. This is even necessary with kiln dried lumber.

1 ~ Cutting Boards
In a cutting board it is best to cut the wood into strips and align the strips so that the edge grain is the cutting surface. That way the cutting board will get thinner and thicker as the moisture content changes.

2 ~ Raised Panels
Try to keep your raised panels as narrow as possible. Make the dadoes for the panels a sixteenth or so deeper than necessary. You can reduce the apparent amount of wood movement by securing the center of the panel by putting a pin nail through the top and bottom rail about in the center.

3 ~ Mortises
Make the mortise slightly longer than necessary for the tenon.

4 ~ The Gory Details
When the tree is cut the moisture content is generally estimated to be 30% or above.
Air dried wood usually has a moisture content closer to 10% moisture content. When air drying wood, the rule of thumb is one year per one inch of thickness. A roundish log is going to take longer to air dry than some rough sawn.
Kiln dried wood is usually 6% to 8% moisture content. This is the ideal for building woodworking projects. Kiln dried wood is generally considered to be at equilibrium.

We don't need to worry about a 25% change in moisture content. At worst we only have to worry about a 5% moisture content change. (Air dried to a desert climate in winter with forced air heating.) We don't need to rush off to the wood movement tables based upon moisture content changes to determine the amount of wood movement. All we need is a general rule of thumb one eighth per foot. The wood that we use will move about 1/8 inch per 12 inches of face grain in a normal home environment.
difalkner and hawkeye10 like this.

Rich
In furniture 1/32" is a Grand Canyon
NoThankyou is offline  
Sponsored Links
Advertisement
 
post #2 of 14 Old 12-09-2018, 07:48 AM
Wood machinist
 
difalkner's Avatar
 
Join Date: Nov 2011
Location: NW Louisiana
Posts: 3,439
View difalkner's Photo Album My Photos
Good stuff, Rich. In the mid 80's to early 90's I had a woodworking business where we designed and built custom furniture, did restorations, repairs, refinishing, etc. I had a sign in my office and the sign read - There are two rules to wood movement: Rule #1 is that wood moves. Rule #2 is that you and I can't change rule number one.

The sign got a lot of comments but also saved me a lot of discussion time when people were looking for a 'why' on something they bought and were bringing in for repairs.

David
hawkeye10 and NoThankyou like this.

David

Curly Wood Shop on Etsy
David Falkner - Woodworking YouTube channel
Our music at church - current videos Airline Baptist BC Facebook Live
Romans 3:23
difalkner is offline  
post #3 of 14 Old 12-09-2018, 10:50 AM
Sawing against the Wind
 
Tennessee Tim's Avatar
 
Join Date: Dec 2010
Location: God's beautiful hills of Middle Tennessee
Posts: 2,381
View Tennessee Tim's Photo Album My Photos
THANK YOU nothankyou LOL!!! I'm glad someone else KNOWS the wood/moisture rules AND isn't afraid to announce them!!! I see SO many issues asked about here that are moisture related BUT the answers usually have nothing to do with "fixing" the actual problem.

Have a Blessed and Prosperous day in Jesus's Awesome Love, Tim
........www.TSMFarms.com.......... John 3:16-21 ..........
Reveling God's awesome beauty while creating one of-a-kind flitches and heirlooms.
Tennessee Tim is offline  
Sponsored Links
Advertisement
 
post #4 of 14 Old 12-09-2018, 12:02 PM
Senior Member
 
Join Date: Aug 2012
Location: British Columbia, Canada
Posts: 5,162
View FrankC's Photo Album My Photos
There are plans out there that are drawn by those that have no concept or concern about wood movement, they are the root cause of many of the problems that we see here.
Unfortunately in many cases there is no fix, all we can do is explain where they went wrong so it doesn't happen again.
hawkeye10 and NoThankyou like this.

Wise men speak because they have something to say; fools because they have to say something -Plato

FrankC
http://sawdustmaking.com
http://woodworkerglossary.com
FrankC is offline  
post #5 of 14 Old 12-09-2018, 11:18 PM Thread Starter
Ancient Termite
 
Join Date: Mar 2018
Location: Huntington Beach, California
Posts: 453
View NoThankyou's Photo Album My Photos
I have been told (Meaning I don't know if it is really true or not.) that in Colonial New England that birch dowels were used in the granite quarries to knock out big chunks of stone. The dowels were dried to as close to 0% moisture content as possible. Then these dowels were forced into the holes drilled in the granite. Finally water was allowed to permeate the birch dowels. The dowels would expand enough to break the granite loose. In winter time water was used for the same task and as it froze the result was the same.

Rich
In furniture 1/32" is a Grand Canyon
NoThankyou is offline  
post #6 of 14 Old 12-10-2018, 12:02 AM
Recycled Member
 
Brian T's Avatar
 
Join Date: Nov 2018
Location: Magnificently mountainous McBride in the Robson Valley
Posts: 321
View Brian T's Photo Album My Photos
The nature of the wood project does not matter. As above, wood moves. And the forces are fantastic.
Common subject item in the university dendrology courses that I taught.


Drop $60,000 or more on a violin and you should be paying attention to constant humidity.
Even a $5,000 guitar, you need constant humidity in the case.
Some homes have humidity rooms for their instruments.


I've seen furniture (a pair of small tables) tear themselves apart as the wood dried.
I've awoken to the sound of wood carvings exploding 3/4" wide in my shop.


Don't forget that there's a lag between changing air humidity and the wood MC%.
You must stay ahead of the changes.
Brian T is offline  
post #7 of 14 Old 12-10-2018, 04:06 AM
Village Idiot
 
epicfail48's Avatar
 
Join Date: Mar 2014
Location: Springfield MO
Posts: 4,638
View epicfail48's Photo Album My Photos
Quote:
Originally Posted by NoThankyou View Post
I have been told (Meaning I don't know if it is really true or not.) that in Colonial New England that birch dowels were used in the granite quarries to knock out big chunks of stone. The dowels were dried to as close to 0% moisture content as possible. Then these dowels were forced into the holes drilled in the granite. Finally water was allowed to permeate the birch dowels. The dowels would expand enough to break the granite loose. In winter time water was used for the same task and as it froze the result was the same.
You know, ive always heard the same anecdote and wondered just how true it is. In my head, theres no way that the wood would be capable of expanding with enough force to crack granite, we use dynamite for that for a reason. On the other hand, i dont know a thing about stone quarries
NoThankyou likes this.

I need cheaper hobby
etsy.com/shop/projectepicfail
epicfail48 is offline  
post #8 of 14 Old 12-10-2018, 04:50 AM
Senior Member
 
hawkeye10's Avatar
 
Join Date: Feb 2015
Location: Murfreesboro, Tn.
Posts: 1,057
View hawkeye10's Photo Album My Photos
My question has always been kiln dried VS air dried lumber. Should you always buy kiln dried lumber or will air dried be okay. I have read that some woodworkers prefer air dried lumber. I have heard just about everything.

Don in Murfreesboro, TN.
hawkeye10 is offline  
post #9 of 14 Old 12-10-2018, 07:47 AM
Wood machinist
 
difalkner's Avatar
 
Join Date: Nov 2011
Location: NW Louisiana
Posts: 3,439
View difalkner's Photo Album My Photos
Dry is dry regardless of the method. I think the advantage to kiln drying is the much shorter timeframe for drying and that it kills off any fungi and critters. But 8% is 8%, at least in my book. YMMV...

David
NoThankyou and Brian T like this.

David

Curly Wood Shop on Etsy
David Falkner - Woodworking YouTube channel
Our music at church - current videos Airline Baptist BC Facebook Live
Romans 3:23
difalkner is offline  
post #10 of 14 Old 12-10-2018, 09:37 AM
Senior Member
 
TomCT2's Avatar
 
Join Date: May 2014
Location: Central PA
Posts: 1,246
View TomCT2's Photo Album My Photos
.... dry is dry ....

there are exceptions. actually, in my experience most seem to be exceptions with a few non-exceptions.

suppliers who work in a big hurry dry it hot and quick in a kiln. they get the "surface moisture" content down (as measure by prong type instruments) or they get the "average moisture" down (as measured by destructive 'oven bake' weight methods.)

however the wood has not had time to reach the "dry state" in equilibrium. which shows up in the KD pretzel shapes one finds at the big box stores. basically the surface has been "over dried" to a depth of ? but the core wood beyond that is not dried to nearly the 'spec' -

it takes times for moisture to migrate through wood so that it reaches a stable moisture content throughout it's thickness. not every lowest cost supplier does that 'right'
TomCT2 is offline  
post #11 of 14 Old 12-10-2018, 09:43 AM
Senior Member
 
Join Date: Aug 2012
Location: British Columbia, Canada
Posts: 5,162
View FrankC's Photo Album My Photos
How wood is dried, kiln vrs air, will also effect the working properties of the wood, however best practices in construction must be followed in any case.
Tennessee Tim likes this.

Wise men speak because they have something to say; fools because they have to say something -Plato

FrankC
http://sawdustmaking.com
http://woodworkerglossary.com
FrankC is offline  
post #12 of 14 Old 12-10-2018, 08:46 PM
Sawing against the Wind
 
Tennessee Tim's Avatar
 
Join Date: Dec 2010
Location: God's beautiful hills of Middle Tennessee
Posts: 2,381
View Tennessee Tim's Photo Album My Photos
Quote:
Originally Posted by NoThankyou View Post
I have been told (Meaning I don't know if it is really true or not.) that in Colonial New England that birch dowels were used in the granite quarries to knock out big chunks of stone. The dowels were dried to as close to 0% moisture content as possible. Then these dowels were forced into the holes drilled in the granite. Finally water was allowed to permeate the birch dowels. The dowels would expand enough to break the granite loose. In winter time water was used for the same task and as it froze the result was the same.
TRUE and in the South it was used also in the hard limestone we have. IF I'm not mistaken , one elderly man told me dogwood wedges were the TOUGHEST!!!

Quote:
Originally Posted by epicfail48 View Post
You know, ive always heard the same anecdote and wondered just how true it is. In my head, theres no way that the wood would be capable of expanding with enough force to crack granite, we use dynamite for that for a reason. On the other hand, i dont know a thing about stone quarries
It WILL !!! LOL!!! I have a few stones in front of this house that have the hand drilled holes that they split by.

Quote:
Originally Posted by hawkeye10 View Post
My question has always been kiln dried VS air dried lumber. Should you always buy kiln dried lumber or will air dried be okay. I have read that some woodworkers prefer air dried lumber. I have heard just about everything.
There's NOTHING wrong with either, nor even GREEN ....IF you know the proper techniques to apply with them.. the BIG SECRET.....there's NOT much to very little difference, IT'S ALL about proper joinery and knowing how/how much it's possibly going to move.

Quote:
Originally Posted by difalkner View Post
Dry is dry regardless of the method. I think the advantage to kiln drying is the much shorter timeframe for drying and that it kills off any fungi and critters. But 8% is 8%, at least in my book. YMMV...

David
LOL!!!! YES and NO!!! 8 is 8......NOT, it depends on how you get there!!!

Quote:
Originally Posted by TomCT2 View Post
.... dry is dry ....

there are exceptions. actually, in my experience most seem to be exceptions with a few non-exceptions.

suppliers who work in a big hurry dry it hot and quick in a kiln. they get the "surface moisture" content down (as measure by prong type instruments) or they get the "average moisture" down (as measured by destructive 'oven bake' weight methods.)

however the wood has not had time to reach the "dry state" in equilibrium. which shows up in the KD pretzel shapes one finds at the big box stores. basically the surface has been "over dried" to a depth of ? but the core wood beyond that is not dried to nearly the 'spec' -

it takes times for moisture to migrate through wood so that it reaches a stable moisture content throughout it's thickness. not every lowest cost supplier does that 'right'
BINGO!!! Pretty good quick explanation...LOL!!!!

Have a Blessed and Prosperous day in Jesus's Awesome Love, Tim
........www.TSMFarms.com.......... John 3:16-21 ..........
Reveling God's awesome beauty while creating one of-a-kind flitches and heirlooms.
Tennessee Tim is offline  
post #13 of 14 Old 12-10-2018, 10:19 PM
Wood machinist
 
difalkner's Avatar
 
Join Date: Nov 2011
Location: NW Louisiana
Posts: 3,439
View difalkner's Photo Album My Photos
I agree, Tim. It depends on how you get there. In my case I know my sawmill kiln dries the Walnut I regularly buy and I know how long it takes. He has a solar kiln and it generally takes about 4-6 weeks per inch to get down around 8% - 10%. I know that's a lot different from large operations where they all but microwave the wood to get it in/out as quickly as possible. So yes, in that case 8% may not be like the 8% I usually buy. But I didn't want to go into that much detail earlier... LOL!

David

David

Curly Wood Shop on Etsy
David Falkner - Woodworking YouTube channel
Our music at church - current videos Airline Baptist BC Facebook Live
Romans 3:23
difalkner is offline  
post #14 of 14 Old 12-11-2018, 04:50 PM
Recycled Member
 
Brian T's Avatar
 
Join Date: Nov 2018
Location: Magnificently mountainous McBride in the Robson Valley
Posts: 321
View Brian T's Photo Album My Photos
It's probable that the pyramids in Egypt were stone quarried with dowels and water.
The hydraulic forces are substantial.. as wood swells when wetted.


Grab ahold of a fence post and tear it in half with your bare hands.
Water evaporation can do it without anybody's help.


As eveybody says, the wood is very slow to respond to drying conditions.
Instead, great forces might be building inside if you rush things.
I can't help but wonder if kiln-drying woods for fine furnishings is really such a good plan.
Brian T is offline  
Reply

Quick Reply
Message:
Options

Register Now



In order to be able to post messages on the Woodworking Talk - Woodworkers Forum forums, you must first register.
Please enter your desired user name, your email address and other required details in the form below.

User Name:
Password
Please enter a password for your user account. Note that passwords are case-sensitive.

Password:


Confirm Password:
Email Address
Please enter a valid email address for yourself.

Email Address:
OR

Log-in










Thread Tools
Show Printable Version Show Printable Version
Email this Page Email this Page
Display Modes
Linear Mode Linear Mode



Similar Threads
Thread Thread Starter Forum Replies Last Post
Scrap wood - any value SpringWind General Woodworking Discussion 9 08-11-2018 04:57 AM
Wood movement in bench top NOLAwoodwork General Woodworking Discussion 5 10-18-2017 12:40 PM
Learning about wood movement. jaystus General Woodworking Discussion 3 03-19-2017 09:19 PM
How long does it take for wood movement to crack in cross-grain glued panel? RichO General Woodworking Discussion 8 11-29-2016 12:51 PM

Posting Rules  
You may post new threads
You may post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is Off
Trackbacks are Off
Pingbacks are Off
Refbacks are Off

 
For the best viewing experience please update your browser to Google Chrome