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Rate my unmilled BP


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1 hour ago, BingBong said:


Is this fast enough to generate enough lift for a 1-inch wide 3-inch long paper rocket? I don't have a ball mill so I just used a mortar and pestle. 

Thrust produced by rocket depends on burn rate of mixture tyoe of rocket motor,core burning have more thrust than end burning rocket.

If you do not have ball mill ( I dont also have)

So in order to control burn rate of mixture

1- all chemicals (oxidizer)used for composition atleast be grinded to very fine mesh like 100 mesh and sieved through fine mesh screen ( 80 or 100 mesh) 4 to 5 times.

2- {wet milling } very efficient for those who dont have access to ball mill.

Wet method I use is as follow.

For BP or lift charge I dont use normal charcoal I use finer mesh charcoal (here in our country it comes as a double filter)

I grind kno3 using coffee grinder until it passes through 100 mesh.

Then I prepare black powder mixture and sieve it 4 to 5 times.

I dont add binder in it.....then I add water In it and knead mixture and add water if necessary.

Then i keep this wet bp in empty  clean cement bag (waterproof) and fold it all over.

Then I wrap this cement bag with jute bag and I ram that wet mixture for 30 to 60 minutes Using heavy Iron rod.

If you dont use jute bag or sack then there is a chance of tearing cement bag and wet bp comes out.

Then i dry this wet milled bp and again sieve it so that it is converted into powder form again.

Then I add binder and make granulated bp for lift.

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