Simple as that, ton of hardened remnants of a belt on a capstan flywheel im working on which won't come off with any cleaning solution and scrubbing. Looking to just take off this layer with sandpaper but I obviously don't know what grit of sandpaper I should be going for to (A.) remove this gunk (B.) make sure the resulting finish is safe for the belt and grippy enough to maintain normal wow and flutter. Thanks!
I used 800 grit for cleaning and 1500-2000 for final finish. Depending on condition, sometimes the motor pulley might need some sanding as well: I do this by powering the motor on a bench supply and keeping a small piece of sandpaper in its groove. The important thing is to sand it uniformly, so keep it mounted and rotate while keeping the paper fixed. In rest, the microscopic scratches won't make a difference, they're just too fine. It is to be noted, for other people reading this thread: obviously, do not sand the flywheel if the gunk can be removed just by using IPA (which is sufficient in the majority of cases).
Have you tried Goo Gone? Be careful you don't get it on everything and make sure you clean it all off. I use Isoproply Alcohol and Simple Green for the cleaning.
Thank you! @Valentin and no @Mister X I have not, however unfortunately the remnants have almost zero semblance to rubber or any pliable material. I only know it's the belt or at least a chemical reaction between the belt and brass because it is only on the portion of the flywheel which made contact with the belt. For those curious, the remnants are a very faded purple color and have caused discoloration on the surface of the brass. The remnants can be felt by gliding a fingernail over it.
Goo Gone should soften it up, then use the IPA or Simple Green to clean it off. It's nasty stuff that seems to corrode the brass, I think that's where the color comes from.
