9 replies to this topic

[Deano 1]

Hi all, probably a long shot, but does anyone have a formula for a strobe pot made with the run of the mill chems?
The only formula's I can find need chems I don't wish to buy i.e. Ammonium perchlorate Magnesium, atomized, Potassium sulfate
Potassium dichromate

While I'm here, what does atomized actually mean?


Ta

[Sparky]

Hi Dean, have you tried some of the Barium Nitrate based comps?


Barium nitrate

51

Potassium nitrate

7

Sulfur

19

Magnalium (-100 mesh)

18

Dextrin

5

I am trying this with a 70 mesh MgAl and may try less by weight to improve the flashing.

[Sparky]

Oh and I think atomised means the metal is formed of spherical shaped particles rather than flakes that you would normally get when ball milling a soft metal. Not sure how they make it that way though and my understanding is limited, I'm sure someone will come along correct me :-)

[Mortartube]

Atomised is spherical in shape. I believe that a fine spray of molten aluminium is sprayed into cool air, where it solidifies, The result being small droplets that become solid aluminium miniature spheres.

[Deano 1]

Thanks for the fast replies fellers. Sparky, you'll have to let us know how you get on with yours.

[Sparky]

I probably won;t get a chance to make anything until after the new year but I've already tried with exactly the formula above and as long as you make pots and keep them short and very wide it will strobe. I used sections of 2 inch tubing.

I would actually experiment with less Mg Al though as the burn was a bit too vigorous I think.

[Deano 1]

I may just have enough -100 mesh mgn for one pot.

[Prometheus]

[Sparky]

Nice video! Is that your own composition, I'd love to know how you got such a solid clean strobe.

I presume it as a formula was something like this:?


Ammonium Perchlorate 60 parts
Magnalium -80 mesh 25 parts
Barium Sulfate 15 parts
Potassium Dichromate 5 parts

I'm not a big fan of handling really hazardous chemicals like Potassium Dichromate so I'd be keen to know how vital it is in a dry composition that is being lightly pressed into paper tubes.

Edited by Sparky, 01 January 2013 - 12:33 PM.

[Prometheus]

Nice video! Is that your own composition, I'd love to know how you got such a solid clean strobe.

I presume it as a formula was something like this:?


Ammonium Perchlorate 60 parts
Magnalium -80 mesh 25 parts
Barium Sulfate 15 parts
Potassium Dichromate 5 parts

I'm not a bug fan of handling really hazardous chemicals like Potassium Dichromate so I'd be keen to know how vital it is in a dry composition that is being lightly pressed into paper tubes.

Yes, the composition used was Shimizu's White Twinkler and is in the video description, but I used 60 mesh magnalium.

I don't think you can avoid using the potassium dichromate altogether, even if you think your chemicals are completely dry and you press it into the tubes without any binder, the magnallium would still react with the ammonium perchlorate over time if it's not coated. The additional 5% may also act to control the strobe rate, but I'm not certain about that. In Pyrotechnica VII Shimizu states that it enhances the regularity and sharpness of the flashes, but I've never seen a copy of it myself.

If you can be careful and take simple steps to minimize your exposure, then there's no reason why you're not capable of handling dichromate safely. Unless you are working with the stuff on a daily basis, I think you'd have to be extremely careless in order to accidentally poison yourself. It's bright orange, which makes even minute amounts easy to spot.

Edited by Prometheus, 31 December 2012 - 03:03 PM.