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Potassium Perchlorate / Aluminum will not ignite.


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Posted

I mixed 70% Potassium Perchlorate & 30% 5 micron Aluminum powder with a paintbrush and welder's helmet & welder's gloves outside. The mixture would not ignite with a Visco fuse. Should I have used German Black Aluminum?

Posted

When mixing flash I generally find the diaper method to be sufficient. With energetic compositions, the simplest method that adheres to traditional safety protocol tends to be the best. I would abandon the paintbrush silliness for the time being.

 

Some Visco fuses can produce quite a bit of thrust. Were you simply trying to ignite loose flash with visco as a test? Igniting flash in this manner can be a challenge.

 

Is your aluminum of the spherical or flake variety? The flake variety is generally regarded as being faster/more reactive, on account of its greater surface area. I've heard of people in the past having trouble with flash made from spherical aluminum.

Posted

Almost any time someone has a problem with flash it is because of the aluminum.

 

"5 micron aluminum" sounds like something from eBay and probably isn't very good if that is the case.

  • 3 weeks later...
Posted
Yes, I have had the same problem with making flash powder... I have fine powdered aluminum [flake kind], and hi grade potassium perchlorate... I followed the diaper method, and nothing! I am completely baffled, what did I do wrong?
Posted

1) make sure the KClO4 is a fine powder and is free flowing.

2) make sure there is no moisture contamination.

3) thorough mixing is very important, the more it's mixed the better.

4) try a small amount of the mixture (less than 1g) with visco fuse, or a smaller amount with a blow torch.

 

I have 325 bright flake Al, works just fine. I have found that standard time fuse will not ignite it though.

 

Ollie

Posted

I guess if you go ahead and try Magnesium instead, it will work, meaning that there's definitely something wrong with your Aluminum (mine too!). I had the same problem and I replaced Aluminum with Magnesium and it worked great.

BUT
I also mix them with 1/1 proportion in weight and it's very loud and quick. so DO BE CAREFUL and NEVER EVER PRODUCE MORE THAN 2 grams, for the sake of your own safety.

 

have fun

 

and please let us know if you managed to make your Aluminum work somehow ;)

Posted
You'll also find that some forms of powdered aluminium will only ignite when contained ie ( blue aluminum ) so if you can run a test by putting it in a pot or something. Just make sure you don't seal it to tight or it will effectively react like a bomb.
Posted
Www.oliverbrown.co.uk this guy is great for supplies he also has a video on the combustion of powdered aluminium.
Posted

Unless you buy from a reputable place there is no way to know your 'flake' aluminum is really flake. Flash does not need to be mixed all that well with good aluminum. If it doesn't easily make an ear splitting boom I almost guarantee it is your aluminum.

 

There are things that can be added to make poor aluminum work but they are things to increase the sensitivity and shouldn't be done if you are new. Splurge and buy good aluminum and you won't be disappointed.

  • 2 weeks later...
Posted

well, i just tried my first perc and al pwd, a tiny mix i might add.. it worked just great.. i see now why all the warnings to be careful! i bought my alum pwd from pyro chem.com i couldnt be more pleased.. be careful pat

Posted

how dangerous is it to grind homemade per chlorate in a coffee grinder to make a powder?

Posted
By itself? No dangers. Just be cautious of cross contamination. Since most coffee grinder can leak ibto the motor, I would use dedicated grinders for fuels and oxidisers. You could consider the single serve blenders as mentioned above as well.
  • 5 weeks later...
Posted

Sound like you have a slow flash aluminum if you confine it should work fine and it should light with a torch

dean

  • 2 weeks later...
Posted

If i were to use Eckart 10890 dark aluminum, would it work in a flash comp.

Posted
I'm almost positive that is a replacement for 809 American Dark. If so it will work well for salutes. It isn't as fine and reactive as German dark but 809 I have works well and since it hasn't been made for a while and I can still get it, it is probably the 10890 replacement.
Posted

Since it touches (well, at least i think so) on the topic here... Sponge / spherical stuff... What would happen if you decided to ball mill it with... ceramic or steel media for a while? (I'm thinking it would eat lead media, and contamination might be an issue to.)

Shouldn't it flatten it to flakes? In the process it should become wider then the 5µm specified when bought (Working with the number from the opening post here...) but a ball mill is near fantastic at reducing the size of things as well..

 

I'm just thinking here, not really paying attention to stuff as letting in small amounts of air (oxygen) to make sure the alu doesn't go of in your face when you do open the container, and so on.

The main point is, wouldn't / shouldn't ball milling make these less useful aluminum a more viable pyro resource?

B!

Posted

If you only want to make flash. That is the main use of fine flake aluminum. There are some formulas that call for a bit of the dark stuff to increase burn rate.

 

And to answer your question, yes a ball mill will reduce the particle size and flatten it out. That's what they do. But you will have to worry about the things you mention. Wearing down your media, contamination, and the risk of a pyrophoric fire.

 

I suggest not trying it without a lot of reading on the subject and taking every safety measure possible. Unfortunately, one of the biggest hazards will be opening the mill jar which will put you in close proximity.

Posted

It was a theoretical question, i don't even have any spherical stuff. I sort of asked since i see this question come up again and again. In reality it should be as simple as milling it, but then, nothing is ever "simple", and care needs to be taken to do it safely. The fire hazard can to some extent be dealt with by running the mill for short periods of time, and opening the jar between cycles. You might be able to get away with with making a small hole in the jar lid, sealing it with tape, and do your milling. When your done, just remove the tape, and leave it alone.

 

But yeah. Alu is nasty, you don't want a flash fire when you open the canister.

B!

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