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I really didn't want to bump Wade's post down because it's really interesting and I'm glad that he's moving on.
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I guess I'm being a slowpoke, but I'm pleased that all five rotors work with very light tension springs, are quiet (with original linkage) and don't stick. I cleaned the rotors and casings by hand, because I didn't want to screw up the old patina on this instrument very much, though I'll obviously have to do something around the mouthpipe.

The installed mouthpipe's clearance around the various obstacles is even better than it was when I dry fit it, which also makes me smile - as this was not an easy bend job. I do have to sit up and use good posture to play it with the mouthpipe that high, but (again) I'm thinking that the instrument's owner is taller than me.

The main slide legs weren't hitting bottom at anywhere close to the same place and the ends were even crooked, so that's all straightened out and I actually - well, you know me - lined it up nicer and it feels much better to pull and push now.

The fifth slide is crazy. It's the old Miraphone length but with super long tubes that duck down behind the rotors and flop loose from after taking 180° turns from the insertion tubes. I don't see any way to easily do anything different and I wasn't asked to.

Since the instrument's owner is obviously accustomed to a very light touch, I'll probably leave springs one through four alone, but I believe I'm going to put a new spring on five, because it's tension is just a little bit sketchy. I'm pretty easy going as far as whatever somebody wants, but that one is just a bit too weak for probably anyone's taste.

I wish I had some of that liver of sulfur stuff (a weird and old school conglomeration of various potassium and sulfur compounds all mixed together) to darken the area around the new mouthpipe tube, but I guess that's really not my responsibility.

bloke wrote: ↑Fri Jan 20, 2023 5:07 pm
I wish I had some of that liver of sulfur stuff (a weird and old school conglomeration of various potassium and sulfur compounds all mixed together) to darken the area around the new mouthpipe tube, but I guess that's really not my responsibility.

Time heals all repair wounds.

York-aholic wrote: ↑Fri Jan 20, 2023 9:38 pm

bloke wrote: ↑Fri Jan 20, 2023 5:07 pm
I wish I had some of that liver of sulfur stuff (a weird and old school conglomeration of various potassium and sulfur compounds all mixed together) to darken the area around the new mouthpipe tube, but I guess that's really not my responsibility.

Time heals all repair wounds.

It’ll get there soon enough.

I have some Liver of Sulpher here. It is on occasion quite handy, but mostly it just takes up shelf space.

the elephant wrote: ↑Fri Jan 20, 2023 10:44 pm I have some Liver of Sulpher here. It is on occasion quite handy, but mostly it just takes up shelf space.

I guess - on a pretty closely related topic, I have a whole bunch of various translucent lacquer tints in little jars here that I rarely use but they come in handy sometimes as well - when trying to shoot lacquer on the outside parts of newly polished old tubas while leaving the decent condition original lacquer on the inside parts (as they would take way too many hours to strip and shine up, and with the finish in good condition, it would seem like an epic waste of time).

... greens, browns, reds, yellows ... combinations of which - if stumbled across in just the right amounts - come really close to matching the darkened original lacquer colors on some old instruments... particularly if the newly shined area is gone over a couple of times with a torch flame - both before and after shooting lacquer.

A friend of mine is a master of tarnishing old metals and blending in repaired areas on collectibles with liver of sulfur. I have not acquired those skills anywhere close to his level. Something that just occurred to me while typing this was that I've never attempted to etch a polished repaired area on an instrument with acid prior to using liver of sulfur. I wonder if roughening up the surface to a non-visual level but enough to increase surface area with etching would help the chemical action..(??)j

EDIT...I just bought a little tub of it. I'm going to try the etching thing (to increase surface area) in addition to the recommended heating.

Here's the shiny area...a quick pass to clean it up...and buffing dirt cleaned up with lamp oil.
The clearance between the mouthpipe and first slide bow (as well as the clearance between the mouthpipe and 5th rotor lever) are both WIDER than shown in the "dry fit" pictures. (30% skill / 70% dumb luck)



...and here are the open bugle pitches (main slide completely retracted) in a 68 degrees Fahrenheit room, and with a Helleberg II-ish EURO shank mouthpiece:

reminder: This instrument "lives" in south Texas, where it's probably never much cooler than 72 inside most any place.

tuning: I can't fix "squirrely", but I can minimize it, and get everything hovering on either side of "squirrely".
You might notice that I barely raised the "sharpest" this tuba can be played" - just to be safe.
(Who knows...?? Someone/someday may decide to stick a "Dr. Young" into the receiver.)

The G's are easily "lipped" down, but why show to where they can be "lipped" when I'm trying to show where they center...??
two different links to the same video:






The valves are quiet, so I guess it's time to remove the last few dents, clean up the slides and insert them, clean up a few other solder joints, darken some of the brass (after the "Liver of Sulfur" compound arrives), call the owner, and ask how this instrument is going to magically float 650 miles back to its home.

The project has been completed.
As soon as that brass-darkening concoction arrives, I'll notify the instrument's owner that this thing is done.
With around a 3/8" - 5/8" pull (in a 69° F. room), everything is either "on" or "on-one-side-or-the-other-of" A=440 (with the euro shank version of the HB2 blokepiece prototype mpc, and me playing it).
It's now a playable-with-an-American-ensemble (and room to pull for hot/outdoor playing) instrument, as long as the player pays attention and listens.

If I end up being proud of how the darkening agent (again: a mixture of various potassium-sulfur compounds) works out, I'll post one more picture.

...back to bloke-owned projects and school-owned repairs (for now)

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I DID find someone local/reasonable to silver plate my shallower-than-Solo-cup blokepiece cimbasso/F tuba/whatever prototype mouthpiece, so - in a couple of days - I'll get that done and begin testing it out on this upcoming February pops big-band-plus-strings concert book.

' new batch of "Liver of Sulfur" (potassium-sulfide-ISH concoction - tarnishing agent for copper-based metals) arrived in the mail, today.

I may do some tests, try to remind myself how this stuff behaves, and then consider blending in the (buffed clean) repairs/alterations on this instrument.

This is my first pass with "liver of sulfur" (a peculiar old-school mixture of various potassium sulfide types of compounds) to re-tarnish repaired areas.

It will need more passes.

I'm going to read more about it, and also chat with a friend who has a lot of experience with this.

The owner of this instrument FINALLY got it back.
(13 hours away...a friend was passing within 35 minutes of blokeplace, and had room for a tuba.)

Horn plays great!
Many thanks

whew...
' good enough for me.