how does one safely clean piano strings? mine have some black spots on them after the piano's most recent servicing.

Hi Pique- 0000 steel wool will work. Be careful not to use a lot of force if it was just tuned; you can de-tune the strings if you do that........Sam

Other techs I know now recommend 3M abrasive pads (the white ones) in favour of steel wool (which has a certain oil content to it)

so it would not be a good idea to use a cleaner or solvent, like windex on a cloth, or alcohol? just concerned that steel wool and abrasive pads leave filings/dust behind.

The residue from steel wool or pads can be blown out or vacuumed. I would not be comfortable with any liquids on the strings, especially the bass strings.....Sam

pique:

Here's some handy advice: Don't use any type of cleaner on the bass strings!!!! Take it from someone who turned copper strings into beautiful, like-new beauty and at the same time ruined them. Anything you do that causes ANYTHING to work between the coils will kill the string (including steel wool, which will cause the fine pulverized powdered verdigris (if that's what it's called) to settle between the coils. Once this happens, you're in big trouble. My advice with copper wound strings -- leave them alone. If they're dull and tarnished, replace the light bulb in your room with lower wattage.

The steel strings can be cleaned. There is a special cleaner that is like an ink eraser with a handle. Works great, and is made for the job. Steel wool is OK, but take it easy. Steel against steel can scratch. It's best to use something softer than steel, so that only the gunk (tarnish / oxidation) is removed, with no possibility of any effect on the steel.

I'm sure there are other opinions on this, but my opinion is that tarnished strings are not broken -- and one should not try to fix something not broke.

Respectfully disagree with Rvaga about the bass strings (except: no liquids). Cleaning is widely done with steel wool or abrasive pads and has been for years. I usually see pianos I service long after the original service date, and have never had this result on bass strings......Sam