Dual Wielding Barb question

[Schuey]

Say I dual wield The Gnasher (Unique Hand Axe) would the effects of the two weapons stack (i.e. 50+50=100 % open wounds) or are the on-weapon attack/damage attributes applied ony to attacks/damage by the atacking weapon? I assume, the non-attack related attributes such as defense, resistances, strength, etc. are additive.

Dave