There is a name for the method of glazing the edges Ted, I looked it up when I was doing the led mods I mentioned, I think the theory went that it’s the fine point between the acrylic melting and catching fire, maybe a heat source not using a flame would be better, I do seem to recall them mentioning using a fine flame though. Maybe it’s a practice thing, you need to do a few of them in order to find the optimum heat and distance.