has anyone ever tried this?

[Brian Doepke]

Good info....thanks.

Brian P. Doepke, (dep-kee)
R.P.T. (Registered Piano Technician)
AAA Piano Works, Inc.
Piano Tuning-Repair-Purchase Consults
260.417.1298
260.432.2043
    www.aaapianoworks.com
 

-----Original Message-----
From: Ron Nossaman [mailto:rnossaman at cox.net] 
Sent: Wednesday, November 07, 2007 2:40 PM
To: Pianotech List
Subject: Re: has anyone ever tried this?



> While I don't know if Mike Spaulding is 100% correct that "it's all in 
> the bends", -------

Yes, he's correct. There's no such thing as pre-stretching 
because wire pretty much ceases to stretch as soon as it's at 
pitch (tension).

This is from Mechanics of Materials, by Larson & Cox, 
published by John Wiley and Sons, 1947

"When an elastic material, such as steel, is loaded at 
ordinary temperature, it deforms in proportion to load almost 
simultaneously with the loading. Thereafter, the load may 
apparently act on the material for an indefinitely long long 
period without causing any further appreciable change in 
dimensions. Even if the material is stressed above it's 
elastic limit, after an immediate deformation there appears to 
be no further change in dimensions until there is some change 
in load."


 From Tool Engineers Handbook, by the American Society of Tool 
Engineers Handbook Committee, published by McGraw-Hill in 1949

"At room temperatures, creep is of no practical significance 
in steels, but does reach measurable proportions in such 
metals as lead, tin, and zinc."


Innumerable sources agree that creep in steel is significant 
above 700°F.

In other words, it's the bends.
Ron N