December, 2006
 All the parts in a box |
 Half the parts laid out |
 Other half laid out |
 Old worn valve pistons |
 Pistons and casings |
Click on a photo to see it larger
I took these pictures at Musician's Repair this afternoon. As of today, the instrument has been disassembled to the degree necessary for the refurbishment. The valve cluster has been removed because all of the valves must be overhauled. In the process, most of the other internal plumbing was also removed. Some of it was damaged, needing replacement. Other pieces needed to be removed in order to get access to sections that need some dent removal.
I would describe the project in these phases:
1) Assessment. Rick Oldham reviewed for Phillips Guild students the work that was needed during a Saturday morning session at
2) Disassembly. Maurice Oldham, Rick’s father, took the horn apart, and that’s where we are at the time of these photos. In the process, there has been light buffing to clean up the joints and to remove any lacquer. Maurice founded the Musician’s Repair Service business some 50 or 60 years ago. He joked that he would tear it apart, then leave for his annual vacation in
3) Valve overhaul. We will send the valve cluster and pistons to a specialty firm. They will bore out the casings to a diameter slightly larger than original, using tooling that is much more precise than the machinery available when the instrument was originally built. That will leave the pistons loose in the casings. The pistons will be polished to eliminate any imperfection. Then they will receive layers of copper and nickel plating to build up to a size to match the new cylinder bore. This will make a too-tight fit. At that point, an expert will "hand lap" the valves. This is done by applying a slightly abrasive "lapping compound" and working the pistons, removing slight amounts of the plating material until there is a perfect balance between fit and action. When they are returned, these valves will definitely be better than new because we are using more precise processes today.
4) While the valves are away, a Musician’s Repair Service technician will remove dents and fabricate any pieces needed to replace broken/cracked parts. He will buff any areas that will be hard to reach after reassembly. He will also degrease all the parts to prepare for reassembly.
5) Reassembly. This is a critical phase. Before disassembly, Musician’s Repair Service took numerous photos so they can be sure to put everything back in its original position. It is important for all the pieces to fit well so there are no stresses that would reduce resonance. All tuning slides will be carefully refitted.At the end of this phase, we will play test the rebuilt instrument to make sure it still performs as before.
6) Finishing. We will have some important decisions to make. The original instrument had areas of satin silver finish and areas of polished silver. The bells had gold wash inside and engraving outside. We will preserve the engraving as much as possible. We'll have to decide how much of the satin finish to reproduce because that requires an extra step of sand blasting.
Finally, we will be replacing the original case which is broken and moldy. We have ordered a custom gig bag made by Glen Conkrite of