Because the slide is entirely mechanical (unlike valves, it has no springs or pads to fail), slide feel is almost entirely a function of cleanliness and lubrication - which makes it one of the more forgiving things to fix on a used trombone, but also one that's easy to neglect.
The two main lubrication approaches
- Cream + water spray: a small amount of slide cream applied to the inner slide tubes, followed by a water spray to help it spread evenly, is the traditional method and generally gives a slower but longer-lasting, more cushioned slide action.
- Slide oil/spray-only products: thinner, faster-acting lubricants that give a quicker, lighter slide feel but typically need reapplying more often.
Which one a player prefers is largely personal - the important point for a buyer is that a slow or sticky slide on an otherwise sound trombone is very often just a maintenance issue, not a mechanical fault, and can potentially be resolved with cleaning and fresh lubrication rather than repair.
What to check when buying used
A slide that has been neglected for a long time can develop a buildup of dried, gummed-up old lubricant, which feels sticky or uneven even if the slide itself isn't damaged - this is worth distinguishing from an actual alignment or dent problem (see the separate article on slide dents), since one is a simple clean-and-relube fix and the other is a real repair.
