As others have already said, the Spurlock tools for cleaning soundboards are great. Or for simplicity, you can just use a soft slightly dampened cloth and a soundboard steel (Schaff #934). With the action out, you can feed the cloth from either the bass or treble end. Just throw the cloth in the washing machine (sanitary cycle) when it gets too dirty and unpresentable. If you do use a soundboard steel, be gentle around the wound strings. It will leave marks if you are too aggressive. Ask me how I know.
That said, this may be a good opportunity to educate your client about the need for a complete cleaning. It only takes a few minutes to pull the action and show the client all the hidden dust that has settled there. I explain that the dust that they see on the soundboard, although unsightly, is not really all that problematic. It is the dust and grit that has settled into the moving parts and felts of the action that is the real problem.
When I do a complete cleaning, the action goes outside, the stack and keys get removed, and everything gets a thorough blowing out with compressed air. Be sure to connect a water filter to the air hose if it's a tank-based compressor so you don't end up spewing rusty water from the tank all over the action (unless of course you live in an area with zero humidity).
For the rest of the piano, I have to say that my Metro Vac-n-blo was my absolute best purchase in 2013. As Paul says, it really sucks (and blows)!
For me, a complete cleaning takes nearly two hours, and I charge accordingly. Of course, if the client chooses to only have me clean the soundboard and plate, that's fine. But if the piano needs more than just the soundboard dusted, I feel it is my responsibility to bring this to the client's attention and then let them choose.
-------------------------------------------
Roger Domeny, RPT
Domeny's Piano Service
Colton, CA
www.domenyspianoservice.com roger@domenyspianoservice.com (909) 824-2561
-------------------------------------------
Original Message:
Sent: 01-26-2014 15:59
From: Gary Howell
Subject: Dust on a grand sound board.
Yesterday I tuned a 1960's era Baldwin grand piano that had a large amount of dust covering the sound board. The owner asked if I was able to remove the dust. I tried using her vacuum but the distance between the strings and sound board prevented any significant suction from reaching the layer of dust. I then thought perhaps I could pull the action and reach in from the front of the piano with some kind of duster on an attachment, but of course, the damper wires block access.
My next thought was that perhaps I should carry with me a portable air compressor and simply blow the dust out. But then of course it would rain dust all over her carpet, couch and everything nearby.
So then, how does one remove all the dust on the sound board, under the strings of a grand piano?
-------------------------------------------
Gary Howell
Melbourne FL
[http://www.cranecreekpianos.com/]
-------------------------------------------