Rusty tines... What do you guys do with'em?

[Groove4Hire]

I got this 88 in the shop that is beyond repair but it has a good deal of parts I can reuse. The tines however are rusty and corroded and I was wondering what procedures you guys have to remove corrotion on tines?

[Ben Bove]

Depending on the level of rust and corrosion - if they are just generally rust colored, you could remove that and still use the tines without worry.  If they have severely corroded where it looks like they've "bubbled up", and if you sand them down with sand paper to reveal pitting or evidence of missing chunks of metal in the tine, it's best that you let the middle section of tines go.  You could probably salvage the tines in the lower bass and perhaps the higher treble areas, but the "high traffic" areas will definitely start to snap off.

I've tried to save a piano with heavily corroded and pitted tines, and after spending forever cleaning them up, the tines began to break one by one.  About 6 in a month.  Reason being, the structural integrity of the tine is compromised when metal corrodes out of it in an irregular pattern.  The diameter of the tine actually becomes thinner at the points where there is missing metal, and when the stress of flexing the tine at these points happens on striking, they're more prone to snapping at these thinned out corrosion points. 

This is a good example of the before and after of the type of tines that would be susceptible to breakage after being cleaned up. 



if you can imagine a tine being flexed in the upward position, at the "anodic site" in the diagram below.