Lead Tubing in Spool Box
By Mike Amoroso
I recently acquired a 1926 model Mason & Hamlin, 7' piano with a model A Ampico in original unrestored condition. I am presently in the process of restoring the Ampico system and I have two questions regarding lead tracker bar tubing.
1 - Since the tubing is more than 70 years old should it be replaced?
2 - What material should be used to seal the tubing tracker bar (one end) and to the "take-off" nipples (other end) ?
The lead tubing does not show any sign of deterioration from the outside. Looks like there was a coat of varnish painted over the tubing, probably to both protect them and to help hold them in place. Do I have to be concerned about deterioration from the inside out? Can this tubing last another 30 to 50 years? If so should I use more varnish or possibly phenoseal over the lead?
The joint between the lead and the "take-off" nipples has failed. I have removed all of the original sealing material which was sort of off-white in color. Someone told me that they sealed with putty. Old fashioned window putty?? I have concerns that window putty would not flow well enough to make a good seal around the lead-nipple interface. Also it would not provide for rigidly holding the nipple so it would not rotate while installing the rubber tubing on the other end of the nipple.
I do have a general purpose two part epoxy (eccobond 286) that will bond and seal to wood, plastics, and metal. I believe this material will do the sealing and bonding job quit well. The only problem will be in the future for the next restoration. The epoxy can be removed but the process is a little more difficult. Some amount of localized heat will have to be applied (heat gun) to break down the epoxy. I expect that the lead tubing would not survive, but if this joint is being taken apart then the tubing has most likely failed anyway. What comments does anyone have about using epoxy?
Michael Amoroso
[ Digest 961231 mentions non-hardening cements to seal the lead tubing
[ to the tracker bar nipples. -- Robbie
|
(Message sent Sat 1 Mar 1997, 13:20:48 GMT, from time zone GMT-0400.) |
|
|
Mechanical
Music Digest™ Archives
