old "elbow" plastic

[Frances Helms]

That all makes perfectly good sense.  However, many of the ones I have run across (should have run over?) have never had a damp chaser installed.
Perhaps they would have fallen apart sooner if they had.  Still the flanges, etc. lasted far better than the elbows. Maybe just wear & tear from the movement?
Fran Helms
Topeka

Don <pianotuna@accesscomm.ca> wrote:

>Hi Joe,
>
>It's quite simple really. The speed of any chemical reaction doubles with
>every 10 degree C. increase in temperature. Most plastics are made with
>polymerization process to make long chain molecules. The long chains
>eventually break down and you end up with very brittle parts. Heat from any
>source will speed the process of depolymerization.
>
>At 10:04 AM 10/23/02 -0700, you wrote:
>>I was told many years ago, (I forget by whom), that the possibility of
>>electrical ions, emitted by the D-Chaser, effected that type of plastic.
>>Okay, it's a stretch, but on every piano, with plastic parts, of that age,
>>and with a D-Chaser, (improperly installed, IMA), this was my observance.
>>The reality is that the catalyst that hardened the plastic, (in the mold),
>>continues to harden forever. IMHO, it is just a matter of time before ALL of
>>the plastic parts, (of that specific era), will fail. The REAL FUN ones are
>>those with wippen flanges, butt flanges, damper levers/flanges, backchecks
>>AND Jacks, made of plastic!
>>Replacing the flanges is not really a big deal, compared to replacing the
>>whole damper lever, sans head/felt. Alignment is always difficult.
>>These things seem to run in spurts. In the seventies I did a whole wad of
>>them. Then, I didn't have any to do until mid 80's. Then there was a long
>>period where I thought, "Well, I guess they've either been given last rites
>>or have been taken care of." WRONG! In the late 90's another wad of
>>them....."same thought".....WRONG AGAIN<G>!!!! .....2000 rolls around
>>another wad of them, ( I did 4 in two months!).....Gawd, Now they're rearing
>>their ugly head AGAIN!
>>How many million of those beasts were made???????? I think they're breeding
>>while they are being left to their own devices!!!![G]
>>Best Regards,
>>Joe Garrett, RPT, (Oregon)
>>
>>Been There, Didn't Like It, So I'm Here To Stay! [G}
>>
>>_______________________________________________
>>pianotech list info: https://www.moypiano.com/resources/#archives
>>
>>
>
>Regards,
>Don Rose, B.Mus., A.M.U.S., A.MUS., R.M.T., R.P.T. Tuner for the Center of
>the Arts
>
>mailto:pianotuna@accesscomm.ca
>
>http://us.geocities.com/drpt1948/
>
>3004 Grant Rd.
>REGINA, SK
>S4S 5G7
>306-352-3620 or 1-888-29t-uner
>_______________________________________________
>pianotech list info: https://www.moypiano.com/resources/#archives
>

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