I painted some control cavities with that Stew Mac shielding paint and noticed whenever I stick my fingers in there to work, black charcoal looking dust easily rubs off on my hands and fingers if I just touch the painted sides. It seems like it could flake/chip off easily. It got me thinking that this stuff might actually cause more problems than it solves if it sheds particles of itself into switches/potentiometers. I ended up painting over it with a clear coat to hold it down. Thoughts?