1) The simple saltpeter/sugar recipe worked well. A significant amount of smoke was produced along with a surprisingly large flame. These smoke bombs are definitely not for indoor use. Batman would have to find another type of smoke bomb if he didn't want to ruin peoples' floors. My only complaint is that the homemade fuse sucks. When making a homemade smoke bomb, buy a fuse: don't attempt to make one. I'd suggest maybe a birthday cake sparkler. That probably would have worked quite well.
2) The recipe which added a touch of honey (or cornstarch) to the recipe was far easier to prepare. When it was lit, it behaved very similar to the first recipe (perhaps this smoke bomb burns slightly quicker).
3) The recipe that mixed the saltpeter and sugar into melted paraffin (wax) was a complete dud. I couldn't get it to light at all. Nothing. I suspect that I added far too much wax. If I were to try this again, I would follow one of the other two recipes and then just at a touch of paraffin, just so that it burned slightly slower.
So all in all, these worked surprisingly well. I would suspect that the remains of such a smoke bomb would leave virtually no clues about the user and so I suspect that Batman might actually prefer such simple homemade smoke bombs to more complex (and therefore more easily traceable) smoke grenades.
1 month ago