Piano World Home Page Forums Our Most Popular Forums Piano Forum Yellowing of keys

Hey Folks,
Just lately I've noticed a slight yellowing of the keys on my 30 year old Yamaha WX7 that I've had about a year now. It's only slight, and goes from middle C up to C6.
I'm not sure if was like that when I got it, or if I'm just noticing now. The piano receives weak ambient light only, from a nearby window, and I'm particular about making sure my hands are clean before I practice.
Is this an inevitability? Any advice on safe ways to whiten them, or products that worked for you is greatly appreciated. There are a few things online, but personal testimonials are better!

WX7 is a midi saxophone, so that must be a typo. Just curious which model you have.

No not a typo, it's a model made for only about five years ( late 80's early 90's ). I guess they decided to recycle the model number for some reason!
Google images will give you a couple examples....

Don't see too many WX7 Yamaha's. I wonder if it had an early version of their ivorite keytops since it was a high end model. We've been able to buff and polish old Yamaha ivorite keytops with good success, but it does require the right buffing wheel and removing the keys from the piano. We have some other techniques as well.

I don't know how to safely describe some potential home remedies usually done on ivory keys, but I bet there is a YouTube video. Still, I'd start by asking your tech if they have the right tools. It really isn't much labor if you have the right tools.

It definitely is a Yamaha upright model ,I have heard of it but sorry Ihave no ideas about what will help.It is not ivory, I am sure.
It is a mystery why this would be happening ?

Does anyone on the house smoke? That'll do it.

Some plastics are more colorfast than others. Upon close inspection, if ivorite, you'll see some texture or visual pattern on the keytop.

Many Yamaha uprights from the 1980's have white tops but strongly yellowed fronts. For the fronts only, painting them white is a better option. Some Yamaha's from the late 1980's through early 1990's had keytops that would turn gray. Fairly rare and I don't know the cause of that issue, but for the graying keytops, replacement is the only option.

Interesting didn't know they recycled model numbers.

Thanks for the info PianoWorks! The keys seem to have a matte finish and on very very close inspection show faint blue-ish parallel lines, perhaps it is the ivorite....it's hard to get much info on this model, but at least the little I've heard has been good.
I think waiting to ask my Tech is a good suggestion....

No smoking BigIslandGuy....I would never hurt my baby!

My 1977 UX had quite yellowed fronts when I had it - I took a few off and sanded and repolished them carefully about 15 years ago. At that time, I realised they were slightly cupped as I sanded them. Looking closer, the surface was slightly crazed. I was at the piano yesterday, the yellowing is now brown (no smokers!!) and the crazing can be seen with the naked eye now, as can the cupping. We won't be worrying about it - it's now 42 yrs old, and really isn't worth a full rebuild - it still plays quite well and my daughter's children enjoy it.

whoa Backto Study, cupped and brown doesn't sound very good (although great to hear it plays well and another generation is enjoying it).
Was it only the fronts? Do you blame the materials used in manufacturing or do you think the issue arose from the environment?
The yellowing on the couple octaves on mine is barely noticeable at the moment, but I'd like to keep it that way. Did the sanding/polishing you did work at the time?
Thanks for the reply!

I worked for a Yamaha dealer when those were sold. I'm pretty sure they were Ivorite.

SuzyUpright, the faint parallel lines confirm it is ivorite. I recommend trying to buff them first, though there are a few chemical treatments if needed.

back_to_study, you can do wonders with the fronts with a little spray paint. You will spend a little time carefully taping everything off, but a few light or dust coats of a white or off-white spray paint will look better and last for years. It may even disguise some of the cupping simply by drawing less attention to the color difference.

That's great to have that information, thanks to you both...
Now that I can confirm the material, I can do a more targeted search.
Just from my initial glance around, the WX7's numbering 4000000 - 5000000 had the first "bad Ivorite" before they made improvements on it. That's me unfortunately...
Discolouration was a common problem with the early stuff. The good news is, on the ones that did turn yellow/brown, it happened soon ( within the first decade say ). Maybe I'll be lucky...

Thanks Sam - her father-in-law is a cabinetmaker, and he suggested the same - he's got a computer controlled machine which he said could trim the fronts to be level and even (CNC?) and suggested painting them with something you'd paint ceramic tiles with.

I think motivation on both their parts is the issue - she's got 5 children. But if we were ever to do serious work on the piano, we'd do that. A couple had cupped so much they were just touching on the front panel, they're the ones I sanded down.

SuzyUpright - it was earlier pianos than yours, I believe.

I've painted several sets of Yamaha key fronts. I set a strip of wood under the keys to raise them up a little bit and to stabilize them and then sand the fronts to remove the cupping. Sandpaper on a block of wood works well for this. You can start with a coarse grit and follow with a finer grit.

After they are sanded I place the keys upside down on a table and clamp them tightly together. I tape off the bottom of the keys and the sides that are exposed and spray them with a can of spray paint. Krylon works well.

The ones I've done have lasted a long time. In fact, I've never had to redo any of them.

Alan, sounds like her father-in-law is having fun with the concept, but making it out to be more of a project. If I had to write a program for a CNC machine or find special ceramic paints, I'd just replace the whole set first.

Bill's description is fast, simple & effective.

Suzy, have you considered asking Yamaha to do something about it? Of course, the product is long out of warranty, but there are makers who will step up, especially if we're talking about a product that actually has a known defective part. A letter would do it. Nothing ventured, nothing gained. They might like to know.

In the end, you will probably be best advised to take Sam's advice, helped by the father-in-law. I would feel very confident with two experienced minds and two experienced hands on the project.

Hey Jeff Clef ( love the name )
Alan is the poster with the more serious issue, and yes who knows....maybe if he contacted Yamaha he would be surprised with the results.
As Sam suggested, I'm going to wait until I see my tech before trying any home remedies ( again you can barely notice it on mine ). Despite being within the range of the 'problem Ivorite' I think if the keys were going to have the same issue as Alan's, it would have happened years ago ( fingers crossed ).