  We study the dynamics of the first order phase transition in the two
dimensional 15-state Potts model, both at and off equilibrium. We find that
phase changes take place through nucleation in both cases, and finite volume
effects are described well through an instanton computation. Thus a dynamical
measurement of the surface tension is possible. We find that the order-disorder
surface tension is compatible with perfect wetting. An accurate treatment of
fluctuations about the instanton solution is seen to be of great importance.
