Testing Johnsons No.2 Flashpowder

Having enquiring minds, Brian and I decided we had to find out if the 40+ year old powder would still produce a flash when ignited. To test this, a small amount (a few grams) of the (agglomerated with age) grey material from the large tin was crushed into a powder and mixed with an approximate equal amount of the white powder, the whole then being put into a small aluminium individual cake tray and placed outside on the patio. The mixed powder was formed into a small cone and a piece of the 'touch paper' inserted vertically into the powder cone. We lit the touch paper and stood back.

Despite its age, the touch paper fizzed & smouldered down into the flash powder exactly as intended - but nothing happened ! There followed the same feeling as when a firework fails to go off. Approach and try again, or stay well back?

As is usual with these things, after a minute or so of watching nothing happening, our courage rose and impatience got the better of us. So the next thing was to drop a lighted cigarette butt into the powder. The butt smoked and smouldered away for a time, in contact with the powder, but still no flash !

As before, a short wait led eventually to a more drastic idea for lighting the powder. A sheet of rolled up newspaper was lit and, when ablaze, dropped over the top of the powder in its small aluminium tray. Even then, 10 or 20 seconds elapsed, and we were on the verge of deciding the powder was now 'dud', when suddenly it ignited with a very bright, but brief, flash of light. Success !! No doubt it produced some smoke, but not so as to be noticeable outdoors.

Maybe aluminium wasn't the best container for the flashpowder. The small tray was almost completely destroyed by the temperature of the ignited flash powder, and very little of the tray remained. Fortunately, Brian's patio slabs seemed to survive !