Cleaning outer tuning slide

[BopEuph]

One of my 4th valve slides is just tough to push/pull. I know it's not the inner slides, since swapping the two slides around (they're identical on this Kanstul) is showing the same outer slide causing the issue.

A bath with Simple Green didn't work, it had a chem clean last summer and the buildup happened again pretty quickly.

Is there a solution here that doesn't involve another full chem clean at a shop?

I'm sure this is the easiest slide to have this problem, as it's with the straight tube that leads to the upper slide.

[bloke]

On a scale of 0 to 100, how would you describe the best that slide ever worked, and do you suspect it's been hit since then, or that it has not been bent?

To make sure I follow up, you might want to tag me in your reply.

[BopEuph]

On a scale of 0 to 100, how would you describe the best that slide ever worked, and do you suspect it's been hit since then, or that it has not been bent?

To make sure I follow up, you might want to tag me in your reply.

Best slide would move freely, like adjusting while playing; a 0 would be stuck completely. This is probably around a 50. It can move with some effort, but once it gets about where it needs to be for intonation, it gets very sluggish.

I don't THINK it's dented; I did look at the outer end of it and it seems pretty smooth. It did get bumped a few months back, but I don't think it was hit hard if I remember. $#!+ happens on gigs, but I was thinking maybe some internal buildup.

[BopEuph]

To make sure I follow up, you might want to tag me in your reply.

@bloke: Just in case you literally meant tagging rather than quoting.

[bloke]

If it's the case that this slide was never ideal, the first thing to do is to get the outside slide assembly absolutely parallel and coplanar. Then (after removing the slide bow from the moving slide) precisely adjust the spacing of the ends of the slide bow (using some dent balls to reinforce the bow while pulling or pushing on it) to the spacing of the outside slide tubes. Finally, it's time to put the inside slide tubes back on and solder the movable slide together while mounted in the outside slide tubes - using the minimum heat required to reduce the chance of contraction while cooling.

Finally, the thing to do is to test for whether contraction occurred or whether the alignment is quite good, and then to use some sort of compound mixed with a lubricant to get the inside and outside tubes to fit each other as well as a piston fits in a casing, except you'll be doing both pairs of tubes at once, rather than just one pair of tubes - as with one piston to one casing.

[BopEuph]

Oh, this sounds a bit above my pay grade. Sounds like a trip to the shop is in my future!

[bloke]

Oh, this sounds a bit above my pay grade. Sounds like a trip to the shop is in my future!

Most any manufactured slide assemblies with tubes that aren't bent or damaged can be made to float, if the owner of the instrument has the money...and takes it to a capable horn fixer (and not just any horn fixer).

[gocsick]

Joe -quick question ...what's your preferred method for checking planarity? Gage pins and a plate with known flatness would be my starting point... but is there a easier working solution this overeducated and under-experienced city slicker doesn't know.

[bloke]

I have a couple of risers that I set on a piece of granite (which works for trombone slides really really well), but - for mounted or mounting tubes on an instrument like a tuba, - they're really isn't much of an option for me other than taking off my reading glasses (which curve of the light waves) and staring across a pair of tubes over and over and over and over until I'm convinced that they are coplanar.
I suppose I could buy a smaller piece of machinist's granite that I could hold in my hand and see if it rocks (though there they are often obstacles that would prevent its use), but I've always relied on my eyes. I probably won't be able to much longer.

I believe the hazard of using some sort of measuring instrument for this and these types of applications (even if the tool is something like Starrett grade and remarkably accurate) is that the person using it isn't quite using it properly. All a person has to do is to not notice that some brace foot is barely sticking up in the way, or that they are pressing a little too hard or something like that.

Even when I have the luxury of pre-building a tuning slide assembly before installing it on a tuba or something like that, it's easy to jack it sideways during the final installation if someone isn't extremely careful and self-aware.

Some people say this stuff is an art. I'm not an artist, but I've been doing it long enough to know most of the ways that I can fock something up.

You know who's really good at this stuff, as well as being incredibly soft-spoken and modest? Yorkboy
I'd wager that York-aholic is as well, but I've never seen any of his work.

back to trombone slides:
Other than maybe one or two brands (and maybe not so much even with them anymore, as production is moved from Europe to China or from Japan to China) brand spanking new tubes are not straight, and often feature a large arching bow (though subtle, but it matters) as well as maybe another smaller one somewhere along the tube. People have this "setting a tube down on a flat surface and shining light or whatever the heck they do" method... but I just mount them on a repurposed wood lathe with one super large pulley to slow it way down and one live center. After checking their ends to make sure they're square (and - these days - sometimes they're not even square on the ends, when new) I mount them on that lathe, turn on the power, and (just as with the coplanar thing) let them spin for several seconds and watch. Very soon, it becomes apparent where the bow is and where the center of it is. I use one of those felt tip Sharpie things, sneak up to the spinning tube to the center of its bow, and mark it... And I'll let it go around 2 or 3 more times to reinforce the mark. I loosen the tail stock, and push down on the marked side (more or less based on how bowed the tube is and based on experience) and fool around with the tube until looks like it's sitting still all the way up and down while it's turning.

From talking to a few other people, apparently using a lathe is nearly if not completely unique, but an old black man who worked in the attic of a old Memphis downtown music store taught it to an alcoholic white guy who taught it to me, and I've sort of learned (experience) a whole bunch of little funny things about putting slides together (once the tubes are straight and round) in relation to heat and what it can do to exert unwanted forces as the heat dissipates, as well as how to counteract or avoid those forces. I can't explain this stuff scientifically, but I know what happens and I know how to work with what happens to my advantage instead of against me. Quite often, what outside playing slide assemblies want to do is to become knock-kneed in the middle (hourglass shaped) when they are soldered together.

Of course, straightening old tubes that have been effed up by user owners or players... That's more challenging than straightening out new ones. I really don't think I charge enough for this work, but I charge what I charge. I judge myself to be quite good at it... At least, most everyone is happy when I'm done - as long as they allow me to do everything that I tell them needs to be done.
Of course, I have "good enough" quality work that I do for trombones that are taken outdoors and belong to schools, but (I know I'm bragging - forgive me) I think some of my good enough work is about as good as a lot of people ever experience from elsewhere, whereby the guy back in the shop big-deals themselves to the repair customer (much more than the way that I'm bragging here in this post).

Something I did very recently...
Over the years, a band director has made the serious mistake of taking his Bach 42 to school - probably for mostly demonstrating but I'd bet also for emergency loaning the students. Both are terrible ideas. Both of his outside tubes were really really messed up. It appeared as though they've been damaged and repaired once or twice before. I got them a straight and round as I could manage (not knowing his budget). The inside tubes I was able to get really quite nice, as those tend to be more rigid and are somewhat protected. When I gave it back to him he let me know that he was wanting to step it up to the next level (in other words, playing like new) so I bought him a couple of brand new outside slide tubes, straightened them on the lathe, assembled, polished, and lacquered the outside slide, and he was delighted.

Something I didn't tell him was this:
Another Bach owner wants me to build him a separate lightweight outside slide assembly for his trombone which has a pretty much perfect slide, that means I have to dial it in to the same .001" as the existing outside slide, because I won't be able to adjust his inside slide assembly to work with the outside slide assembly that I would build for him...

... so I used the repair (described just above) as a practice drill for it. When I put those new tubes on that band director's outside slide, I built that slide to the same last 1/1,000th of of an inch of spacing as before, and was able to drop his inside slide assembly (remember? I was previously able to straighten and repair the inside slide tubes very satisfactorily) right into it without doing any adjustments to the inside slide assembly at all.

I don't really advertise the trombone slide work. It's real picky and sort of boring, and I end up standing at the lathe with my head bent down a lot. I've figured out how to repair tubas (as well as crap like that marching baritone discussed in today's other thread) while mostly sitting in a chair.