I'm trying to build a propane volcano. It will release short burst of propane from a BBQ tank and then it will be lit by a constant flame made by either a butane torch or something else. I have a basic idea on how to do this but I need some kind of device timer to release the propane. I have this kind of device on a fog machine I have and I would use the device in that but I also need it for this project. If worse comes to worse, I could do this manualy but help on the safety and mechanical details would be much appreciated. Thanks:)

Hi,
This could be a little expensive because you would need a timer for a solenoid valve, for gasses.
There are timers for Gas Lamps, outside the home. But, these may not be interval timers.
Doing a search might produce something.
You definitely need something that is for combustible gasses; otherwise any spark from a solenoid open-close valve could cause you a lot of problems!