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How to make extremely reactive KP

Minamoto Kobayashi

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Hello forum!
Here is another nice pyro-tutorial :giggle:
This time I will explain how to prepare a powerful KP granulated powder.
The same procedure can be applied also to make classical BP powder.

Until the mix is wetted, there is no danger of deflagration, but when the mix is granulated
and well dried it become extremely reactive and dangerous, so do not try to manage
the dried powders at home or inside closed rooms!
Please avoid synthetic clothes or other yarns that can spark, always use brass or lead medias, silicon spoons,
wear gloves and filtering masks.
If possible maintain the naked feet on the floor or use a antistatic bracelet connected to the ground.
Some big moistened rags near the working area are suggested to limit damages or injiuries in the worst scenario.

KP powder is similar to the BP powder but much more reactive because the Potassium Nitrate is replaced
with Potassium Perchlorate.
The percentage of each chem is slightly different form the BP formula.

You need Potassium Perchlorate (KCLO4), Sulfur, fast Charcoal and Dextrin:


Placing 100x1cm diameter brass balls in the bottom of a rock thumbler cylinder:


Filling the barrell with 70% KCLO4, 18% Charcoal, 12% Sulfur.
Add 2 grams of dextrin every 100 parts of the mix: this allow to create solid grains when they are dried,
otherwise the grains will be weak and friable.
The amount of the total weight powders involved is proportionally to the barrell size.
Usually the best choice is to fill the media with powders just a little bit over them:


Adding enough denatured alcohol to create a slurry mix. The mix must be quite liquid.
If You do not hear the medias hit one against another during the mill process, the mix is too dense and You need to add more alcohol:


Starting to mill the slurry mix. I had to open the device box and put a fan to cool the motor because the brass balls
are heavy and the motor will be stressed out.
Usually with 100 brass balls, the barrell correctly filled and the right rotation speed, 1-2 hours is the right choice:


After the milling, stop the device, extract the barrell, put it in vertical position, and wait at least 1 hour to allow the decantation of the mix
on the bottom. In that way You can save some alcohol useful for another milling process:


If You want You can tilt the barrell to facilitate the alcohol recovery:


Now separing the slurry mix from the media balls with the aid of a kitchen strainer and spreading it over a waxed paper:


After some hours most of the alcohol is evaporated and the mix tends to break:


Breaking all the plaques with hands to create a raw mix:


Wet the powder with enough demineralized water:


Make solid balls pressing the wetted mix with the hands.
If You are unable to make compact rounded balls because the mix is friable You need to add other demineralized water.
If the balls are too wetted they will not hold their form and sit down like a molten blob, so You need to add some dry mix.
This is a foolproof try-and-error method:


Break the balls in two parts like an apple, then press and crawl at the same time one half by time with the hands along a 8 mesh woven wire
If You make correctly this passage, You will obtain much 8 mesh grains and very few 20+ mesh powder (also called meal).
Under the 8 mesh woven wire there will be a 20 mesh one. The 8 mesh grains will be captured and will rests over the surface, while the 20+ mesh grains will cross the 20 mesh voven wire and will be caught in the drawer at the lowest point of the device:


And finally the dried powders:


It is very important to make perfectly dried powders to obtain a maximum burst performance.
Usually, after the first passage with my drying device (only suction fans, no heat), I use a semi-professional
dehydratator at 122 °F for one hour to be sure that no water or alcohol is trapped inside the grains.
After cooling the powders it is a good idea to place them inside hermetic boxes with some drying bags.

That's all!

Richard.
 
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paul1598419

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That was interesting. But, your compounds to mix together equal 102%. That can't be right. Might want to revisit the percent of each compound to be used here. Looking forward to seeing what you do with this. (y)
 

Minamoto Kobayashi

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That was interesting. But, your compounds to mix together equal 102%. That can't be right. Might want to revisit the percent of each compound to be used here. Looking forward to seeing what you do with this. (y)
Hello. The mix is right. Dextrin do not alter the properties of the mix. However I make a mistake that I have promptly corrected: 2 grams of dextrin every 100 parts of mix, not 2% .. sorry!
 
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paul1598419

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If that is true then why is it 2% dextrin? You have compounds measured in percent by weight or volume. They add up to 102%, which doesn't make sense at all. If the dextrin amount makes no difference, why add it as a percent of the compounds?
 

Minamoto Kobayashi

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No, not 2%. ... 2 grams every 100 parts. It is different.
Here is the original formula:

https://pyrodata.com/compositions/KP

This is a very trustable database of EVERY working composition created and well tested.
I changed the procedure but the formula is the same.
If a thing works well, I never ask why work in that way .. I simply use it. :LOL:
 

Minamoto Kobayashi

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In attachment You can find many original formulas of a great spanish pyros guy called Jopetes.
As You can see, not all formulas reach the total of 100%. Sometimes less, sometimes more.
If You like that the sum of all chems reach exactly 100%, You must recalculate the percentage of each chem, but the result will be the same.
 

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paul1598419

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Ah, I see you changed the 2% to 2 grams. But, does that mean 2 grams of dextrin regardless of the amounts of KClO4, charcoal and sulfur? Using the % sign makes your formula confusing as this means an amount, by weight, compared to the other compounds. If you mean 70 grams KClO4, then say that. I was trying hard to make sense out of your formula, but got nowhere fast. Thanks.


Edit: I see from the formula you linked to that the dextrin is 2%, by weight, of the total weight of the mixture. That makes more sense to me. So, you can mix these as a percent of the KClO4, charcoal and sulfur. Then add 2% by weight of dextrin to the weight of your mixture.
 
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kecked

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What does the sugar do? Carbon source or drying agent?
Neither...binding agent. Per wiki
 

Benm

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Afaik it's used as a binder indeed, but it is definitely also a fuel with KClO4 as the oxidizer.

If you need to get perfect stiochiometic mixtures you should als add some more KClO4 to burn the dextrin, though at 2% this will not matter all that much.

But for most part, be very careful with handeling such mixtures. As far as i understand the perchlote ones are somewhat prone to spontaneous ignition. Whilst wet with alcohol or water that's not a big problem, but once dried out it's probably best to use them soon. The nitrate mixtures can kept for longer periods of time safely, but the perchlorate ones you should not keep in places where ignition would cause your house to burn down.

Unless confined they will not "just explode" but catch fire - still not the best thing to have around the house.
 

Minamoto Kobayashi

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I have 2 KG KP batch stored into an hermetic container with some dessicant gel bags since one year and nothing happened.
Chlorate and Ammonium Perchlorate, especially in sulfur presence, tends to auto-ignite. A little shake can also ignite the mix.
But Potassium Perchlorate is much more safe.
I have tested the stability of the KP simply putting some grains of KP over an anvil and I hitted the grains with a big hammer more and more times: nothing happened!
But if You take a pill of a pure chlorate and repeat the same thing, the pill wiill explode!

KP is used as burst enhancer for 2" and 3" shells in traditionally chinese build.s Some grams at the center of the shell inside a paper bag
create a stronger burst. If what You have say was true, all the chinese shells should be exploded during transport
from China to the other parts of the world.

KP, but also fast BP, can become dangerous also if it is not confined, if a critical mass in reached. In fact a certain quantity the KP simply burn very fast like a flash, in large quantity it can deflagrate and cause the same damages of a detonation, if not worse.
 
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Benm

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Most explosives can become dangerous under certain conditions. I don't think it's the perchlorate itself that's responsible for that, but contaminants in it like chlorates could be. For building fireworks they probably don't use pro-analysis grade chemicals, so who knows what's actually in there in smaller amounts.

That hitting it with hammer does very little is not that meaningful: you could probably spend days hitting ammoniumnitrate power or pellets with a hammer and not get a single bang. Even bags off the stuff (used as fertilizer) can just fall of a truck or be in one that gets into a car crash and nothing happens. But when you get unlucky with the stuff you get the largest industrial explosions.

Also, that it usually doesn't go off doesn't mean it never will, a few years ago a truck full of the stuff ran off the road in australia, and eventually 50 tons of it exploded - luckly after the driver was able to escape the truck.
 




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