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

Most modern pianos made over he last 150 years have improperly shaped V-bars.

I have reshaped 100's of V-bars in my 50 years as a piano technician/rebuilder.

There are times when makers case harden V-bars. This is bad for tone and string endurance, and can make shaping the V-bar to a proper V shape impossible without causing even quicker string failure than the more rounded profile engenders.

Most Yamaha V-bars I have tried to shape resist cutting like they are case hardened, but don't feel to the file exactly the same as case hardening presents.

Steinway has at times case hardened their V-bars and may be doing so at the present time. Usually it is done so slightly as to be easily removed when shaping the V-bar to a true V-shape. (Although it does ruin ones metal file.)

I suspect this is because the V-process methods produces quicker cooling which reduces the percentage of the graphite form of carbon in the metal. Slow cooling of molten carbon steel produces the highest amount of carbon in the graphite form. This makes the alloy softer and with increased natural lubricity.

High self lubricity at the V-bar string termination point allows the string to self machine and work harden the exact spot the string is touching the V-bar so as to maximize the pivot termination principle of the plate, and minimize abrasion and work hardening of the string, (otherwise known as metal fatigue).

My understanding is the V-process makes for more uniform castings which reduces the amount of custom fitting to build a piano around it.

The foundation of a great piano is a high quality casting. One that has high self lubricity and high internal damping of vibration. The V-process plates I have examined that I knew were V-process had harder metal. I suspect it is possible to use V-process and get slow cooling like the wet sand method usually produces. But I know too little about the subject to prove it.

What I do know is harder plates allow strings to couple more longitudinal mode energy to transverse modes which makes for a more "noisy" tone. And I know that hard string termination points do much the same thing regarding L-modes as well as wear out the wire.

Poorly positioned tuning, hitch and agraffes also contribute to poor tuning stability and clarity of tone. So drilling the casting must be precisely done.

Every piano inspection by a professional should assess the profile and hardness of the V-bar. There is no excuse for manufacturers to still be botching this critical specification. I first published the proper specs for V-bars in the late 1970's. I have seen recent Kawai pianos that seem to meet my V-bar specifications, I hope they make all their pianos that way and that every other maker moves to adopt the practice. To do otherwise is gross negligence to their customers.

Many rebuilders have adopted the proper V-bar specifications. They have met the test of time. Now it is time for manufacturers to step up to the standard.

He primarily sells used/rebuilt instruments - and currently has Kawais and Yamahas in stock. Every time I've visited his store there were late model Yamahas and Kawais on the floor - as well as several other brands including Steinway, Mason and Hamlin, Baldwin, Knabe, Pramberger, Young Chang, Weber, Petrof, Charles Walter, Bluthner, Hailun and others. Diverse inventory.

The CX line can use V-pro because they are made in high volume. The SX line can as well because they are almost exactly the same design with different woods and hammers. The CF pianos are a different design requiring a different plate.

Shigeru Kawai also use V casting for the same reason.

Steve has rubbished Yamaha pianos on account of the V casting before. He also told us a story about how they used cheap synthetic material in the hammers instead of wool, which I think turned out not to be true. He has an axe to grind against Yamaha.

The low cost Chinese made Hailun pianos use wet sand casting, so it's not restricted to high end pianos.

Well that narrows the source down to a known reliable source.

Good point !!

That's what I've read, i.e. that wet sand plates are less consistent in size/dimension so that more of the wooden case must be custom made, whereas V-process plates are more consistent in size so that more of the manufacture of the wooden case can be automated.

I would think that if the plate did have an effect on the sound, it would only be certain parts of the keyboard. Perhaps those notes with frequencies close to the resonating frequency of the plate. I doubt the plate could make every note brighter from A0 to C8.

I think this article from the PIano Buyer should answer all the questions in this debate:
https://www.pianobuyer.com/article/sales-talk/

The video about the two methods posted in this thread is from a dealer who competes with Yamaha and Kawai and is IMO full of bias and misinformation.

At the end of the day, you still have a cast iron plate with either method, with good compression strength but brittle and prone to cracking and a PITA to fix.

Anyone heard of making a welded steel plate? Just wondering.

Yes - Dave Rubenstein uses a CNC water jet cut welded steel plate: http://www.pianosrubenstein.com/r371.html

Paul.

It is very rare for a plate to crack. Definitely not "prone".

Did you check the dealer’s website? He has both Yamaha and Kawai grands for sale. Go back and read Carey’s post after you said this dealer must be biased the first time. Carey has shopped there more than once; I just looked on the store website.

This article needs updating to include Steinway's No-Bake method.

I would guess that the plate probably doesn't make that much difference to the sound. The idea that wet sand cast plates produce a better sound seems to be speculation with no real evidence to substantiate it. And if manufacturers or dealers promote this it's probably just part of their marketing strategy and not necessarily true.

If wet sand cast plates were really so much better, I seriously doubt Yamaha would use them in their SX pianos or Kawai in their Shigeru Kawai pianos. Manufacturers have, after all, a lot to gain by producing a better sounding piano than the competition.

Then I stand corrected about his not selling Yamaha and Kawai. Obviously, I didn't see Carey's post. It's pretty shocking that a dealer would say negative things about pianos he sells, so I think it was perfectly reasonable for me to assume he didn't sell them. If you read the PB article you'll see that much of his information on the video is not correct according to the article.

Once when I was at a Yamaha dealer he told me that Kawai pianos require $5000 per year in maintenance costs and that they have "inferior" plastic parts. When I was at the Kawai dealer, they were keen to point out that at a recent piano competition, not one of the pianists chose to perform on the Yamaha. Another Yamaha dealer was keen to discourage me from purchasing Hailun by telling me stories about broken hammer shanks in Chinese pianos and only being able to sell it for $3000.

Many piano dealers love to rubbish the competition, so this story about v cast plates having inferior sound could simply have its origin in piano dealers/manufacturers trying to discourage people from purchasing competing Asian pianos.

There probably is no greater expert on piano manufacturing than Del Fandrich (at least one who comments in public on these topics). Here are some comments taken from the 2012 thread linked below.

https://forum.pianoworld.com/ubbthre...-have-bought-a-steinway.html#Post1850871


These support the position that there is no qualitative difference between vacuum casting and wet sand casting, including the comparison of a model that has used both plate types (emphasis added):



These support the notion that the choice between the two methods is purely an economic decision, or cost consideration, and also covers why a manufacturer might choose not to use vacuum casting on larger models when then do use it for shorter ones (again, emphasis added):



This discussion is from 2012, so the 7ft "tipping point" in decision making may have changed (I don't know).


TLDR: Just focus on this quote from the Idiot's Guide to Buying a Piano that Del thought was significant enough to quote:

If V cast plates really were noticeable inferior, Kawai and Yamaha would have long ago switched to a different process, or found a way to eliminate its shortcomings. They're not going to say, "V cast plates produce an inferior piano, but save us a bit of money! Win!"

He most certainly does. You know what he's going to type on any given thread before you even read it.