[pianotech] Bridge pin question

Allan allan at sutton.net
Sun Jun 21 16:32:41 MDT 2009


 

Would this new Gorilla super glue Ed Sutton told us about do, anyone?

 

Ed Sutton wrote on may 31: ( What is the kicker he sprayed?

 

Gorilla brand Super Glue "contains tint rubber particles which make it
impact resistant."

 

My first tests confirm that Gorilla Super glue and Super glue gel have
unique working qualities of value to piano technicians.

 

1) Bench top test of pinblock scrap with tuning pin loose in the hole. I
swabbed the hole with Gorilla Super glue and let it harden, then drove the
pin. It felt very tunable, not "crackling," and after about 25 times
back-and-forth swings of the lever (about 45 degree swings), it still felt
the same. 

 

2) Dog chewed corner of ebony pedal box. Made a "mold" by taping gummed
package tape to the box, and squirted Gorilla Super glue gel into the mold.
Sprayed kicker and let it harden for about 30 minutes. Peeled off the tape
and pared it with a chisel to fit the contour. Sprayed with primer and black
lacquer. Good result.

 

3) Drilled a 3/16" hole in pinblock scrap, filled with Gorilla Super glue
gel, and inserted a #7 bridge pin, vertical, 3/8" of the pin sticking out.
Sprayed with kicker and let harden for about 5 hours. Pared the top flush
with a chisel and then tapped the pin with a hammer until it was bent 45
degrees. The glue collar didn't crack or chip.

 

This stuff seems to perform as advertized. It is strong and more impact
resistant than standard CA. The "thin" glue is a bit thicker than standard
thin CA, and the gel is "gel." Both take somewhat longer to harden than CA
glue, which I find comfortable. It is easy to carve at first, harder to
carve after a few hours.

 

I think this glue has good potential for use in piano work, such as in
repairs of music desk hinges, loose key tops, possibly for loose and popping
tuning pins, and bridge and bridge pin repairs.

 

Available at hardware and home supply stores. (Wherever Gorilla Glue is
sold!) Use at your own discretion and let us know how it works.

 

Ed Sutton

 

 

 

 

Allan Sutton

www.pianotechniquemontreal.com

  _____  

From: pianotech-bounces at ptg.org [mailto:pianotech-bounces at ptg.org] On Behalf
Of Geoff Sykes
Sent: 21 juin 2009 16:07
To: Pianotech at Ptg. Org
Subject: [pianotech] Bridge pin question

 

Greetings all --

 

After 11 years of complete non-use I was called in to tune a 1966 Hamilton
(by Baldwin) console so the young daughter could start taking lessons. Then,
after about six weeks, I was called back to investigate a buzz, or rattle,
that had started since that first visit. What I found was the right string
of C4 sounding like a paperclip had been wrapped around it. 

 

What I discovered was that the bottom bridge pin on that string had worked
its way out far enough that there was no longer any bend in the string
across the bridge and therefore no termination. The string was rattling
against the top bridge pin. The bridge around many of the bridge pins showed
signs of a previous tuner aggressively seating the strings. This particular
string even showed nicks in the wire so I guess this is not a new problem
for this piano. I also noticed that many of the strings are going across the
bridge with bridge pins in such a straight line that I'm surprised that
other notes are not also exhibiting the same problem. 

 

Anyway, I took a screwdriver and tried to see if I could even move the
problem pin, or perhaps even re-seat it a bit. The bridge pins on C4 happen
to be directly behind a plate strut so access was NOT easy. But a little
leverage and POP, the pin just popped back into its socket and the buzzing
went away. But it shouldn't have because there was still no tension of the
string across the top bridge pin. What had happened was that putting the pin
back in place had somehow moved the top of the string just enough so that
the hammer was no longer striking it. At which point I remembered that when
I first tuned this piano I found a good 10 or 15 notes with hammers not
striking the right string. Time and budget prevented me from correcting that
problem and I wound up just plucking the right strings to get the unisons
in. C4 was apparently one of those notes, and now that the piano was
actually being played the bridge pin for the right string had worked its way
out enough to cause this problem. 

 

So, today's question: The bottom bridge pin for the right string of C4 is
still technically loose and sitting in a very worn hole so this problem will
return. It's the only pin that is showing this problem but, except for the
previous technicians abuse, the bridge looks pretty good. No noticeable
cracks or anything. Just this one very worn hole. I'm looking for
recommendations on how to repair this one pin so that I can then go in and
correct some of the regulation problems. 

 

I look forward to your comments.

 

-- Geoff


 

. Geoff Sykes, RPT
. 626-799-7545
. www.ivories52.com <http://www.ivories52.com/>  

 

Checked by AVG - www.avg.com
Version: 8.5.375 / Virus Database: 270.12.83/2191 - Release Date: 06/21/09
05:53:00


No virus found in this incoming message.
Checked by AVG - www.avg.com
Version: 8.5.339 / Virus Database: 270.12.83/2191 - Release Date: 06/21/09
05:53:00


-------------- next part --------------
An HTML attachment was scrubbed...
URL: <http://ptg.org/pipermail/pianotech.php/attachments/20090621/5bcf952f/attachment.htm>


More information about the pianotech mailing list

This PTG archive page provided courtesy of Moy Piano Service, LLC