13 replies to this topic

[ridley]

ssssssssssss

Edited by ridley, 14 February 2015 - 10:01 PM.

[Bonny]

I just made a small quantity of 50/50 Magnalium/Potassium Percholate. I placed it in a paper envelope and when lit it seemed to burn with a what looked like a magnesium flare before going off. Is this normal?

I was thinking of using it as a break on small shells but timing would be difficult if this is normal.

Ridley

ps when it did go off it was quite impressive

Sounds like your ingredients were not fine enough. What was the particle size of the MgAl?

[MMMMMM Pyro]

I agree with Bonny,

Half a gram of 50:50 MgAl/KClO4 goes really quite loudly for me in the open.

What mesh MgAl are you using?

[ridley]

I agree with Bonny,

Half a gram of 50:50 MgAl/KClO4 goes really quite loudly for me in the open.

What mesh MgAl are you using?

I have not got any screens at the moment so hard to say, certainly looks pretty fine, according to ebay atomised whatever that means.

I ground the Percholate before mixing which certainly helped. First time was without grinding, took a while to go, second time was with took less time but certainly no instantaneous.

Ridley

[krs]

try the ratio of 70/30 (MgAl 70 / KClO4 30) i know its supposed to be the other way around, but my old batch of perch used to report louder when mixed it with magnalium using that ratio. could never figure out why..

[ridley]

try the ratio of 70/30 (MgAl 70 / KClO4 30) i know its supposed to be the other way around, but my old batch of perch used to report louder when mixed it with magnalium using that ratio. could never figure out why..

I tried that and it just made a flare.

Ridley

[krs]

I tried that and it just made a flare.

Ridley

all I could think of is either
the MgAl isnt fine enough, bad batch of KClO4 or they havent been mixed together enough.
are you using digi scales or something accurate?

[ridley]

all I could think of is either
the MgAl isnt fine enough, bad batch of KClO4 or they havent been mixed together enough.
are you using digi scales or something accurate?

Iam using a digiscale, though low masses it doesnt seem to register accuratly, if I place a piece of paper on it and then start adding to it nothing happens. So I place something on it to get the scales to start to register and then add to that.

The KCl04 is from Inoxia, seems quite lumpy, perhaps it is damp? I use a pestle and mortar on it before mixing.

Ridley

[KarlosH]

I had the same problem, but for Mg/Al flash is better Black powder for ignition. When I am mild magnalium in grinding mortar with etanol(¨not whirl up dust) and good milling(cohesion), in the last time, magnalium was wery dark, and flash too. Flash exploded with loud noise without casing, only on surface in small hill cca 5g.
The most of problems with flashes are joint with size of metal particles (mesh). Magnalium is often coarse grained.
Bye.

[karlfoxman]

Ridley, for breaking shells its not uncommon to use whistle. This when mixed well and using fine ingredients burns very fast, its safer than any sort of flash. I suggest you read up on mixing and using flash. Also get some decent scales, they should not get stuck. If they do then they are not working well, have a look to see if you have spilt some chemicals in them. If they still do not work as they should I would invest in some new ones that work.

Are you sure you have Magnallium and not just plain atomized aluminium powder? Also read up on Atomized, the structure of the particles is a main factor in burning speeds. Read up on the subject before creating more threads, I see you have started about 4 threads and you only have 14 posts!!

[concept]

I’m having problems igniting my 70/30 perc/al flash powder. When I try and make a small firecracker or something similar it will not ignite, but when I try and make larger salutes e.g. 2g or more it works fine. I’m using 1.8mm visco fuse in both cases, any ideas why it isn’t working on a smaller scale?

[W.P]

It's because of 2 things:

1. Your chemicals aren't mixed well enough
2. The mesh of oxidiser is almost always too large due to moisture and not screening it separately.

Edited by W.P, 15 February 2008 - 05:19 PM.

[BrightStar]

From my limited experience with ordinary Perc 70/30 you need to make sure that the visco not only touches but is also embedded in the composition for reliable ignition. A brief spray of sparks doesn't always make it pop. This is a real nuisance in aerial salutes where the case may be spinning and the charge compacted in the wrong place.

One trick is to put a couple of strands of good blackmatch in the cracker, wrapped around or adjacent to the visco. Remember Perc doesn't react until almost 600 C whereas your BP covered match will ignite at 300 C and guarantee the ignition of the rest.

Edited by BrightStar, 15 February 2008 - 08:05 PM.

[MDH]

Or he could take the risk if he's careful enough and just add some sulfur. That would probably help it react much more quickly.