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I want to do a vinegar bath on the valve cluster. I'm going to cork off the lead pipe, main slide, and the valve casings. It's a 5/4 Kanstul BBb, 4-valve.

A regular bath isn't getting everything, and I kinda need the horn too much to put it in the shop right now.

Think a gallon is enough to do the trick?

I did this recently, on a much smaller tuba, but a gallon was plenty.

Good to know. How'd the horn turn out? Anything you'd have done differently?

BopEuph wrote: ↑Wed Sep 20, 2023 3:59 pm Good to know. How'd the horn turn out? Anything you'd have done differently?

It really removed most of the crud. I used cleaning vinegar, which (I think) has about 20% acidity as opposed to normal white vinegar's 5% acidity. If I were to use regular vinegar, I probably would've let it sit for longer, but I was afraid of the acid etching the brass (not sure how valid a concern that actually is).

I just removed the main slide, plugged up the main slide and lead pipe with rubber stoppers that I bought at Home Depot, and filled it up with vinegar from the main slide with a funnel. After maybe 10-20 minutes, I turned it over (since it wasn't all the way full), to get the vinegar to contact the other side of the interior bore. I finished off with a large-sized cleaning snake and most of the green crud came out, and I was sure to hose it out with a water hose and a soapy cleaning snake to neutralize any remaining acid. This was on a tuba that had sat neglected since the 1980s and was never cleaned, so I am sure your Kanstul is in better shape!

I think I also removed all the slides and cleaned those separately, and plugged up those open tubes with stoppers too, but I guess I could've left them in. Getting the vinegar into the valve circuitry was tricky, so I elected to remove the pistons and plug up those holes, too.

Thanks! Yeah, I was debating on either leaving slides in or cleaning them separately, but it sounds like what you chose was less of a hassle. Some of the tubes are straight pipes with slides on either end so I could simply cork them and fill them separately, and then throw all the slides in a container to soak with vinegar separately.

I don't know about cleaning vinegar, but food grade vinegar is something I've used with my slides overnight, and the brass comes out nice and shiny inside the slides. I don't think etching would be an issue with at least food grade, but not sure about cleaning vinegar.

Yeah, even after a bath about a year ago, water was still draining green from the water keys, and some of the slides can't go in all the way at this point from the calcium buildup. It's time to get a real cleaning on it.

Use cleaning vinegar. It’s cheap - buy two gallons. Remove slides, cork the ends. Fill up through the leadpipe. Soak the slides in a tub/container. 3hr soak for everything. Uncork, drain, and rinse thoroughly. Lube, oil, assemble, play. GTG

I was actually planning on leaving it overnight. Is that overkill?

BopEuph wrote: ↑Mon Sep 25, 2023 8:48 pm I was actually planning on leaving it overnight. Is that overkill?

Three hours should be enough.

Cool, then I might be able to let it sit while running errands. Thanks!

So, I'm currently FINALLY doing this, and I learned a few things:

1) Two gallons was just barely enough to do the Kanstul AND a trombone. I'm just doing that as well as potential bone gigs are (surprisingly) lining back up. I corked off the outer slide and they're secure enough that I was able to polish the slide while the vinegar was soaking in it.

2) The groove from the valve guides prevents a full seal from forming in the casings. I'm hoping the vinegar that's sitting in there still is at least clearing out the calcium deposits where slides were locking up.

3) I have all my slides soaking in two separate containers. One is getting WAY bluer than the other...which has the 4th valve slides and were the ones which had the most calcium buildup. So I'm hoping that the calcium is still clearing out of them.

4) The smell of vinegar makes me very hungry.

If y'all want to speed up the reaction, add hydrogen peroxide (whatever percent). Just keep an eye on what's going on.

UncleBeer wrote: ↑Mon Nov 27, 2023 7:19 pm If y'all want to speed up the reaction, add hydrogen peroxide (whatever percent). Just keep an eye on what's going on.

I might have to try this. One of the fourth valve tubes is still really sluggish. Guessing I didn't get all of the calcium buildup in it.

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Hydrogen peroxide, vinegar, and salt (in some proportion, plus water) is a common way to force a patina/rust on metal surfaces.

I never said it wasn't dangerous. When getting residual lead out of leadpipes I'd use glacial acetic acid + hydrogen peroxide. It's essential a pickling dip. Everything comes out clean & shiny.




(disclaimer for all you old women: skull & crossbones, etc.)

Metallurgist here - If you need to clean quickly you can use dilute HCl (muriatic acid) and scrub with a nylon brush. Immediately neutralize with Baking soda solution. Dilute HCL is generally safe.

I am leery of mixing any acid with an oxidizer (hydrogen peroxide), as even with cleaning vinegar this can create a pretty potent etchant and lead to pitting in a very short time.

Dents Be Gone! wrote: ↑Tue Nov 28, 2023 5:45 am Anyone else thinking of cleaning anything with 30% cleaning vinegar should really do some research on the potential dangers and how to handle it.

Oh yeah. I totally used 6% vinegar because I didn't want everything to be so fast that I lose track of time and mess something up badly. And 6% vinegar was like $5 at the grocery store, compared to $25 for 30%. Left in the vinegar long enough, everything shined up nicely.

I've never seen a half gallon jug of cleaning vinegar for sale for any more than four bucks, even with all of this top down engineered hyperinflation. Admittedly, before all these trillions of dollars were printed so quickly during this shutdown thing, I could buy a half gallon jug for a buck, so it has gone up 400%, but it's still only four bucks. I can't find any pH level marked on the jug that I have, but I have to believe that it's far less acidic than the chemical I use to clean instruments. I believe this because I can leave this vinegar on my hands without my hands becoming irritated, and - if I don't wash of the other acid - which I use to clean instruments - off my hands pretty quickly, they become irritated. I do see instructions on my cleaning vinegar jug instructing me to dilute it 50%, but I've never done it, and it's what I use to clean really dirty windows.

The acid that I use to clean instruments can weaken lacquer after leaving an item in there way too long, but candidly, I've left some parts in there overnight accidentally once or twice over the last forty years, and those parts I left in that much stronger acid were hardly eaten away at all, I'm sure this depends on how much water I have mixed with that stuff. To give someone an idea of how strong I tend to leave that instrument cleaning acid it usually takes only about 5 to 10 minutes to clean all the lime out of an instrument that's really caked with it on its interior. Actually - the couple of times when I goofed up and left parts in my instrument parts cleaning acid for way too long, they measured the same with my calipers as they did before I put those parts in there.

Finally, don't confuse this cleaning acid with the old chromates that were used to (not clean, but to brighten) brass in the past. That stuff would eat an instrument away into nothing if left in there too long.