I’m an idiot.
Posted: Mon Apr 17, 2023 10:22 am
No pictures yet—I failed to make photos as I went. But a proper full disclosure will eventually require pictures, which I will add.
I purchased a very old and battered Giardinelli-branded B&S 101 at the Army workshop. It was an impulse purchase driven by my general respect for the design and history of these instruments, and because this one played beautifully.
And the price was squarely within the junker range.
I decided the time had again come to demonstrate utter lack of repair skill, and once again prove that knowledge and skill ain’t the same thing.
Initial condition:
Bottom bow bashed in with sharp creases, upper bow bashed in at the usual crash-landing spot, a bit of bell damage, severe dents in the exposed fourth-valve branch, several deep dents right under the valve linkages, misaligned main tuning slide, and seemingly hopeless linkage and valve wear.
Objective: good playing condition and not an embarrassment from audience distance. Plus, fun in the shop with dangerous tools.
What could possibly go wrong?
I’ll populate this thread very slowly with details and pictures to backfill the story and report future “progress”—slowly because it’s Spring yard season and I’m in the middle of a work travel marathon.
Summary so far:
The bottom bow dent was sharply creased through the guard plate and the half-inch guard wire. I removed the guard wire in the hopes of being able to lift the dents with magnets.
That was a joke; you can laugh.
So, I removed the guard plates and pulled the bottom bow so I could get into it with dent rods. In so doing, the brace between the MTS sleeve and the bottom bow gave way and broke. Lessee, my silver solder is around here somewhere…
The bottom guard plate should have been scrapped. It was stretched, wrinkled, dented, warped, and just short of wadded up. Everything I’ve read says it’s hopeless. Bloke told me that beginners usually fail at straightening them the first few (dozen) times they attempt a repair. But I’m stubborn, and I hate the notion of the guard plate being missing from a rotary tuba. More on that later.
(I have what Ferree’s used to call the “student” set of screw-on dent balls, a MDRS kit, a 3/4” dent rod that I lengthened by inserting it into a 2” steel bar into which I machined a 3/4” bore, a curved dent rod, a good dent hammer, a couple of rawhide mallets and various plastic hammers, and a Goss air-acetylene torch with an assortment of tips. To that, I added a wire-pull dent-ball kit from Ferree’s with an assortment of balls ranging from 0.695 to 0.745. The nominal valve bore is 0.748. I also have a 1-hp bench motor for buffing.)
When the bottom bow came off, it sprung open about 3/4”. Grrrr! Rounding it and closing it really needed draw rings and annealing, and I didn’t want to anneal it and make it soft. So I left it oval, but still more open than with the dent. Hey, it played well already.
Using the dent rods and magnet kit, I lifted the dents, but there were so many work-hardened ripples that it will never be smooth. Plus, I’m unwilling to make it thinner by sanding it. Once all the lacquer is off and it turns brown, the ripples will be harder to see.
I also lifted the dents out of the valve branches by pulling dent balls through them in increasing sizes up to 0.735. The 0.745 ball wouldn’t turn all the corners, and clearly B&S had left some ovals in the tubing bends. Fixing that was more remanufacturing (and disassembly) than I was willing to attempt, considering my objective and lack of skill. Smooth and factory-looking was not possible, but at least the bore is somewhat restored. Again, I’m unwilling to sand out imperfections.
After that, I brazed the broken brace, which is much closer to my comfort zone in terms of general shop skills.
I reinstalled the bottom bow after making it fit without tension, and then located and soldered the braces. They are fixed length and ended up in slightly different spots. That gave me the opportunity to align the MTS properly.
The bottom guard was hopeless—the edge was stretched and it’s too thin and springy to straighten. I do not own a Z61 dent machine and don’t have a mandrel I can use for shaping. So, I needed to straighten it on the instrument, which means the nickel-silver guard had to be softer than the brass. I put the #12 tip on the torch and annealed the guard fully. Then I could hammer it enough to shape it without moving the brass underneath. Then, I wired it down with about forty wraps of steel wire. I worked on the wrinkled edges some more, and then soldered it down.
It has the waviness of the ocean in a stiff gale. But it’s installed.
Upcoming:
Same treatment for the upper bow guard, which is a bit straighter to begin with.
Straighten and install the heavy guard wire.
Clean to remove traces of flux and the flux neutralizer.
Shrinking the valve bearings to remove axial wear.
Adjusting the rear caps to remove longitudinal wear.
Installing nylon pin guides on the S-links for the stop arms and fit the linkages properly.
Touch up the bell.
Remove remaining lacquer on outer branches. Clean up the bell polish.
Again, I’ll make some photos and add them.
Finally, my purpose in documenting this is to demonstrate why the untrained should not do their own repairs on instruments they depend on.
Rick “not the first time I’ve proved my own repair incompetence” Denney
I purchased a very old and battered Giardinelli-branded B&S 101 at the Army workshop. It was an impulse purchase driven by my general respect for the design and history of these instruments, and because this one played beautifully.
And the price was squarely within the junker range.
I decided the time had again come to demonstrate utter lack of repair skill, and once again prove that knowledge and skill ain’t the same thing.
Initial condition:
Bottom bow bashed in with sharp creases, upper bow bashed in at the usual crash-landing spot, a bit of bell damage, severe dents in the exposed fourth-valve branch, several deep dents right under the valve linkages, misaligned main tuning slide, and seemingly hopeless linkage and valve wear.
Objective: good playing condition and not an embarrassment from audience distance. Plus, fun in the shop with dangerous tools.
What could possibly go wrong?
I’ll populate this thread very slowly with details and pictures to backfill the story and report future “progress”—slowly because it’s Spring yard season and I’m in the middle of a work travel marathon.
Summary so far:
The bottom bow dent was sharply creased through the guard plate and the half-inch guard wire. I removed the guard wire in the hopes of being able to lift the dents with magnets.
That was a joke; you can laugh.
So, I removed the guard plates and pulled the bottom bow so I could get into it with dent rods. In so doing, the brace between the MTS sleeve and the bottom bow gave way and broke. Lessee, my silver solder is around here somewhere…
The bottom guard plate should have been scrapped. It was stretched, wrinkled, dented, warped, and just short of wadded up. Everything I’ve read says it’s hopeless. Bloke told me that beginners usually fail at straightening them the first few (dozen) times they attempt a repair. But I’m stubborn, and I hate the notion of the guard plate being missing from a rotary tuba. More on that later.
(I have what Ferree’s used to call the “student” set of screw-on dent balls, a MDRS kit, a 3/4” dent rod that I lengthened by inserting it into a 2” steel bar into which I machined a 3/4” bore, a curved dent rod, a good dent hammer, a couple of rawhide mallets and various plastic hammers, and a Goss air-acetylene torch with an assortment of tips. To that, I added a wire-pull dent-ball kit from Ferree’s with an assortment of balls ranging from 0.695 to 0.745. The nominal valve bore is 0.748. I also have a 1-hp bench motor for buffing.)
When the bottom bow came off, it sprung open about 3/4”. Grrrr! Rounding it and closing it really needed draw rings and annealing, and I didn’t want to anneal it and make it soft. So I left it oval, but still more open than with the dent. Hey, it played well already.
Using the dent rods and magnet kit, I lifted the dents, but there were so many work-hardened ripples that it will never be smooth. Plus, I’m unwilling to make it thinner by sanding it. Once all the lacquer is off and it turns brown, the ripples will be harder to see.
I also lifted the dents out of the valve branches by pulling dent balls through them in increasing sizes up to 0.735. The 0.745 ball wouldn’t turn all the corners, and clearly B&S had left some ovals in the tubing bends. Fixing that was more remanufacturing (and disassembly) than I was willing to attempt, considering my objective and lack of skill. Smooth and factory-looking was not possible, but at least the bore is somewhat restored. Again, I’m unwilling to sand out imperfections.
After that, I brazed the broken brace, which is much closer to my comfort zone in terms of general shop skills.
I reinstalled the bottom bow after making it fit without tension, and then located and soldered the braces. They are fixed length and ended up in slightly different spots. That gave me the opportunity to align the MTS properly.
The bottom guard was hopeless—the edge was stretched and it’s too thin and springy to straighten. I do not own a Z61 dent machine and don’t have a mandrel I can use for shaping. So, I needed to straighten it on the instrument, which means the nickel-silver guard had to be softer than the brass. I put the #12 tip on the torch and annealed the guard fully. Then I could hammer it enough to shape it without moving the brass underneath. Then, I wired it down with about forty wraps of steel wire. I worked on the wrinkled edges some more, and then soldered it down.
It has the waviness of the ocean in a stiff gale. But it’s installed.
Upcoming:
Same treatment for the upper bow guard, which is a bit straighter to begin with.
Straighten and install the heavy guard wire.
Clean to remove traces of flux and the flux neutralizer.
Shrinking the valve bearings to remove axial wear.
Adjusting the rear caps to remove longitudinal wear.
Installing nylon pin guides on the S-links for the stop arms and fit the linkages properly.
Touch up the bell.
Remove remaining lacquer on outer branches. Clean up the bell polish.
Again, I’ll make some photos and add them.
Finally, my purpose in documenting this is to demonstrate why the untrained should not do their own repairs on instruments they depend on.
Rick “not the first time I’ve proved my own repair incompetence” Denney
