[CAUT] Lacquered hammers

[Ron Nossaman]

Speaking of less than stellar scales in production pianos (and speaking 
of Samick), last week I tuned a Samick SU-143M, that I had tuned for the 
last five years or so. The low string of the F#-3 bichord popped as I 
pulled it up to pitch. Two splice attempts also popped, so I brought it 
home for replacement. Out of curiosity, I took measurements and put them 
in my scaling spreadsheet. It's an 0.032" core, 0.047" outside wrap 
diameter, and an 865mm speaking length. According to Sanderson's math, 
that puts it at 73% of breaking strength at pitch. That goes a ways 
toward explaining why the splices failed.

So here we are. The wrap is about 0.007, which is already smaller than I 
like, so there's no hope of increasing the core and reducing the wrap. 
You know that in plain wire, the break% doesn't meaningfully change with 
a wire size change. With wrap this small, a similar situation occurs. By 
increasing core size to 0.036", with 0.007" wrap, I can get 66% break, 
and let the inharmonicity fall where it may. What I'd like is about a 
100mm shorter speaking length, but that's hard to get with a field repair.

Welcome to the world,
Ron N