New Rocket Propellant (Gunpowder)

Details from a short detour about using gunpowder as rocket fuel (which ended up going nowhere, literally)

After some correspondence with a rocketry veteran I am shifting to rockets using gunpowder (This turned out to be not true, I instead switched to the superior KNSB propellant)
This would come at a increased burn rate and chamber pressure (increasing the burn rate even further), which would result in more powerful rockets
a nice bonus is that the charcoal leaves a nice trail of sparks, increasing the rockets aesthetic potential by 75%

There are a few things to consider, first off, gunpowder can go from burning really fast (what we want) to exploding (not what we want) so to prevent accidental pipe bombs the casing material is going to be changed from PVC piping to glue reinforced paper

While no casings have been made thus far, I have made a new batch of gunpowder
I have done this before while making a miniature cannon a while back, so it was nothing new

The Recipe is the same as the Chinese invented in 1300, which is as follows

  • 75% Potassium Nitrate (KNO3)
  • 15% Charcoal (C)
  • 10% Sulfur (S)

All of this is by weight
For simplicity i made a 100g batch, so 75g KNO3, 15% C and 10% S
I ground up all the ingredients, added them and mixed them together (quite simple really)

This is technically a green mix (as in all the ingredients ground together without any solvents added, such as water or ethanol) so its technically not gunpowder
But, I have to add water anyway to solidify the fuel with some diy dextrine (more about to that later), so I’m not too worried about it

75g Saltpeter, 15g Charcoal, 10g Sulfur
Mixing (but for a hour+)
Propellant (Green mix)

(This section will house a Gunpowder VS Rocket Candy burn speed test when i have the opportunity to make it)

Because the explosion risk involved with gunpowder, the casing material will be altered to minimize damage if a runaway oxidation (aka a explosion) is to occur
And this propellant will have to be cast differently, since it needs to be rock solid to keep shape while burning
to achieve this some binder will be added (in this case dextrin, wallpaper glue (powdered) should also work

This procedure has yet to been done, but the idea remains the same

  • Things needed are: Wooden dowel with a diameter of the desired inner casing diameter (also as a packing rod), paper (sturdy), wallpaper glue or dextrin (i made some a while back by baking corn starch in a oven) which will be refered to as binder, some ground up clay (cheap kitty litter), and the propellant (in this case gunpowder)
  • First for the casings, mix the binder with water in the appropriate amounts, then coat the paper with plenty of glue, wrap these around the dowel (adding some Vaseline or oil to help separation) and let it dry when enough has been added
  • Using the dowel and some powdered clay, pack clay into one end to seal it
  • Mix propellant and binder with water or ethanol (ethanol is quicker but less safe) and scoop it into the casing, then lightly compact and use something akin to a pencil to “core” the rocket
  • Let it dry and harden

For legal and personal reasons, this is not something you should do at home, especially not with these instructions
I’m just starting out and am not yet proficient in rocketry at all
I am not responsible for anything you do, just be safe

Results will be in a different post at a later time

I am also formulating a plan for a liquid fueled rocket engine
its in early stages, but I will post updates on this site at a later time

That’s all

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