Piano Finders Tech Talk

Tech Talk with Kendall Ross Bean

Seasoning Pianos for Different Climates

Note: This is a reprint of parts of a discussion on the PianoFinders discussion board.

Question: Is it true...

Is it true that new Yamaha pianos shipped to the U.S. for sale are prepared specially for the North American climate? As opposed to say, pianos intended for sale in Japan). How can they possibly do this, seeing as we have so many different climates in the U.S.? What are the possible consequences of buying a so-called "gray market" piano (one originally intended for the Japan market and climate that has been imported to the U.S. for resale?) - 13 Oct. 1999

Answer: Yes, there are different season procedures...

Thanks for your question. It is an excellent one. I apologize for taking so long to respond, but I had to do some research. Like you, I had been hearing different stories from different (potentially interested) parties. Dealers of new Japanese pianos seem to have one position, and dealers and wholesalers of used (so-called "gray market") Japanese pianos another.

I decided to call Yamaha Corporation of America in Buena Park, CA and see what they had to say.

As a result of this inquiry I discovered that apparently, yes, there are different seasoning procedures for Yamaha pianos destined to be sent to the U.S., and different parts of the world.

I also have a request into Kawai for information regarding this same issue. Hopefully, I will be posting this info later, after I receive it. I did, however, get a good deal of enlightenment from Yamaha on this subject. Incidentally, the Yamaha spokesperson's biggest frustration, really, was that more people don't call them directly to get the real story. I understand, though, how some people might be reluctant to do so, because, similar to the way they may view the local dealer, they also may not consider the manufacturer to be completely impartial or candid. However, Yamaha seemed very willing to share the inside story and set the record straight.)

According to the Yamaha representative, there are indeed three different lines, or "processes" in the Yamaha production facilities, which he referred to as "wet," "dry," and "superdry." However, in addition, there are other significant differences between the pianos that are destined for the U.S. or Japan, or other countries, including such things as different stringing scales, and different hammer types.

The pianos that come to the U.S., he indicated, are from the "superdry" process or line. One of the major reasons for this is, he said, is our widespread use of both central heating in the winter, and air conditioning, in the summer, both of which tend to dry out the air, making for a more "arid" climate. (As opposed to Japan, where "open air" is more the mode.) Pianos destined for Japan (and Asia in general) are taken from the "wet" line, since Japan is an island and tends to be more on the tropical or humid climate side. Pianos destined for say, Europe, are taken from the "dry" line. (Of course, there are many nations, and many different climates, and the actual assignments (internally, at the factory, that is) of which pianos come from which lines is probably more complicated, he acknowledged.)

The fact remains, however, that, just like Asia or Europe, the United States actually has many different climates and even "micro-climates" within relatively small geographic areas. Our climates run to both extremes (arid, and humid) and the whole spectrum in-between. It is also difficult to understand how any piano manufacturer can compensate in advance for all possible climatic extremes that a piano might encounter. I suggest there are a few factors that should be kept in mind while contemplating how (and if!) this can possibly work:

1. Any piano, no matter how well its wood is seasoned, will ultimately have problems with warping, failed glue joints, loose tuning pins or soundboard cracks and/or compression ridges if exposed to an extreme enough climate. A piano whose lumber is seasoned or dried to a very low moisture content can have just as many problems if it ends up in Florida or the deep South (or other places in the U.S. which can get very humid) as a piano whose lumber is dried to a higher moisture content, and then sent to the Mojave Desert or one of the arid states such as Arizona or New Mexico.
2. No piano manufacturer can completely prepare a piano against humidity fluctuations or extremes it may encounter. A major factor of how a piano survives through the years is the amount, or degree, of care exercised by the piano's owner in protecting the instrument from extreme or adverse climate conditions. For anyone really serious about maintaining their piano in optimum condition, they should look into climate control systems for the instrument. (This may not be necessary if the person lives in a moderate climate where the humidity remains at a fairly constant median level. In either very dry climates or very humid ones, though, climate control should be considered more essential.)
3. New pianos "specially" prepared for the U.S. market can easily end up in worse shape than a used piano that was originally sold for and in Japan (which later ends up in the U.S.), simply because of adverse climate conditions, or lack of proper care, in the home, regardless of what the outdoor climate is. And due to the wide range of climates we have here in the U.S., it is possible that, under certain conditions, a piano that was originally seasoned for the Japan "climate", might be better off here than one that was targeted for a "dry" U.S. climate (which "dry climate" is far from universal, or even the rule here.) If Yamaha's objective, on the other hand, was targeting a theoretical indoor climate, represented by frequent use of air conditioning and heating, and a well-insulated home where the windows and doors are often kept shut, then they should be made aware that, just like in Japan, many Americans also believe in "open-air" living; and also many don't have air conditioning, like to keep their windows open, and/or rarely use the heater.
4. People do move to different parts of the country, and sometimes out of the country. They often take their piano and other furniture with them when they move, and pianos are frequently very treasured possessions. If Yamaha prepares the U.S.-targeted pianos for a dry climate, does that mean that people who buy such an instrument can't subsequently move it to a humid environment, and will have to either leave it, store it, or sell it? I'm sure that if this came out it would definitely make it less attractive for someone to buy a Yamaha piano, and I doubt that Yamaha, (or any other piano manufacturer for that matter), would support this idea, although it is implied by Yamaha's paradigm of different climates needing different seasoning procedures.
5. While manufacturers often like to think they have control over, or can predict, how the wood in their pianos will respond to different climates where they may be sent, the reality is that there is much about wood that is still not well understood, even by people who are very experienced with it. Facts and figures about drying wood to certain moisture contents with a target humidity or environment in mind may sound convincing to the lay person, and be fine in theory, but in the real world wood usually has a mind of its own, and tends to behave however it pleases, so it often defies predictions about how it will react to certain environments. For this reason certain vital parts of a piano are expected to, and frequently do, change dimensionally within a certain anticipated range: any piano tuner can attest to the fact that the soundboard crown goes up and down, and tuning pins become tighter or looser in the block due to seasonal humidity changes. Other parts of a (well-built) piano are designed to compensate for dimensional changes, so that any swelling or shrinking of wood components can be contained, allowing the piano to still function normally. All this has come to be expected, as a result of many years of experience building pianos. To suggest that a piano's wood can be controlled, even with local humidity control devices, or any sort of factory pre-seasoning procedure, so that it does not expand or contract at all, is unrealistic.
6. There are several things about the construction of pianos that tend to mitigate the effects of humidity changes on the wood. The fact that there is a thick polyester or polyurethane finish on most Japanese pianos, that tends to seal the wood off from, or protect it from extreme or sudden humidity changes, and the fact that the piano's soundboard and pinblock are usually also coated with some kind of finish also, both help to keep a piano's wood more dimensionally stable. (It is true that no finish completely seals wood off from humidity changes, but certain finishes can provide substantial insulation.) In addition, much of the wood in a piano is laminated, so that layers of wood overlaid over others help restrict or restrain each other from much dimensional change in the areas that matter. Even a piano's soundboard and pinblock are laminated. All these things may help explain why the "gray market" pianos (ones originally seasoned for, and intended for the Japan market and enviornment) have survived much better here than anticipated.

The Yamaha rep verified that there were problems with some of the first Yamaha pianos to be imported to the U.S., due to (according to Yamaha) seasoning problems (i.e. the wood not being dried enough at the factory for our climate), back around 1960. He also indicated, however, that Yamaha went to great lengths and expense to rectify the problems, often going so far as to send factory engineers and personnel out to the problem pianos to ascertain the causes and repair the instruments, ultimately ending up replacing the tuning pins in thousands of instruments. In 1963, the three different seasoning processes were reportedly instituted at the factory.

Communications from Yamaha Corporation of America regarding the "problem" pianos that were first sent to the U.S. in the early 1960's, (when Yamaha began exporting them here) seem to focus on loose tuning pins being the main source of difficulty, and state that most of those pianos sent here suffered loose tuning pins within the first couple of years. Officially this was attributed, by Yamaha, to be due to their engineers being unaware of the level of dryness that existed in the U.S. Yamaha contends that the dryness was due mainly to indoor conditions: the result of insulated houses, heating and air conditioning drying out the air in which the pianos were kept. Yamaha's expressed concern was that some of the pianos originally intended for the Asian climate (so-called "gray market" pianos that are currently being bought used in Japan and exported for resale in the U.S.) might exhibit problems similar to those first brought here in the 60's, before Yamaha's engineers had experience producing pianos for so-called "dry" climates such as ours.

The way the pinblocks and other wood in these 60's vintage Yamahas were seasoned may actually have been only part of the problem, or not as big a problem as it initially seemed. Over the years, many piano technicians have observed that Yamaha tuning pins seem to be somewhat looser than what they have come to expect in new U.S. pianos (especially ones made by Baldwin, which in recent years have had a reputation for having very tight pins). It is possible that this contributed to the initial complaint, as this may have been many technicians' first exposure to Yamaha pianos at the time. Unfortunately, we are not told how loose the the pins were in these first Yamaha pianos to be shipped here. Many assume they were not tight enough to hold the piano in tune, but this may not have been the case at all. They may simply have not been tight enough for the U.S. technicians, who very likely would have been the ones to first bring the problem to Yamaha's attention.]

To listen to some of the opposition to the "gray market" instruments, you might get the impression that these pianos would literally fall apart upon arrival here or shortly afterward, with soundboards caving in, pinblocks delaminating, and cases warping. Such has not proven to be the case. Incidentally, Yamaha's warranty relief for these pianos brought over in the 60's, that developed loose tuning pins, (and according to Yamaha there were thousands of these pianos) was simply to replace the tuning pins with oversize ones, a job that might take a technician or competent factory worker a day to complete. -No mention of soundboards or pinblocks being replaced, or pianos being sent back to the factory. Are these pianos still here? Yes. Are they still being played? Yes. Are they in any worse condition than pianos later specifically seasoned for the U.S. climate? Not from anything I have seen. ]

I will be posting more later on this subject as I learn more, but perhaps this will help to answer at least part of your question. So yes, from what I have been able to ascertain, there are currently definitely different wood seasoning and/or construction procedures used in the Yamaha factory for pianos intended for different destinations. Whether or not there is anything that could be construed as representing one universal "dry" climate here in the U.S., or whether the different Yamaha seasoning procedures are truly effective, or necessary, are entirely separate matters. It would be interesting and helpful to know to what moisture content, exactly, the wood for the different pianos is dried, and to what range of climate humidity Yamaha feels the pianos would best be suited, so that piano owners and potential buyers can have some idea about the ideal environment for their piano, rather than just being issued a blanket statement (assumption) that "these pianos are best for U.S. climate," -which, for reasons previously stated, is really far too broad a generalization. We have many humid climates here, some even bordering on the tropical, and it is simply not true that a piano pre-seasoned for an arid environment will do equally well in a humid one. In addition, piano owners have the choice today of several effective humidity control systems, and are much more knowledgeable about the effects of humidity and environment on their instruments than in years past. In my opinion they could definitely benefit from knowing in which circumstances they would need one for their Yamaha.

It is true that Yamaha makes different piano models with different stringing scales and features for different world markets, ostensibly because of different cultural preferences in piano tone and styling, among other things. (This is also true of Kawai). Again, we have the difficulty here of cultural stereotypes: i.e., Yamaha's U.S. piano buyers all live in a dry environment and all like one certain type of piano sound and one certain type of piano style, so we we will build all our pianos for them a certain way (when put that way it begins to sound rather incredible, doesn't it?)

If you don't enjoy being lumped in a group with everyone else, or stereotyped, it is possible you might actually prefer a Kawai or Yamaha that was intended for a different market than the U.S. I have played many pianos that were originally intended for Japanese consumption, whose tone I actually preferred over the U.S. targeted models. In this sense, Yamaha & Kawai may end up with much the same problem that Steinway has had with its Hamburg models, trying to keep the two markets separate. It is interesting to note that with the Hamburg Steinways as well, the rumor was that they would fall apart upon arrival here, not having been intended for our climate. But you would have to talk with a dissatisfied U.S. owner of a Hamburg Steinway about that, and so far, I've yet to find one.

Overall, my sense is that, based upon what I have seen from appraising, repairing, rebuilding and playing numerous pianos of both types over many years (both "gray-market" as they are called, and pianos originally intended for sale in the U.S.), the different seasoning processes are simply not as great a factor in the overall longevity of the piano as some dealers of new Japanese pianos would have you believe, especially given the fact that we have so many different climates here in the U.S. While proper seasoning is very important in the building of a piano, I truly haven't seen any of these so-called "gray market" pianos that has simply "fallen apart" upon arriving here; or, for that matter, any that have shown any problems other than what are common to used pianos everywhere. The major factor in how pianos survive, in any climate, seems to depend much more on how owners take care of them after they have left the factory.

P.S. Incidentally, the Yamaha spokesperson indicated also that if you call or e-mail them with the serial number of the piano, they can tell you the original intended destination of the piano, whether U.S. or Japan.

Answer: Reflecting on ramifications of attempting to season piano lumber...

18 Nov. 1999 I have not heard back from Kawai yet about this issue of different seasoning methods for pianos intended for different destinations, so I think I need to send them another e-mail or place another phone call.

In the meantime, I have been reflecting on some of the ramifications of this idea of attempting to season piano lumber differently for different climates. It seems it would be a good idea if indeed the manufacturer knew precisely what type of humidity the piano was headed for; but as previously stated, here in the United States we have so many different humidity conditions and climates that it would seem almost impossible to account for every circumstance.

For instance, one of the most critical areas of a new piano, as far as seasoning, is the wood used for the soundboard. Generally the soundboard is "baked", or dried to a very low moisture content before installation in the piano, lower than anything the piano (hopefully) would encounter in any intended destination. The reason for this is because the soundboard must maintain a certain curvature or "crown" as it is called. If, after installation and/or shipment to it's destination the soundboard continued to lose moisture content, or shrink, there is a danger that it might lose all of it's crown, and the piano would lose a good portion of it's tone quality. Hence, most manufacturers today tend to "overdry" or "overshrink" the board slightly, before installation, in order that the board will swell up again after installation, and hopefully maintain that curvature for a reasonable length of time (many years). Because the soundboard is restricted within the walls of the piano's case or rim, any taking on of moisture or expansion after installation will increase the curvature of the board, as the board has noplace else to go. (This is somewhat of a simplification, but it is true in general.) In other words, if push comes to shove, the manufacturer would rather have the soundboard swell up (curvature increase) after installation rather than shrink (curvature decrease). As we all know, soundboards are going to eventually lose crown over the long run any way, (and pinblocks lose their grip on tuning pins) as the wood continues to shrink ever so slightly over many years, so it's really all just a matter of time.

Now imagine that a manufacturer envisions sending his piano to a moist or wet climate. Perhaps he tries to compensate by not drying the soundboard to as low a moisture content, for fear that it would swell up too much after installation, and get, at the worst, undesireable things such as compression ridges and rib separations, even step fractures (similar to what the earth does when there is a fault), if the wood decides to swell beyond it's capacity. (Which is something that has happened on some new pianos, even of finer make, when the manufacturer baked the soundboards a bit more than they should have). On the other hand, if for some reason this same piano were sent subsequently to a very dry climate, the soundboard might continue to dry out and shrink, possibly creating cracks and loss of crown.

Now if a manufacturer envisions sending the piano, on the contrary, to a very dry climate, and dries the soundboard down to a very low moisture content before installation, lower than the dry environment he forsees sending the instrument to, then if the piano indeed ends up in a dry environment, all very well and good; but what if it ends up in a more humid or damp environment? Compression ridges and step fractures are almost certain to appear, as the board tries to swell back up more than it's elastic limits; and in the worst case, the board may even crush itself in places or warp away from its ribs. (I have actually seen this on a certain high quality U.S.-made concert grand where the lumber was "superdried" at the factory, and then the piano delivered to a more humid locale.) In the pinblock, if it becomes swollen with excessive moisture, you may end up with tuning pins that are too tight, and which may actually break when attempting to turn them, or be so hard to turn that it is impossible for the tuner to tune the piano.

Now every piano tuner is aware that soundboards do shrink and swell with the seasons; and with the turning on and off of heating and air conditioning at various times of the year (unless the home is equipped with some very sophisticated humidity control).

How in the world CAN a manufacturer compensate for all the possible destinations a piano might find itself in? What might be the best way to season this soundboard? Perhaps neither low nor higher moisture content, but some sort of in-between median?

And what about humidity control? Is it possible that a certain amount of seasonal flexing of the soundboard is actually beneficial, and helps it maintain it's flexibility? Or is it best to keep the soundboard from swelling or shrinking at all?

Any ideas?

Answer: After talking to Kawaii..

20 December 1999

Well, here I am, back again to report, after talking to Kawai. It seems that, like Yamaha, Kawai in the past had different seasoning procedures for pianos intended for different world "climates" (at least 2 different lines, it was reported to me). I was also told, however, that Kawai has recently decided to discontinue the different seasoning procedures and have only one seasoning process, the same as most of the world's other piano manufacturers. If this is so, it casts some doubt on Yamaha's insistence that pianos need to be seasoned differently for different destinations, because Kawai, also, targets its pianos not only for Japan but for all the world, and is a maker of some of the world's highest quality instruments.

In my last post on this subject, I discussed some of the complications of trying to target the seasoning of pianos for different areas of the world. . Again, we have to stipulate between "indoor" and "outdoor" climate. The outdoor climate may be one thing. Indoors, because of central heating or air conditioning, it may be another. It may well be that the "indoor" climate is much more of a concern to piano manufacturers than "outdoor."

For example, what if the piano is seasoned for, and shipped to a wet climate but later ends up in a dry one? (-within the 10 year warranty period). -Or is shipped to a home that's in a wet outdoor climate, but where the indoor climate is very dry because they run the heater (air conditioner) all the time? On the other hand, if a piano manufacturer anticipates a dry or arid climate, what happens if the piano is sent to a home in arid environment generally, but inside the home it is very humid because of a high water table near or under the house, or a swimming pool nearby, or because the family takes lots of showers and boils pasta in an uncovered pot every night for dinner. Suppose in either case the owner of the piano subsequently calls up the piano company and says "my piano tuner says the soundboard on my piano has lost its crown" (due to excessive dryness) or- "my tuner says the soundboard has compression ridges and has buckled away from the ribs in places" (because of excessive moisture). Then the owner may demand warranty relief, and what's the piano company to do? Whose fault was it? The piano manufacturer's, for not being able to accurately prophesy where the piano would end up? Or the owner's, for not taking into consideration what might happen when moving his piano from a wet to a dry climate, or vice versa, or the effects of central heating and air conditioning, or the other factors discussed above?

Apparently piano manufacturers have chosen to address this problem in a number of different ways. Some recommend the use of piano climate control, such as a Damppchaser Humidity Control System. Others have opted to install "laminated" soundboards with plywood type laminations rather than solid spruce planks joined edge to edge. These "laminated" or "plywood" soundboards are much more immune to cracking, warping, or loss of crown from humidity fluctuations. (But many pianists feel there is a compromise in sound quality with these boards.) Different types of pinblocks with different kinds of laminations have been tried as well, some more impervious to moisture than others. (Tuners often say pianos with these types of pinblocks are more difficult to tune, however.)

Most piano manufacturers seem to have opted for only one seasoning procedure for their pianos, a sort of median somewhere on the spectrum between "wet" and "superdry." It seems they have either found a happy medium, or else have thrown in the towel on trying to target pianos for different climates, (much of which is out of their control after the piano leaves the factory), and the small number of pianos with problems resulting from being outside the range of proper seasoning can be absorbed by the warranty program.

However, all piano owners should be made aware of the effects of humidity fluctuations on their instruments. It remains a problem to be addressed, both by the piano industry, and consumers.