Dissolving gunk

[ds21]

Would grain alcohol be okay to try and dissolve gunk in my inner slide that remains after a professional chem clean?

[Posaunus]

Hard for me to imagine that there's much "dissolvable gunk" after a proper chem clean. Usually just mineral deposits (not dissolvable) or residual polishing compound (if used) or oxide (both removable after repeated swabbing of outer slide.
In any case, I expect that pure alcohol will do no harm - evaporates rapidly.
Good luck.

[ds21]

Here's a photo:https://www.dropbox.com/scl/fi/dm5eljsb ... h3nvs&dl=0

[AtomicClock]

Take it back to the professional and ask them to finish the job?

[Blabberbucket]

Your photo link doesn't work for me.

[JohnL]

Here's the pic.

thumbnail.jpg

[tbonesullivan]

Never really seen gunk like that.

[JohnL]

Never really seen gunk like that.

At least some of that looks like pitting to me.

[hornbuilder]

That has not been fully cleaned. It needs to be put back into the pickle for longer. It should then be scrubbed with a bristle brush on a slide rod, with detergent to remove the remaining deposits.

[Doubler]

Never really seen gunk like that.

At least some of that looks like pitting to me.

I agree; it looks like pitting to me, too.

[Posaunus]

Is the photo of the interior of an outer slide? Do both upper and lower appear similar?

Do you know the history of this trombone and how this could have been caused?

[harrisonreed]

That looks like inner slide corrosion to me

[ds21]

These photos are of the inside of the upper inner slide, where the leadpipe is. Here is one photo from before the chem clean and two after.

beforechem.jpg

afterchem1.jpg

afterchem2.png

[ds21]

@hornbuilder
What kind of solvent can I use--vinegar, acetone, grain alcohol? And is a regular flexible snake adequate, or do I need a stiffer bristle?

[hornbuilder]

Again. That has not been completely cleaned. Take it back to the shop and ask them to finish the job

[ds21]

I'm going to try vinegar. That must be what @hornbuilder meant by spending more time "in the pickle". The last photo looks like raised bumps to me, hence not corrosion.

[Chronos91]

Will the shop not take it back? Pickles are acid baths, but it looks like whatever the shop did just didn't finish.

[ds21]

@Chronos91--the only shop I have access to is quite a distance from me, and I don't want to be without my horn for another two weeks. How long can I leave the vinegar sitting in the inner slide tube without damaging it?

[Posaunus]

Not to be too pessimistic, but your vinegar bath is unlikely to remove these deposits. Your tech did not do a good job of cleaning your slide. (Wonder what the outers look like?) So unless they are willing to take responsibility and finish the job, it's not worth taking back to them. And two weeks is a joke. This is a 2-3 hour job, including polishing of both inner and outer slides. Consider finding another (better) tech.

Once you get a good slide, you can avoid such damage in the future by a regular careful hygiene procedure that you can do yourself at home (after every use if possible). [Think dental care!]

[Chronos91]

If you're going to try it on your own, I'd start with just cheesecloth and a polishing cloth and vigorous scrubbing. If that doesn't work, you can try scrubbing with the cheesecloth wetted with vinegar or another weak acid in cycles with thorough rinsing. But I'd imagine it's going to take a ton of effort or not work like Posaunus guessed. Commercial cleaning baths are probably much more concentrated solutions (and likely not acetic acid based anyway). But any chemical use on your instrument is at your own risk.

[brassmedic]

This is a 2-3 hour job, including polishing of both inner and outer slides.

So you're assuming no shop has any backlog, and is just waiting around for jobs to come in? Unrealistic.

[Matt K]

I think they were more referring to the expectation that if you were in the queue to have slide work done and got that back, they'd take it sooner if the job really wasn't finished.

I do agree with Harrison; although it's hard to tell from the pictures just due to the nature of trying to capture an image of such a small, dark space... as a non-technician, this looks like corrosion to me rather than just gunk.

Finding a tech to do good slide work can be tricky. I had just found someone I liked in the area I was in before I moved

It may be worth it to ship it to someone who really knows trombone slides. It's annoying, but when you get someone who actually knows how to make a slide work well... it's hard to go back to even a mediocre slide.

[ds21]

I guess the corrosion guys were at least partly right. A pinhole leak has developed. I'll be replacing the tube.

[ds21]

Mods, please delete this message.

[Posaunus]

This is a 2-3 hour job, including polishing of both inner and outer slides.

So you're assuming no shop has any backlog, and is just waiting around for jobs to come in? Unrealistic.

Of course you're right Brad. I'd assumed that ds21's tech would put this unfinished job at the head of the line, or at least allow him to schedule an appointment.

I'm lucky enough to be within striking distance of a couple of excellent slide techs who take "walk-ins" for straightforward slide restorations. Often same-day service.