633 replies to this topic

[NeilB]

Hi, are there many formulas that don't use the regulated chemicals. I notice alot of them use potassium perc and barium's. I'm going to try some willow/tiger tails and some glitter comps to start with but is there any colour comps?

TIA, Neil.

Edited by NeilB, 17 September 2017 - 09:32 AM.

[Arthur Brown]

I've seen some variant veline comps using nitrates and magnalium with parlon, using the appropriate metal carbonates for colour.

The EPP permit is a simple application form, then you can buy more easily. 

[NeilB]

I've seen some variant veline comps using nitrates and magnalium with parlon, using the appropriate metal carbonates for colour.
The EPP permit is a simple application form, then you can buy more easily.

Now this does interest me as I was originally going to start with the veline system.

It's not the EPP that worries me just the A&K. I just don't think I would be able to convince an ELO that i am competent and actually need it as I have no qualifications or background in the subject.

Thankyou.

Neil.

[samboradford]

Do folks want to offer a quick show of hands as to who is still struggling to get their "competency" demonstrated, if there are significant numbers then I think that's something we (I) as a group could help with.

[maxman]

Me! Only GMP as far as I know

[Tinderbox]

Here's his formula:
 
Name of composition: long lasting gold glitter
Composition Type: glitter
Creator: Pirotex
Color/Effect: dark charcoal tail with many flashing sparks 
Preparation: Pump with water or 25% alcohol in water
 
NaNO3 - 47%
Charcoal (airfloat) - 40%
S - 6%
Dextrin - 7%
+10% magnalium (granulated 50-70 mesh)

Just had a go at a 100g pumped batch. I have dextrin but instead subbed it for 3.5g red gum and isopropanol. I did not want to introduce water to an already hygrohappy mix. On first ground test the pumped stars burn like a lump of wood. Small yellow flame and remains like a dense red hot solid. The ash when cool is solid. So...I have little hope of these breaking up properly from a regular shell break. Instead they may fall as incendiaries..

The do smell lovely though. Might crush them all up and chuck in a bit of meal dust then re-pump....will let you know.
 
https://www.youtube....h?v=sgaa5USYhmw

[martyn]

Try one in a star gun.

[megabusa]

Yep, as Martyn says you have to use a star gun.

 

I have tested many stars that looked almost 'dud' on the ground, but come to life when fired in the air.

[Arthur Brown]

That formula is close to "tiger tail" which performs like a dud on the ground, but performs well when blown through the air. Try the star as you wish to use it and cut it small til you are confident that it will burn out before reaching the ground.

[Tinderbox]

Test one complete. Performed as expected. Dull yellow blobs falling to ground from a very high altitude.

I am aware of ground tests v's shot tests but I always do a ground test before anything else. Been doing this stuff a while. The reasoning behind me testing on ground was to get a close up personal sense of how this formula works. The red gum was always going to alter things which is why I halved the 7 for 3.5.

I shot a 100g batch from a 3/4" ID rocket. The stars were generously primed with good willow BP using the red gum liqour.
I like my rockets to perform as traditional skyrockets. High altitude, soft dump/bouquet break. No hard thumping shell-breaks for me.
However, these stars will no doubt shed a lot more material under those forces. But, it's not what I want so......I knocked up another 100g this time with 10% meal strait from the mill. Just done a ground test as these stars a drying like Billio. Rock hard too. Yep, it burns more feircly and actually started sputting yellow fizzing sparks. The glowing residue falls apart with no stick poking into small heaps. I am more hopeful now.

Another test tomorrow......

PS Took a video of the first rocket...too pants to even upload.

[Tinderbox]

The new stars worked better despite humidity really getting to them. Still very slow but they did actually feel damp. Burned more like a vibrant yellow firefly. Not giving up yet. I'll just have to dry them in a warm air box and then bag them up in a ziplock with a sachet of silica gel. May even pop them in a bag inside the rocket header.

[megabusa]

The new stars worked better despite humidity really getting to them. Still very slow but they did actually feel damp. Burned more like a vibrant yellow firefly. Not giving up yet. I'll just have to dry them in a warm air box and then bag them up in a ziplock with a sachet of silica gel. May even pop them in a bag inside the rocket header.

 

Don't force-dry them too quickly or the moisture will get 'driven in' & they will never dry.

 

I found stars with a high charcoal content would dry after about 3 weeks without any added warmth.

[Tinderbox]

I wasn't using water. I was using alcohol and red gum. I understand the term driven in. These stars absorbed moisture from the humid air due to the hygroscopy of the Sodium Nitrate hense my experimental use of an alternative binder to water and dex'. The experiment continues to get them working properly. Gonna try a different solvent based binder. PVB maybe. Just need to find someone selling it.

[Tinderbox]

Further tests on Pirotex's Sodium Nitrate based Magnalium "long Glitter" stars. Not strictly a glitter as no spritzels are formed. Just the delayed ignition of MgAl. Same as Slow Gold really but a really wonderful effect. I've tried using the same formula but using KnO3 and that works really nice. lovely fizzing, shimmering white flashes. Millions of them.

I tried the same formula this time using the Sodium Nitrate as to Pirotex formula using water and dextrin. Pressed 3/4" stars. Dried them out for over a week. Popped them in a sealed container with handfuls of desiccant sachets (colour indicating ones) and now they are solid. Weighed every day the same star to make sure moisture was leaving and now they are dry BUT...I have this problem now (can't post picture?). Stars have expanded out and cracked and may have compromised integrity possibly with a reaction between MgAl and Nitrate? I used 1% boric Acid. Any thoughts? Not tested these yet.

[cooperman435]

Apologies for the slow reply, I had looked for my pictures from a similar experience to try and share what I did to cure it.

If I recall I had the exact same issue with pumped/pressed comets in that they seemed to dry almost completely without incident and then at the last moment crack up if they contained Mg or Mgal. I was trying to find out if Al had the same reaction too before replying.

They were Resin bound, bp based with varying grades of Mgal and mg granules and I believe the only reliable cure I found was linseed coating the metal beforehand in an old wok!