The teapot at the office had gone leaky. Instead of throwing it out, I offered to adopt it. With some other lamps in mind I thought I might also give the teapot a new life as a lampshade.
First I started to cut the bottom out with an angle grinder. The teapot turned out to be a double-walled affair and quite a bit of trapped tea came out once there was a hole. When everything was dried up again I found out that cutting neatly around the edge of the bottom was difficult. I wanted to get as close to the wall as possible, but without damaging the wall itself, and an angle grinder is not really a precision tool. I ended up cutting away tiny triangles and using a sanding disc to clean up around the edge.
With the bottom cut out, I started working at the top. The lid needed to be fixed so it wouldn't come off when the lamp was hanging. So with the lid closed I tried bending the edges of the lid outwards. This didn't work since there was limited space for me to work and the edges turned out to be very sturdy. Then I tried soldering the lid closed, but that didn't work either. My soldering iron didn't have the power to heat up all the metal to soldering temperature and I was afraid of discolouring on the outside if I were to use more powerful tools such as a blowtorch. In the end I glued the lid in place and that worked just fine.
To hang the lamp and feed the power cord in, I needed a hole in the top of the teapot. So I unscrewed the black knob form the top and drilled through the threaded hole with a slightly bigger diameter. The metal part of the lid had a threaded rod sticking out the top, so I drilled from the bottom instead. All that was left to do was feed a cord with light socket through the top and hang it.
While writing all this down I realized the teapot could do with a mains earth connection.