Acclimating Wood

[tablesawtom]

I am going to respond to several posts here. And yes I understand butcher block, but I didn't know they were self healing and other things, learned, something. But most cutting boards I see are laminated long grain. And that is what most people think is butcher block even though both you and I know the difference. But the whole post revolves around Photobug's post about a butcher block style project. I assumed it was for a work bench top which is not what he said. My misunderstanding. But the question is about acclimating wood. My answer is still the same whether it is actual butchery block or a laminate., Because it will first be a laminate until the boards are shortened to become butcher block with the end grain being the primary surface. Again the post is about acclimating wood and not about process.

It looks like Photobug's  shop is in the basement although he didn't say. My shop was in my basement for the first 35 years.  And here in Iowa  one has to run a dehumidifier in the basement for over half a year. I get that.
My shop is now about a mile away in a building. But I do have a good quality bench top table saw, and a good sliding cut off saw in the single stall garage. And yes I do have to back out my wife's 69 Pontiac convertible mussel car out of the garage if I want to use them. A lot of times I will go over to my shop just to cut a board rather than move her car out, do what I have to do, and then clean up the mess and put the car back in. I really feel for the woodworkers who share a garage with a car. I feel I am very fortunate not to have had to deal with that setup on a long term basis.

 So garage, basement, different parts of the country and even different species of wood all share different problems with wood. Humidity being the major problem, Back to with Photobug's original question, hence percent of moisture.

And finally , covering all by bases, is the fact that most of you work for a living. If married and have children you have another set of circumstances concerning your hobby. And all of these things compete for your shop time. I used to joke that one can tell when there is prosperity in a household. dad got a new pair of work shoes. shop time come last. So what I am saying is that one can start on a project, life gets in the way and it maybe a week or two before one can  get back to it. In other wards a week end project may take 3 or 4 weeks to complete.

Please let my know if I am about on target with things that effect the hobbyist woodworker in general. I am not trying to be arguementive, just to level the playing feel because it plays apart in all of my previous answers. I know I am debating against a long standing notion that all wood related problems are cause by moisture. And that one has to let wood acclimate before working with it, although some will differ on how the wood has to be stacked. 

Tom

[tablesawtom]

Next on the list is there is a difference between air dried and Kiln dried. Three is also a difference between hard wood and construction grade lumber, both have different grading scales, kind of like apples and oranges, both are fruit in name only, different application.  

I do not like to deal with air dried because I would not like to get mixed up and put some of each in the same project. Which leaves kiln dried. It is my understanding that kiln drying does 10 things to wood I don't remember all 10 but it stiffens the board, kills all the bugs and remove's all excess moisture from the wood. It is my understanding that it even removes the moisture from the cells and the only way to get it back in the cells  is to reheat the wood and surround it with steam and leave it of the entire time it took to remove it in the first place.  6 to 8 percent is the norm and it become unprofitable to try to do better, the law of diminishing returns.

Since the question is about moisture content then is stand to logic that the wood has to take on moisture. But it is fiber moisture and not total wood moisture. And moisture like heat,  it travels from greater to lesser and with  heat, the greater the temperature difference, the faster the the heat flow.  And the transfer slows down as they get closer to equalization. The same it true with moisture. Remember the old commercial , Bounty the quicker picker upper. 

Have to close will be back.

Tom

[Petertaylor]

John said, “The best options are to either let the wood fully acclimate to your shop or use it as soon as you get it home. Using wood with large gradients in MC almost always turns out badly.”

Here’s my experience this week.  A carpenter brought me some clear wood from the lumber yard. I don’t know what species, but not hardwood. The boards were 1x12x12, and 1x8x12.  He asked me to make some 3’ x 4’ panels and then do some edge routing. Time was of the essence, so I cut the boards to four-foot lengths, then added dowels so they would fit together and be flat while clamping with glue.

It was 45 degrees in my garage, so everything went to the basement for the glue-up.  In the morning when the clamps were removed, the individual boards within the large panels had cupped!  Lots of sanding was required before the edges could be routed. Perhaps the boards at the lumberyard had been in a stack and began to dry when lifted out.

[MichaelMouse]

Next on the list is there is a difference between air dried and Kiln dried. Three is also a difference between hard wood and construction grade lumber, both have different grading scales, kind of like apples and oranges, both are fruit in name only, different application.  

I do not like to deal with air dried because I would not like to get mixed up and put some of each in the same project. Which leaves kiln dried. It is my understanding that kiln drying does 10 things to wood I don't remember all 10 but it stiffens the board, kills all the bugs and remove's all excess moisture from the wood. It is my understanding that it even removes the moisture from the cells and the only way to get it back in the cells  is to reheat the wood and surround it with steam and leave it of the entire time it took to remove it in the first place.  6 to 8 percent is the norm and it become unprofitable to try to do better, the law of diminishing returns.

You could benefit from a bit of time reading Forest Products Laboratory -- Forest Service -- USDA l (fs.fed.us)  

Which is, in large part, a work by the same Hoadley referenced elsewhere.  Hardwood/softwood definitions to start, because you seem confused. Kiln drying is another thing.  You'll also  learn air dry and Kiln dry lumber at equilibrium are pretty much equal, assuming a competent kiln operator, as it's easier to ruin the wood in a kiln than stickered in the barn.  Bound and unbound moisture is an important concept, as is hysteresis.  

Anyway, read the handbook.  It's paid for, and you'll get a better handle on reality.

To follow up on butchers' blocks, knives spread the fibers on the surface rather than slice, and they close back up.  Also, in the old days they were scraped to remove excess meat/fat nightly, then salted.  Not Mortons, but salt which attracts moisture expanded to close any endgrain gap left by a too aggressive chop.  They would eventually be scraped lower in the work area, but the use involved far exceeded any home use.

[tablesawtom]

I am not confused about hard wood and soft wood. They are different species and are process under different grading scales. Air drying will only take you to about 15 percent moisture content. If a person was to store the wood properly stickered high up in a barn or a garage with a loft and no insulation where the temperature can reach a prolonged temp of at least 120 degrees , which can't be done because of the cooling of night time temperatures then 05 store it for 3-5 years then they could be equal. You are also saying that it is not a good idea because to many people can't dry wood properly.  To witch I say that people who make there living operating saw mill and kilns have to do it properly or they will be out of business. 

So I ask you hard wood is hard wood and soft wood is soft wood and they are  processed to different standards, What part of that don't you understand. Maybe you should read your own hand book. 

Why can't some of you really read  and I mean read for understanding at what what is really written instead of finding fault where there is none.  Read all the posts not just the last on and not just flying off the handle at my last response. And I didn't bring up butcher block the original poster did. I found a statement interesting but I have never made a putcher block piece of wood and I do not intend to ever make one so I don't really care about how it is preserved. Don't you dare put that on me.

And I would like to tell you what you can do with your previous book because I am not going to worry about 2 percentage poinst when it braking down lumber. and when glue is applied the moisture is increased and changes everything. That is why bisques can telegraph through when not done properly. 

Do what you want to do , I can't help you.

Tom

[photobug]

It looks like Photobug's  shop is in the basement although he didn't say. My shop was in my basement for the first 35 years.  And here in Iowa  one has to run a dehumidifier in the basement for over half a year. I get that.
My shop is now about a mile away in a building. But I do have a good quality bench top table saw, and a good sliding cut off saw in the single stall garage. And yes I do have to back out my wife's 69 Pontiac convertible mussel car out of the garage if I want to use them. A lot of times I will go over to my shop just to cut a board rather than move her car out, do what I have to do, and then clean up the mess and put the car back in. I really feel for the woodworkers who share a garage with a car. I feel I am very fortunate not to have had to deal with that setup on a long term basis.

 So garage, basement, different parts of the country and even different species of wood all share different problems with wood. Humidity being the major problem, Back to with Photobug's original question, hence percent of moisture.

For the record my shop is in a two car garage.  Except for storing household supplies it is dedicated to the shop space only.  For the last 17 years I was traveling and working and had a cheap tablesaw and a chop saw, I would wheel the tools and work outside whether it was snowing or sunny out.  Even with an enclosed shop I still do as much outdoors as I can, initial break down, sanding, planeing, etc.

I went ahead and started processing the wood and it has remained flat after a few days back in the shop.

[MichaelMouse]

I am not confused about hard wood and soft wood. They are different species and are process under different grading scales. Air drying will only take you to about 15 percent moisture content. If a person was to store the wood properly stickered high up in a barn or a garage with a loft and no insulation where the temperature can reach a prolonged temp of at least 120 degrees , which can't be done because of the cooling of night time temperatures then 05 store it for 3-5 years then they could be equal. You are also saying that it is not a good idea because to many people can't dry wood properly.  To witch I say that people who make there living operating saw mill and kilns have to do it properly or they will be out of business. 

So I ask you hard wood is hard wood and soft wood is soft wood and they are  processed to different standards, What part of that don't you understand. Maybe you should read your own hand book. 

1.  Hardwood is not necessarily "hard wood," nor are softwoods all "soft woods."  Basic concept of deciduous or coniferous species divides them.  Use the terms properly, or sound uninformed. 
2.  Air drying will get you to any moisture content depending on the relative humidity in the environment. That's what dry kilns do, lower the relative humidity of the air.  Some - dehumidification kilns - don't even heat the air to do it.  Good kiln operators follow a routine which brings the wood down slowly, to avoid checking, stressing or "case-hardening."  The humidity is often elevated in the final stage by introducing steam to reduce that stress.  
3.  As I type this, the furnace is pumping warm air on me, the furniture, and the wood stored in my basement.  I look at the humidistat on the wall and see it's a human-comfortable 50 %.  If it stays that way, wood will descend or rise to ~8.5%.  Won't stay, of course, because the air that's heated to 68 degrees today started out at 65% RH according to IBM.  As winter sets in, that will drop considerably, and without adding much beyond human/canine respiration, interior will go to ~30% here.  Wood will follow to 6%.  Those in the south who use air conditioning to suck moisture out of the air can do the same.  
4. Hardwoods (proper term) are indeed graded differently than softwoods.  You'll find the standards by googling the proper term now that you know it.

FWIW, 4/4 hardwoods harvested in winter here and stacked/stickered outdoors with a cover, will be at ~10%MC by the end of September, when I take them into the basement.  By January they'll be at that 6%, and possibly below, depending on how cold it gets outside.  Safe to use in furniture.  Your location will vary, but only within the reality in the handbook you want to read.

[jteneyck]

1.  Hardwood is not necessarily "hard wood," nor are softwoods all "soft woods."  Basic concept of deciduous or coniferous species divides them.  Use the terms properly, or sound uninformed. 
2.  Air drying will get you to any moisture content depending on the relative humidity in the environment. That's what dry kilns do, lower the relative humidity of the air.  Some - dehumidification kilns - don't even heat the air to do it.  Good kiln operators follow a routine which brings the wood down slowly, to avoid checking, stressing or "case-hardening."  The humidity is often elevated in the final stage by introducing steam to reduce that stress.  
3.  As I type this, the furnace is pumping warm air on me, the furniture, and the wood stored in my basement.  I look at the humidistat on the wall and see it's a human-comfortable 50 %.  If it stays that way, wood will descend or rise to ~8.5%.  Won't stay, of course, because the air that's heated to 68 degrees today started out at 65% RH according to IBM.  As winter sets in, that will drop considerably, and without adding much beyond human/canine respiration, interior will go to ~30% here.  Wood will follow to 6%.  Those in the south who use air conditioning to suck moisture out of the air can do the same.  
4. Hardwoods (proper term) are indeed graded differently than softwoods.  You'll find the standards by googling the proper term now that you know it.

FWIW, 4/4 hardwoods harvested in winter here and stacked/stickered outdoors with a cover, will be at ~10%MC by the end of September, when I take them into the basement.  By January they'll be at that 6%, and possibly below, depending on how cold it gets outside.  Safe to use in furniture.  Your location will vary, but only within the reality in the handbook you want to read.

That is absolutely correct.  You don't need a kiln to dry lumber to whatever % moisture is needed to make furniture in your area of the country/world.  Where I live in the NE air drying outdoors will bring the wood down to 12 - 14% moisture.  If I cut 4/4 wood in the Spring it will be down to that range by Fall.  8/4 will be down to 18 - 25%, depending upon the species; by the following Summer it will be down to 12 - 14%.  In any case, once it gets down to 12 - 14% it's not going to dry any further unless you bring it into some location with a lower RH.  I use two low temperature kilns, but a basement or other conditioned space works fine, too, it just takes longer.  

The advantage of kiln drying is it's faster, reduces defects in the early stages of drying (which can be a big problem with uncontrolled air drying), and commercial kilns can heat the wood to 140F near the end of the cycle which kills any bugs in it.  Beyond that it doesn't matter how you get the wood down to 6 - 8% moisture, or whatever is the appropriate range for where you live.  

John