Jeff, nice video. I want You to know about that "powdery stuff" You're adding to Your plastic that makes it float. That's Glass Microbubbles/Microspheres. They're very thin-walled GLASS bubbles...bubbles, with air inside. Be beyond careful messing with that stuff. You can inhale them then You'll have glass in Your lungs. They can drift in the air and get in Your mouth, eyes, nose.
Work on Your system of handling that stuff...it's pretty dangerous.
