Piano World Home Page Forums Our Most Popular Forums Piano Tuner-Technicians Forum Rust spots on strings

Sorry if this has been discussed in the past, but I was wanting to get a general opinion on some small spots of rust I've noticed on my Kawai GL30 strings.

Background....I've had the piano from new for about 18 months now, and I've noticed about 3 or 4 small spots of rust recently, mainly on the mid to treble strings. They are only about 1mm in length.
I know there was one small one when first delivered, but I didn't give it any thought.

I expected that over time this will start to occur. And I know you will tell me that it really depends on the environment and atmosphere it lives in.

It is situated in a very atmospheric stable double brick house near an internal wall, (not brick) and away from any windows. The house is about 12 km inland from the coast. Admittedly the humidity in the room has frequented the 70's quite a bit over that time, but it generally doesn't move around too much.
(The piano was bought setup from an airconditioned showroom far inland by 250km, having a dry climate.)
Most of the time I have the piano completely covered with a cover, and often just play it with the lid closed with the cover pulled back a little from the fall board.

I'm really just wanting a feel on whether that is a quick time period from new to expect the odd rust spot to appear,


thanks


Chris

Probably from hand sweat from the stringer. I wouldn't worry about it. Some people might take to steel wool. But sounds like you have string cover felt which helps with dust which can contain moisture.

I have the same on my GL10. Doesn't seem to be a problem.

joggerjazz +1, maybe someone touched the strings with his hands.

Maybe clean the strings next time, after the tuner/tech did his work?

I would not use steel wool though, I think it might change the thickness of the strilngs at some spots leading to unevenness. Maybe some tech could comment more on that.

I have a GL10 that's 2 years old and don't have any rust, I don't know what's normal. One thing that can contribute to rust on metal is changes in temperature. For example if you keep your house cool overnight and the strings cool down, then turn the heat up in the morning and that warm moist air hits the cool strings, moisture can condense which may lead to rust. It doesn't sound like that would be likely in your case because you keep the lid down and the piano covered.
I would have imagined that tuners would wear light cotton gloves to avoid touching the strings. Fingers have acid, oil and moisture on them. If I were going to try to clean the rust, I would use a nylon based pad that we call scotchbrite over here, not sure what they're called down under. I use scotchbrite on woodworking equipment to remove rust without damaging the fine finish.

Thanks guys, I'm not overly concerned. It's more my interest in the rate at which it might occur into the future. As we all know, the differences in environment is the major contributor to the differences between pianos.
Thanks Mark, we do call them scotchbrite also, I do have some under the kitchen sink. I've seen Youtube videos where piano techs use steel wool for cleaning the strings, but I feel that is only appropriate when large areas need to be cleaned in pianos undergoing refurb. I wouldn't consider that for small areas, in an otherwise spotless piano. I don't like the idea of any scouring type abrasions for the oxide dust they would leave on my pristine soundboard. I've been thinking of using a cream type compound on the end of a cotton tip. We have a marvelous Australian cleaner called Gumption. It is a cream based kitchen cleaner which while having abrasive cleaning properties, seems to be non scratching. I use it on the kitchen sink for instance, and it's good for glass and polishing my induction cooktop. I'm not due for a tune until July, which I hope will happen and not be delayed due to this awful affliction, so I'm reluctant to do anything drastic which might upset a strings tuning. It will be better for leave well enough alone if my delicate cotton tip is not successful,


Chris

Regarding string unevenness how would that change the sound of the piano? I rubbed a few strings with a scotch brite to get rid of some black rust and am concerned that i may have changed the sound of the strings. Although it could be just a placebo effect.

Excessive humidity can be the culprit if you notice that the unwound steel strings are developing spots of black oxidation. Keeping a grand piano closed when not in use is helpful and occasionally very carefully vaccuum cleaning the strings with a soft brush to remove dust which attracts dampness is useful.

Scotch brite cloths are effective in removing the spots, but do NOT try to clean the copper wound strings with a scotch brite as it will clog the copper windings. Remove only the spot and do not try to clean the entire string.
Apply minimal pressure to the string as any excessive force can stretch the string and or affect the tuning.
Careful attention to this string maintenance will keep the inside of your grand piano looking pristine.

Vertical pianos are less prone to rusting strings as long as the instrument is in a humidity controlled environment. Cleaning strings in an upright is also a more complicated procedure as the action has to be removed and the strings are less accessible.

Good luck!
Robert.

Steel wool leaves behind particles that easily .....rust!
Ian

How do you know if you put too much force. Does it change the sound of the strings if you were to rub too hard?