cephus
Slow Children Playing
As a control, I am keeping a string in the packet in my desk drawer and I will put it on my guitar and tune it at the conclusion of the experiment to prove exactly nothing.
muttley600
Banned
That link proves nothing other than ignorance on the subject is more widespread than maybe we at first suspected.
It's all well and good carrying out a back room experiment that by it's very nature has too may flaws in it to prove anything conclusive in either direction but the real data is out there already both in terms of the physics of a vibrating string and the properties of the materials being discussed. They can be obtained from professional institutes and standards agencies. Many people here who both work and deal with these phenomena on a daily basis have pointed these things out to you. Until you go read and understand them no one here other than trolls and idiots are going to take you seriously.
I will start with the simple part which is the physics, and ask you the question again.
The pitch or frequency of a vibration string is the product of it's mass per unit length and stiffness and the tension in the string? Which of these properties has changed and how?
TelePaul
J to the R O C
Does a dirty string have more mass than a clean one? All the crud on my fingers has got to go somewhere, no?
Sky Blue Lou
Well-known member
I would think an old string has less mass. Corrosion/oxidation should do this.
lou
lou
Sky Blue Lou
Well-known member
What is the difference between stiffness and tension and how does that affect pitch?
lou
Victory Pete
Banned
Zaphod B
Raccoons-Be-Gone, Inc.
If a piece of iron is left untreated it will develop rust, which is iron oxide. The iron has bonded with oxygen, not lost anything, so you'd think it would gain a bit of mass.
Victory Pete
Banned
Interesting point, but could it also add? Oxygen, salt and other elements could be adding to the mass. Just a thought.
VP
Sky Blue Lou
Well-known member
I disagree. Old rusty metal weighs less than new clean metal. Rust/oxidation is essentially the same process as fire. As a material rusts/burns it loses mass.
That's what I've picked up along the way anyhow. I could be dead flat wrong. I'm real curious now though. I like to know when I'm full of shit.
lou
Zaphod B
Raccoons-Be-Gone, Inc.
I disagree. Old rusty metal weighs less than new clean metal. Rust/oxidation is essentially the same process as fire. As a material rusts/burns it loses mass.
That's what I've picked up along the way anyhow. I could be dead flat wrong. I'm real curious now though. I like to know when I'm full of shit.
lou
Yeah, I'm curious, too. That old rusty metal you refer to may have been out in the elements getting rained on, which would wash off some of the rust. I can't think of how a piece of iron with a rust patina, kept in a protected environment, would lose mass but, hell, what do I know?
VomitHatSteve
Hat STYLE. Not contents.
I disagree. Old rusty metal weighs less than new clean metal. Rust/oxidation is essentially the same process as fire. As a material rusts/burns it loses mass.
That's what I've picked up along the way anyhow. I could be dead flat wrong. I'm real curious now though. I like to know when I'm full of shit.
lou
If I recall high-school science correctly, rust does cause certain metals to decay. Some metals oxidize in such a way that the outer, oxidized layer of metal protects the inner layers, so they don't keep rusting (this is galvinization). Other metals, such as iron decay when they oxidize, so the outer layers flake off, exposing the inner ones to the oxygen.
Sky Blue Lou
Well-known member
Okay, I'm full of shit.
A quick search showed that Lavoisier proved the rusting process adds oxygen and hence weight to the object. So fuckin' sue me.
I think the confusion for me stemmed from something PukeChapeauEtienne (keeping in the French mode to honor Lavasier - poor bastard) just posted. Flakes.
lou
A quick search showed that Lavoisier proved the rusting process adds oxygen and hence weight to the object. So fuckin' sue me.
I think the confusion for me stemmed from something PukeChapeauEtienne (keeping in the French mode to honor Lavasier - poor bastard) just posted. Flakes.
lou
TelePaul
J to the R O C
I really don't think 'crud adds mass' my most profound contribution to science but regardless, you'd have to measure the mass of each string. Not sure how you'd do that. Triple beam? Highly impractical.
muttley600
Banned
Stiffness is a material property that relates to youngs modulus and the stress strain relationship. It is defined by Youngs modulus of elasticity and describes a metrials ability to resist a force applied to it.. It is usually a constant for any give material but can be different in some materials depending on the direction of orientation in which it is measured.
Tension is a force applied to an object and directly opposite to compression. Materials are also measured to give values for tevsile strength as well as compression strength, sheer etc.
muttley600
Banned
More importantly it destroys the uniformity of the strings mass and stiffness per unit length. The same is true of all those dents that fret contact causes as strings wear. Any change in the strings uniformity in these terms will effect the ability of a string to intonate correctly and hold correct pitch. ZB mentioned this earlier if I recall correctly.
Sky Blue Lou
Well-known member
Thanks for the explanation. I basically knew that part - although not in such technical detail - but how does stiffness affect pitch given equal tension and mass?
lou
muttley600
Banned
It doesn't essentially but it is a vital component of guitar string in that it stops the string stretching under prolonged tension as VP postulates.
The stress/strain graph of just about all materials used for strings shows a basic curve and a point at which the material fails and the line just drops to zero.. That point is point of failure and occurs right after or very close to the point of maximum deformation.
DrewPeterson7
Sage of the Order
Ahh, that makes sense. I never really got WHY older strings tended to intonate poorly - I could hear that it was happening, I just couldn't think of an explanation.
Of course, I've probably dedicated approximately 30 seconds to meditating on that - while restringing, I try not to think of much of anything, to make it go faster.
M
mixsit
Well-known member
I always figured the dents' and the crap' but now to mention a string that has streched would have less diameter wouldn't it -and a looser wrap? Never thought of this before but stands to reason.
Victory Pete
Banned
Well if crud, corrosion and oxidation adds mass, then it seems to me that would increase the tension for a given frequency. If this is the case my string in the experiment was not old enough. I am going to try to "age" a set of strings on one of my guitars, I will not clean or powder them to hasten the aging process. If my strings are so clean because of my cleaning methods, (which I believe works great). Then my strings wouldnt support this "crud and corrosion adds mass theory".
VP
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