W.P

Long story short, my home made mill is no longer functional due to a blown motor and I would like to opt for the easy option of buying a mill off another UKPS member. I don't mind if it's a second hand Chinese mill, I just need something that works quite frankly! Anyone got a small mill they don't need any more?

Today during chemistry classes our teacher decided to do a little demonstration of exothermic reactions. Although highly unnecessary he has a compulsion to demonstrate as much as he can practically in order to help us remember, however today was a step too far!

He first started off with a basic thermite demonstration, I'm guessing he placed around a gram or two in a crucible inside a dish of sand. Nothing fancy, lit the magnesium ribbon and the thermite reaction took place, everyone in the class being "amazed at the wonders of chemicals" except me, expected. Next he took another crucible and placed it on top of a gauze above a lit bunsen burner, told us it was "just some black copper oxide" then set us some paper work to get on with.

Around 5 minutes later there was a loud "thud" noise accompanied with a bright flash and a cloud of black smoke (this was INSIDE the lab by the way). The observation screens protected us from the flying pieces of ceramics and obviously everyone was surprised. I looked at him, his cheesy grin masking what I believed to be sheer ignorance or plain insanity! I told him "that was NOT JUST copper oxide was it, sir."

He responded almost under his breath as to not inform the class of what the actual contents of the crucible, in case they try to repeat this experiment. It was actually black copper oxide and magnesium mixed together. I asked him whilst recovering from the black smoke exactly how much was in the crucible, turned out to be eight grams. So not only did he just create 8g of flash powder he also placed it in a ceramic crucible (which is almost famous for it's tendency to fragment) but then placed it above a bunsen burner behind a class of students.

I asked him a third question: "Where did you get this idea from?". He responded with "I tried it earlier just to see if it would work, but the first time I was peering over the observation screen just to check whether a reaction was taking place and 'poof!' up in my face it went!". Bare in mind this man has a Master's Degree in chemistry.

Insanity or Stupidity?

Recently I've done some small scale experimentation involving zinc powder and potassium perchlorate. I tried a variety of different ratios in order to come up with what I believe to be the best mixture. I concluded that this composition burned the fastest:

Potassium perchlorate 1: Zinc powder 9

(Yes, the oxidising agent is the lesser part)

Obviously I took basic safety procedures which was diapering outside with heavy duty gloves and face mask.

Any thoughts on this composition?

Hello. I am new to this site and I have a question that i need answered. When ever I buy potassium nitrate it normally comes in large quantities (due to its commercial use) but i find that it clumps together. If it is absorbing moisture from the air then wont that mean:

1. Mixing compositions accurately will be effected due to the weight of the water being counted

2. The performance of the composition (with the exception of BP) will be worsened- especially in Mg/KNO3 flash powder + nitrate flash

3. Possibly will it effect the quality of BP?

Just to insure that these don't happen, i normally order small quantities from specialist pyro dealers and create BP with it within the same day of opening the bag.

SO... if the hygroscopicity does effect the performance then is there anyway of storing it in a moisture free environment without going too extreme (silicone based moisture control and all that nonsense)

And sorry again if this was posted before.

Thanks.