5 replies to this topic

[Powderman]

I would really like to know what is safe to do with AP and what is not. I have googled some safety information but it does not answer my questions... My AP is crystalline, not powder. So it needs to be safely pulverized - what methods are OK?

Do I risk my hand shaking small plastic bottle with AP to make it free-flowing? What about handling dry stars? Any advice, precautions, experience with AP is welcome...

[cmjlab]

I don't use a lot of AP because I prefer to use Potassium chlorate for some of the comps I use and don't have the space to use them in different spaces. I only use it for strobe fuel.

But I'll start the list with the top 3 I know of, in order of importance:

1. Explosion Hazard // Potassium Chlorate: Do NOT use around Potassium chlorate, or any other chlorate, generally to the point where it's not a great idea to even mix/use/handle it in the same shop as handling Potassium chlorate. The concern being double displacement between chlorates and AP to form the much more dangerous and unstable organic salt - Ammonium Chlorate (i.e. explosion hazard). This also includes cross use of tools, storage containers etc.

2. Displacement and Hygroscopicity - Potassium Nitrate: Avoid contact between AP and Potassium Nitrate, especially in the presence of moisture (like KCL03) to avoid formation of Ammonium Nitrate and absorption of water to render comps/stars/etc, useless. Some people report the ability to make something like a AP star, and prime with a non-water binder like nitrocellulose, then roll a KNO3 based comp over that and have it work if used pretty quickly (i.e. not stored).

3. Sensitivity: I've heard of sensitivity to impact in a couple instances, but I've not tried or observed this. I have observed the tendency of strobe comp to behave like flash though (as I think most of us have at least seen the video of 500g being set off).

[Sulphurstan]

I ball milled my AP with dedicated * ceramic balls, and everything went fine! I'm always very cautious with milling (for example I don't mill BP)

*By dedicated, I mean the ceramic balls were new and never used for any other mixture, to avoid traces of KN, S, KP or whatever you mill here and there..

Edited by Sulphurstan, 14 February 2023 - 07:12 AM.

[cmjlab]

That's an excellent point. The AP sensitivity must be ONLY when mixed with other chemicals to form a completed or partial composition (i.e. strobe).

[idea]

I have some 400 micron AP but i need it to be at least 90 microns, is using a ball mill a safe option to make a fine powder?

[cmjlab]

I think Sulphurstans response is the best advice - use clean mill jar and clean media to avoid criss contamination or unwanted reaction.