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I have a Casio CDP-130 that I bought a few years ago as a vacation instrument; I visit family for 8-10 days once a year, and I wanted something cheap, but with a minimally decent keyboard (weighted, graded) so that I have something to noodle on and make sure that my chops don't totally deteriorate while I'm away from home. It mostly does the trick, but MAN are those glossy keys slippery ... It's not really an issue for the white keys, mostly just the black ones. I was wondering if there was someway to make them more like matte keys - either literally, or at least closer to feel, so that my fingers get a little more grip. Anyone ever done this? Any ideas? I was thinking I might just try to scuff them lightly, with the finest of sandpaper, or maybe find some matte finish tape and put little strips on the tops of the black keys. Other than that, I'm stumped ... Suggestions welcome! (Yes, I know: "Buy another piano." At some point, but I want to get my money's worth out of this one first ... )

I'd try sandpaper first. "Wet-or-dry", from the auto parts store.

Vacuum up the dust, as you create it.

Sand the keys on the piano? Is that the implication?
I think it would be best to remove the keys first.

If not ... wouldn't some dust still slip under the keys?
And don't Casios have the usual dome rubber contacts?
It wouldn't take much dust to render the piano non-functional.

Sanding the keys one might be concerned about tiny particles causing havoc on your sensors.

Grit might make its way into the grease and moving points ruining the action.

Also the keys may be coated to protect the plastic from sweat, UV light, etc. With damaged coating you might end up with weakened keys which may become yellowed or damaged more quickly.

This might sound bizarre but I would turn it upside down to sand it so any loose particles fall away from the keyboard.
If you can support it it at the far ends up high to give you easy access this just might work.
Finish by dusting or running over a damp cloth.

There is a chemical you could easily keep under control that would take the gloss away. You would just dampen a rag and carefully wipe it on each key. Don't over wet the rag. You would not have any moisture, dust or sand paper debris getting into the mechanism. You would need to get into some tighter corners so approaching these areas with a fine artist's "dry brush" technique using an artist's paint brush could work.

As mentioned, there is probably a coating on the surface to resist dirt and discoloration. Once the surface was effected by the de-glossing process of your choice you could apply a protective coating that has a matte or satin finish.

If you search for piano key top polishing on google and on PW's technicians forum you will find tips and videos. But if you attempt any process without first removing the keys from the DP, you seriously risk ending up with a nicely renovated keyboard on a DP that will not work anymore...

Anyway, please report your experiments :-)

And what chemical would be that? Many acids and bases are guaranteed to fully remove all types of scratches along with glossy and protective finishes. However, they will also corrode the rest of the plastic key top...

I doubt there would be any protective coating on the keys. I can't see the benefit, and the cost would be objectionable.

The keys are just molded plastic. If the plastic needs any special characteristics it will be in the plastic formulation.

Hmm, well, you folks are scaring me! We'll see if I have the guts to try anything ... Thanks for all the suggestions and input!

When I recommended sanding the keytops, I wasn't thinking about the effects of plastic dust on the mechanism below the keys. So my original advice morphs into:

. . . Turn the DP upside down, support it at the ends, wear a mask, and lie on your back to do the sanding.<g>

I don't know if I can take that seriously, or not. I wouldn't use any "chemicals" on the keytops. Too much chance of doing permanent damage. A chemical strong enough to attack the plastic, has a good chance of producing long-term goo.

There have been lots of complaints, here, about the textured surfaces on some PX-xxx keyboards (including my PX-350). I never found it a problem. My childhood baby grand had high-gloss keytops; I don't think they bothered my playing, either.

Have fun, and report back if you do something (whether it works, or not!) --

Dust is the biggest enemy. I have some fine line scratches on keys of my Kawai ES 110 and tried very very fine 1500 sandpaper on one key with a mini Vacumn going like when the dentist works on your teeth . Sucked up the lil bit of dust but key actually looks worse than before: dull smudge with more scratches. Finally convinced myself to let it be.
One view on u tube of dissecting these slabs cured me.

Yeah, unfortunately you learned the hard way that you can't use sandpaper to take scratches out of gloss (at least not as a final step). You'll need fine polishing compound and a buffer (or a lot of elbow grease), and you don't want to do it with the keys still on the keyboard.

Yes, with special emphasis on you don't want to do it with the keys still on the keyboard.

I also suspect the keys are just molded plastic but plastics & coatings have evolved so rapidly, it would not surprise me if keys are coated. Or at least a polish was applied with a soft buffer. Particularly for higher end keys. Testing that is beyond my pay grade. . .



1500 grit is not particularly fine for finishing glossy plastics like piano keys. Also there are different grit standards so make sure to understand what you are actually using (e.g. P1500 might be ~800 in Yankee ANSI). There are online conversion charts online.

My polishing experience is more with polishing bare and finished metals/woods. But I have polished some plastics and some headlights. A simple headlight refinishing tutorial is probably not a bad place to start research for general plastics work (even though this is "restoring" the failed coatings on polycarbonate). As a general matter, for polishing you really need to gradually move up grits from say 1000, to 1500, to 2000, to 3000, to polishing compound, etc. Certain "sandpaper" requires water to help clear contaminants from the grit, reducing effort and extending abrasive life. Final processes might use special dry disks (which are rather incredible technology), then a buffer polish with protection. This is time consuming and expensive.

https://motherscarpolish.com/headlight-restoration/
http://multimedia.3m.com/mws/media/...ion-system-detailed-instruct-for-use.pdf

For digital piano keys, "sandpaper" and polishing compound produce plenty of dust and contaminants. I think you really need to remove the keys from the unit as dust is well known to cause issues with contacts. Also dust will get into the pivot points and grease. Also, some plastics may be coated for texture, protection from sweat, UV light, etc., so polishing could cause some performance issues with coatings. Polishing long narrow keys manually will be a challenge by hand so getting even results is tough; and you may have a bais towards corners, so expect soft plastic keys to end up a bit narrower and more rounded.

Depending on where the scratches are, you might be able to use that expensive blue painting tape to mask off all nearby crevices between keys etc. for very minor work. Then tape plastic tarp to fully wrap around the keyboard a few times to prevent dust issues. But I really don't think this is very practical.

Finally, make sure any protectants you apply to the keys are OK for constant contact with skin.

If you're trying to get rid of light scratches in plastic, I would use Novus plastic polish #2, the one for light scratches. I haven't used it on a piano, but I've used it before for automotive plastic parts. It was designed for motorcycle windshields and helmets.

You are talking about a temporary situation of spending some time on a backup piano during 8-10 days out of 365 for which your stated goal is to not have your
"chops totally deteriorate " .... and are seemingly seriously considering DIY procedures for defacing the keys as the solution ... ?

With due respect, this seems a bit much ado overkill, no offense intended ... maybe its just me, especially since I do not have the benefit of familiarity with your chops. I do have the confidence to say that if you have chops, they will not totally deteriorate after 8-10 days of either inactivity OR activity with slipping fingers.

Perhaps your fingers tend to slip especially on black keys because the fingers are too slippy combined with chops not regularly applying fingers to black keys with just the right amount of angle & force for not slipping ? .... just a thought .

For years my hands & fingers tend to be too dry IE. slippy, literally "dishpan hands" . When I find them slipping across piano keys, I leave the keys alone and do things to make my fingers more tacky .... have never tried sand paper but I have focused more on placing fingers onto keys more squarely ...... this and a bit of moisturizer suffuciently absorbed into skin usually helps with this problem.

Good luck!

Put a small bit of sellotape on your fingers while you're playing and you should be fine.