196 replies to this topic

[MDH]

We can't forget that there are also catalysts. Ferrous Sulfate is one.

[Arthur Brown]

BP has been around since possibly 1400 using charcoal sulphur and nitrate. Once you have good three component BP THEN you can consider rate modifiers! Simple BP is so important to the history, development and manufacture of fireworks that it is a worthy project.

Good BP, then good BP reliably and repeatably.

Edited by Arthur Brown, 04 August 2008 - 06:31 AM.

[BlackMesa]

Hello again, i have had some improvement on my BP today, as before it was very difficult to ignite and burned very slowly.

With proper weight measuring this time and milling my charcoal and sulphur together as well as individualy milling my Kno3.

The result was much better, the BP now lights very easily and burns alot faster.
The problem however is, it still produces alot of this white/green resin which in my attempted rockets must be slowing down the burn rate as it gets clogged up inside.

Could milling the Kno3 with the sulphur and charcoal stop this problem?
I'm quite nervous to do this as i dont want an exploding ball mill on my hands. (its a slow mill but made of plastic with stainless steel medium)

im using 75:15:10 by weight.

My rocket was a bit of a tragedy really, the engine seemed to be working but it remained on the ground hissing out for several seconds then made a muffled bang and lifted about 3 inches off the ground.

[portfire]

BlackMesa- Nice to hear your BP is getting there, but the only real way to get quality BP is to mill all 3 chemicals. When milling the 3, your not just making the particals smaller and mixing them well. What happens is that the action of the milling process is in fact "impregnating" the charcoal with fine particals of sulphur and KNO3, making a more reactive, faster, cleaner burning BP.

Regarding rockets, what size are they? Smaller rockets require a fast burning BP, and are they 'End-Burning' or 'Core-Burning' ?

And don't worry too much, I'm sure alot of us were nervous milling our first batch (I still get nervous) just take all the necessary safety precautions, even do a risk assessment if you want.

[digger]

BlackMesa- Nice to hear your BP is getting there, but the only real way to get quality BP is to mill all 3 chemicals. When milling the 3, your not just making the particals smaller and mixing them well. What happens is that the action of the milling process is in fact "impregnating" the charcoal with fine particals of sulphur and KNO3, making a more reactive, faster, cleaner burning BP.

Regarding rockets, what size are they? Smaller rockets require a fast burning BP, and are they 'End-Burning' or 'Core-Burning' ?

And don't worry too much, I'm sure alot of us were nervous milling our first batch (I still get nervous) just take all the necessary safety precautions, even do a risk assessment if you want.

Just a quick additional note. Make sure that you have suitable milling media when doing this (lead brass possibly ceramic etc absolutely NO steel bearings of any type)

[BlackMesa]

Just a quick additional note. Make sure that you have suitable milling media when doing this (lead brass possibly ceramic etc absolutely NO steel bearings of any type)

OK thanks for the info again digger and portfire, the only other type i have readily availible is glass, will that work? Im considering ordering some ceramic ones from inoxia though when i make my next order

Edited by BlackMesa, 04 August 2008 - 03:41 PM.

[portfire]

OK thanks for the info again digger and portfire, the only other type i have readily availible is glass, will that work? Im considering ordering some ceramic ones from inoxia though when i make my next order

No probs......Glass is a NO NO! This has been discussed before, It will make comps more sensitive. Wait until you get some propper media. I use the 20mm ceramic balls from inoxia for BP. Also cooperman sells lead media

[BlackMesa]

No probs......Glass is a NO NO! This has been discussed before, It will make comps more sensitive. Wait until you get some propper media. I use the 20mm ceramic balls from inoxia for BP. Also cooperman sells lead media

Okay, good job i asked about the glass - still waiting on my ceramic, i was wondering if lead air rifle pellets (2.2) could be used as medium? i have hundreds of these but will these be too soft and contaminate my BP?

[Bonny]

Okay, good job i asked about the glass - still waiting on my ceramic, i was wondering if lead air rifle pellets (2.2) could be used as medium? i have hundreds of these but will these be too soft and contaminate my BP?

Airgun pellets are too small to use for milling. They lack the weight to grind powders up. They could be melted and cast into media though. The lead would be soft and may not last that long, but would work as a temporary fix until your other media arrives.
To cast cylinders, drill 5/8" or whatever through a 5/8" (or whatever size again) thick pc of wood. Clamp it onto another pc of wood and simply pour the melted lead into the holes. Allow to cool and pop out the cylinders.

[BlackMesa]

Can you get good quality BP from milling it wet (if you have a sparking medium) and letting dry out in evaporating basins?

The only reason i could see why not is the Kno3 will re-crystalise in too large crystals?

What % water should i use to damp it?

[dr thrust]

anything is dangerous with a sparking media! and youll just get a sticky mess forming around the media, stick to non sparking dry milling its been just fine for hundreds of years!

[Hi-Fi.re]

Slightly off topic but, my parents say that the electric meter goes awal! when the washing machines turned on so does using the washing machine motor for a ball mill have the same effect and has anyone noticed any changes in the electricity bill since they got a ball mill, without including the effects of the "CREDIT CRUNCH".

Thanks Ryan,

[phildunford]

Ryan,

It's the water heating element in a washing machine that takes most of the power.

The power used by the motor is alot less. A 1 horsepower motor is about 700watts, but I would think most washing machine motors were a quarter of that. It should say on the 'rating plate' on the side of the motor.

The cost of electricity is expressed in Kilowatt Hours. ie 1 KW hour is how much power is taken by a 1KW device running for one hour.

With this, you should be able to work out how much your ball mill runs will cost...

[digger]

Slightly off topic but, my parents say that the electric meter goes awal! when the washing machines turned on so does using the washing machine motor for a ball mill have the same effect and has anyone noticed any changes in the electricity bill since they got a ball mill, without including the effects of the "CREDIT CRUNCH".

Thanks Ryan,

I doubt you will notice any difference unless you are making powder on an industrial scale.

The motor that I had lying around which I used on my mill is 1/2 hp (375W), running from an invertor drive at about 1/4 of the max rpm so less than 100W if it were under full load which is not (it will turn 50Kg without any trouble).

So lets assume 100W even though this is higher than it will be in reality that is 1KWhr every ten hours (my mill needs 6 hours to make a batch) a kwhr is around 15p so it should cost less than that to make a batch.

By the way a washing machine motor is a bit of a pain to use unless you can salvage the control system too and modify it to allow for control of the motor.

Dam beaten to it.

[Hi-Fi.re]

Thanks Guys,

Hopefully my parents will come round to the idea now i have the basic facts. I have two motors a 1/4 hp from a washing machine and a 1/3 hp which looks like it came from a cement mixer its huge! i think ill go with that one.

EDIT: Its worked a treat, Mission accomplished!

Edited by Hi-Fi.re, 05 August 2008 - 10:14 PM.