Here is the problem: everyone agrees that timber to be used on furniture must be as dry as possible, preferably at 7% to 8%. The only way any of us who do not live in Death Valley or the Gobi Desert can get wood that dry is to kiln dry it. Yet most of us don’t have kilns or even room for kilns. So, we must buy dried wood or have it dried. However, if we want to buy economic quantities, we have more on hand that will be used in a couple of days. In the mean time, the unused wood will equilibriate to our shop or storage shed humidity. This is usually fairly close to the MC of air dried wood stored under the same conditions.
SO, how the heck do we get dry wood? Isn’t is a waste of money to buy kiln dried wood that will be stored in non-airconditioned and heated space?
Joe
Replies
The advantage of kiln-dried wood is not that the endpoint moisture content is any different; the advantage is that you get there faster and more reliably. The hard part of drying is getting the vast bulk of the water out of the wood; this is the part of the process that kiln drying speeds up. Once you've gotten down to the 10-12% range, the remaining acclimatization to indoor humidity levels usually takes only a couple of months to get "close enough."
I don't think that it's correct to say that wood used for furniture should be as dry as possible. It should certainly be dry enough that it's somewhere close to the expected range of MC fluctuations in its final resting place. But air-dried is usually close enough for that. What's important is not that the wood be bone dry, but that you know what the actual moisture content is, and build accordingly.
-Steve
Edited 3/10/2008 12:30 am ET by saschafer
Joe,
Kiln drying vs. air drying comes down to economics for the most part. You might think that the energy costs and the repayments on the investment in a kiln would make kiln drying more expensive, but for many operations it is not so. A typical kiln cycle might take 30 days to complete. Compared to air drying for let's say, 2 years, the economics starts to swing in favor of the kiln. The air drying operation, in my theoretical example, would need 24 times the inventory and the space in order to equal the turnover of the kiln.
Either way, once the wood has been dried to 8% or so, it will acclimate itself to whatever conditions are present, as you say. That's exactly what we need.
There are a few notable cases where the end results are quite different, such as walnut which really appreciates air drying. On the other hand European beech gets its reddish tint from a shot of steam in the kiln, and therefore cannot be air dried to the same end result. But commercially speaking, these are just interesting footnotes.
So in fact your conundrum doesn't exist. Buying air dried lumber would be (in general) more expensive than the kiln dried which you are getting now.
David Ring
http://www.touchwood.co.il/?id=1&lang=e
Indeed, what you and Jeff say makes perfect sense. My frustration was that I constantly read about an 8% to 9% ideal that I can't possibly achieve. I allow for movement when I build, but have always wondered if I would be better off if my lumber was at that ideal -- which I can't reach. Anyting I store is going to be at 11% to 12% within a month or two.
Of course, once it all goes into a climate-controled environment, it will drop back to about 8%.
Joe
Edited 3/10/2008 10:01 am ET by Joe Sullivan
Joe
I have been building almost all of my furniture using air dried wood (never seen a kiln) for almost 10 years now. For the species I work in, mainly cherry, maple, and walnut, it is no problem at all. However, when I need a load for a piece, say 100 bf or so, I remove the rough timber from my drying shed, and sticker-stack it in my shop for a good month to 6 weeks ahead of time. My shop is humidity controlled in the summer with dehumidifiers (2), and the shop acts as the final kiln. When the wood is at equilibrium with the shop, which is close to the humidity level of a home, it is ready to build with.
You do not have to put the wood into a "kiln" to get it properly dried. Stress free moisture removal is what matters most. Air drying just takes longer.
Jeff
PS The key word to all that bs I just blurted out is "equilibrium". That's all that really matters.
Jeff has it right on.<!----><!----><!---->
"Stress free moisture removal is what matters most" this is really what kiln drying is all about.<!----><!---->
the other part is this.<!----><!---->
Most wood machines nicely at 7% MC.
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Up the moisture content to 10-12% and you will get tear out where you would not get it at 7%. This is normally not an issue for hobby type stuff. But for commercial operations who run lots of wood and produce cookie cutter parts it’s a big deal.
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I have run large batches of wood for paneling and it does make a difference when you hit a wet board. Regardless of grain direction wet wood does not machine or work as nicely as wood at 7%.
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Wood that is to dry also suffers from a machining point of view. Get it to dry and it will splinter and tear. It’s really hard to get it to re-absorb moisture and it takes a long time.
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That all said I use air dried for almost everything unless I can’t get it. It’s difficult to get African mahogany logs in <!----><!----><!---->Minnesota<!----><!---->.
sleepy,
Not being picky but is it true that wood gives off moisture faster than it absorbs it once it is dry? Also, is wood that is too dry susceptible to burnishing/burning too?
Regards,Bob @ Kidderville Acres
A Woodworkers mind should be the sharpest tool in the shop!
"is it true that wood gives off moisture faster than it absorbs it once it is dry?"
No Bob. Wood generally gets wetter faster than it dries. There are some general proviso's and conditions that have to be met for that to be the case, but it's generally that way.
Let's say some wood goes from 7% MC to 12% MC in four weeks due to increased RH, ie, from about 40% RH to ~60%RH.
Return the wood to the original RH conditions, ie, 40% RH and it will take longer to get back down to 7%MC, perhaps a week or three longer.
It's all a bit theoretical and requires controlled conditions, and we haven't even looked at moisture gradients in the wood, but that's close enough without getting too technical. Slainte.
Richard Jones Furniture
Edited 3/12/2008 3:04 pm by SgianDubh
Richard,
Return the wood to the original RH conditions, ie, 40% RH and it will take longer to get back down to 7%MC, perhaps a week or three longer.
OK, you just hit upon the part I don't understand, I think. :>) This is going to sound really dumb but.......... Hey I'm an old fart, what can I say, I need to take this one step at a time.
Suppose I have wood that is @ 7% MC. Are you saying that if left in 40% RH it will stay @ 7% MC?
Regards,Bob @ Kidderville Acres
A Woodworkers mind should be the sharpest tool in the shop!
"Suppose I have wood that is @ 7% MC. Are you saying that if left in 40% RH it will stay @ 7% MC?"
Yes. There or thereabouts: within a percentage point either side of 7% anyway. Some woods get a little drier at that RH and some stay a little damper. But 6.5% to about 7.5% MC is where most wood species end up if they're kept at a constant 40% RH.
However, there are almost no places where RH remains constant. It's changing all the time, so the theory only properly applies in specified and controlled conditions, perhaps, for example in particular museum conditions, or special storage situations,... or a controlled experiment, something like that anyway. Slainte.
Richard Jones Furniture
Edited 3/12/2008 3:24 pm by SgianDubh
Ok, now I get it. Sorry for being such a do do bird about this.
Regards,Bob @ Kidderville Acres
A Woodworkers mind should be the sharpest tool in the shop!
One of the things that confuses people is that relative humidity of the air and moisture content of the wood are both measured as percentages, but they're not the same thing. They are, however, related, although temperature also plays a role. There's a table in the Forest Products Laboratory's Wood Handbook that shows the humidity/temperature/moisture content relationship (it varies somewhat from species to species, but not much). Some representative values at 70°F:
RH
MC
20%
4.5%
30%
6.2%
40%
7.7%
50%
9.2%
60%
11.0%
70%
13.1%
The moisture content varies a few tenths of a percent as you go up or down in temperature, but the temperature-related component is pretty small overall.
-Steve
Here's an extract from something wot I writ that I take into account when making panels. Others might find it useful. Slainte.
"There is another important characteristic of wood movement to take into account when creating furniture parts. A solid wood panel made up of edge jointed narrow planks, e.g., a table top, raised and fielded panel in a frame, cabinet top, etc, will experience tensile stresses across the wood grain and the joints as it shrinks, and compression forces as it expands. The cross grain structure of the wood, and the joints, are both better able to survive under compression forces than they are under tensile forces. In this case a table top glued up of planks at about 13%MC during construction will shrink when put into drier RH conditions. A typical house in the UK exhibits about 40%RH during the winter. This equates to wood eventually reaching about 7.5% EMC. The panel is at some risk of splitting as it shrinks.
On the other hand consider the case of a glued up panel made with planks that are 7%MC at the time of making. During the summer, when internal UK house RH values are approximately 60%, it will expand as the wood moves towards 11.5%MC, which represents its EMC at that RH. Here, the joints and grain experience compressive forces, which are less likely to cause grain or joint failure. Subsequently the panel will experience seasonal change over its entire life and will expand and contract to suit. The tensile forces and compression stresses within a panel will alternate as the seasons pass and it settles into a routine where the joints are usually able to withstand these stresses and survive very well. But, importantly, joint failure during the first year of an edge jointed panel’s life in service tends to happen most commonly when the wood shrinks after construction rather than when it expands. As a general rule of thumb it’s safer to glue up wide panels of very dry wood (6% - 7%MC) than to use damper wood, e.g., 12%- 15%MC. (See also Sections 7, 7.1, 7.2 and 7.3)"Richard Jones Furniture
Richard,
I'm sure I'm overlooking something here, so bear with me. Other than stating the obvious, i.e. that a panel will more likely split from shrinkage than while undergoing swelling, why is it more likely that a panel will split upon its first shrink cycle (if built in high humudty), than upon subsequent ones (after it has first swelled, as a panel) over its lifetime? That is, assuming that the movement is not restrained?
I can see that if 1) the shrinkage is restrained- as by a glued crossgrain batten or "clamp", of course the panel will be likely to split when it it tries to shrink, or 2) if, built dry, and swelling is restrained, compression set may cause cracking/checking upon the subsequent drying cycle, or 3) the glue-up was compromised (dirt, freezing, out of date adhesive), the first test of glueline strength may prompt a failure.
But what in your experience has caused you to (if I read your post correctly) advocate doing panel glue ups only in periods of low humidity?
Ray
Ray, it's a result of the effect of hysteresis. Hysteresis means a lag, eg, a time lag or, in another example, the difference between wood drying from, say 13% to say 7%, and the reverse, ie, gaining moisture from 7% to 13%. Wood experiences both these forms of hysteresis.
The time lag hysteresis refers to the fact that wood doesn't immediately change size when it's to subject to changes of RH, either higher RH or lower RH.
Dry a piece of wood from green to 15% MC and at that point the width is, let's say 250 mm. Continue drying until it's 7% MC and the width at that time could realistically be 245 mm. Let the wood regain moisture until it's returned to 15% MC, and the chances are it won't be quite back to 250 mm. It might only be 249.8 mm.
Subsequent redrying to 7% will take it back to 245 mm, the same as before. Raise the MC again to 15%. It will measure 249. 79999 mm, or something almost immeasurably smaller than 249.8 mm.
In other words once the wood has gone through the first drying and moisture regain cycle the size differential hysteresis effect is minimised. Hence, in panel glue ups the initial shrinkage due to moisture loss causes slightly greater tensile stress on the glue joints than subsequent shrinkage a year two into the shrinkage and expansion cycle. Greater stress, however small, equals increased risk of joint failure.
It's particularly the case if you're fond of using air dried woods that have never seen 7% MC since the tree was felled. Less so in kilned wood that at some point was kilned to 7% MC.
I hope I managed to explain that clearly enough. Let me know if not. Slainte.
Richard Jones Furniture
Edited 3/13/2008 4:34 am by SgianDubh
Thanks Richard, for the explanation. Seems we are literally splitting (heh, heh) hairs here, especially if the wood one is building with has sat in the loft for more than one change of seasons. Hysterical over hysteresis? Or histrionics? Lets hope not.
In examining old work, it is apparent that over the years, more shrinkage has occurred, than swelling. This may be due to the effects you've lined out, but I believe moreso a result of the overall lowering of relative humidity in our living spaces(summer and winter) by central heating/ air conditioning, since the mid 20th century.
In preparation for the upcoming celebrations on the 17th, I've laid in a supply of Guinness ( a six course meal), and for dessert, a bottle of that elixir, Irish Mist (I get misty, whenever it's near). I recently heard of a drive to make St Patrick's day an official holiday here in the states. Is it as big a deal in the UK? Somewhat surprising was the revelation that corned beef and cabbage was seldom, if ever on the Irish table, as it is "the" dish to serve here on the great day. Guess that green beer wasn't often on the menu in Blarney, either...
Erin go bragh,
Ray
"In examining old work, it is apparent that over the years, more shrinkage has occurred, than swelling."
I wonder if that's just an artifact. Put a piece of wood in compression cross-grain, and there is little if any visible evidence of anything going wrong. Put that same piece of wood in tension instead, and it will crack.
-Steve
steve,
You may be right. Experience is, after all, anecdotal. However, in an attempt to salvage my statement:
I've seen more loose drawer fronts than sticky ( swollen) ones, other than repairs due to recent flood/water damage.
Ditto loose cockbead repairs on same. Always too long on the ends of the fronts, never too short, when you pull them back down.
More breadboard ends protruding past table tops, battens past desk lids, than vice versa.
"Round" tops, and turned spindles gone oval due to shrinkage, than the opposite.
Solid end cases where the drawer bearers have pushed the backboards off when the ends shrank, not pulled loose and flopping around inside from swelling of the ends.
Drawer bottoms that have pulled out of their grooves in the fronts, rather than showing damage to the backs from swelling- dovetails sprung apart, bowed backs.
Door panels that have pulled out of their grooves than have pushed the frames apart.
I have gotten the rare call, in the height of summer humidity, to come and open a tall clock door, drawer, or chest lid, that is inexplicably "locked" without a key being available, so it does happen. But not often.
Ray
You have a vaild point Ray. Old stuff was made from air dried wood (as it was) went into houses more akin to a decent shed with intermittent heating, and therefore higher average RH all year. Old houses today have been insulated and climate control added. Modern houses are generally even better insulated with even better climate control. Therefore the old stuff dries out more today than it did even 50 or 60 years ago, and certainly more than it did 100 or 200 years ago.
Also the hysteresis effect regarding change in dimension across board width and thickness is a bit like many a brand new coil spring or a cushion. When new, both a coil spring and a cushion are a certain size. Compress both to a smaller size and release the pressure. What happens? Neither quite returns to their original size, and never will again. Similar effects have been noticed in various measuring instruments for instance, and other media.
Does wood behave the same way? Yes it does to a small measurable amount. Wood cells that have become very dry and therefore somewhatdistorted never fully return to their original size and shape if rewetted. Close to their original shape and size maybe, but they never revert to where they started when they were at fibre saturation point (fsp) or above Slainte.Richard Jones Furniture
Hey Ray,
This whippersnapper sounds like a young R. Bruce Hoadley, using all them fancy words like, somewhatdistorted!
Almost sounds like he knew what he's talkin about ya reckon?
Can't wait to get the book Richard. How close are ya?
Regards,Bob @ Kidderville Acres
A Woodworkers mind should be the sharpest tool in the shop!
"using all them fancy words like, somewhatdistorted!"
That's just fatfinger syndrome (sic) and lack of proofreading before posting Bob. You didn't mention my other new word, ie, "vaild" in that post did you.
There's a bit to do yet on my manuscript. I've three or four sections to complete. I've set a deadline for this summer/autumn. I'm getting a bit tired of it, especially as I've been piddling around on the job for nearly three years. I have far too much other work to do to devote all my energies to the job, so it's a slow and sometimes very frustrating process. Slainte.Richard Jones Furniture
Hang in there Richard,
Who knows, you may become famous for your literary talents and woodworking may become your hobby instead.
Looking forward to the book. Of course I will get an autographed first edition but don't you be charging extra for the autograph. :>)
Regards,Bob @ Kidderville Acres
A Woodworkers mind should be the sharpest tool in the shop!
in general that is true. the tree is a lot better at getting water into the wood than the air after you cut it. it takes a lot of water to bring the wood back up and it takes a long time. I have never had wood that was too dry; but I have talked to people that have had it happen; like with rafter drying and solar kiln drying. it only happens to them once because it basically destroys the wood.<!----><!----><!---->
I put shelix heads on my jointer and planer; I can't believe I ever used a straight blade cutting machine. So I don’t care about MC as much as I used to.<!----><!---->
you guys should read this one. <!----><!---->
http://www.woodweb.com/knowledge_base/Techniques_for_Equalizing_and_Conditioning_Lumber.html<!----><!---->
wood web has tons of great info on sawing and drying.<!----><!---->
Gene Wengert-WoodDoc is one super wood guy.<!----><!---->
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I'll offer some tidbits from a boatbuilder's perspective of working with higher moisture contents that are generally contrary to what furniture makers experience, and you may find them interesting:1) Wood density affects moisture content significantly when mixing softwoods and hardwoods. In a typical wet winter here, outdoor cedar can be at 12% while the White Oak adjacent to it will be at 19% MC.Given a choice between Doug Fir and White Oak in below-waterline framing on moored boats than remain wet, DF is often a better choice simply because it remains drier in service. DF is significantly less rot resistant than WO but spends less time in service below the 20% MC threshold required for rot. WO can reach 30% MC in a submerged keel, while DF rarely reaches 20%.2) Shrinkage from 30% to 20% MC isn't as linear as the shrinkage from 15% to 8%. Don't use furnituremaker's online linear algorithms like "The Shrinkulator" when working with boat wood. Use the USDA tables.3) Wood can certainly be too dry, especially planking stock. Plank a boat tightly in a relatively dense and unstable species like DF using kilned lumber at 7% MC, place it in an environment where the below-waterline planking rises to 16% and the above-waterline 12%...and if the swelling doesn't break every frame in the boat, the planks will experience severe "compression set" from plank edge damage and the boat will be a permanent weeper and leaker after periods of low humidity and maintenance time ashore.A practical application:http://www.woodenboat.com/forum/showthread.php?t=76449Order of Stability in Riftsawn Boat Wood Species - Percent Shrinkage Green to Oven Dry as an Indicator of Relative StabilityNorthern White Cedar Radial 2.2 Tangential 4.9 (R+T)/2 3.5
Honduras Mahogany 3.0 4.1 3.5
Khaya 2.5 4.5 3.5
Redwood, 2d Growth 2.2 4.9 3.5
Western Red Cedar 2.4 5.0 3.7
Eastern Red Cedar 3.1 4.7 3.9
Atlantic White Cedar 2.9 5.4 4.1
Eastern. White Pine 2.1 6.1 4.1
Teak 2.5 5.8 4.15
Incense Cedar 3.3 5.2 4.25
Alaska Yellow Cedar 2.8 6.0 4.4
Purpleheart 3.2 6.1 4.65
South American Cedar 4.0 6.0 5.0
Iroko 4.0 6.0 5.0
Sassafras 4.0 6.2 5.1
Okoume 4.1 6.1 5.1
Spanish Cedar 4.2 6.3 5.25
Black Cherry 3.7 7.1 5.4
Black Spruce 4.1 6.8 5.45
Tamarack 3.7 7.4 5.55
Baldcypress 3.8 6.2 5.6
Port Orford Cedar 4.6 6.9 5.75
Dark Red Meranti 3.8 7.9 5.85
Black Locust 4.6 7.2 5.9
Sitka Spruce 4.3 7.5 5.9
Sapele 4.6 7.4 6.0
Douglas Fir 4.8 7.6 6.2
Longleaf Pine 5.1 7.5 6.3
White Ash 4.9 7.8 6.35
Black Ash 5.0 7.8 6.4
Yellow Poplar 4.6 8.2 6.4
Rock Elm 4.8 8.1 6.45
Slash Pine 5.4 7.6 6.5
Apitong 4.6 8.2 6.5
Light Red Meranti 4.6 8.5 6.55
Black Walnut 5.5 7.8 6.65
Tangile 4.3 9.1 6.7
Western Larch 4.5 9.1 6.8
Angelique 4.6 8.2 7.0
Ipe 6.6 8.0 7.3
White Oak 5.3 9.1 8.0
Live Oak 6.6 9.5 8.0
Greenheart 8.8 9.6 9.2
Edited 3/13/2008 1:15 pm by BobSmalser
PS The key word to all that bs I just blurted out is "equilibrium". That's all that really matters.
That is the key.
One thing that has not been mentioned that deserves a bit of consideration is make it a rule to mark Air Dried and Kiln Dried if you inter-mix. You might pile some wood together and use them in a hurry at some point like I did. Not good. The pins and dovetails on that project did not meet a few days later. Lesson learned.
Additionally, the color and working characteristics of AD vs KD is important. I like to carve AD wood. In my shop, I work a bunch of hard curly maple for longrifles and half-stocks. I start with 12/4 wood. I am on a 4 year cycle. I am collecting wood today for 2012. It sounds like a pain but its not that much trouble. You get accustomed to the schedule. The end result is wood you can count on. Very few surprises in my experience.
Color is also important to some woodworkers. AD and KD walnut just don't look the same. Currently, I am building 3 desk/bookcase projects. All of the stiles and rails are quartersawn AD stock. The color and stability are pleasing to the eye. In my case, I want the sticking to be even and not draw the eye from the wild figure of the panels.
Its all AD and like you said- there's good equilibrium and some slack for the little surprises.
dan
As you stated, the only time of inconvenience for starting the collection of useable air dried stock is in the beginning. I started using my own milled lumber about 10 years ago. It took a few years, but since, I've almost never been without plenty of lumber to choose from for jobs. Once in a while, I'll run short, and need to buy some KD stock. I can never, ever find stock equal in color and vibrancy, as well as character, as I can in my own wood shed.
Keeping the wood shed filled, and replacing what you use each year with freshly milled logged will always provide plenty of workable stock to use.
I do not give a rats a$$ about utilizing every square inch of every board. I choose boards, always from the same tree, to build pieces with that have the necessary characteristics of the wood to make the piece stand out. If I rip off and toss 2 1/2" of cherry into the fire, sobeit. Having plenty of self milled stock on hand to choose from allows for a little extra scrap for the wood burner.
Jeff
PS Here's some tables I made with some air dried cherry flitched slabs. The grain is beyond what you can find available at a wood supply house, at least around here.
No question - you have the key in hand. The patterns and intent are obvious to me.
Of all the woods that I am most dissappointed in when I go to a wood supplier its cherry. Here in NC the cherry is impossible to match and the boards are not very wide. I haven't found a 14" clear cherry board in years. You know the drill.
dan
Don't fret. By the end of this year, I'll have several thousand board feet of wide cherry flitches on hand for sale. We'll shpek on it later.....
;>)
Jeff
Put me on the list.
As said, 7-8% is not an absolute. What you want is to have your wood acclimated to the environment within which you are building or where it will ultimately reside.
I live in coastal North Carolina. My average summer relative humidity is 75-85% therefore my wood will acclimate to about 12-13%EMC during the summer. Indoor relative humidity in my house is about 50% so once I build it, I can expect it to dry out to about 8%EMC.
Howie:
Our outdoor and indoor MC are about the same as yours. I always assumed it woud be better to build with wood at 8% because that is where it will go indoors. Of course, I have never had the luxury, because my storage is not conditioned.
J
Joe,
Actually no, almost nobody agrees that wood should be as dry as possible, wood should be at the equilibrium point with the humidity in your shop, so that it won't be changing shape as you work with it.
Later, when the wood is part of a piece of furniture, it will almost certainly gain or lose moisture, especially if it is poorly stored in an attic or basement, or moved to an area with a much different climate, so the the piece will have to be designed to allow for wood movement or it will self-destruct.
Neither of the above two observations are changed by whether or not the wood is kiln dried. Kiln drying is done primarily for the economics of the lumber business, there is nothing magical about it, or the 8% moisture figure, it is just a common standard.
John White
John:
I am relieved by the answers including yours. Around here, 8% wood in the shop is an occasional accident. I have done a lot of carpentry, and a limited but decent amount of real cabinet/furniture work. As my skills improve, I reach a bit with each new project. Was afraid that at some point, the lack of "dry" wood would stop me. This bit of paranoia came from the many magazine articles I have read in which 8% or so is cited as a sort of standard.
Joe
Hi John,
wood should be at the equilibrium point with the humidity in your shop, so that it won't be changing shape as you work with it.
So given the above, at least the woodworker can come close to allowing for movement knowing what conditions the final piece will experience, yes?
Regards,
Bob @ Kidderville Acres
A Woodworkers mind should be the sharpest tool in the shop!
It is much, much, better to have the wood stabilized to the shop conditions before you start. You can, in theory, calculate how much more a tenon will shrink for instance, but you can't use that information in a practical sense to make the joint fit better, and wood when it shrinks, sometimes warps and that is best discovered before construction begins. Also resawing wood that still has moisture to lose will almost always lead to cupping in the resulting stock that must be allowed to equalize before the resawn boards can be used. You can use the knowledge that the components of the piece will later shrink or expand to allow for enough room around the edges of panels in their frames and the like, but for the actual construction a stable wood MC is a real advantage.John W.
John,
Perhaps I misled you, sorry. I always let the stock acclimate to the woodshop as you suggested before. I was thinking about during the parts creation phase as you addressed in your last paragraph. Just wanted to make sure.
Thanks,Bob @ Kidderville Acres
A Woodworkers mind should be the sharpest tool in the shop!
I misunderstood, but no harm done.Having the wood stabilized to your shop conditions allows you to reliably know which way the wood will be moving in the future so you can leave the appropriate amount of room for the wood to expand and contract. When the wood is quite dry, during the winter here in Vermont, I know that the wood will only be expanding in the future so I leave little extra room for further shrinkage and most of the room for expansion when fitting the panels in their grooves for instance.John W.
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Indeed, Bob, I have considered that, but there is resistance from my roommate of 28 years, SWMBO.
J
Of course, the bigger question is "What is Bob doing buying Hershey's chocolate syrup by the case?"
I have so little room in what passes for my shop that I store the bulk of my wood in a 10x20 rental storage unit. A fair amount of room, but no climate control.
-Steve
Hmmm.
I had better not let my 10-yr old see that and get the idea that chocolate syrup CAN be bought by the case. Life as I know it would end.
Bob- That seems to be what folks think. I just built countertops out of oak, all of which is at about 13%. I went to elaborate trouble to give it expansion and contraction room -- but far more for contraction because the eventual drop from 12% to 8% across a 24" top will mean significant shrinkage.
The worry, though is about what happens with high-finish case work. I can frame and join moderately well. I can make boxes with floating raised panels a la the 17th century and before -- although with less skill, of course. But what happens with later work. Say, just for duscussion, that an 18th century highboy was built out of 13% wood. With all those tight joints and wide expanses, is it just going to crack once it goes into the house?
J
Hi Joe,
With all those tight joints and wide expanses, is it just going to crack once it goes into the house?
That depends. Now there's a decisive answer for ya, but without knowing how it was/is constructed............. Assuming traditional construction methods of the 18c. I would guess yes.
You know it's going to move with seasonal cycles right. I would guess one question is what's going to move most? The top, sides/ends and the back of the piece right? I think if construction is such that this movement is not restricted there shouldn't be a problem.
I'm just trying to think it through and maybe the brain is all wet/dry! To me it seems that with varying widths of the components they are going to expand/contract in varying amounts. That to me is the conundrum. If construction takes this into account then the pieces shouldn't crack.
Regards,Bob @ Kidderville Acres
A Woodworkers mind should be the sharpest tool in the shop!
I know that I have too much wood (assuming that's possible) when I start storing it in my bedroom, as I have done in the past.Chris @ flairwoodworks
- Success is not the key to happines. Happiness is the key to success. If you love what you are doing, you will be successful. - Albert Schweitzer
Here's the problem when your shop is damper than your house and your rough stock hasn't been stuffed behind an interior door long enough.
Those sweeping edges weren't part of my design:
Right. Just what I was afraid of. Oh well.
A couple of months ago I took 19 sizeable oak and walnut logs in to be sawn. Most are between 25 and 30 inches at the small end. I can't use that much wood in 20 years, and 20 years is plenty long enough for it all to equilibraite to about 12% or so.
Maybe SWMBO will relent. Hahahaha. Good one, if I do say so myself.
Joe
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