Propane Bubbles Posted on 2016.12.202016.12.18 by Lumpy Propane Bubbles – Passing the Flame Ball More Stuff You Shouldn’t Try but Probably Shall I shall not lie. I have done this. We did it in high school chemistry class and we were all carefully supervised. While it is reasonably safe, you can still get hurt. I do not endorse trying this without supervision.