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Re: Dueling 186s - Twin Restorations

Postby The Big Ben » Sun Apr 14, 2019 1:13 am

Hurrah! That's quite an achievement! Here's to many more!
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Re: Dueling 186s - Twin Restorations

Postby Ken Herrick » Sun Apr 14, 2019 1:39 am

Well done!!

Looking forward to more reports on these 186s.
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Re: Dueling 186s - Twin Restorations

Postby roughrider » Sun Apr 14, 2019 9:06 pm

A terrific picture of your low brass section!
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Re: Dueling 186s - Twin Restorations

Postby the elephant » Mon Apr 15, 2019 2:15 am

Thanks! I am not sure I gave credit to our excellent players.

Adam Almeter - prin
James Wilson - 2nd
Joel Grizzelle - bass (former MSO prin, oddly enough)
Ken Lyon - tenor tuba (MSO bass trombone, but a euphoniumist by nature)
Yours Truly - 105 mm Howitzer

More 186 stuff should start to trickle in starting the 18th or 19th. Sorry this is taking so long, but "busy is bread" if you're a musician.
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Re: Dueling 186s - Twin Restorations

Postby the elephant » Thu May 16, 2019 5:26 pm

Well, I have not yet been able to clear out the carport so that I can work. I have a major problem with one of my cars and need to get it fixed. Until then it probably will stay put. I will take a more careful look at it tomorrow afternoon, but I may have to have it towed about 60 miles to a dealership to see if they can get this ridiculous bolt out — they have all the dealership Miller Specialty Tools for the job.

Anyway, today I spent two hours working on all my nice rotary Miraphone rotary valves. I have available for these two horns the following:

Intended for CC in this thread
• New style 1st — 2009 (unused)
• New style 5th — 2015 (unused)

From the BBb in this thread
• Old style 1st — 1971
• Old style 2nd — 1971 (rotor swapped with 2nd on CC due to stripped out stem threads)
• Old style 3rd — 1971 (leaks in one of the two unused positions)
• Old style 4th — 1971 (leaks in two of the used positions — good 1st/2nd candidate with modifications)

From my parts bin
• Old style 1st — 1978
• Old style 2nd — 1978
• Old style 3rd — 1977 (two good positions, but might leak in the other two, cannot confirm until 4th is removed from stack)
• Old style 4th — 1974 (damaged casing, leaks in all four positions, upper bearing out of round, probably junk)

Currently on CC in this thread
• Old style 1st — 1971 (leaks at top bearing when closed, okay when open, casing has off-center vent that needs to be re-drilled)
• Old style 2nd — 1971 (has 2nd rotor from BBb parts horn)
• Old style 3rd — 1971 (may leak, not tested, but I have issues with this valve when playing very loudly)
• Old style 4th — 1971 (leaks for sure, but not sure how badly)

I have swaged all the old valves not currently installed on a horn. With the rear cap screws adjusted to removed runout these all move very quickly and lack any audible slop/clicking in either axis. (I love that tool!) I have not yet swaged the bearings on the CC that I play every day. I have decided that if I find any leaking in these valves that I will replace the rotors with new ones, and then swage them if needed. I don't want to compress the bearings to fit the 48 year old rotor stems and then not be able to install new ones because they are now too tight.

I *want* to install all new style rotor units, but they are about $300 each and I am not willing to wait until I have that kind of disposable money sitting around at one time. I have two, so I would need about a grand for the other three with shipping, and Ed does not seem to have any that fit together, as though he may have mixed parts to work with. Whatever. I could look into buying directly from Miraphone, but I am sure that with shipping the cost would be about the same and it would take over a month longer to get them. (I *will* check with Miraphone, but I am planning on working around what I have here, which is cheap and immediate.)

So the 1st on the CC has a large, slightly off-center vent that needs to be closed up because it leaks a bit when the valve is down unless I press very hard. The threads on the CC 2nd rotor were ruined and had a spiral insert very much like a Helicore that you use on stripped-out engine block head bolt holes. Both the CC 3rd and 4th rotors seem to leak a little bit.

I plan on having four 1st/2nd units installed on the CC if I can work that out. All of the uninstalled 1st/2nd units are really solid with no leakage at all, but three of them have very loose rear bearing plates; they fall out if you turn the valve over with the rear cap off. I need to think about this issue. I also need to have a set of five very good valves for the BBb, especially if I cut it to CC (again, just for personal amusement).

Of the two leakers: both are worn heavily in the two positions you use, but the reverse sides are like new and do not leak at all. One of these is a 3rd and one is a 4th, and with modifications could be turned into solid 1st units. The one 4th that leaks in all four positions is probably toast. It leaks badly with any of these eight rotors installed, and the bearing is a bit bent. If I can figure out a way to tap the casing walls back into shape to save the leaking thing I will try. As it is, there will be zero loss if I trash it in the attempt, so why not learn more fun stuff? I have to use some of my Prussian Blue gear pattern paint that I use when I set up an axle differential, and that ought to give me a decent idea of where the leaks are. After that and it is just guesswork and tapping.

Usually you use a bright yellow gear paint as the ring and pinion gears are black. Since this valve is a much lighter color I will opt for the darker paint. Here is a photo of a ring and pinion having the contact pattern checked using the yellow stuff. You can see how that color would be hard to read inside a tiny and yellowish rotary valve casing. The Prussian Blue is a dark blue that should be easy to read.

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Gear paint is made from a very fine and evenly ground pigment that with the oil base is guaranteed to be a certain number of thousandths of an inch thick. It should be ideal for checking tolerances on something as clunky as a rotary valve cylinder wall gap. I am hoping that it is in this case, at least. In this case the thickest or darkest part of the pattern will be the leaks. Since these are tapered, the whole face of each part meets at the same time when the rotor drops into place. I am hoping this stuff will be as non-tacky as when I use it on gears, but this is a different metal and it might not leave an accurate pattern when the rotor is dropped out of the casing. We shall see. Perhaps I can save this banged up, old rotor unit, and perhaps I will trash it. Either way, the process should be educational for me.

In all three cases, the 4th rotors seem to leak. I do not know why, since these are the least used of the four basic valves. Perhaps there is some wear point that is not obvious, having to do with the linkage arm? I doubt it, but you never know. It is just really weird that in the case of all twelve of the old valves that all three 4ths are leakers. Hmm…

Whatever.

And now for a fun photo…

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I seriously cannot wait to get that damned car out of the carport so I can set up my bench again and get back to work. UGH! :mrgreen:
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Re: Dueling 186s - Twin Restorations

Postby roughrider » Thu May 16, 2019 6:56 pm

Huzzah! You're back!!
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Re: Dueling 186s - Twin Restorations

Postby the elephant » Mon May 20, 2019 10:20 pm

This afternoon I cracked open the new tank of acetylene and did some stuff.

I currently have between 18 and 20 tuba rotary valves in various states of disrepair. I have one complete set of four from the 1971 BBb 186 and a set of also-rans from two 186 BBb tubas from about 1978. Both sets have gimp 4th valves (stem damage and leaks). Both have one that leaks on the two work sides while the unused sides are very tight. I don't really understand what is happening here. I know that the valves normally only ever rotate through two of the four possible positions, but the entire valve rotates at the same time. Why would they wear on only two ports? Air pressure does zero to the metal. Perhaps these school horns had kids for decades blowing cokes and lunch and stuff through them and the acids, over time, caused one of the port faces to develop a gap? Hmm…

I remembered how I used to cope with crystalized soft solder that would not re-melt for disassembly, and I also have better gloves and such for tightly holding and twisting apart two very hot chunks of metal without too many burns to my fingers and palms. Therefore, I was able to recover every ferrule without damage. Four MUST have been hammered on; Miraphone sometimes has VERY tight tolerances between parts, so pulling them apart when they are very hot can be difficult and frustrating for me. I recovered all six of the short, dished ones that connect two valves together. The two different eras of 186 mean that the figurations on these make them two distinctly different sets; they are not "mix-and-match" by any means. I also recovered all four long ferrules to the leadpipes and waterkey legs.

Then I learned something that many of you may already know. I never had a reason to investigate the top bearing plate and how it is installed into the rotor casing tube. I thought it was a press-fit bearing plate like on the backside, but that the nickel silver "cap" was actually what it looked like. It isn't. The cap with the nice figurations is actually as thin as the slide tubes and such. It has the figurations as well as the knurled edge stamped into it, and that edge is just as thin as the cap. So the entire top bearing plate is a single, thick piece of brass with a thin nickel silver veneer on top.

All this time I thought the knurled edge of the top of the valve was a solid piece of nickel silver that had been silver soldered in place with the thinner brass top plate. So the reality is that this is a bit less robust than I had believed for most of my life.

Live and learn.

I know this because the three ferrules that had become stuck to that valve took a LOT of heat to get free, and I had to use flux and sold solder to get the crystalized stuff to flow again. Some of that flux and most of that heat went under the veneer and it simply fell off. I cleaned the snot out of the brass top of the casing and the inside of the "coin" and soft soldered them back together. For some reason this one had nearly no solder beneath it, so I flowed in a bit more to hold it down fully.

Also, when it fell off it hit the cement floor. I had to do some light tapping with a small anvil and a small leather mallet to get it to lie very flat against the brass bearing plate. I used some slide tube to hold it in place with two chunks of 4x4 to hold everything together until I could get it soldered down well.

What an unexpected hangup but I learned a LOT.

I did no cleanup work at all beyond soap and water to remove all the grit and flux and such. I will scrape, sand, file and buff everything nice and clean tomorrow or the next day. Before that I think two of them need to be swaged again, as I was too gentle and they still have a little bit of slop.

Half of these will go on the BBb 186 and half will go on my K-90 project horn whenever I get back to that. Note that I think three of my valves (one for certain) on the CC 186 leak enough to notice it. When I tear it apart I will remove the valve and leak test them, possibly swapping out any that I have in this collection that might be better (action or leaks). The BBb will get the next best four, etc.

I have to get over my hangups regarding the bell garland install for the BBb bell. I need to get the bell to a point where I stop wanting to mess with it and do the damned job. I keep overthinking it and am wondering how it could possibly work the way it reportedly does using the techniques I know. Bell garlands are a special type of voodoo for me.

Here are some photos from tonight.

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Re: Dueling 186s - Twin Restorations

Postby roughrider » Tue May 21, 2019 12:24 am

Keep up the great work!!
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Re: Dueling 186s - Twin Restorations

Postby the elephant » Tue May 21, 2019 2:12 pm

Change in plans...

I had wanted to replace all four valves to match my brand new 5th valve as I already had a brand new 1st valve on hand. That left me with three new valves to buy. After paying for the 5th I realized this would be very costly. Instead, I bought a Ferree's swaging tool.

Well, some of these old valves, now sporting very good action with no noise still have significant leaks, meaning that I may end up three valves short for another project. I am not confident in my ability to fix these leaks. This CC has some leaking, too, but it is pretty minor. So my solution (for now) is to pony up the $$$ to get the three matching, brand new valves, but from Miraphone. And now that I have an estimate for the parts I need I can see that I should have inquired about this much earlier as the prices are very reasonable.

I committed to buying the three new rotary valve units at the end of the month. So, when the time comes, I can detach the four rotors in one piece from all the slide tubing, assemble the four valves, and solder all the tubing back on. Neither easy nor simple, it will still net me a classic tuba with brand new valves, which makes me super happy. I love this tuba! Thanks, Dan M. (if you are reading this)! I am glad I was the guy who got to buy this from you, and that it did not go to someone else.)

So I am adding three more to match these two…

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Re: Dueling 186s - Twin Restorations

Postby roughrider » Tue May 21, 2019 2:57 pm

Elephant, you are living proof that great tubas and great players find each other. Carry on!
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