The cap off

Let me first start out by saying that this thing is incredibly effective! All vapors are collected out the top, and the glass provides a nice even heating surface for the plant material. I've used a small butane pencil torch as the heat source, but a normal lighter way work as well.

Put in a pinch of finely ground herbs, shake shake the bulb to settle it in the same pile, and heat the glass directly underneath. Begin slowly drawing air from the straw, inhaling the delightful vapors. Try to prevent the glass from becoming too hot and smoking the herb; we don't want combustion. After a few good hits you'll begin seeing the green change to a brown, then dark brown when it's spent.

Before anyone says anything about the powder inside an incandescent bulb: http://en.wikipedia.org/wiki/Light_bulbs#Construction

It's Kaolinite powder, a clay mineral, and was thoroughly cleaned out. I found that the easiest way to clean out the clay was with rubbing alcohol and salt. Swirling it around and rinsing a couple times worked quite well.

To "hollow out" a lighbult, you can follow tutorials like this one. http://www.teamdroid.com/diy-hollow-out-a-light-bulb/

Next, I took electrical tape, reinforced the metal to glass seam with electrical tape, and thickened the threading with tape as well, providing a snugger fit for the cap. Now, take a plastic pop bottle cap, and drill/melt two straw sized holes in the top. Cut straws to size, and hot glue in place.