Neoprene Tubing/ Fire !!
By John A. Tuttle
The Headline read, "Player piano burns but house is spared".
Fortunately, or unfortunately, depending on your point of view, that headline appeared in my local paper in 1990 and it was MY house they were talking about.
I had been working all day on a player that had already been inspected by the customer and was scheduled for delivery and I had gone out that evening with a friend. For legal reasons, I called the arson squad when I returned home (11:00 PM) to find the freshly refinished, completely restored and fully automated 1917 Lauter/Humana completely scorched on the outside. (For those truly interested in all the sorted details, I will draft a letter and send it to you upon e-mail request.)
At about 1:00 AM, it was determined that the push-button switch I had installed earlier that day (the switch was mounted in the left wall/upper half of the spool box) was faulty and when it arced it set the cotton/polyester sheet (I was using to keep the dust off) on fire. As it spread quickly down the sheet , it caused a "flash fire" on the freshly finished parts (17 coats hand-rubbed lacquer) and the hardwood floor. The fire destroyed the veneer. It's repair/replacement is another story.
Having been an electronics technical responsible for calibration and repair of electronic testing equipment for a number of years in my earlier days, I was not convinced that the switch was to blame. So I did a little testing on my own. However, I did not test switches.
At this point I must back-track for just a moment. When I installed the switch, I determined that the external power connections (tabs, connectors) were uncomfortably close and exposed. And even though they posed no real danger to the operator (since they were outside of the spool box) I elected to "insulate" the connections with a small piece of black neoprene tracker bar tubing thus eliminating the possibility of accidental shock. After soldering the connections, I slipped the tubing over the joint. Nice, neat and clean. Because of the close proximity of the connections, the two pieces of tubing slightly touched each other. I thought, "boy, it's a good thing you decided to separate those connections, it would be easy to short them out."
Well, for those of you who know the ingredients of neoprene tubing, the resultant fire is no mystery but to those of you that don't know, black neoprene tubing uses carbon black as one of its ingredients. Carbon is an extremely good conductor of electricity and when put between 115 volts AC and ground ("0" volts AC) it becomes a resistor (an electronic device which allows but limits the flow of electrons and gives off heat). If the amount of resistance is too small (as compared to the difference voltage), the current (the number of electrons/second that flow) flowing through the "resistor" will cause it to burn up.
In this instance, the resultant "burning-up" (or carbonizing) of the neoprene tubing was significant enough to set the sheet on fire. The rest is history.
I hope this true story will educate at least two people. Then two people will tell two people and they'll tell two people, etc., etc., etc. My attitude is that the loss I suffered is meaningless unless it can be utilized to educate someone else and ultimately prevent a similar mishap.
Am I embarrassed by this incident?? No. I learned a valuable lesson and the insurance company paid for the refinishing, re-veneering and the other 1917 Lauter/Humana that I located and purchased for parts. (The Serial Numbers were less than 100 apart and the models were identical, but the cases were slightly different owing to the fact that they were all "hand made". ---------------------------------------------------------------------------
John A Tuttle "Self-Playing Pianos" E-mail:tuttleja@concentric.net
407 19th Avenue 908-840-8787 (leave message)
Bricktown, NJ 08724 Rolls:1-800-870-8784 (leave order)
"We Keep Your Music Rolling" http://www.concentric.net/~tuttleja/
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(Message sent Fri 9 Aug 1996, 22:17:47 GMT, from time zone GMT-0400.) |
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