TromboneChat

While cleaning my mouthpiece I noticed some hard deposits in the stem part of my mouthpiece. I assume it’s calcium? How do I clean those out? I’m afraid vinegar will hurt the sliver. Any safe way besides taking it into the shop?

I moved your second post out of sight. I guess you missed the note that you don't see your posts until you have had two accepted.

As to the deposits, they are possibly calcium carbonate, but could also be some complex oxides. Vinegar won't hurt the silver, but it may not take the deposits off either. You can try using a good cream polish and see if that takes it off.

A quick dip in hydrochloric (or muriatic) acid, which is how rotors are often "cleaned", would do the trick, eh? Not sure what, if anything that would do to the silver. Maybe not worth all that hassle if you don't have the acid sitting around.

Also, what about CLR? If the deposits are just internal to the shank, I should think you'd be able to plug the end, set the mouthpiece in a hole in a board (or something similar) with the cup up, put some CLR in it up to the throat, and let it sit for "a while".

I'd be more concerned about how the deposits got there in the first place. I guess just from lack of frequent cleaning or rinsing of the mouthpiece?

Right I cleaned the mouthpiece but only was running the brush from the cup side into the hole. I needed to brush from the opposite end as well. Still, it was not frequent enough, I’m sure. I should know better

Well, I think the brushing from both ends depends on what style of brush you use. If you use a brush in a cylindrical form (rather than the, perhaps more common, conical form), there's no need for the bi-directional brushing. I actually brush my mouthpieces very infrequently, but I do RINSE them. And I clean them thoroughly now and then. Like when I clean and re-lube the slide on the trombone. And I've never seen deposits on any of my trombone or tuba mouthpieces. However, a lot of this may depend on body chemistry.

My shanks are raw brass and I never see those kinds of deposits on them, but I do see that on plated mouthpieces. I think it's fairly likely that it's not entirely "deposits," but a bunch of little defects and pitting in the plating that's inside the backbore.

Well good news. The little white bumps disolved when I soaked the stem in a shot glass with 50-50 white vinegar and water. It took about 3 hours and I watched it frequently to make sure the silver was not etched or anything. I would scrub the inside with the mouthpiece brush every hour or so. I then soaked in baking soda and water just to be safe. The inside is clear and smooth. I had tried just really hot water alone at first but made no difference.
Hope this helps others.....

I've had those deposits before, little white spots on the inside of the shank near the end. I leave them in. They double my range and make me play faster