Epoxy and Q cell vs Poly and Q cell

One for the chemist’s amoungst us. How come you can add two or three times the amount of Q cell into an epoxy resin mix compared to a polyester resin mix?

The epoxy resin almost becomes more fluid with the first quantities of the micro balloons.

Maybe the epoxy molecules are smaller and get within the spaces or something?

Any idea’s?

Don't know, but epoxy resin is stronger and more flexible, so you can dilute it more and still be strong.