How to Clean and Polish a Piano's Finish Without Ruining It

The most common self-inflicted piano damage we see isn't inside the instrument — it's on it: a once-gleaming case hazed by furniture polish, swirl-scratched by the wrong cloth, or ringed by a glass of water on the lid. Piano finishes are tougher than people fear and fussier than they assume, and the right method depends on which finish you have. Here's how to tell, how to clean each, what to do about scratches and rings, and the honest answer on covers.

First: which finish is it?

High-gloss polyester — the mirror-black (or white) finish on most pianos built since the 1970s–80s, especially Japanese and newer instruments. It's a thick, hard plastic resin: very durable, very scratch-visible, and it shows every fingerprint.

Lacquer — the traditional finish on older North American and European pianos and on many satin and wood-grain cases: thinner, softer, and slowly porous. Ages to a warm patina; more forgiving of small scratches, less forgiving of solvents and moisture.

Satin or open-pore — a matte or brushed finish (often lacquer, sometimes polyester) with a directional grain. Cleans easily but must be wiped with the grain.

Not sure? Polyester feels like glass and reflects like a mirror; lacquer has a slight softness and warmth, and very old lacquer may show fine crazing. When in doubt, treat it as lacquer — the gentler regime.

How do you clean a piano's finish?

• Dust with a soft, clean microfibre or a feather duster — lightly, because dust is abrasive and dragging it across gloss is how swirl marks are born. On satin, wipe with the grain.
• Fingerprints and smudges: a microfibre cloth barely dampened with water (wring it hard), wiped gently, followed immediately by a dry cloth. Never a wet cloth, never dripping.
• Frequency: dust weekly; damp-wipe when it needs it. Keys have their own method (here).

What should you never use to clean a piano?

Furniture polish or spray. The silicones and oils in Pledge-type products build a haze on polyester, soak into lacquer, and make any future finish repair nearly impossible (refinishers can't get the silicone out). This is the number one finish mistake. Glass cleaner, alcohol, vinegar, or any solvent on lacquer — they soften it. Paper towels on gloss — they scratch. Anything abrasive on any finish.

How do you polish a high-gloss piano?

Polyester can be brought back to mirror with a dedicated piano polish for high-gloss finishes (non-silicone, sold by piano shops) applied sparingly with a microfibre in straight lines, then buffed. It's for occasional restoration of shine, not weekly use. Lacquer and satin generally shouldn't be "polished" at all — clean and leave them; a good lacquer finish glows on its own.

How do you fix scratches and water rings on a piano finish?

• Fine swirls on polyester: a piano-specific polishing compound removes light ones; deeper scratches are a refinisher's job (polyester can be wet-sanded and buffed by a professional, invisibly).
• Scratches on lacquer: minor ones often blend with a lacquer-safe cleaner; deeper ones need a touch-up by a finish specialist.
• Water rings (the glass on the lid): white rings in lacquer are moisture trapped in the finish — a refinisher can often lift them; don't try the mayonnaise-and-hair-dryer folk cures on a piano. Prevention is a hard rule: nothing on the piano lid, ever — no drinks, no plants, no vases. Rings, spills, and a vase that tipped into a grand are all things we've been called about.
• Chips at the corners: a finish specialist; not a DIY filler.

Should you cover the piano?

A breathable cloth cover on a piano that goes weeks unplayed keeps dust off (and dust out of a grand's open strings). Two rules: never plastic (traps moisture; can mark the finish), and never cover a piano to hide a smell or dampness — that seals the problem in (the musty-piano guide). A piano that's played daily doesn't need a cover; keeping the lid down and the fallboard closed when idle does most of the job.

The finish is the least of it

A case's condition matters for pride and resale; the instrument's condition matters for music. Keep the piano off the radiator and out of the sun (placement) and both stay right. If a finish problem is bigger than a cloth can handle, we'll tell you honestly whether it's worth a refinisher's time — and refinishing a good piano's case is real craft, not a Saturday project. Ask during a visit.

Common questions

Can I use furniture polish on a piano?
No — silicone-based polishes haze gloss finishes, soak into lacquer, and make future finish repairs nearly impossible. Use a barely damp microfibre for cleaning and a piano-specific non-silicone polish for high-gloss finishes only.

How do I remove scratches from a black gloss piano?
Light swirls: a piano-specific polishing compound applied with microfibre. Deeper scratches: a finish specialist can wet-sand and buff polyester invisibly. Never use household abrasives.

Should a piano be kept covered?
Only if it goes weeks unplayed — with a breathable cloth cover, never plastic. A played piano needs only its lid down and fallboard closed when idle.