Hartford, CT
Quoted from swampfire:I discovered when I rebuilt mine that the wax really is oily. Probably carcinogenic too, or at least it smelled like it. There’s a place that sells a complete kit for replacing everything inside the globe, google “Goo Kit”. I’m looking for a cheap made-in-China lamp to try this on.
I discovered this fact in 1990 when college roommate from hell had a friend turn over slightly annoying college roommate’s lava lamp to shake it up. Unlike those of us who lived in the suite, the friend didn’t know about the broken cap and proceeded to shake the contents out across our living room, where it then sat and congealed bc RFH and SAR fought over who should clean it. Decent roommate and I had nothing to do with the party (and were sick of the two of them destroying the suite on us, so we moved out early, leaving the two of them to eventually deal with the clean up and paying the damages. 
But other than that one miserable incident, I love lava lamps!
