I have a MIDI controller keyboard that I have cleaned in the past with disinfectant alcohol wipes, which I know is a bad idea because it degrades the rubber over time.
Well, the rubber on the pitch bend and modulation wheels has indeed degraded, and the surfaces texture is awful, uneven and sticky now. My fault… I know.
So does anyone know of any way to fix, or even improve, this kind of nasty rubber surface degradation once it occurs? Sanding? Applying oils? Is there any way I can even slightly restore these controls back to their original soft-touch rubbery glory?


WD40 evaporates?
Anyway, my go-to is paper towels, cotton swabs and isopropyl alcohol.
Alternatively, if it’s a flat surface I may just stick it over with some tape. The glue will make additional mess, but that’s a problem of future me, and at least I won’t have to care about it now.
Yes. WD-40 isn’t a lubricant. The “WD” stands for “Water Displacement” (the 40 means “40th formula”). It’s intended to be used on rusty parts to remove any moisture before adding a lubricant. It has a tiny amount of oil in it, which does provide some amount of lubrication after it’s applied, but come back in 30 minutes and it’s back to being squeaky again. Always spray some penetrating oil after.
Wd40 has a small amount of oil dissolved in a large amount of volatile solvent.
So most of it does evaporate, and OPs method cleans up residual oil
A lot of compressed canned things are something suspended in a solvent, and when let out of the container the solvent evaporates leaving behind whatever stuff was dissolved in it. I can’t speak if it’s the solvent or something in the WD-40 that has the effect the previous poster is talking about.