I’ve become slightly obsessed with erlenmeyer flasks.  I love their shape.  I used a diamond tipped Dremmel bit to cut off the base of one using a makeshift jig and then cast the flask in poly-urethane (gross) and then tried to pour concrete in.  I built a really simple jig that I cut out of duron on the laser cutter and unfortunately it floated up into my mold as I poured the polyurethane.  Rookie mistake.  Iteration 2 coming soon.  I want to make it into a lamp shade.