Piano World Home Page Forums Our Most Popular Forums Piano Forum Wet Sand Casting versus "V-Pro" Casting for Piano Harps

This is from Steinway Europe site:

"STABILITY AND BALANCE – THE IRON PLATE

The Kelly Foundry in Springfield (Ohio, USA) produces the cast-iron plates for Steinway New York and Hamburg. They are produced by a traditional moulding process using synthetic sand. The cast-iron plate stabilizes the overall structure of the grand piano and absorbs tension from the strings.

The iron plate itself is the only part of the grand piano that does not resonate. Its weight and the high carbon content of the grey cast iron prevents the strings from losing vibration energy. Steinway craftsmen work on the iron plate with a drill and milling machine and then sand and bronze it by hand. The final step in this phase is painting the incorporated Steinway & Sons lettering by hand."

Link to page:
https://eu.steinway.com/en/a-legend/manufactory/iron-plate/

The French magazine Diapason enlisted French pianists Michel Dalberto and Valentin Cotton to compare 6 uprights. Michel Dalberto is a professional concert pianist and Bechstein artist.

The Boston UP-132 with vacuum mold plate dusted 5 European made uprights with wet sand plates, including being found to have superior tonal properties.

https://www.artist-pianos.com/boston-vs-handmade/

BDB, I am well aware of break point and elastic limits in various portions of many scales. Hard V-bars show great string breakage starting immediately on the notes in the compass above the agraffes. The general increase in BP and elastic limit that occurs as one moves up into the treble of most piano scales is not that abrupt at the break between V-bar and agraffes.

In fact the first few V-bar notes are often at less BP than the last few agraffe notes.

Paper clips are not high carbon steel. Your analogy is senseless.

Even if Ed and Steve are right that V cast plates have a higher probability of treble string breakage when tuned extremely frequently, it doesn't seem to be an issue for most Yamaha and Kawai owners and wouldn't think it needs to affect a purchasing decision.

The transition between agraffes and capo bars is usually much lower than the area where significant breakage occurs. I usually see breakage in sizes smaller than 15, and the transition is usually 16 or 16-1/2.


Give some examples! Show the math! If that happens so often, and you know this to be the case, you should have those figures right at hand.


Paper clips are usually made of steel. I do not know whether the carbon content is greater or less than that of music wire, and I doubt that you do, either. Nor do I think you know what properties the carbon content changes. I suspect that one could anneal music wire, which would not change the carbon content, and bend it back and forth in one's hands and it would break just like a paper clip.

I don't own a piano with a v-pro plate, but what I notice when I read about the purported inferiority of v-pro plates is that everyone in the business of selling pianos with wet sand plates has a different explanation of why v-pro plates are inferior.

There may be an analogy here with laminated soundboards. While early laminated soundboards were poor quality, these days it's not clear that they produce an inferior tone, and they even have some advantages with regard to longevity and tuning stability. But few high end manufacturers would risk the bad press of a laminated board, and it remains obligatory to advertise that your piano has a "solid spruce" soundboard.

Yamaha uses sand casting in their CF4 (6'3" - 191 cm) and CF6 (7' - 212 cm) grand pianos, and V-Pro frame in their S7X (7'6" - 227 cm) grand piano.

Here is Yamaha's statement for the metal frame used in CF series grand pianos:

"Metal Frame

The frames are individually hand molded and sand cast to enhance the strength and stability of the pianos. This contributes to the outstanding tonal character and sustain of the series. The CF6 and CF4 feature an open pin block design which improves both the attack and sustain of the notes."

Link to the relevant Yamaha webpage:
https://europe.yamaha.com/en/produc...nos/cf_series/features.html#product-tabs

This quote came up in the last thread on this topic as well. It's just marketing copy, and does not necessarily mean that sand cast plates have better tone or more sustain.

When I was shopping for a piano, I was initially concerned that the Yamaha SX/CX pianos had poor sustain in the treble. So I compared against a Bosendorfer 214VC which was right next to them. The Bosendorfer was extremely crisp in the high treble, with almost no sustain. The Hailun 218 I played had exceptional sustain in the high treble, at about one fifth the cost of the Bosendorfer. The point is, even a very expensive piano using a sand cast frame can have very low sustain in the high treble. So we shouldn't be too quick to assume that sand cast plates lead to "outstanding sustain".

It wasn't just me who thought the Hailun had outstanding sustain, a piano tech working on another piano nearby commented on this while I was playing. The dealer thought the laminated soundboard might have been responsible, as the grain on the outer layers points at a different angle and allows the vibrations to move in all directions instead of just along the grain of the core. Wouldn't it be ironic if a laminated soundboard led to better sustain than the high end brands?

I believe Yamaha.

It's interesting that if you go to the part of their website for the CX line of pianos, they point out that they use a V-pro plate for inferior tone and less sustain.

In their promotional booklet Yamaha claim that their pianos aren't their best anymore after 10 years. They make this claim in the context of trying to encourage people to buy a new Yamaha instead of a used one. Perhaps Hakki also believes therefore that Yamaha pianos are only good for 10 years.

The Yamaha quote says almost nothing. First of all, it's inconceivable that anyone thinks a V pro plate is not strong enough so the first sentence means nothing. The second sentence does not say that wet sand casting is superior to V pro in terms of the tone produced or the sustain.

This is obviously because of the processing of the wood in the rim.

That's not what Ed is saying. The condition he describes can happen with any hardened plate, regardless of the manufacturer. I've encountered it too often in Kawai KGx pianos, long discontinued and not all of them but too many. It's not a by-product of V process, but a by-product of case hardening

Furthermore, I've never stated V plates don't sound good. There's enough crap sounding wet sand cast pianos and enough great sounding v pro to disprove this. My statement is at the very top of the top there is almost a certainty of a difference and I contend Yamaha knows this and uses sand on only these pianos as sand or v pro will have an insignificant difference on other pianos, and my evidence is that's exactly what they do and I'm not sure v pro costs more and if it did the marketing benefits to Yamaha would be worth it.

Marketing is about making you believe that you should pay more for something that doesn't really cost much more to produce than the competing product. "High end" audio cables (especially digital cables) are an example of this. Top tier piano manufacturers also market on their exclusiveness and artisanal qualities. Something that sounds hand made, like a sand cast plate, carries a lot of marketing value, but makes no difference in actual physical properties that could affect the sound in any way that a double-blind test could reveal. There's way more variability in all of the other sound making portions of a piano that would make it impossible to tell the difference between how any different type of plate casting techniques could affect it.

That's exactly what it is. Tradition is a hard thing to break especially when some of those traditions are propagated by the stalwarts of everything Steinway. I don't think Yamaha wanted to leave anything to chance when they designed their flagship piano including giving competitors or anyone the opportunity to say anything negative about the CFX grand. So it made a lot of sense for Yamaha to go the "traditional" route in designing a flagship piano both from an economical standpoint as well as a marketing standpoint. It has nothing to do with what virtuoso pianists think- most of whom don't even know how a piano works, but if you tell them it was built like a Steinway, they know what that means.

Interesting observations, pyropaul.

I can’t remember how many times I heard arguments back in the 80s about whether a Trans Am was just a Firebird with plastic cladding and a big bird decal on the hood, or a true upgrade, and, for that matter, whether a Firebird was just a rebadged Camaro. And it didn’t help that various features and options could further blur the lines on these and other models.

Sometimes there are significant differences between models, features and options, and sometimes not so much.

Each consumer needs to find the combination of these, and price, that suits them.


I like the advice above about auditioning the pianos (that fit the shopper’s search criteria), and picking the one most preferred (regardless of manufacturing processes (or where it was made, for that matter)).

For $75k, one might get a Steinway S or a Shigeru Kawai SK7.

V-pro plates are sand cast. The process is more automated. V-pro casting produces a more consistent plate that more closely conforms to specified geometry. Wet sand plates require more work by hand. The statement does not articulate to what the enhanced strength and stability is being compared when rated as greater. Is it greater strength and stability than wet sand plates without as much attention given by hand or greayer than v-pro plates? The text provides ZERO indication of which, so it conveys no information about whether v-pro plates are inferior to or the the equal of wet sand plates.

This is what Yamaha is saying about V-Pro frames:

"Expertise in frame making shines through in robust quality.

The frame in a modern piano must be able to withstand a total string tension in excess of twenty tons; not only does the frame work together with the wooden body to support the string tension, but it has a profound effect on the instrument’s sound. Yamaha makes its own frames, relying on a method of casting referred to as the “vacuum process,” developed over many years to create some of the best piano frames in the world. During this time we have built up a storehouse of knowledge on factors such as the manner in which controlling the temperature and composition of casting, and even the coating used on the frame itself, affects the acoustic characteristics of the piano. This is a major reason that Yamaha is able to ensure reliable quality when crafting our pianos."

Link to the relevant Yamaha webpage:
https://europe.yamaha.com/en/produc...nos/cx_series/features.html#product-tabs