“The oft-repeated advice of arranging boards with the growth rings in alternating directions is nonsense. If your stock is stable and flat at the begining, it will tend to stay that way. If it is still gaining or losing moisture when you assemble it, it will likely warp. “
Found this on the “Popular Woodworking” site and wondered if this was true. Any comments?
dlb
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The undisciplined life is not worth examining.
Replies
Oh Boy!
This ought to be a goodun. Could make it well past 300 posts!
I agree with Mr. Frid. Let the posts begin!
Regards,
Bob @ Kidderville Acres
A Woodworkers mind should be the sharpest tool in the shop!
Edited 4/2/2007 9:08 pm ET by KiddervilleAcres
Brings up a good point - What is the largest number of replies to a posting? Maybe this post will break the record! But more importantly I hope to gain, & hope that others gain valuable insight into this problem. It seems that all we can really do is try to minimize movement as we will never completly stop it.
The undisciplined life is not worth examining.
Edited 4/3/2007 9:00 am ET by dlb
Edited 4/3/2007 9:02 am ET by dlb
As long as the stock acclimates in my shop, and it always has time too, I always arrange strictly on appearance.
I go strictly by the most astheticlly pleasing arrangement of the boards and never have a problem.
The key is acclimation, low moisture content, and species. I work in walnut, hard maple and cherry. Those species are a flatboarders best friends.
Bill
Do you typically glue up your tops/panels from the widest boards you can find, or multiple narrow boards. I'm going to be making a pair of end tables that will be 20" wide and I am hoping to make both tops from the same mahogany board that is almost 11" wide. I've heard that the figure is what to go for, and don't pay so much attention to the growth rings. Tom"Notice that at no time do my fingers leave my hand"
I've only done one wide glue up. I used two 10" sections of the same board for a small tabletop glue up.
I used walnut and had no problems.. the table is still in our gameroom where the kids use it for everything from homework to board games.
Thanks, Bill. Tom"Notice that at no time do my fingers leave my hand"
Alternating growth rings on a table top is New Yankee Workshop nonsense. I doubt that Norm even worries about it anymore, as he has learned much about wood since his first few seasons.
The critical factor is making sure that the wood is at equilibrium with your workshop, and is given the proper amount of time to acclimate. Also, following some simple rules during the milling process, like removing the same amount of wood from each side of the board, help tremendously in avoiding warping.
A common mistake in making table tops is glueing one up, and when dry, laying it on your bench before closing up shop for the night. Only one side of the top is exposed to fresh air, and it dries out a little more than the unexposed "side down", and the table warps. Stickering it and allowing it to have air circulate around both sides, and it won't move.
Just a couple issue's to avoid. There are many others. I'm sure this thread will bring most of them out.
Align your stock for aesthetics, and pay attention to the characteristics of wood, and you'll be fine.
Jeff
Well, Before anyone answers this, they should first ask themselves the question. How much do you care about your work? Do you look at it as your legacy like having children? will this be the essence of you when you are gone? How do you regarded others perception of you, through the work that you do?
Do you really think that simply acclimating a bit of lumber to the conditions of your shop for a few weeks after you bring it home from the supplier is enough to stabilize it for eternity? Ha Ha Ha. Get real. I am afraid that most readers on this forum have a misconception of what stabilizing to EMC really means, and how easy the hard knocks of life have a way of kicking the cr**p out of that term.
I have had architects insist that I do something their way, after it resisted , and had them sign off on releasing my responsibility, and had them call only a year or two later with problems. The humidifier system quit during the dead of winter, and not only did my doors split, 100 year old murals shed about 10% of their image from the shrinkage of the wood under brittle paint.
How much furniture do you think has been totaled in Florida, and over through Louisiana over the last few years. You can NOT think only in terms of a STABLE environment FOREVER. If you care about your work, then you MUST think about movement forever after.
OK. Just to say alternate the growth rings is only the tip of the iceberg. It is partially true, but there is so much more than that, I am not sure a chapter is enough. A thorough understanding of the relationship of tangental / radial ratios, then incorporating that into the curves of the annual growth rings gets very complicated.
I thought I was a pretty good professional woodworker for about 30 years before I started working green, and got a sawmill before I really learned to appreciate how it all comes into play.
So, If history has taught me anything, it should be assumed that the wood will always be susceptible to a swing in the MC. EMC only hold true under perfect circumstances in a perfect world. If you think that is where you live now, great, but when you look into your crystal ball, tell me how it looks from where you are, keeping in mind energy shortages, and exploding population growth.
I completly agree with your assesment of the question. When starting any project the first thing that think of is wood movement. And I know that after I mill up the timber and built the piece that over time it is going to move. You can't stop that, so why not take every precaution to eliminate as much of that movement as you can. But to just think, Oh that's not going to move on me. I have let it sit and reach EMC it's all good from here on out, is just a sign that you don't truly understand the medium in which they are working.Kaleo
http://www.kalafinefurniture.blogspot.com
Keith,
As you know,there is a difference between acclimatising wood before building, so that it is not in motion while you are cutting and fitting joints, and providing for long-term seasonal movement in your construction techniques.
Further, in my experience, most wood moves a lot more in its initial seasoning from green (saturation) to dry (equilibrium) than it does thereafter. There are always exceptionally unstable species, (hard maple for instance) unstable pieces (like reaction wood), and unusual circumstances (attic or cellar storage, transporting from Seattle to Albuquerque). As you say, with care, these can be avoided, worked around, or planned for.
A while back I worked on a desk that had been built in moist England, shipped to humid South America, and then moved to Northern VA. It did well til its first winter in a centrally heated home, when it basically fell to pieces. Should we think less of its builder, long dead, because he did not provide for such a globe-trotting future for his furniture? How about the stuff that got to take a swim during and after Katrina? Are the makers to be condemned for "allowing" the drawers of their chests to swell shut, and hide glue to dissolve, after being filled with water?
It is really impractical to make allowance for much more than "normal" seasonal movement, plus a margin of safety, for normal furniture. Otherwise, a lot less furniture would cost a lot more, making it a lot less accessible for the folks that use it. That is how standard procedures and rules of thumb evolve, to allow for a practical balance between affordability, and durability. After all, we are just building furniture, the future of mankind does not hang in the balance on the design decisions we make.
As an aside, I've been reading both "The Wheelwright's Shop", and "The Nature and Art of Design", one of which describes the change from time honored practices to modern innovations in a dying trade (wagon making), which is in essence an elegy on the death of a craft that was very labor intensive, and linked very closely to the natural world. The economic changes wrought by capitalism after WW I were the cause of the demise of that way of life, in the writer's opinion. The other book's main contention is that economy (cost) is the primary force affecting design decisions. Fascinating swirl of ideas, and there are parallels that can be drawn in our time, about our craft.
Regards,
Ray
Myth.
There's nothing you can do to stop wood movement, but this isn't the solution either. Rather than be slightly cupped it would be wavy? Doesn't seem like a good solution either.
It seems to me that in Bob Flexners Finishing book he makes a reference to how a tabletop will cup in the long run. It's always up towards the source of moisture (table tops are wiped down etc), regardless of grain orientation.
Lots of old furniture was made with wide planks, which of course would preclude any switching grain orientations.
I recall the article that Buster2000 mentioned in post #9. I think he pointed out that the planks in a wood deck all cup upwards regardless of their grain orientation (mine sure do). His contention was that the differential due to moisture applied to table tops (in cleaning and use) was likely the cause of cupping rather than changes in moisture content from humidity.
dlb, this is an old and ongoing debate. As others have alluded to, and I agree with, there is no 'right' or definitive answer. There are a whole host of factors to consider.
For instance, the quote you provided that has the blanket statement that boards should not have the growth rings alternated is, I believe, also nonsense. It's nonsense because it fails to account for production methods other than high quality bespoke craft furniture. For a mass production factory making hundreds of solid wood panels in one large batch this alternating of growth rings can make perfect sense. It doesn't always make sense, but it can.
As (I think) Keith alluded to in his post a book could be written on this subject. If not a book, certainly a series of chapters, something I'm in the middle of doing.
Here is just a short list of some subjects a woodworker needs to get their head around before your question can get a well reasoned and considered response:
A common piece of advice is to allow purchased wood to acclimatise to the workshop prior working it, e.g., making a solid wood panel. Does this make sense if the wood you've purchased is at 7.5%MC and your workshop is going through an extended period where it experiences an average RH of 75%? The wood will eventually acclimatise to these conditions and reach an EMC of about 14.5%. Let's say you use this 14.5%MC wood to make a table top intended for a modern house.
Modern houses typically experience RH values of between about 40% and 60% (here in the UK.) You'll get somewhat different numbers in other parts of the world, e.g., Arizona or in intermittently used holiday homes on Gulf Coast Texas. And who says that a piece of furniture will only experience modern house conditions? What about long term storage in a damp store, or a move to a very dry part of the world?
Wood that experiences seasonal RH values between 40% and 60% normally swing between about 7.5% and 11.5% MC. So gluing up panels out of wood that measure about 14.5% MC at construction time means they will shrink once put into service. Then the question relates to the effect that tensile shrinkage forces have on the glue lines as the panel shrinks, as well as what distortion might be induced by that shrinkage.
Might it not have been better in the circumstances described above to glue up the panel from the wood as soon as it was purchased and measured approximately 7.5% MC in a relatively damp workshop? There is good evidence that glue lines survive better when experiencing compressive forces as the panel expands in width to suit a higher RH than they do when they experience tensile forces induced by shrinkage.
I suspect all I've done here is create more questions than answers for many visitors to this forum, but I think they're questions and subjects a serious woodworker will find worth thinking about.
Anyway, I probably won't be able to contribute to this thread again for a couple of weeks after this post. I'm about to pack my bags and get away from work for a fortnight. Funnily enough I'm heading off to that climatic hell-hole known as Texas to catch up with the American side of the family. That means a surfeit of gnats pee ice cold beer, too much sun and humidity, huge gas guzzling environmentally unfriendly trucks, near free gasoline (even if it's up to $4 a gallon), and the motto that goes something like, "Bigger isn't always better--- but it is bigger," ha, ha-- ha, ha, ha. Slainte.
Richard Jones Furniture
Edited 4/3/2007 7:30 am by SgianDubh
Richard.. call me when you get to town. That promise of ice cold beer still stands.
Bill 713-252-1134
Thanks Bill. Will do. Slainte.Richard Jones Furniture
Hi dlb,
It's not true.
I'm trained in traditional cabinetmaking according to a centuries old guild-based system, and the accepted trade wisdom is, indeed, that boards are alternated cup-up and cup-down.
The boards do move with changes in humidity, even if they're properly acclimated in a workshop prior to starting out.
I'd also wonder how many people join quartersawn boards correctly in the higher end work, ie: heartwood side to heartwood side and sapwood edge to sapwood edge. This is because the heartwood and sapwood change thickness differently with changes in air humidity, and if they're mismatched, you end up with a perceptible ridge at the glue line that comes and goes.
However, the part of the statement that says your boards move more and your furniture ends up out of square badly if you use improperly seasoned timber in the first place is indeed correct.
I'd wiped out this post by accident twice before posting and note that RJ had posted in the last ten minutes, so I'll apologise in advance for the hastily worded reply and possible repetition of others' advice.
Cheers,
eddie
edit:
the accepted wisdom here is heart side up on a back sawn board at the edge of the panel also, as the final shrinkage of the timber means that the panel cups down and hides any gap between the table rail and the table top.
If you're building in a dry environment and shipping to a humid one, this would not work, and the table top would be reversed, ie: heart side down.
Edited 4/3/2007 5:30 am by eddiefromAustralia
The first part is absolutely true, but the last part about gaining and loosing moisture makes no sense; lumber never stops taking on or giving off moisture. I never bought into the idea of alternating the growth rings, and after I became more aware of the effects of it on the finished piece, I became dead set against the practice. Wood is much like carpet, in that it appears to change color depending on the direction from which it is viewed, in wood this is called the reflectivity. Flipping pieces to alternate the growth rings almost guarantees the reflectivity will be an issue. I wet the wood with water or paint thinner and look for the best orientation with regard to reflectivity. I also avoid book matches for this reason. The attached photo shows the top of a curly maple bureau, viewed from opposite ends; you can see how much difference there is in the intensity of the curly, depending on the direction it is viewed from. Think of the poor appearance the top would have had if the reflectivity had been ignored.
Since stopping moisture changes is nearly impossible, so it has to be lived with, by detailing the joinery and finishing properly.
Rob Millard
http://www.americanfederalperiod.com
You're so right Rob, that top would have looked quite awkard if half of it had shown curl and half didn't when viewing from one end and then it would have swapped from the other side. The way you put it together is the only reasonable way. In this case you can't have it both ways. All we need to do now is add a bit more Norm bashing into this thread and it'll get big numbers for sure.RonEdited 4/3/2007 8:44 am ET by Ronaway
Edited 4/3/2007 11:38 am ET by Ronaway
OK, c'mon let's stir up this pot and get her roiling!
Rob, I agree with you completely, unless of course I were making a washboard! In that case I would alternate the grain on very thin boards to get the waviest surface possible. Also mist one side so it would really roll!
Regards,Bob @ Kidderville Acres
A Woodworkers mind should be the sharpest tool in the shop!
I've always assumed that the boards would still cup, but if they were alternated one would cup upwards, the next downwards, there by offsetting the problem. The results would be a wavy top as opposed to a half moon top if they all cupped the same direction. But, I've never been naive enough to think that this would stop the wood from moving.Woody
I am with those who say "Go with what looks good and ignore the alternating-grain myth."
On several occasions I have forgotten (what I know is necessary) and left a glued-up top on a bench without stickers. The top always cups - in one large "U", up or down depending on the change in humidity. If the "alternationg" theory is valid, why doesn't the top 'bend' with the grain in a wavy pattern?
Frosty
Frosty, Gaining a little moisture on one face of a homogenous material link MDF will cause the same results. That is not the same as changing the MC all of the way through the whole top.
OK. Good point.I've never had any problems with any of the many tops I've glued up - always with regard to grain match, not the alternation process. But - my projects have stayed in the same city for many years - however, humidity swings in SE Michigan are considerable from winter to summer.Whoops! I just remembered a piece I sent to my son in Florida. No problems over the last five years. I guess luck is more important than technique.Frosty
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