19 replies to this topic

[Pretty green flame]

Name of composition: Silver cascade, modified
Composition Type: Silver streamer
Creator: Some guy from AFN, i just modified it a bit to suit my preferences
Color/Effect: Very bright with aluminium sparks (essentially a silver streamer)
The Composition: (by weight)

KNO3 - 45%

Magnesium - 15% Note: The Mg should not be very fine or of the very reactive flake variety or it will result in a flash. 100mesh is the limit.

Aluminium atomized - 30%

Sulfur - 10%


Any Precautions/Incompatabilities: Magnesium should be treated with linseed oil to minimize the chance of accidental ignition.

Precedure/Preparation: Ball mill together the KNO3 and sulfur then diaper in the metal powders. Bind with a 10% solution of shellac in alcohol. The stars should be pumped.

Video will be posted this evening, probably.

Edited by Pretty green flame, 09 September 2006 - 08:51 AM.

[Pretty green flame]

Here it is, as i promised. An action shot of the star burning (on ground, will do future tests in air)

[rocket]

Just a quick one about the shellac as I’ve never used it before nor have I used this method to bind stars.
Just say I’ve got a 10g batch do I just weight out 1g of shellac and dissolve in alcohol and add the comp.

Also would methylated spirits work to dissolve the shellac?

[TheSidewinder]

Yes, it's one additional gram of shellac to a 10 gram batch of comp.

You're better off mixing the shellac with the meal by screening or bag-mixing, then adding the alcohol. Methylated spirits should work fine.

M

[rocket]

Thanks for that, now to bunnings to get some shellac

[Pretty green flame]

Just a quick one about the shellac as I’ve never used it before nor have I used this method to bind stars.
Just say I’ve got a 10g batch do I just weight out 1g of shellac and dissolve in alcohol and add the comp.

Also would methylated spirits work to dissolve the shellac?

You make a 10% solution of shellac and then you add the solution to the composition, only so much that until you get the right consistency for pumping.

[rocket]

Ah k cool I see what you mean. I’ll do it that way then. I got shellac for $15 for 300g I don’t know if that expensive, also found some xylene during my trip to the hardware store but I don’t have a use for it as yet.

[rocket]

Update:
I must say these star look great. Had a bit of a problem though I add to much solvent so I thought to my self I no I’ll warm it up and evaporate it, so I did the after a with I noticed a bad smell coming from it I did think much of it at the time so I continued to pumping the then drying. I ended up making the room that I had them drying in smell horrible. What I think coursed this was the sulfur.

What do you guys think?

[Pretty green flame]

Are they getting any warmer, if so, you might have a problem, probably water in the solvent.

[rocket]

Nah there cold, well there not warm to touch any way.

[TheSidewinder]

That smell wasn't Ammonia, was it?

If so, you're getting a reaction of some sort. Are you sure you didn't have any water in the mix? Methylated spirits can contain a fair bit of water, IIRC?

M

[rocket]

Well I don’t know what ammonia smell like so I don’t know, but it did smell a bit like something was rotting (as me sis found out, lol).

When I first added the comp I noticed some bubble but very little I came to the conclusion that is was from me mixing it.
After I took it off the heat it was a yellow colour that’s why I thought it might have had something to do with that sulfur in the comp.

[Frozentech]

Well I don’t know what ammonia smell like so I don’t know, but it did smell a bit like something was rotting (as me sis found out, lol).

Do you have pet cats ? If so, ammonia smells like cat piss, or a cat litter box that needs cleaning.

[rocket]

Well I don’t know what ammonia smell like so I don’t know, but it did smell a bit like something was rotting (as me sis found out, lol).

Do you have pet cats ? If so, ammonia smells like cat piss, or a cat litter box that needs cleaning.

No i can say it did. It may have been the shellac.


Update: It was ammonia that I smelt, I made some MgAl the other day and it smelt strongly of ammonia

[Bonny]

Sorry to drag up a really old one here...
I was itching to clean up some chems, and had some 100m Mg laying around. I made a batch of cut stars with this formula. They turned out quite crumbly... I'm going to re-wet and pump as soon as I slap together a small star pump. Anyway, I put a couple stars on a pc of visco and they took fire quite easily. The burnrate was faster than I'd have thought and the effect was a nice shower of silver sparks. I'll probably pump 3/8" stars and then step prime.

[Bonny]

I finally got around to testing this comp in a shell. The video is not that good, but the silver great in person. This was a 3" can shell burst with 4:1BP/vermiculite and 1 tbsp of whistle as a booster.

http://www.youtube.c...F59c&hl=en&fs=1

[elstevo]

do these stars need to be primed?

[Mumbles]

It's a good idea to prime everything.

[Pretty green flame]

Indeed it is, these stars especially, either a step prime or the Fence post prime.

[Bonny]

IIRC, I used a 3 layer step prime with this comp. The last layer of prime (BP only) applied as a thick slurry into which I dipped the stars and then rolled them in granulated BP.