BigG

Well, I admit I have not been around for a while.... must be three years or so? In any case, learn the craft carefully and enjoy it. Oh, and hello for all the regulars - nice to see so many familer names still going strong....

 

BigG

As promised – here is a formula that uses calomel for chlorine donation. Unfortunately, it uses Potassium Perchlorate – but maybe one day every UK pyro will have access to that.

Lancaster describes this as “very old-fashion but beautiful pillbox stars.”

Lilac:
Potassium Perchlorate: 60
Shellac: 10
Strontium Carbonate: 5
Copper Oxychloride: 5
Calomal: 20

Pressing and corning would not necessarily ?improve? burn rate. The idea behind corning is that it increases the surface area that can ignite and allow fire to flow between the corned grains. Let me try to explain.

Imagine black powder pressed into a fountain. The only ?exposed? layer is the top of the fountain. When that layer ignites ? it ignites the layer under it and slowly advances down the layers until reaches the bottom of the fountain. The fire cannot advance quickly because only one layer is available for ignition.

Now imagine corned (!) black powder just drops into the fountain. When you ignite the top layer ? since there are spaces between the corned black powder, the fire just shoot down and ignite the whole fountain almost instantly. The force of the ignition causes the gases created by the fire to ?blast? out of the top of the fountain. This is why corned black powder is also called ?blasting powder?.

So the same powder have the same burn rate, in both corned and powder state ? but by corning we allow more of it to catch fire simultaneity.

I?m horrible at explaining things hope someone out there understands me

BigG