273 replies to this topic

[Joeeee]

It will definitely twinkle.

what type of aluminum? atomized?

[Joeeee]

35 BP
20 KNO3
7 BaNO3
10 Sulfur
8 Charcoal
10 Aluminum
8 Delay-Agent
2 Iron Oxide

That's probably a bit overfueled. I used to use it in 1" ID, 4" tall fountains with a very wide choke.

Barium nitrate is really needed for the effect to work.

Just start with a mixture of:

25 BP
35 KNO3
16 Sulfur
14 Charcoal
10 Aluminum

Then start substituting or adding small amounts of other ingredients, such as barium nitrate, sodium chloride, barium carbonate, sodium or calcium carbonate, antimony or iron sulfide, and a flash enhancer like iron oxide and calcium sulfate.

what type of iron oxide? and what type of calcium sulfate? and you should mix them both ?

Edited by Joeeee, 15 February 2010 - 01:07 PM.

[Creepin_pyro]

but what type of aluminium? atomized?

"-200 mesh, spherical" - that would be spherical Al...

You can use flake, spherical, atomised and others for glitters depending on the effect you want to achieve - pyrotechnic formula is not an exact science and experimentation is often required to fine-tune the effect, especially where glitters are concerned.

[Joeeee]

35 BP
20 KNO3
7 BaNO3
10 Sulfur
8 Charcoal
10 Aluminum
8 Delay-Agent
2 Iron Oxide

That's probably a bit overfueled. I used to use it in 1" ID, 4" tall fountains with a very wide choke.

Barium nitrate is really needed for the effect to work.

Just start with a mixture of:

25 BP
35 KNO3
16 Sulfur
14 Charcoal
10 Aluminum

Then start substituting or adding small amounts of other ingredients, such as barium nitrate, sodium chloride, barium carbonate, sodium or calcium carbonate, antimony or iron sulfide, and a flash enhancer like iron oxide and calcium sulfate.

I had try it but something is missing ... and what about delay agent how you do it?

[Creepin_pyro]

Your posts are a little confusing - what exactly are you having trouble with?

Here's another formula with more complete notes - might be a little less complicated... taken from rec.pyro:

"54.8 Potassium Nitrate
11.0 Charcoal (fine hardwood works ok)
7.3 Sulfur
8.4 Antimony Trisulfide (-325m)
7.3 Spheriodal Aluminum (-200m)
5.3 Sodium Bicarbonate
0.5 Boric Acid
5.3 Dextrin

Moisten with water to a stiff dough. Granulate through an 8-mesh screen
onto paper in a thin layer. Dry by airflow or breezy sunlight (avoid
direct, still wind, overhead sun).

This will produce a nice 8'-10' gold glittering gerb when choked to about
33% of the tube i.d.

It has a very pleasing "buttered popcorn" color and puff size.

LLoyd"

[Vic]

Barium nitrate is really needed for the effect to work.

Why is this please?

[seymour]

I've had success with Winokur Silver glitter gerb A

55% Potassium nitrrate
10% Aluminium (atomised, medium, the usual stuff for glitters. Formula calls for 150-325 mesh, I used -45 micron)
10% Sulfutr
10% Charcoal (airfloat)
5% Barium nitrate
5% Fe2)3 (Red Iron oxide)
5% Barium carbonate.

This will produce a nice 8'-10' gold glittering gerb when choked to about
33% of the tube i.d.

I think that opoint needs emphasising for those who are trying out glittering gerbs. If you have too narrow a choke the effect is ruined, as it is very delecate. You can have it wider (with a loss of effect height), but making it too tight will prevent most, if not all spritsels from escaping, and it will all get drosse3d up.

[Mumbles]

The other thing I was always concerned about is if the choke is too narrow the spritzels can be ejected too fast and the melt layer blows off. You can occasionally see this in videos of glitter shells or comets. They will have a very bright center or lift charge from a mass of aluminum reacting at once. I've found it more common with brocades. Maybe the coarse charcoal or Ti affect the viscosity. I have a video where you can see this effect well, but alas it is posted on APC, thus can't be viewed right onw. Usually a little prime prevents this, though can actually replicate it if there is metal in the prime itself.

Edited by Mumbles, 17 February 2010 - 07:50 PM.

[MDH]

Why is this please?

Barium oxides are powerful light emitters. This effect can also be seen in barium nitrate flash powders, which produce a much sharper silver than potassium nitrate flashes. Though non aesthetically, it delays the aluminum flash - I have theories as to why it does this, but I am not 100% certian. Lead nitrate can be used to produce a similar effect.

[spanner]

Your posts are a little confusing - what exactly are you having trouble with?

Here's another formula with more complete notes - might be a little less complicated... taken from rec.pyro:

"54.8 Potassium Nitrate
11.0 Charcoal (fine hardwood works ok)
7.3 Sulfur
8.4 Antimony Trisulfide (-325m)
7.3 Spheriodal Aluminum (-200m)
5.3 Sodium Bicarbonate
0.5 Boric Acid
5.3 Dextrin

Moisten with water to a stiff dough. Granulate through an 8-mesh screen
onto paper in a thin layer. Dry by airflow or breezy sunlight (avoid
direct, still wind, overhead sun).

This will produce a nice 8'-10' gold glittering gerb when choked to about
33% of the tube i.d.

It has a very pleasing "buttered popcorn" color and puff size.

LLoyd"

Additional notes for this comp:

Let me add -- I mean a STIFF dough... it should not have enough water to "sheen".
And don't let it sit wet for long. Granulate it quickly in thin enough layers so it can dry completely in a couple of hours. Most glitters will suffer from remaining wet too long.
I use +5% dextrin in my gold glitter comp for gerbs. It forms a free flowing, non-dusty granulate that compresses almost as hard as a wet-pressed star. LLoyd

[Vic]

I've found it more common with brocades. Maybe the coarse charcoal or Ti affect the viscosity. I have a video where you can see this effect well, but alas it is posted on APC, thus can't be viewed right now. Usually a little prime prevents this, though can actually replicate it if there is metal in the prime itself.

Mumbles can you link to the video yet, it would be interesting to see?

[Mumbles]

I unfortunately cannot right now. The new domain only has the forum on it right now, the files are to come a bit later. I will see if I can't download the file and get it hosted somewhere else for you though.

[Edit] I stand corrected, I just couldn't list the directory like I used to be able to. Try this. I think it's the right one, I just can't watch it right now.

http://www.amateurpy...les/Brocade.wmv

Edited by Mumbles, 28 February 2010 - 09:51 AM.

[Joeeee]

I need a very good formula of red/green colored twinkler gerb .. not bullshit !! .. anyone have a formula?

[seymour]

A pink glitter gerb is indeed possible, but neither the glitter nor the colour are likely to be of a great quality.

What you want to do, to get a good effect, is to make a gerb with red or green strobe stars in a base mix which ignites and ejects them. Strobe stars should work fairly well in this, since they naturally have a slow burn rate, but on the other hand, they can be difficult to get to work well, and you will not only need to get a good strobe going, but you want them to burn for exactly the right time.

The effect you want is indeed possible, but it's going to be very tricky and time consuming to get all of the many variables working together perfectly.

For coloured strobes, there are two types; those which are based on Ammonium perchlorate, Magnesium and a sulfate (In your case, BaSO4 or SrSO4, depending on the colour), and the other type, based on Barium or Strontium nitrate, Sulfur, Magnalium and Chlorine donors. The Ammonium perchlorate ones work better, but you have to work with Ammonoium perc and magnesium, and this involves dichromate coating and binding with nitrocelluloseto prevent reactions. Then you will of course need to use a barrier prime to seperate the AP strobes from the base mix, assuming it will be Potassium nitrate based.

The Nitrate strobes will have much less problems with incompatabilities, but the effect is even harder controll, and usually ammounts to a shimmering, rather than a true on-off flashing, and just to be annoying, the published formulas all have exotic chlorine donors, which being extremely toxic, ilegal pesticides, are hard to get.

To get a good effect I suggest making the strobing microstars very small, so that they give only one or two flashes (therefore making it easier to avoid a gerb which scatters strobes that burn for a while on the ground), and coating them with a delay prime, so that they get out of the gerb before flashing.

A good delay prime is one called 'glusatz', which burns for '30 seconds an inch' (quoting from http://www.creagan.n...ns.html#glusatz)

Glusatz

Barium nitrate 75.5
Charcoal (AF) 10
Sulfur 10
Meal 3
Cab-O-Sil 1
CMC 0 .5
Dist. water +6 (dissolve CMC first then add remaining ingredients)

If you are going to be using an Ammonium perchlorate strobe, you will want to modify it slightly to remove the Potasium nitrate part of the formula. It should not perform much differently if you replace the meal portion with the KP burst charge. You will also need to bind with NC if you useAP, so that the prime acts as a barrier between the strobe and the Nitrate based base mix (Unless you want to throw in yet another variable which will need lots of testing and use a perchlorate base mix).

Anyway, on to strobe mixes... Here are a few from Passfire....

Meinhart Green
46 Ammonium perchlorate
18 Magnesium, Atomised 100-325 mesh
18 Barium sulfate
10 Barium Carbonate
5 Parlon
3 PVC
2 Potassium dichromate

Bind with NC, of course...

Winokur green Twinkler #1
49 Barium nitrate
18 Sulfur
11 MgAl, Granular, -60 mesh
9 MgAl, Granular, -200 mesh
6 Hexachloroethane
5 Dextrin
2 Potassium dichromate
0.5 Boric acid

Meinhart Red
50 Ammonium perchlorate
18 Magnesium, atomised -325 mesh
16 Strontium sulfate
10 Strontium carbonate
5 PVC
3 Parlon
2 Potassium dichromate

Bound with NC...

Kosanke Red Strobe
34 Ammonium perchlorate
24 Sulfur
15 Strontium carbonate
12 Magnalium, granular, -60 mesh
5 Hexachlorobenzene
5 Dextrin
5 Potassium bichromate

Best of luck, you are trying to do a very difficult thing!

[Creepin_pyro]

I need a very good formula of red/green colored twinkler gerb .. not bullshit !! .. anyone have a formula?

You should really clarify exactly what you mean by 'twinkler gerb'!