Empty hand animation?

[Aabaddon]

Im trying to animate 2 kinds of arms, one when hands are empty and one when they are holding an object, the problem starts when trying to hide parts in 2 different animations, if i try to hide one position when holding an object and the rest of the time show that part simply both parts disappear (im trying to make something like the evoker that can change its arms without ruining vanilla animations for better combat, iron spells and musket mod)