[pianotech] blackening rusty tunning pins

[tnrwim at aol.com]

Wim, fyi:
f I am cleaning up an old piano in the shop, I would use the rust
onverter on the pins and afterwards for rusted strings, I use
allistol gun oil with a ScotchBright pad to clean the strings. The
ust comes off very easily, almost like it is dissolving. Obviously,
ou can only clean about half to three quarters of the string
ircumference this way, but there will remain some Ballistol residue
n the strings that will prevent further rust.

Greg

Cleaning rust off the strings is fine, for cosmetic purposes. But the main problem with rust on the strings is at the pressure points and the strings, like at the agraffs, the capo bars, the tuning pins, bridge pins, etc. That is where the string breaks. So cleaning the pins and strings is nice, but it won't prevent the string from breaking.

Wim



 



-----Original Message-----
From: Douglas Gregg <classicpianodoc at gmail.com>
To: pianotech <pianotech at ptg.org>
Sent: Wed, Feb 1, 2012 5:33 am
Subject: [pianotech] blackening rusty tunning pins


For Joes sake.
 attached another photo of the rust restoration on the tuning pins.
he color balance is better on this one, though the magnification is
ess. There is indeed rust on the pins on the right side. If there
ere no rust, the converter would not change them to black (on the
eft side). It does nothing to polished metal, or painted metal for
hat matter. IF there are rusty bare spots on the painted plate, it
ill also turn those spots black.
 Rust Converter is a water-based primer, containing two active
ngredients: tannic acid and an organic polymer. The first ingredient,
annic acid, reacts with iron oxide (rust) and chemically converts it
o iron tannate, a dark-colored stable material. Tannins are a group
f water- and alcohol-soluble natural products extracted from fruits,
oak) trees and grasses. The second active ingredient,
-Butoxyethanol, is an organic polymer that provides a protective
rimer layer. The overall chemical reaction converts rust into a
table, black protective polymeric coating that serves as an excellent
rimer for both oil and epoxy based paints. You can spray treated
uning pins with a thin coat of  clear lacquer to make them glossy if
ou like. It stays on pretty well even after several tunings.
The formula name for tannic acid is
,3-dihydroxy-5-({[(2R,3R,4S,5R,6R)-3,4,5,6-tetrakis({3,4-dihydroxy-5-[(3,4,5-trihydroxyphenyl)carbonyloxy]phenyl}carbonyloxy)oxan-2-yl]methoxy}carbonyl)phenyl
,4,5-trihydroxybenzoate.
I just  thought you would want to know Joe, since you asked.
 There is also an ethanol alcohol carrier and ether propellant. So
on't smoke while spraying.
It is correct that bluing is an oxide. True gun bluing is an
lectrochemical conversion coating resulting from an oxidizing
hemical reaction with iron, forming magnetite (Fe3O4), the black
xide of iron. Black oxide provides minimal protection against
orrosion, unless also treated with oil. You might notice a thin film
f oil on a new set of blued pins. They do rust in the box anyway with
ime.
None of the products in rust restorer will remain in liquid form for
ore than a few minutes on the pins and it does not creep into the
inblock. There is no oil or silicones. The ethanol and ether are gone
n seconds. The tannin reaction takes about 15 minutes so don't expect
nstant blackening.  I do recommend spraying it lightly from 4
ifferent directions in order to get an even coating without soaking
he pins unnecessarily.
Wim, fyi:
f I am cleaning up an old piano in the shop, I would use the rust
onverter on the pins and afterwards for rusted strings, I use
allistol gun oil with a ScotchBright pad to clean the strings. The
ust comes off very easily, almost like it is dissolving. Obviously,
ou can only clean about half to three quarters of the string
ircumference this way, but there will remain some Ballistol residue
n the strings that will prevent further rust.
AND NO Joe, Ballistol does not creep up the strings and down the pins
o soften, rot or otherwise damage the pin block. To follow up a
revious concern about Ballistol (that I routinely use for center pins
hat are sticking or sluggish), Ballistol is entirely safe for wood.
t has been used for 100 years on guns with wooden stocks that are
recision machined to fit perfectly with the steel components.
nything that would soften or weaken gun stock wood would never have
urvived the test of time. Ballistol is antimicrobial due to its basic
H and thus prevents growth of bacteria and fungi that are the primary
ause of wood rot.  The basic pH also helps control future rust by
eutralizing amino acid from your fingers or the H2SO4 in the
nvironment coming out of all our catalytic converters on our cars.
I buy Ballistol on line from Midway USA.com.They have a good price and
ast delivery. I carry a spray can or two with a straw in my kit at
ll times and have bulk cans in my shop too for cleaning strings or
pplication with a syringe.  I have no affiliation with Ballistol or
idway USA. I just love the stuff and won't leave home without it. I
earned about it from another old piano technician who had used it for
0 years. I have used it for about 7 years. (but I'm old too)
Doug Gregg
lassic Piano Doc
outhold, NY


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