Hammer flange question

[Israel Stein]

Monday, October 30, 2006 <allan at allangilreath.com>  wrote

> Geoff,

>From experience on this particular vintage of this brand there were some issues on original felt surface condition 
>and pinning. Lubrication and alcohol/water sizing don’t work so repinning is required and, so far, is a permanent 
>repair.

 >Allan

>Allan L. Gilreath, RPT


Allan,

You are right. I was told that this is a problem unique to Young Changs from that era (80's and early 90's), and the use of solutions, lubricants, etc. is not advisable in this case - whatever the pros and cons might be in other cases. What's happening here is a chemical reaction in the bushing. It occurs under dry conditions and a lot of fast playing when enough friction heat is generated between the bushing cloth and the center pin for the reaction to occur, which causes the bushing to tighten up or even freeze. The important thing to do here is to replace the center pin after reaming out the bushing - if you reuse the same Young Chang pin, the problem will recur next time someone plays the Minute Waltz (or any other fast passage work) in low humidity. In the later YC pianos they eliminated the problem by changing their process. 

I had a piano teacher client back in Boston in the late 80's - early 90's with a brand-new YC grand who was constantly on the phone every winter (when the forced-air heating had the humidity down to the 30% range) with a few frozen hammershank flanges. I must have reamed/repinned all her shanks two or three at a time over 5 winters. Never did take any of my advice as to how to prevent recurrences... 

Israel Stein


>>From: pianotech-bounces at ptg.org [mailto:pianotech-bounces at ptg.org] On Behalf Of Geoff Sykes
>>Sent: Monday, October 30, 2006 12:19 PM
>>To: Pianotech at Ptg. Org
>>Subject: Hammer flange question

 >>Greetings all --

 

>>I have a customer with a Young Chang G-175 on which I'm going to go in and do some regulating. It's a 1987 so I
 >>know that it's in the middle of the growing action brackets years, but so far it shows little, if any, signs of this 
>>happening.

>>Most of the hammer flanges in this piano are too tight, giving from one to two swings at best. Today's question is
>> about hammer flanges.

>>If a flange is too loose, the bushing would usually need to be re-pinned, yes? That said...
>I understand that there are three ways to deal with too-tight flanges:
 >>1) repin - remove the old pin, replace and/or ease the bushing and repin
 >>2) lubricate - with Protek, Goose-Juice, Naphtha+Silicon, etc.
 >>3) ease - Alcohol and water

>>What would you consider to be the requirements for any of these treatments? In other words, why and when do you 
>>choose one of these treatments over the others?

>>In the case of this Young Chang, the bushings and pins are clean, showing no signs of verdigris.

>>Looking forward to the discussion.

>>Geoff Sykes

-- Assoc. Los Angeles