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I thought I'd share this with you. I have this 1920's Heintzman upright on which the ivories were replaced for plastic keytops. I assume that before installing the new keytops, the tech who did the job did not sand the top of the keys to a perfectly straight surface because on most keys, the glue had "sucked in" parts of the keytop, creating small depressions that you could feel when running your finger across the key.

While searching on the net, I found a page where a guy described how he sanded the keytops on all of his pianos, and how that made the keys feel like ivory. I thought I didn't have much to lose so I gave it a try and I must say I'm impressed with the result. I layed sheets of sandpaper on a flat surface and sanded each key individually. I first used coarse grit to make the surface straight and eventually finished with 280 grit and 0000 steel wool. Maybe a finer grit would be even better, but now the keys feel great, indeed a bit similar to ivory, "warmer" so to speak.

If anyone wants to try this I suggest you have a good dust extractor close to where you do the sanding, as you probably don't want to breathe the plastic dust...

And I'm thinking that 150 grit is bringing it pretty close to the ivory on my other piano.

Though I imagine there were different finishes on the ivories of different pianos...

I like the rough...

If you dont buff the keys after sanding they will get dirty soon.

but I understand a slighly scratched surface may be nicer under the fingers.

plastic and acrilyc glass keys top can be sanded and buffed.

Just be cautious with the heat it produce.

Even old Yamaha ivorite covers can be sanded to get rid of the grayish problem (of the 90's) then buffed.

It is not staying really for 15 years, but it helps, while the real solution there is to buy a complete Yamaha keyboard, delivered ready to install with not too much trouble..

I did this recently and was surprised, that there still is a kind of ivory style structure in the plastic. From what I read here, I thought, that on the early ivorite key top, the ivorite was just a small layer on top of plastic key.

It is hard to say, if the key tops still have the same ivory feel like the original key tops, as they were pretty dirty and worn before sanding. But in fact, they feel very good. I did not buff them to a completely shiny surface, as the owner was afraid they would get slippery.

It doies not get slippery, it is a semi porous material. Yes the "ivory" style is in the whole thickness.

If not buffed it get dirty sooner, can be cleaned but that material have a reaction with the finbger's persiration (as I understand it) so a buffing may protect your job longer.

A new keyboard is not that expensive so if you have pulley, worn mortises, you can think about it as a definitive answer.

I recently sanded a whole keyboard and it was not a so long job (around one afternoon) using an electric sander, and compressed air to clean the sanding papers. The good choices of paper and control on the surface to avoid "too much" scratches, helps at the end of the job.

If you dont really buff it is even simpler.

Water, alcool and soap are perfect to clean the wooden sides.

a drop of alcohol helps to close the opened balance holes. (some alcohol mixed polycarbonate resin can help to reinforce the closed holes) those sort of rosins are availeable for old furniture rebuilding (cristals that can be soled in all sort of solvents) I used Paraloid B with some success (I am not convinced by the "glue milk" success. gluing a chip of wood in the hole is worth in case of really large hole.

Thank you for your detailed tips.

Hi all - The sandpaper on the bench method (described in the initial post), holding the key face down and moving the key back and forth (not the sandpaper) is the best method, in my opinion, of flattening out a ripply surface. I usually go down to 400 grit wet/dry paper (or finer), then either scrub with 0000 steel wool, if a satin finish is desired, or polish on a polishing wheel using a double buffing wheel and a bar of Nu-White (Schaff cat.no 426).

Have the buffing wheel going as slow as possible and really go easy, especially on the notches around the sharps - it's really easy to melt the corner if you apply to much pressure. If all you have is a 1 speed grinder, I would not recommend trying this, as you most likely will damage the keytops. Wait until you can afford a good, variable speed grinder to mount your buffing wheel on.

Hint: If you're using a grinder with lamp, use a clear glass appliance bulb and look at the reflection of the filament coming from the ivory as you polish it to judge how much sheen you have. Usually, 2 or 3 swipes over the wheel (in the direction of the keystick) is about all you need to bring out the shine, if that's what you're after.

For anyone who does this work for others, here's a heads-up (1 page) promo you're welcome to use: ( "Polishing Imitation Ivory Keytops"). I've left the space for contact information blank so you can print in your own. Chuck Behm

Yup. We did this all the time at the shop I got my training at, only we used Scotch-brite pads. With repeated playing, you will burnish the tops with your fingers, and it will likely have to be redone. As for the tech who replaced your keytops.... you should ask for your money back, because that is absolute BS.

I concur on that point. For technicians wanting to try keytop replacement themselves, but hoping to avoid this type of scenario (problems arising from keytops glued on uneven surface) here's a segment from Journal article that describes alternative ways of avoiding that unhappy situation: ( In-House Keytop Replacement - With That Outsourced Look - part 1). Keep in mind that opinions vary (greatly) when it comes to specific tools and techniques, but this will give food for thought for anyone contemplating doing this work themselves with better results.

The main point of contention between technicians (for this segment of the article) is for which tool is best to use for preparing the top of the keystick. After many go around with various technicians I would have to say that most techs seem to prefer the Wagner Saf-T-Planer (I think that's how it's spelled) which I wasn't aware of when I wrote the article. I still use the table saw, and stick to my comments about it in the article. Used correctly it is both safe and very accurate.

Oh, and going back to polishing imitation ivory, one thing I forgot to mention about using a buffing wheel with polishing compound is that every few keytops, rake the surface of the wheel with a flat-bladed screwdriver, and apply new compound.

For either cleaning up old tops or applying new ones, careful workmanship will pay off huge when it comes to customer satisfaction. (You won't have unhappy customers writing in to PianoWorld wanting to fix the problems you caused!) Chuck

You need to go to a fine grit to avoid scratches in the surface. If they are really warped I'll start with a 320 on a piece of glass, then to 400 and finally 600 on an orbital sander. Buffing brings up the satin gloss. If you don't buff and rely on playing to 'buff', then your keyboard will have an uneven gloss; better in the center and fronts of the keys with the extremes and rear of the tails still dull. A buffing wheel makes the gloss uniform.

I agree with that, but I discovered it is possible with an orbital sander that is reverted and secured in a vice or fixture.

BUT ..;) one have to choose the grit correctly
USe blowed air after each key to clean the sanding paper

Take care not to push more on one side than the other.

It works fine with ivory.

WHat I use is 600 1000 2000 and even, 3000 grit on foams, for automotive paint) in case the ivory is very thin in the center due to wear, and I dont want to make them thinner (which will occur if I plane them to a flat surface)

THe neat sanding allows an easy buffing in the end.

a special tool with metal teeth is used to clean the wheels, or a simple hard wood block.

My buffing wheels are impregnated with tallow, this avoid a lot of dust (some tallow is yet included in the polishing pastes, but not so much)