I get asked ALL the time “What do i do about the dust in my piano”. Let me reassure you that dust is NOT an enemy to pianos. The outside of pianos – the cabinet is simply furniture. The inside – the strings, keys, action – think of it like a car. Do you worry about dust on your car engine? Of course not. Piano keys have a type of dust ‘trap’ which is the keybed. As seen in the picture below, when you take the keys out there are paperclips, dust, coins. None of these affect the piano performance. Heat and humidity fluctuation are the enemies to pianos – not dust.
So go ahead and dust the outside and leave the insides alone. Now if you own a grand and you’re tired of looking at dust under the strings – again, it’s cosmetic but i can understand that you want to have it clean and bright looking. I own a soundboard cleaner which is simply a long aluminum strip that i attach a dust cloth to. When asked to clean under the strings, I remove the grand lid and do a proper job of cleaning. It requires some effort and know-how but worth the results. Just one cautionary note: If you want to either vacuum or dust the inside of your grand, be REALLY careful with the dampers (pictured right). If the wires that hold these in place get bent, they affect the sustain and will require adjustment. My advice, you can dust the gold cast iron, the strings, the soundboard, the tuning pins, but leave the dampers alone. Hope this helps.