How often to apply grease on slides?

[Leto Cruise]

My slides currently work very well, but in the past I have encountered many tubas whose slides are rusted and immovable. I really only find the need of using the 1st and 2nd tuning slides, so is there a need to frequently apply grease to the other slides? I don't want them to become rusted, so how do I prevent it? Sorry if I'm asking a rather obvious question, but how often should the slides be greased? Once a day, once a week, once a month? Help is appreciated.

[SplatterTone]

If the valves fit properly and are aligned, you should never need "grease". Although a light bit of valve oil is useful. I suspect the "rusted" slides you have seen were in horns that were constantly put away wet with the slides never removed and never cleaned.

[Wyvern]

If the valves fit properly and are aligned, you should never need "grease". Although a light bit of valve oil is useful.

Using valve oil on the 2nd slide sounds a good idea, with the slide being so close to the valve, particularly on F.

[Dean E]

Greasing and oiling the tuning slides, for me, is part of a periodic maintenance and cleaning process.

Main Tuning Slide. I use grease on the main tuning slide, which I clean whenever it gets too sluggish for my comfort. After cleaning with a soft cotton cloth, such as a patch of jersey cloth from an old t-shirt, I reapply grease to the main tuning slide. I use a slide grease that is the same brand name as the valve oil. I would not switch brands except after a major hot water & soap/vinegar cleaning. Out of an abundance of caution, I do not want to ignore the many warnings against combining different greases and oils.

On a very loose main tuning slide, the performer would use slide grease to resist gravity from causing the slide to drop out.

Valve Slides I use slide or valve oil on all valve slides, including those I pull. Every month or so I clean those slides with oil and a soft, cotton cloth to keep them free. I apply a few drops of oil to one leg of a slide and insert that one leg into the outer slide. Push and pull, rotate, remove and wipe down. Repeat on both slide legs until the cloth wipes clean. On some slides there will not be much room to rotate the slide with only one leg inserted.

Valve oils are a recipe containing (1) light, volatile, ingredients mixed with (2) heavier lubricants. Over time, the lightest ingredients evaporate, leaving a heavier, sludge-like substance. That sludge is guaranteed to thicken and harden with time--like paint. It is just a matter of time before the thickening and hardening happens.

Making things worse, if a horn is stored for long time periods, with moisture trapped in the slides (and valves), the moisture (and the acids it contains) react with the brass to grow solid, green, deposits, which further tighten the slides. The growing, green deposits physically expand to occupy the tiny clearance space, normally .001 inches to .003 inches. The green deposits expand and physically bond to the inner and outer slides, which is not a good thing.

That is why greasing and oiling should be part of the cleaning process.