Howdy folks,

I restore vintage electronic and acoustic musical instruments, however, I'm relatively new to acoustic pianos. Anyhow, I recently bought a Yamaha CP70 stage grand piano for $120(Australian).
For those unfamilliar with this model, its a 73 note, small scale grand piano with transducer pickups on the strings for use in FOH PA systems and Rock concerts. I had been after one of these rarities for over 10 years.

It's a basket case that a guy had sitting in his garage in peices for about 8 years, in fact the only thing that is completely assembled is the iron harp assy complete with the strings and electronics. This is the most complex project I have ever undertaken.

What I would like to know from everyones far superior knowledge is regarding rusty strings.

The iron harp frame and strings all have suface rust, and I was wondering, if I should get rid of all the existing strings clean the frame repaint it and re-stringing all of the 73 notes?

Is sanding back, re-painting the iron harp frame and re-stringing a crazy suggestion?
Or is there a far simpler solution?

Cheers,

David

PS: I know this place is just about pianos, but I have successfully rebuilt a number of instruments including a 1973 Hammond X5 organ and a 1965 Hohner electric piano (similar to a Fender Rhodes). Please don't go nuts at me I'm only new here.

Hi, you must take sizes of all the strings, there will be progressivly different thicknesses which need to be measured, for the bass strings they will need to be send as a set for duplicating unless Yamaha has a spare set laying in a wharehouse somewhere.

As it is build like a piano, to restring it must be approached as you would restring a piano - note the neatness of the coils, e.g. you dont put strings on and tie them off as most guitarists do!

Yamaha CP70 has bichords throughout (apart from the bass) if the strings are coated with a thin layer of rust I would suggest cleaning them with scotchbrite as tone will not differ a great deal by restringing because of the pick ups and the hammers are leather (unlike the wool found on acoustic). Try this first and see if your happy with the sound, as stringing the bass is castly a especially with such a short string on the CP70 the difference would be minimal, the amplifier could balance out the discrepancies anyway. Try it.

What you do in this cases is: take an eraser made of rubber (for pencil)and clean each string from end to end then clean all of them with a rubber cloth those use for car detailing then unwind those strings that have wire wound copper (BASS AND TENOR RANGE APPROX) take them off an make a tight loop with the string, you can use may be a tube to loop the strings, that will help to take off the rust and it won't damage the string when you put them back twist them a little bit. good luck!

Thanks very much guys, these are all really great sugestions. I have since read up on piano tuning and I know I'm not ready to undertake replacing all of the strings, besides it's just too bloody expensive. For the time being cleaning the strings is good enough for me.

Thank you all,

David Krappon
Australia