Right way to de-flare a tuning slide

[gocsick]

I almost have everything on the MW 20 tip top. The rotors are fast the linkage are quiet... still not as fast and smooth as my son's Miraphone 186 but much better then when I got it. First and 4th valve slide are super smooth and fast. Got the little dent out of the leadpipe... In fact I recently was telling the previous owner how much I really like this tuba.

The one thing left...that is really starting to annoy the heck out of me is.. the 3rd valve slide is scratchy and slow due to one leg being slightly flared at the bottom. I am guessing it's was "too loose" and at some point someone "fixed" it with a tapered mandrel. It's take a bit of effort for long pulls on that slide (which is frustrating because the slide is long enough for 1234 pedal B to be playable with a good pull). Also Db below the staff tends to run a bit sharp so a slide pull there really helps.

I know I could always cut the bottom 16th of an inch of that leg... but I was wondering if there is a better way to do it..I could also remove that leg chuck it up on the lathe and hit it with a roller burnishing tool... but I don't have a lathe with a collet chuck anymore... and I worry about a 4 jaw maring/ distorting the surface and creating a bigger problem.

So what's the "correct way" to fix this?

[bloke]

You can insert it about a fourth of an inch into the outside slide tube with some grease on it and use rotational sideways force to take the flare shape back down closer to cylindrical.

Something else that can be done - or that can be done in addition to this is some stuff with actual repair tools, or a third option is to do the first thing suggested and then un-solder the tube and turn it around backwards, dumping the messed up end into the bow connection ferrule.

[LeMark]

Can you check the OD with a good caliper and see how far up the tube the flare extends?

[UncleBeer]

I like using draw rings for shrinking tubing and making leadpipes. Works great!

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[gocsick]

Can you check the OD with a good caliper and see how far up the tube the flare extends?

It is only about a 1/16th inch. At 2mm the OD is right at the tip it is about 4 thou over (0.1ish mm) but not uniform.

So when it was expanded they used a really wide flare.

[LeMark]

For a 16th of an inch, I would be tempted to shorten the tube

[MiBrassFS]

Years ago I had some half round/flat pliers that I used for stuff like this (usually the opposite condition) when doing school repairs (took seconds…). They came from a place called Music Medic. They’re sold as tone hole pliers for saxophones. I modified them to suit my needs, but they were owned by the place I was working so I left them behind. I bought a new pair from Music Medic, but they were garbage and I had to do a bunch of work to them. I still am not happy with them. I now use some half round/flat parallel pliers sold to jewelers. Better, cheaper…

A straight, round mandrel and a ring burnisher is probably the “correct” way to fix this (sounds like someone shoved a dent ball in there…), and I do that, too, depending…

[bloke]

My shrink rings have a gap between probably three quarters of an inch and 1-1/2 inches. LOL

I guess I should buy some more that are in between those sizes, but I seem to get by okay.

[MiBrassFS]

All I have is one of those old C shaped ring trombone slide burnishers.

Should I spring for more…? I’ve thought about it…

[bloke]

All I have is one of those old C shaped ring trombone slide burnishers.

Should I spring for more…? I’ve thought about it…

Back when I had money, I bought some of those huge ones and just hung them up.. never using them.

Eventually, I pulled them down and started messing with them.

They are really nice for getting bottom bows and really large top bows of tubas round instead of just smooth. ... Like if I finished really making a 6/4 bottom bow look nice, but it's between an eighth of an inch and a quarter of an inch out of round halfway across (as the Holton ones often are before they're even damaged), it's sort of cool to be able to have them end up both smooth and round. Of course, that has to be done before the inner and outer caps are reinstalled...

... But as far as the small shrink rings are concerned for tubing, yeah, I use them a lot and I think I use them more than I realize.

I'll tell you one thing that I use a couple of sizes for:

As trombone playing slide tolerances have become more and more sloppy, which allows manufacturers to end up with smooth feeling slides yet they sag and drag in seventh position, I use whatever size seems just right to barely shrink down the bottom of the stock area of inside slide tubes so that when they sag, they glide on a curved edge, instead of a hard edge.

Hell, I didn't manufacture those slides... All I can do is try to make them the best they can be.

[gocsick]

You can insert it about a fourth of an inch into the outside slide tube with some grease on it and use rotational sideways force to take the flare shape back down closer to cylindrical.

That worked surprisingly well. It's not perfect but it isn't nearly as scratchy and moves relatively well. Not silky smooth and fast but much better. It isn't uniformly right along the entire length.. so I will have to look closer... the outer might be slightly out of round at points along the length too.

[bloke]

Why is everyone surprised when stuff I suggest works?

[MiBrassFS]

Why is everyone surprised when stuff I suggest works?

Well… Heh, heh…