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MMD > Archives > May 1996 > 1996.05.27 > 05Prev  Next


Chapell Player Piano
By Craig Brougher

Sounds like what several others have had happen to them when using the patent leather, Larry.

The fix is (relatively) easy if that is the case. Here is the problem: When you use patent leather, you are using a material that has a very "sticky" surface, in that it seats perfectly air tight on metal, but will not slide to adjust. All valves have to be able to seat each time. They are not like the valves in an engine. They are not machined. They have to be able to seat by tipping just a little each time they are played, and then when they reseat on the inside valve seat, the same thing must happen or it will not hold air.

If the total seepage of each valve was no more than a #70 drill bit, which is about the size of a pin, the total leakage would be 1/4" hole drilled right through the reservoir. So if only one valve wasn't reseating for you, it could practically stop that player cold. Here is what to do:

Get some TFE mold release spray, like the kind sold through Graingers Supply. Remove the inside valve plates and give them about 6 coats each, allowing them to dry between coats. do the same to the leather-- with maybe 1-3 coats. Test it first before replacing it. Make sure you feel a definite difference. you want it to be able to slide easily without the stickiness associated with patent leather on plated brass. Whatever it takes for one test valve, it will take for all. once you are satisfied that this is what will work, do it to all of them. Whether or not this is the problem directly, do it anyway, or you will be very sorry.

Another common problem has been that the pressure collars are too tight against the valve disks and will not allow them to tip easily. If they cannot effortlessly adjust as they operate, they cannot seal regardless of the slickness of the surface. Suede on metal valve plates is no problem. Corrected calf isn't either, as long as it isn't lacquered. But patent leather is vinyl and that's another breed of cat.

There is only one other possibility that comes to mind on this player. It could be that the pouches are too close to a few of the valves, standing them open just enough that you can't develop any vacuum. So you may find you have a multiple problem. Don't get your valves any closer than a 1/16" to a pouch on that player, and better, try an 1/8" between centers, since neither pouches or stem lifters are all that true and straight. The valve will operate faster, as well.

I would like to congratulate you, Larry, for sticking with it and giving your customer his money's worth regardless what it may cost you in time to do so. I too have had to take care of problems in the same way, particularly when I first started. It will make you "expert" more quickly than anything else I know of. Too many rebuilders just write this stuff off. You are to be commended.


(Message sent Mon 27 May 1996, 11:38:07 GMT, from time zone GMT.)

Key Words in Subject:  Chapell, Piano, Player

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