Horror Story: Epoxy on Tracker Bar Nipples
By Terry Smythe
Over the past 10 years or so, I've been quite successful in declining to restore for other people. However, I was recently persuaded by a friend of many years to "have a look" at his new pumper player piano -- in less than a year, it has stopped playing about 20 notes in the mid-treble.
His piano is out in British Columbia, so he removed the upper action, built a first class crate, and shipped it to me. Here's what I found. Perhaps someone can suggest some appropriate help.
The piano is from the late 1920's, containing automatic sustain, theme accents, and a transposing tracker bar. First time I've encountered both theme accents and transposer in a single tracker bar. The piano is understood to be restored. Interesting. The plot thickens. ... :-)
1. First thing I find is that it still contains original pot-metal tubing, fabric covered, much of it crushed. This tubing is still imbedded, in what appears to be shellac as a sealant, in the manifold board at rear. Single valve system. Bench test at 30-inches vacuum reveals few notes playing properly, many play constantly (leaking shellac I suspect), no reiteration on any notes, slow returns on many, generally very poor performance. One year old restoration? Hmmm. ...
2. The overall problem relative to intermittent and poor performance goes deeper than just the old pot-metal tubing. In addition to the tubing, I now suspect valves and possibly pouches. These I cannot test without actually tearing down the action and physically examining the pouches, valves and bleeds. Likely it's quite straightforward.
3. Some notes play constantly, confirming early suspicions about the old tubing and their poor seal on the rear manifold board shellac sealant. Atmosphere is clearly leaking into some of these tubes, inflating the pouches constantly, holding open the valve constantly, not possibly to shut off.
4. From the components on the spool box deck, I deduce that the piano is equipped with theme accent pneumatics, likely alongside each side of the bottom bellows. The deck contains a theme cut-off on rewind, and the spool box contains theme and sustain on/off switches. Unfortunately, the theme rubber tubes are connected to nothing. This tubing is there, passes into the bundle behind the bar, and there they sit, appearing to be hooked up, but in fact hooked up to nothing.
5. The present tracker bar is not original. The original tracker bar would have provided for both sustain and bass/treble theme ports. In fact, this tracker bar has provision for sustain only. Somebody has machined an additional hole on the bass end that may have been intended for bass theme, except that is has been machined in the wrong place. So, while there is indeed a brass nipple behind the new port, nothing is attached to it. The tip-off is that its insides are still gleaming clean; no air has ever passed through it. There is no comparable port on the treble end of the tracker bar.
6. The tracker car does contain a nifty transposing capability, but it doesn't work. It cannot possibly work. It appears that the original tracker bar was removed, but leaving behind the old pot metal tubing which, by some form of brute force was fitted to the replacement tracker bar. Much of the old tubing was damaged in the process and short lengths of rubber tubing was substituted. It likely had zillions of leaks when first assembled, so the entire tracker bar nipple array was immersed in what appears to be epoxy cement, making it a solid mass.
7. Rotation of the transposing knurled wheel should ordinarily move the center part of the tracker bar back and forth behind the music roll, transposing the music output into whatever key desired within a range of six. Movement of that center portion is totally dependent upon freely moving bundles of tubing behind the bar. The solid mass of epoxy bonded tubing cannot possibly move freely. That tracker bar ain't goin' anywhere!
8. To provide for transposing capability, the tracker moves under the paper on pairs of parallel slide rails. This bar must therefore have gaps at either end into which the parallel rails must slide. The space consumed by these gaps would ordinarily have within it theme ports for bass/treble theme accents. So there is none.
9. As a consequence, he has neither transposing nor theme accents. The tracker bar cannot possibly move through its full transposing range and it does not contain the needed theme ports.
Overall, I have a fairly clear perception that whoever attempted to restore this action did not understand how a player piano works, got into trouble part way through, and tried to finish it by brute force. The intermittent poor performance is clear evidence of both leaky tubing and faulty valve performance. I expect to find stiff, torn and perfor- ated pouches upon internal examination, along with plugged bleeds.
The 88-note pneumatics have been recovered with suitable material in a neat, clean fashion, and appear to be properly re-glued to their decks. Curiously, two different kinds of fabric has been used, both similar in weight, thickness and flexibility, but quite different in materials. Two decks in gray rubber/cotton, and the remaining deck in shiny black rubber neoprene/nylon. The finger lifters all appear to have been properly reinstalled back on their original pneumatics, undamaged. All push rods move freely their felt guides. That portion of the restor- ation appears to have been done reasonably well.
I am uncertain if the transposing tracker bar can be salvaged, as I have never experienced such a situation. Epoxy is ordinarily intended for use in situations where it will never ever be removed. I have my doubts that it can be removed. Has anybody experienced such a situation before?
I have a feeling that he will have to abandon the transposing feature and hopefully find a tracker bar with sustain and theme ports. Thoughts of others? If anybody has such a tracker bar available, I would appreciate hearing about it.
Interesting, the mess we sometimes get ourselves into trying to help our friends. "Oh Well, okay. I'll have a look at it, and let you know. ..."
And so it goes. :-)
Regards, Terry
Terry Smythe smythe@mts.net
55 Rowand Avenue smythe@freenet.mb.ca
Winnipeg, MB, Canada R3J 2N6 (204) 832-3982 (voice/fax)
http://www.winnipeg.freenet.mb.ca/~smythe
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(Message sent Sat 28 Dec 1996, 03:48:58 GMT, from time zone GMT-0500.) |
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