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How dry is dry ?

Started by bama20a, January 26, 2013, 09:14:37 AM

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bama20a

I've got some Cherry that was cut, I know at least 15 years ago.
Anyway it is in my shop (unheated or cooled),If I was to have indoor furn-build with some of it what kind of problems am I likely to have.
I was thinking to build a desk from it. Thanks Mark,,,,,,
It is better to ask forgiveness than permission

metalspinner

If it's been in your shop for a month or so, it should be acclimated. Stickering it in the shop will help move it along a little faster. Eventually, all wood will acclimate to its existing environment.  If the wood is built into a piece of furniture, it will still acclimate. 

Designing the furniture so the wood can move will keep it from splitting as the wood shrinks and swells over the years. Floating panels in frames and table tops with "sliding" hardware connections are just a couple of building techniques.


I do what the little voices in my wife's head tell me to do.

4430jd

I have found out that after many wood working projects, that putting a good sealer on both sides of the wood pevents any problems. I saw my own lumber with a Woodmizer Lt 15, air dry ( cherry,walnut, oak and ash) 1" per year.

WDH

If your shop is not heated or cooled (mine isn't either), then you will get a little shrinkage if you build the project in the shop, then bring it inside.  You can plan for that shrinkage in the design, paying close attention to cross grain situations.  If the grain is all oriented the same way, it will generally all shrink about the same and you will be OK.

Here is a maple sewing cabinet that I made my wife.  It was built out of air dried lumber in my unheated or uncooled shop.  I allowed for shrinkage in the design.  You can see where the top and sides shrank a bit looking at where the trim meets the back.  The trim was cross-grain to the top.  The top and sides shrank about 1/8 of an inch. 



  

Since the top and sides had the grain oriented the same way, it all shrank as a unit. Still, I used z-clips, also called tabletop fasteners on the underside of the top so that the top could move independent of the sides.  The z-clips fit into biscuit slots on the sides and are screwed to the top.  If the top moves more than the sides, the clip will move in the biscuit slot to accommodate any movement.  This pic shows the underside of the top with the z-clips.



  

Here is the completed piece after being in the house about 2 years. 



 

Ideally, if you plan well, you could bring all the lumber into your house and sticker it in an out of the way place for about a month, and it will acclimate to your house.  However, if you take it back to the unheated or uncooled shop to build the piece, and that takes a month in your spare time, it will re-gain the moisture that you so diligently worked to lose.  There are no free rides or instant pudding  :).  You always have to plan in wood movement in the design to account for seasonal changes in moisture content.  Kiln dried lumber is great if you can store it in a climate controlled environment and build your piece in a climate controlled shop.  Unfortunately, I cannot, so I have to find ways to use air dried lumber with a design that accounts for the wood movement that will occur.  It is a challenge, however.
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

Axe Handle Hound

WDH's advice is very solid and if you follow it you'll have a great end result.   In my opinion, people have been taught to be afraid of using air dried lumber, but without real justification.  Advance planning can alleviate the concerns over wood movement and brushing a finish on a project built of air dried walnut is a definite "WOW" moment for any woodworker. 

SwampDonkey

I've used both air dried and kilned. The kilned I have used is set in a warehouse that is unheated so really not much advantage over my air dried lumber sitting in the barn. It moves with the moisture gradient like any other wood. Design for movement as stated.

Nice cabinet there WDH. I like maple. :)
"No amount of belief makes something a fact." James Randi

1 Thessalonians 5:21

2020 Polaris Ranger 570 to forward firewood, Husqvarna 555 XT Pro, Stihl FS560 clearing saw and continuously thinning my ground, on the side. Grow them trees. (((o)))

WDH

Good old red maple.  I actually love working with red maple.  It is not as "soft" as most people think.
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

Tree Feller

Building to accommodate wood movement is a good practice, even if the wood is kiln dried and kept at the kiln-dried MC during construction. When the RH changes, the wood will move regardless of how or how much it was dried.

Consider also the environment where the completed furniture will live. If you build with wood at 12% MC and put the furniture in a home that gets down to 20% RH in the winter (not unusual in northern climes), that equates to a 4.5% MC. On a flatsawn, 12" wide Cherry board, the total shrinkage is 1/4". That's a lot of movement to tolerate, regardless of construction methods used. It's almost a given that problems will occur.

I'd say the first order of business is to determine the current MC of the wood and compare that against the seasonal RH of your home. (if you don't know it, a hygrometer is cheap and readily available at home centers, Radio Shack) Then, you will know how much movement to plan for and if it is too much. The wood is probably at a lower value than wood that is air-dried outside because inside an enclosed barn, it doesn't see the near-100% RH that it would outside. The same thing is true of your shop, even though it is not climate controlled.

I've corresponded a couple of times with Garrett Hack, a well-known furniture maker in Vermont who works exclusively with air-dried lumber. He brings the lumber into his shop when it has reached EMC outside and let's it acclimate and dry even more...usually to around 8% MC. (his shop is heated in winter)Then he builds furniture from it. His opinion is that one can build with 10% MC lumber and accommodate the movement but it's not easy. Like WDH wrote, there are no free rides.
Cody

Logmaster LM-1 Sawmill
Kioti CK 30 w/ FEL
Stihl MS-290 Chainsaw
48" Logrite Cant Hook
Well equipped, serious, woodworking shop

WDH

I tested some red oak I was going to use for wainscotting.  I stickered it behind the couch from April to September.  The equilibrium M% was 9.5%.  Attached is the excel file.  I need to do this for the winter too.
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

bama20a

Thanks everyone for the replys,Sorry I haven't responed sooner,But I've just come in,been gone for a week.
Tree Feller: You was saying about it being air dried outside,It was for around 10 years with just a top on it,I've had it in my shop for about 5 years now,It is some fine looking wood,I've planed down some of it just to see,I't does look GOOD, Although some worm holes are there, Mark,,,,
It is better to ask forgiveness than permission

Tree Feller

Quote from: bama20a on February 02, 2013, 02:12:05 PM
Thanks everyone for the replys,Sorry I haven't responed sooner,But I've just come in,been gone for a week.
Tree Feller: You was saying about it being air dried outside,It was for around 10 years with just a top on it,I've had it in my shop for about 5 years now,It is some fine looking wood,I've planed down some of it just to see,I't does look GOOD, Although some worm holes are there, Mark,,,,

What I said, perhaps not clearly, was that the EMC inside your shop is lower than it is outside, even though your shop is not heated/cooled. Chances are the wood is ready to work right now.

10 years outside will not get it any drier than a year outside will. It reached EMC well before even a year was elapsed. Seasonal changes in RH is the only effect on the dryness from that point onward. It's the same with inside your shop. Once the lumber reached EMC...probably within a few weeks, it was not going to get any drier.

As you observed, leaving wood outside to dry for extended periods doesn't do much of anything except invite more critters to munch on it.
Cody

Logmaster LM-1 Sawmill
Kioti CK 30 w/ FEL
Stihl MS-290 Chainsaw
48" Logrite Cant Hook
Well equipped, serious, woodworking shop

bama20a

Thanks Tree Feller: Another question, Once I do decide what to build out of it,If I was to cut it down to rough size & bring it inside of the house, ( I've got a man cave well sort of ;D),Would that help any? & If so, how long shall I leave it in there before use?
It is better to ask forgiveness than permission

Ianab

What's the difference between your inside and outside humidity? That's what affects how wood moves.

In this part of the world it's pretty much similar, but in colder climates there can be a big difference between the outside air and the heated air inside a house. In that case it may be better to bring the wood inside and sticker it for a couple of weeks to let the moisture equalise.

Also, if you have attic space you can store some wood there, and it will stay similar to internal moisture levels, and so be ready to use as needed.

Otherwise, as long as you take normal seasonal movement into account when building stuff, it wont move a LOT as it adjusts anyway.

Ian
Weekend warrior, Peterson JP test pilot, Dolmar 7900 and Stihl MS310 saws and  the usual collection of power tools :)

Tree Feller

Quote from: bama20a on February 02, 2013, 03:10:29 PM
Thanks Tree Feller: Another question, Once I do decide what to build out of it,If I was to cut it down to rough size & bring it inside of the house, ( I've got a man cave well sort of ;D),Would that help any? & If so, how long shall I leave it in there before use?

It's hard to give an exact time without knowing the MC of the lumber and the average RH of your home but I'd guess around two weeks. Just realize that even though you acclimate the lumber to your home environment, it will re-acclimate to your shop environment during construction. There's not much remedy for that unless you want to tote the lumber and project from the shop to the house every night until it's finished.

You don't have a location listed but the RH is probably lower now than it will be in the warm months. That means that the biggest movement will probably be expansion. Plan for that in your construction methods and you should be fine.

FYI - if you are going to be doing much future woodworking, I'd suggest you get a decent moisture meter. If you know the MC of the lumber and keep track of it as it acclimates, it sure removes a lot of guessing about when to use it. A hygrometer for the shop is a good idea, too, and they are pretty inexpensive.



Cody

Logmaster LM-1 Sawmill
Kioti CK 30 w/ FEL
Stihl MS-290 Chainsaw
48" Logrite Cant Hook
Well equipped, serious, woodworking shop

WDH

Managing M% is quite the challenge when building furniture. 
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

SwampDonkey

Wood, even when it's dead it still moves no matter how many whacks you hit it on the head with a hammer. :D
"No amount of belief makes something a fact." James Randi

1 Thessalonians 5:21

2020 Polaris Ranger 570 to forward firewood, Husqvarna 555 XT Pro, Stihl FS560 clearing saw and continuously thinning my ground, on the side. Grow them trees. (((o)))

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