Dear WW: perhaps you might have butane cylinder with burner nozzle, such as plumbers use
for small jobs. Incidentally, at one point my second daughter took care of widow of guy who
invented Pyrex glass. She gave my daugher a desk he had handcrafted for himself. I wish I
still had it. When I was ten, you had to be very careful to heat urine specimen to test for
sugar, with Benedict's solution. If you had hot flame with green cone in center, and almost
invisible pale purple outer flame, and put test tube right into it, it would shatter every time.
You had to use reducing flame, meaning lower amount of oxygen, giving gellow color to flame,
and only slowly move test tube into flame, taking it in and out. Just the addition of a small
amount of borax makes the glass wonderfully fracture resistant. That guy ought to have gotten
a Nobel Prize for it. It's just as important as stainless steel, for instance. I think I'll try to look
up the guy's name. Something like Kieve. May he be on a particularly comfortable cloud in the
Hereafter. PS your hardest problem is going to be finding soft glass rod.