How to make hot BP indoor safely (lab intensive)

[MinamotoKobayashi]

Hello forum.

The following procedure is the result of many different techniques that I have learned surfing this forum, internet,

and with the help of a great friendly and disposable user named NeighborJ.

Of course I have also added something of my own.

 

Here is the needed tools for the whole procedure:

 

1. A ballmill (or modified rock thumbler);

2. 100x 1cm brass balls media;

3. An hydraulic press;

4. A star plate;

5. 8 and 20 mesh woven wires;

6. A pot and a big spoon;

7. A minipimer.

8. A large sheet of waxed canvas.

 

Here is chems needed:

 

1. Potassium nitrate: 400 grams;

2. Pine charcoal: 80 grams;

3. Sulfur: 52,2 grams;

4. Dextrin: 21,2 grams;

5. Demineralized water: 200 ml;

6. Ethyl alcohol.

 

 

First of all the pine charcoal, the sulfur and the dextrin must be ballmilled all together:

 

With the correct medias size, the correct number of medias, the correct barrel diameter size, the correct rotation speed and the barrell half-filled,

usually 1 hour is more than enough.

 

Now it is necessary to boil the demineralized water into a pot. Large pot is recommended.

Important: first wait until the water is boiling, then dump the potassium nitrate into the water. Do not use KNO3 with anticaking, it will slow a lot the

BP performance!

Gently mix the water+KNO3 with a spoon (stainless steel or silicon items are preferable) until the water will boil again.

At this point the KNO3 should be completely dissolved.

 

Dump the ballmilled mix into the hot water+KNO3:

 

It will be very difficult to dissolve the dry mix in hot water containing KNO3, so please be patient and stir and squeeze the powder until it looks like a dense paste.

It is advisable to do this step outside, because a lot of charcoal powder can float in the air.

 

Now, with the help of a minipimer, the wetted BP can be transformed into a very fine, uniform and velvety matter:

While using the minipimer, a little spray of ethilic alcohol will reduce the surface tension and help the mix to dry fastest. Do not exceed with alcohol or the KNO3

will precipitate.

 

The mixture is spread over a long sheet of waxed canvas:

It is important to leave the mix about 24 hours to let dry them enough. It is advisable to not put the mix near heat sources, or the potassium nitrate try

to recrystallize on surface. Anyway, very few and tiny crystals of recrystallized KNO3 can be visible on mix surface after 24 hours.

 

After 24 hours the mix is dry enough to be pressed:

 

Pressing the mix with the help of a star plate with a pressure of 2 tons:

The few water in excess will be squeezed away while the chems particles will be mixed more intimately.

 

These are the BP cylinders ready to be granulated:

 

With the help of my precious multipurpose device the BP cylinders will be granulated.

The upper woven wire is 8 mesh while the internal woven wire is 20 mesh.

The finest powder (the so called "meal") will be collected inside the drawer:

 

To obtain as much as possible 8 mesh powder and few meal it is better to not "scratch" the cylinders against the woven wire, but rather press the cylinders

while moving them in one direction.

The quantity of each powder depends how much dried were the cylinders: in fact a cylinder too wet will create granules that tends to stick agains one to another,

while a cylinder too dry will create much meal and very few granules. This is a classic "try and error" procedure.

The powders are ready to be dried:

 

Here is the granulated BP completely dried:

Now the BP is extremely flammable and will be treated with the utmost care and attention.

 

The powders are placed in two different hermetic containers with silica gel bags and an indicator for moisture levels:

 

That's all!

Tomorrow I will post a video showing the +8 BP while burning. Outdoor, of course

Edited April 10, 2018 by MinamotoKobayashi

[Mumbles]

Safe is not a word I would use to describe this. It's basically just a slight modification of the CIA method with the added (an unnecessary) hazard of using an immersion blender on a comp. Additionally, as soon as you start drying it, the material really should be outdoors.

 

Of course we've been over this several times before, yet you continue to work indoors and try to convince yourself it's safe. It's not. Trust me, I speak from experience of things going very wrong.

[MinamotoKobayashi]

Hi Mumbles.

I tried to light the powder with and without the use of a minipimer. There is a difference. Light, but there is. It is an unconventional value added.

And this avoid some possible lumps inside the mix.

 

Since the mix is much liquid because it contains a lot of water, it is impossible to ignite.

I tried with a blowtorch to ignite it, but nothing happens, also if I insist a lot.

 

The place where I work now is an isolate cottage placed in the middle of a maize field, so no risks for my neighbors anymore, don't worry.

In the worst case I will have free popcorns

Edited April 10, 2018 by MinamotoKobayashi

[NeighborJ]

I make the bulk of my powder with a similar process. The main difference is, instead of pressing and corning I add some meal from a previous batch to the over wet batch until it is the correct moisture content to screen granulate it.

 

It does make a good powder for lift and burst but there are some things which I still do 3 component milling for (rockets). For that, i just toss some of the meal in the ballmill for an hour just to fluff it up then regranulate it.

[Simoski]

Looks GREAT mate, keep up the good work.

 

One improvement that I can suggest: The pressing will slow your powder down.

 

Look below at the black powder burn rate versus density graph taken from "The Influence of Physical Properties on Black Powder Combustion" by Ronald A Sasse of the US Army Armament and Research Command 1981.

 

 

similar findings by the same Author in 1985 "A comprehensive Review of Black Powder"

 

Edited May 29, 2018 by Simoski

[Baldor]

You don't always want the faster BP possible, Sim. Some times, the same energy released over a longer time is what you want, for example, for lifting large shells. Also in rockets. You want the maximum pressure your tube and nozzle can withstand, but no more, and for as long as possible. Applied to firearms, you want the maximum pressure the barrel will withstand, during as long a time as possible. This is why cannons loaded with too fine BP exploded.