196 replies to this topic

[BlackMesa]

Ok my method of getting my charcoal powder from the brick is this, take the brick and rub it with a very fine sand paper into a bowl, via a sieve (to catch flakes that fall off) To mix the milled sulphur with my carbon it goes into a screw cap container filled with steel nails and bolts which is then shaken for about 10 minutes, seems to get it pretty fne although obviously not the ideal way of doing it. Sanding the charcoal has given me much finer powder than crushing it, but its a lengthy proccess

[digger]

Ok my method of getting my charcoal powder from the brick is this, take the brick and rub it with a very fine sand paper into a bowl, via a sieve (to catch flakes that fall off) To mix the milled sulphur with my carbon it goes into a screw cap container filled with steel nails and bolts which is then shaken for about 10 minutes, seems to get it pretty fne although obviously not the ideal way of doing it. Sanding the charcoal has given me much finer powder than crushing it, but its a lengthy proccess

Once you get your decent scales, try making 10 grams in a pestle and mortar to see the difference. This will still be slow powder as even thought the particles will be small they are nowhere near as small as they will be from grinding the whole lot up in a ball mill for 8 hours or so.

So from what you have said it would appear that you have two problems, particle size of your ingredients and your CIA method will cause large crystals of kno3 to grow (thats particle size again).

So get a mill sorted and you will soon see it is the only way to make BP easily. There are plenty of threads on hear about making a decent mill and what materials to use for your milling media.

[BlackMesa]

Once you get your decent scales, try making 10 grams in a pestle and mortar to see the difference. This will still be slow powder as even thought the particles will be small they are nowhere near as small as they will be from grinding the whole lot up in a ball mill for 8 hours or so.

So from what you have said it would appear that you have two problems, particle size of your ingredients and your CIA method will cause large crystals of kno3 to grow (thats particle size again).

So get a mill sorted and you will soon see it is the only way to make BP easily. There are plenty of threads on hear about making a decent mill and what materials to use for your milling media.

Okay well thank you Digger for your time, im sure i will be making plenty more posts soon so in conclusion your analysis is my measuring and particle size, which can be solved via a ball mill and more accurate scales, when i get this right no more resin left over?

In normal BP would that resin occur but be vapourised is what i couldnt get my head around chemicaly, trying to know that this leftover actualy was but if your saying its my particle size that makes me assume it as burning to cold or i was not having an efficient enough reaction?

[digger]

Okay well thank you Digger for your time, im sure i will be making plenty more posts soon so in conclusion your analysis is my measuring and particle size, which can be solved via a ball mill and more accurate scales, when i get this right no more resin left over?

In normal BP would that resin occur but be vapourised is what i couldnt get my head around chemicaly, trying to know that this leftover actualy was but if your saying its my particle size that makes me assume it as burning to cold or i was not having an efficient enough reaction?

No in normal BP this would not happen. When I first made BP when I was 13 (many many many years ago) I had a similar problem. It was the result of too much kno3 and not even close to being mixed well enough.

[BlackMesa]

No in normal BP this would not happen. When I first made BP when I was 13 (many many many years ago) I had a similar problem. It was the result of too much kno3 and not even close to being mixed well enough.

I will take your advice Digger, im sure it will pay off - i'll send you a video if i get it right one day:)

[Hi-Fi.re]

Just a simple question guys.

I recentley made 100g BP and it burns relatively slow and leaves behind alot of White residue.
Its not been Ball Milled as i attempted the CIA Method and used nail varnish remover with acetone to help dry the Powder.

My first thought is it contains too much Sulfur, i belive i used something like 74-KNO3 14-C 12-S
So would i be ok to make another 100g batch low in sulfur say 75-KNO3 15-C 9ish-S and ball mill the two batches to correct my mistakes or does the problem lie elsewhere.

Thanks Guys.

[dr thrust]

hi 75,15,10 is what you want ballmill 1- 8 hours depending how fast you want it, which depends on what your using it for, fast for lift, slow for rockets ect

[Hi-Fi.re]

Thanks chris hopefully i havent messed up a whole batch. next time ill just keep it simple

[Bonny]

Thanks chris hopefully i havent messed up a whole batch. next time ill just keep it simple

If the batch is bad, just make it into a fountain...no waste then, and it's a good beginner project.

[Arthur Brown]

BP isn't just a mix of C, S and nitrate! The process is important.

First a light fluffy charcoal willow or pine for starters, milled till it passes 400mesh

Second KNO3 milled to pass 400 mesh.

Third Sulphur milled to 400 mesh.

Then weigh out your chosen mix 75;15;10 is a good start.

These components intimately mixed will be a product called green mix

Then damp the greenmix with 5% water and mill for some hours, this makes the mix much more intimate and the burn rate will go up. This re-dried is probably the most brissant of BP mixes.

Damped with 5% by weight of 5% red gum milled greenmix can be put through a ricer or garlic press or rubbed through a sieve to make graded granules of BP

Milled greenmix can be kept damp and pressed into pucks, and allowed to dry. This is the highest density of BP possible. If these pucks are broken (corned ) then the size of the corned granules is the grade of the BP.

If the materials come from modern sources they are likely to be finer in quality than any available when BP was a military stores material! Old established BP factories had willow trees on site for the best source wood, and kilns on site to produce the best charcoal.

Failures in making BP nowadays usually start with coarse grains poorly incorporated.

Find yourself a piece of 400mesh sieve and mill things til they pass through.

400mesh greenmix is a good start to make BP
200mesh greenmixis a poor start
coarser than 200mesh will result in the sort of spitting hissing mess you describe

Edited by Arthur Brown, 02 August 2008 - 03:28 PM.

[digger]

BP isn't just a mix of C, S and nitrate! The process is important.

First a light fluffy charcoal willow or pine for starters, milled till it passes 400mesh

Second KNO3 milled to pass 400 mesh.

Third Sulphur milled to 400 mesh.

Then weigh out your chosen mix 75;15;10 is a good start.

These components intimately mixed will be a product called green mix

Then damp the greenmix with 5% water and mill for some hours, this makes the mix much more intimate and the burn rate will go up. This re-dried is probably the most brissant of BP mixes.

Damped with 5% by weight of 5% red gum milled greenmix can be put through a ricer or garlic press or rubbed through a sieve to make graded granules of BP

Milled greenmix can be kept damp and pressed into pucks, and allowed to dry. This is the highest density of BP possible. If these pucks are broken (corned ) then the size of the corned granules is the grade of the BP.

If the materials come from modern sources they are likely to be finer in quality than any available when BP was a military stores material! Old established BP factories had willow trees on site for the best source wood, and kilns on site to produce the best charcoal.

Failures in making BP nowadays usually start with coarse grains poorly incorporated.

Find yourself a piece of 400mesh sieve and mill things til they pass through.

400mesh greenmix is a good start to make BP
200mesh greenmixis a poor start
coarser than 200mesh will result in the sort of spitting hissing mess you describe

I don't see the need for the first part of your processing.

If you have a mill to grind the chemicals (with suitable media) then just weigh out the chemicals and chuck em in, there should be enough water in the nitrate unless it has been oven dried first (only a fraction of a 1% is required to make good powder).

I have done extensive experiments regarding methods and pre milling makes no difference at all other than it takes allot longer. The worst thing I did regarding milling was to pre-dry the nitrate. The powder took many more hours to make a good powder (at least with the carbon that I used in the experiments)

Run it for however long your mill design requires and you will have a fast powder even before further processing.

P.S. I would like to see you pass ground Sulphur through a 400 mesh sieve, that must be quite an annoying task along with the pain of cleaning the mill.

Edited by digger, 02 August 2008 - 05:45 PM.

[phildunford]

Agree with digger! There is a lot of agonising about making good BP.

75 15 10, chuck it in your mill - you will get good BP. (obviously better if you press and corn as well).

What matters is:-

1) A good efficient mill (a bad one works, but takes a long time).

2) The quality of your charcoal.

Pre milling or very fine ingredients may reduce milling time, but is a fuss. Sometimes I don't screen the charcoal at all, just crush it and give it a bit longer in the mill. You can be doing useful things while the mill is running - not screening charcoal (yuk).

As to water content, I don't add any. Without a lot of fuss, you can't know how much moisture there is in your charcoal anyway. I do add water when I press and corn of course...

I am having good success with adding red gum and alcohol to create a granular powder (as mentioned on Skylighter and elsewhere on the forum). Fraction more expensive, but for small quantities and for people without presses etc, very promising.

Edited by phildunford, 02 August 2008 - 08:57 PM.

[Gary]

Ensure that you have top quality ingredients:

1)Ensure that your potassium nitrate is pure. Purification is easy enough: dissolve your potassium nitrate in very hot (near-boiling) deionied or distilled water until you have a very concentrated, almost saturated solution. Then allow to cool down very slowly to a temperature of 5-10 celcius (once it has cooled to room temperature, put it in the fridge for further cooling). You will find that crystals of potassium nitrate form from the 'mother liqour'. Separate these crystals by filtration, then wash them with several small portions of cold deionised/distilled water. Allow the crystals to dry. What you have are snowy white crystals of very pure potassium nitrate.

2) Do not use flowers of sulphur as your sulphur source: it contains added calcium sulphate, an inert material which will inevitably result in a slower burn.

3) Use willow or alder charcoal, not BBQ briquettes.

Edited by Gary, 03 August 2008 - 07:36 PM.

[digger]

Ensure that you have top quality ingredients:

1)Ensure that your potassium nitrate is pure. Purification is easy enough: dissolve your potassium nitrate in very hot (near-boiling) deionied or distilled water until you have a very concentrated, almost saturated solution. Then allow to cool down very slowly to a temperature of 5-10 celcius (once it has cooled to room temperature, put it in the fridge for further cooling). You will find that crystals of potassium nitrate form from the 'mother liqour'. Separate these crystals by filtration, then wash them with several small portions of cold deionised/distilled water. Allow the crystals to dry. What you have are snowy white crystals of very pure potassium nitrate.

2) Do not use flowers of sulphur as your sulphur source: it contains added calcium sulphate, an inert material which will inevitably result in a slower burn.

3) Use willow or alder charcoal, not BBQ briquettes.

1.) Why do you think that recrystallisation is required of kno3 to make good BP?. Agricultural grade is far better than our ancestors would have had access to and they seemed to make perfectly good BP.

2.) I agree that flowers of Sulphur should not be used, but that is down to the fact that the distillation process used in producing this form of Sulphur can produce sulphuric acid. I believe flowers can have as much as between 1% - 2% acid, however I would imagine modern production techniques will have a lower value than this. This acid obviously causes problems when the BP is used for the production of other formulations that have metals added to them.

Where did you get your information on the addition of gypsum (Calcium Sulphate)?. What purpose does this serve?

Edited by digger, 03 August 2008 - 08:41 PM.

[phildunford]

Flowers of sulphur as such does not contain any contaminants (apart from the possible acidity). It just describes the process used to make the sulphur.

Now dusting sulphur, bought from garden centres almost certainly does contain contaminants, but this is not the same thing.

The exact process used to make sulphur is not always made clear and as such you should use a certain amount of caution. That said, I have tested the sulphur I use from Garden Direct (25KG bags) and it seems completely neutral.

The panic about acid content mainly comes from the days when chlorate/sulphur mixtures were common. These were even more unstable if acidic sulphur was used (although older processes also produced less pure chlorates as well). No one in their right mind would use such combinations these days.

The consensus in Lancaster seems to be that chlorate stars are OK in manufactured gunpowder, as no mixing (intimate contact) can take place.

Certainly in BP used purely as a propellant I would not be too worried about the type of sulphur...