I've just joined the group and need advice. I'm working on a project (won't bore you with the details as to why) but ideally I could do with a lave lamp approx 5 feet tall or 1500 mil tall. All the lave lamps I can find today are only a fraction of that. Do lamps of this size exist or am I asking for the impossible, based I assume on the chemistry involved.
You could get a Lava Colossus. They are four foot tall. They are spendy (about $1,100) and, while I don't have any direct experience, people that have one on this forum say they have issues with leaking caps and the dye leaking into the fluid.
A long time ago they made another four foot tall called the Lava Imperial. These are more stable, but they are near impossible to find.