What happens if I increase the amount of water on water based epoxies?

I am using a water based epoxy coating that is composed of a resin and a hardener. There is a specific amount of proportion to use to obtain the optimum cured coating. But I am trying to introduce some dry pigments into the resin then I add the hardener. However adding the pigment increases the viscosity of the mixture and the obtained coating is thicker. 


Since I cannot increase the amount of resin or hardener without influencing the optimum condition, I was thinking since it is a water based coating, I could still have the same amount of functional reacting groups and just increase the amount of water in the resin to make the mixing of pigment with the resin easier ?! 


But I am afraid during the drying process, the evaporation of the extra added water might influence my coating ! 


Do you know what could happen in this case ? 


