TromboneChat

The ultrasonic thread talked a little bit about various deposits.

We all know some of those deposits seem to be lime. They look like it, they dissolve in acid, I haven't questioned it.

But where would that come from? Condensation seems unlikely, and while trombonists do sometimes use tap water, those same deposits appear on euph, tuba, trumpet, etc.

Is there enough in our spit?

Trees, I thought?

https://en.m.wikipedia.org/wiki/Lime_(fruit)

It's not just spit. When we play, we exhale droplets of moisture, which contain various minerals. Some of those droplets end up staying in the horn. When the water from those droplets evaporates, it leaves behind the minerals.

There's water vapor in the air we exhale, too, but that's different from droplets. Droplets are small bits of liquid water; water vapor is a gas (though it can condense into droplets under the right conditions).

If I were to take a wild guess as to the composition of the mineral deposits inside a brass instrument, I would expect them to resemble dental calculus (tartar) with the addition of some oxides of copper and zinc.

https://en.wikipedia.org/wiki/Calculus_ ... omposition

harrisonreed wrote: ↑Sun Jul 05, 2020 7:47 am Trees, I thought?

https://en.m.wikipedia.org/wiki/Lime_(fruit)

I thought that you get one with a coconut?

Let me call my doctor friend,
Andy

Most of us use water mist to lubricate our slides. (Not so for euph, tuba, trumpet, etc.) If we use tap water for our spray, and the water is "hard" (high mineral content – mostly calcium & magnesium) as it is where I live, the evaporated water will leave mineral deposits on the slide, which can be very difficult to remove. Once I discovered that, I switched to using distilled water for my slide spray. I bought a gallon of distilled water 4 or 5 years ago for ~$1.25. It's only about half empty. My slides (which I do swab and wipe clean regularly) no longer accumulate these deposits. That distilled water has been one heck of a bargain!

I thought lime was just a broad name for gunk because it’s kind of green...

Lime: a solid that consists of calcium oxide often together with magnesium oxide.

elmsandr wrote: ↑Sun Jul 05, 2020 7:58 am

harrisonreed wrote: ↑Sun Jul 05, 2020 7:47 am Trees, I thought?

https://en.m.wikipedia.org/wiki/Lime_(fruit)

I thought that you get one with a coconut?

Let me call my doctor friend,
Andy

Clever! I like it.

Elow wrote: ↑Mon Jul 06, 2020 12:05 am I thought lime was just a broad name for gunk because it’s kind of green...

Sometimes it probably is.

I'm referring to the hard whitish deposits that look something like the bottom of a teapot ends up.

They don't come off easily.

The water vapor we breath into the horn that condenses should be pretty close to distilled water, i would think, and not leave lime. Our saliva that gets aerosolized as we blow past wet mouth surfaces would have some. I suspect more of what we let out the water valve is the saliva but I don't know how you would measure.

In the times of COVID it would be nice to know. Some people get more spit than others, and it may be that they just generate more saliva in the mouth that gets grabbed by the air stream. I have a friend who plays recorder with me sometimes, and he plays amazingly dry. Most of us get a burble from the recorder bore getting wet and we have to clear the windway, but he just plays on and on.

I know I produce more moisture then most players as I generate a lot of heat when I play and my body likes to dump that excess heat through respiration. I live in an area with soft water and haven't noticed any limescale build up in my instruments over the years.

Short answer: it comes from your body.

There are minerals in saliva, a small amount of which end up going into the instrument. After lots of this, you can get buildup.