I know this use is unconventional and maybe not too relevant to metalwork, hopefully that doesn't piss anyone off.
I want to apply soot deposits to glass in a swirl pattern. I've used pure acetylene to do this before on other surfaces, it produces long strands of soot that float through the air and make an interesting pattern when they land on something. Hard to control but looks interesting.
I no longer have acetylene, I don't know if it's available anywhere in small tanks, like propane or MAPP is? Are there any other gases that will burn and produce smoke like acetylene? I need maybe 2 minutes worth of gas so I really don't want to buy/lease a tank and pay near $100. I can't transport the gas to another shop either.