All you need is some glass, some sand, sea water and some way of mimicking the ocean and (bam!) you get sea glass.The beach glass machine
I wanted to do large volumes, so I borrowed my uncle's cement mixer to mimic the ocean. The steel fins inside mimic large rocks. I started breaking wine bottles into small pieces and stole some sand from the kids play box, adding it all to the mixer. Since I didn't have any sea water handy I just filled it with tap water and turned it on. After an hour I checked and the sharp edges were all broken off, after two hours there was some frosting and smoothing and after 4 hours et voilà-- I had sea glass! With the capacity of the mixer I will have my garden path in no time.
Mark Frauenfelder is the founder of Boing Boing and the editor-in-chief of MAKE and Cool Tools. Twitter: @frauenfelder. His new book is Maker Dad: Lunch Box Guitars, Antigravity Jars, and 22 Other Incredibly Cool Father-Daughter DIY Projects