15 replies to this topic

[littlejohny]

Hi, I have recently made some sulphur less BP to see how it performs instead of ball milling it I decided to use the CIA method, I decided to use the CIA method because I was using balsa and it doesn't mill very well.

First of all I weighed out 80 grams of KNO3, 10 grams of balsa charcoal, and 10 grams of radiata pine charcoal.

Secondly I placed 400ml of methylated spirits into the freezer to cool down for 3 hours.

After 3 hours I placed a small pan on the stove with 20ml of water, and heated it until boiling temp was reached. Then dumped in my 80grams of KNO3 and added more water until it was all dissolved.

I then proceeded to add in my charcoal witch took a ridiculous amount of time to get incorporated into the liquid because of surface tention with the balsa.

After it was all incorporated I removed the 400ml of methylated spirits from the freezer and placed into an empty ice-cream container. After stirring the mixture on the stove for 2-3 minutes I quickly dumped the mixture into all the methylated spirits cooling it as fast as possible. Placing the ice-cream container back in the freezer for 1hr stirring every 10 minutes it was about 10 degrees c when I placed it into the freezer.

After 1hr I removed the ice-cream container from the freezer and strained this mixture through a fine piece of cloth and squeezing out allot of the liquid, I tried my best to get as much as I could of the mixture into the cloth (which was practically all of it)

After granulating through some fly screen and onto some newspaper I set it aside to dry for 1 day.


Now heres my problem In theory with 100% perfection I should have ended up with 100grams of powder, allowing 10 grams to be lost through filtration ETC, so leaving me with around 90 grams, onto the scales I had a dismal amount of 50 grams.

Now how can I possibly loss 50 grams of powder because I definately know that I didn't lose that much through filtering.

[pyrotrev]

Johnny - how much extra water did you have to add to dissolve the KNO3?

[neo]

try to crystalize all of the water to see how much KNO3 there is, and if there isn't 50 grams, then you can be very confused..

[littlejohny]

Johnny - how much extra water did you have to add to dissolve the KNO3?

I kept adding water until all the pottasium nitrate was disolved and began to add my charcoal, I wasn't happy with the consistency it was all clumpy so I added more water to make it into a thick soupy mixture. Other than that I didn't really measure how much I put in I guess with the carcoal and everything there would have been about 100ml of soupy mix in the small pot.

try to crystalize all of the water to see how much KNO3 there is, and if there isn't 50 grams, then you can be very confused..

how can I separate all the water from the methylated spirits to re-crystallize the Pottasium nitrate

[Mumbles]

To get the KNO3 out, just let all the liquid evaporate.

As for the liquid, that seems like a lot. It boiling water KNO3 has a huge solubility at boiling. I think it is around 250-300g per 100mL. 30mL should have pretty much done it.

[littlejohny]

To get the KNO3 out, just let all the liquid evaporate.

As for the liquid, that seems like a lot. It boiling water KNO3 has a huge solubility at boiling. I think it is around 250-300g per 100mL. 30mL should have pretty much done it.

I used as little water as possible but because of the density of balsa charcoal I had to use that much to get it to get it into the water (very technical words). but yes I do know that kno3 has an incredible solubiltity at boiling temp 225grams per 100ml. I feel stupid not thinking of just letting it all evaporate well its too late now anyway.

[littlejohny]

Well I have It working alot better now, 80 KNO3, 20 Charcoal. It seems to burn alot faster though there is a fair amount of pearling , any suggestions on the ratio I will try 75 KNO3, 25 charcoal and see how that goes.

[alany]

I use 8:3 when I make sulfurless BP.

[fishy1]

Well I have It working alot better now, 80 KNO3, 20 Charcoal. It seems to burn alot faster though there is a fair amount of pearling , any suggestions on the ratio I will try 75 KNO3, 25 charcoal and see how that goes.

3:1 works well for me (same as 75:25)

[littlejohny]

I'll try 3:1 and 8:3 and compare them I was looking on Alany's composition database this morning and found the 8:3, when did you add that?

[alany]

Last night.

Its been in the magazine for a while now, burn rate tests and prime mainly, but I've shot stargun tests with it too when I was out of everything else.

[littlejohny]

Its been in the magazine for a while now, burn rate tests and prime mainly, but I've shot star gun tests with it too when I was out of everything else.

I tried the first batch of 8:2 as lift, didn't work until I either glued a small disk over the tube or rammed paper down there. How does it fair against Normal BP as lift.

What do you mean by its been in the magazine for a while?

[alany]

With good charcoal it is nearly as fast as sulfur containing 15:3:2 BP for me, it definately seems to be less gassy, so you need to use more than you would normally. This makes some sense as the sulfur normally mops up the potassium that is now stealing oxygen.

I made about 150 g 4 months ago, granulated part of it and kept the rest as prime. It's been a slow mover, I don't use chlorates much and rockets are my main focus so the granulated stuff isn't used much either.

[littlejohny]

With good charcoal it is nearly as fast as sulfur containing 15:3:2 BP for me, it definately seems to be less gassy, so you need to use more than you would normally. This makes some sense as the sulfur normally mops up the potassium that is now stealing oxygen.

So you are saying that sulfurless BP is nearly as fast as normal BP? I have always read it is supposed to be 3x faster

[Pretty green flames]

So you are saying that sulfurless BP is nearly as fast as normal BP? I have always read it is supposed to be 3x faster

In davis's book it's stated that sulphurless powders do burn more slowly compared to normal BP but this may not be a bad thing.

Sulphurless powder allowed the use of bigger guns becouse when the powder is first ignited it burns slowly but as the presure rises so does the burning speed of the powder.

The slower burning allowed for construction of bigger but not so heavy guns, the guns had thinner walls which reduces weigth.

Sulphurless powders were the most succesful form of black powder to be used in rifled guns at long ranges.
It should also be noted that sulphurles powders were used in forms of special grain designs, single-perforated hexagonal prisms, which allowed for faster burning as it burned from the inside out and the outside in.

And the 3x times faster than BP theory, i guess it's true. The rate of burning is measured by taking a sample of the powder and sealing it into a "tube that should not be used in pyro" and igniting then measuring the velocity of explosion. Also, don't you think it's a bit weird that BP should burns at the speed of ~350m/s, i for one never get a powder that fast. 350m/s is the velocity at which it explodes at.

I hope that this clears things up a bit