a way to harden styrofoam?
I have been working on a metal mechanical iris for a while now and have been looking for a few things, but one thing that has me scratching my head is having a base, or cam wheel. its just a circle with grooves in it. i decided to use plain styrofoam for this so it will be lightweight and easy to cut, but when i tried it the cam wheel easily crumbled with enough force applied. is there any way to harden styrofoam with a spray or something of that sort? it needs to be somewhat slidey, so it can move well, so nothing like a rubber spray.