Hi jalberghini, welcome to ATP !
An easy way to cover a styrofoam ball with Quikwall is to make a rather thin slurry and work that into the styrofoam by hand as much as you can. After that thin layer is worked in, I then add a layer of thicker mix over the top. The thin mix "grabs' the styrofoam, then the thicker mix grabs the thin layer. If you have any other questions, I'm more than happy to help.
What are you planning on making?
