I’m an idiot.

Projects, repair topics, and Frankentubas
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Rick Denney
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I’m an idiot.

Post by Rick Denney »

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
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the elephant (Mon Apr 17, 2023 2:12 pm) • York-aholic (Mon Apr 17, 2023 6:20 pm) • Inkin (Tue Apr 18, 2023 9:32 am)


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Re: I’m an idiot.

Post by Ace »

Rick, contrary to some people on this board, I would not refer to you as an "idiot". After reading your post, I am impressed. How about we call you "courageous"?

Best, Ace
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Post by Rick Denney »

The difference between bravery and foolhardiness is fine. It has to do with outcomes. If the instrument achieves the objective, it will be bravery.

Rick “the jury is still out” Denney
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Re: I’m an idiot.

Post by bloke »

Bring your bits-and-pieces down here, and use my tools, as TOOLS add FAR MORE phu¢king up potential.

(If you wish, you actually can.)

Beg Tom to ask Jinbao for a knock-off of your bottom bow cap. You know they make those by the buzillyunz.
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Re: I’m an idiot.

Post by Tubajug »

As previously stated, you sound far from incompetent.

When I tell people that I do some repair work/frankentuba-ing for a hobby, I tell them I'm only brave enough to work on my own instruments. Very rarely do I accept working on other people's instruments, unless it's something super quick and simple (I've soldered thumb rings and things back on for people).

I'm anxious to see your photos!
Jordan
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"No one else is placed exactly as we are in our opportune human orbits."
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Re: I’m an idiot.

Post by the elephant »

Outstanding, Rick. I look forward to reading and gawping at your upcoming posts on this tuba.

Best of luck!
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Post by Rick Denney »

Here are some pics. Still dirty, covered in baking soda to neutralize the acid flux. Ran it over the buffer with tripoli just to get a view, but that means lots of buffer schmutz and even still some burned lacquer. Very little solder cleanup so far.

As bought. The pose hides the dents, but they are deep:
Image

In the work area. Dent rod, torch in the background, etc. The wires I used to hold down the bow guard are on the floor at lower left.
Image

The backside. The fourth-valve branch was bashed in. Now, it’s just wavy, but at least mostly maintains the bore area.
Image

These were big dents under the valve paddle bar. The scars are visible but the bore is restored.
Image

The brace I had to braze back together:
Image

The brace I had to relocate:
Image

The worst of the guard installation:
Image

A little better here:
Image

The upper bow, dedented but no guard yet:
Image

The audience perspective view. As photographers say, proper viewing distance hides a multitude of sins.
Image

Rick “fitted but did not yet solder the wire guard—but now again on the road” Denney
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Post by Rick Denney »

the elephant wrote:Outstanding, Rick. I look forward to reading and gawping at your upcoming posts on this tuba.

Best of luck!
Gawp=laugh and point.

But I get to a point where more hammering starts going backwards, and I decide it’s as good as it gets at this stage of learning.

Rick “a man has got to know his limitations” Denney
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Post by Rick Denney »

bloke wrote:Bring your bits-and-pieces down here, and use my tools, as TOOLS add FAR MORE phu¢king up potential.

(If you wish, you actually can.)

Beg Tom to ask Jinbao for a knock-off of your bottom bow cap. You know they make those by the buzillyunz.
I might sign up for a week’s lessons someday.

But it occurred to me a new cap wouldn’t fit…the bow has to be perfect to fit a perfect cap.

Rick “but a dent machine would have helped in perfecting the bow” Denney
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Re: I’m an idiot.

Post by bloke »

You'd be surprised at how much you can tease them together, as long as you don't have something that's really lumpy.

Maybe sometime I can get a week of traffic engineering lessons, so I could get a job designing freeway interchanges, preventing the lives of cars at intersections, and such things at that. There's only a few tricks to that stuff. :eyes: :smilie8:

It looks like you're going to end up with something okay there.
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Post by Rick Denney »

“Okay” will be good enough.

You remind me of when I first became a consultant after having worked in state and local government managing traffic signals. My new boss wanted me to host a brown-bag seminar at lunch during an upcoming week to tell the fresh hires how to design and operate signal systems, so they could be like me.

I thought “so, 15 years of steep learning curve passed along in an hour?” Yeah, sure.

That was 30 years ago.

But an hour to a person who has thought about it for 15 (or more) years can mean lots more than an hour’s worth of progress.

Rick “now distills that experience into two-day training classes, but for those prepared to take some big steps” Denney
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the elephant (Tue Apr 18, 2023 11:41 am)
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Re: I’m an idiot.

Post by YorkNumber3.0 »

.
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Re: I’m an idiot.

Post by bloke »

Brass is an alloy of iron and mud.

Some spots behave as if iron, and others as if mud.
Last edited by bloke on Tue Apr 18, 2023 1:14 pm, edited 1 time in total.
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Re: I’m an idiot.

Post by York-aholic »

YorkNumber3.0 wrote: Tue Apr 18, 2023 8:13 am I’ve seen worse results done by paid individuals.

“It ain’t rocket science, it just takes practice.”
And I've paid for worse....
Some old Yorks, Martins, and perhaps a King rotary valved CC
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bloke wrote:Brass is an alloy of iron and mud.

Some spots behave as if iron, and others as if mud.
Yup.

Rick “hand-hammered” Denney
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Post by bloke »

other factors as well, including the particular shapes of dents
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Post by YorkNumber3.0 »

.
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Post by Mark »

You should have done it all with your lathe.
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Re: I’m an idiot.

Post by bloke »

Mark wrote: Wed Apr 19, 2023 11:22 am You should have done it all with your lathe.
The way I make really messed up bottom bows look perfect is to mount them between centers on my lathe, and run it at the fastest possible speed.
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Post by Rick Denney »

bloke wrote:
Mark wrote: Wed Apr 19, 2023 11:22 am You should have done it all with your lathe.
The way I make really messed up bottom bows look perfect is to mount them between centers on my lathe, and run it at the fastest possible speed.
My lathe isn’t fast enough.

Rick “only 1000 rpm—that would require 20000 rpm, and also the curvature of the space-time continuum” Denney
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