A 100w light won't get hot enough to bust a mason jar. I think the hard part about your project is going to be turning the jar into a tube. You can buy "hurricane glass" (the glass that goes over kerosene lamps), and that should be perfect.
well i was going to try and do the samething we use to do as teens when we wanted to make a beer bottle into a hot knife hooter.It work i say 5 out 10 times perfect.Just the bottom breaks off.U take a normal kitchen knife or 2 and drop them threw the bottle making the handles of the knife hitting the bottom of the bottle.It does work.But thanks for the idea im going to look for some right now.Thanks
if you fill the jars withlittle stones then swirl them around the bottom for a while ,then witha snapping downward movement the bottom will fly off,nice clean break