<HTML>James, There is seldom need for DC units installed in this region, the SF Bay A= rea.  I'm not sure of the relative humidity, but it is very temperate. =  Most of the old pianos that have spent their lives in this area, if ca= red for, are in good condition.  I so seldom see rust on piano strings,= that seeing it on a piano this new really surprised me. The house is a newly remodeled, multi-million dollar home with digitized= this and that, climate control, yada, yada...which is another reason I was = taken aback by this. I made several recommendations based on my observations, but whether or = not they are necessary depends on a couple of things.   I'll wait and see if a few more people want to guess at it, then I'll le= t you know what I'm pretty certain is the cause. Dave In a message dated 2/13/04 5:49:38 AM Pacific Standard Time, jkelly1722@= earthlink.net writes: <BLOCKQUOTE TYPE=CITE style="BORDER-LEFT: #0000ff 2px solid; MARGIN-= LEFT: 5px; MARGIN-RIGHT: 0px; PADDING-LEFT: 5px">A lot will depend on the en= vironment the piano is in and where it came from, how it was stored etc etc.= Give me more details- are you in a high humidity location ? have you measur= ed the temp and r/h in and around the piano ? what type of house is it- new = old drafty ? I hope you have looked at the possibility of a full dampp chaser and un= dercover for this piano ? I am on the coast of SC and see all types of rust issues. New piano rus= t in no time- I tuned a Pearl River Grand the other day with rust pits on mo= st of the high treble/non damped strings. One trichord had crusty rust near the tuning pins on all 3 strings.  Tr= y as I do it is hard to convince people that humidity control systems are ne= eded here. I have a full system in my Wurlitzer console and you can not find 1 rust spot in it. We had an incredible hum= id summer and without a dc it would have been a rust bucket. Over the winter= it has called for water about every 2 weeks because the relative humidity i= s low.  You mentioned you think you know the cause - what do you think it= is ? Is the piano near windows or ac/heat vents ?   </BLOCKQUOTE> </HTML>