273 replies to this topic

[BigG]

It's okay. I'm on the case. I'll soon have a full Spanish script for him - not through translators.

The first English-Russian translator did create some amusing results. They tried the sentence “The flesh is weak but the spirit high” on it. They translated it from English to Russian and put the results back through the translator to English. It came back as “The meat was horrible but the drinks were great”. Go figure….

Anyway – we are getting of topic again. Fountains Formulas Only!

[adamw]

Yes, please now everyone (including me!) back to the topic.

Castillareno - If you use 'flake' titanium please be careful with ramming because the formula can be sensitive when using this type of metal. A safer type is 'sponge'. Also, a good effect can be made with coarse aluminium (be careful for heat generation with KNO3 reaction) and iron.

[Creepin_pyro]

I've just obtained some MagNAlium, and would like to know how to incooperate it in some crackling fountains. Meal with 5% Mg/Al added seems to give a nice crackle, but I can't find any specific crackle formulas. Anyone used Mg/Al in this way?

[BigG]

I've just obtained some MagNAlium, and would like to know how to incooperate it in some crackling fountains.  Meal with 5% Mg/Al added seems to give a nice crackle, but I can't find any specific crackle formulas.  Anyone used Mg/Al in this way?

Look for crackling stars or dragon eggs topics. They contain formulas for crackling stars. Please don't post any crackling stars formulas in this thread.

[dfk]

I don't think a crackle formula would be too out of line in fountain formula thread as there is such a thing as a crackle fountain.
Nevertheless, crackle formulas can be found in pyro formula.

I've just obtained some MagNAlium, and would like to know how to incooperate it in some crackling fountains. Meal with 5% Mg/Al added seems to give a nice crackle, but I can't find any specific crackle formulas. Anyone used Mg/Al in this way?

Its not as easy as just throwing some MgAl into some meal, a crackle fountain is a matrix mix of meal and a percentage of cracker granules. I think it is burl that explains a process of obtaining the granules using a screen but these can also just be cut. Percentage wise, I think 10% granules is a good start and you can take it up to 25%, it all depends on the desired density of your crackles.
just remember to make your fountain nozzle big enough for your granules.

Good luck, be safe.

Marcus

[Charged]

[QUOTE]

Take a tube about 30mm ID, 125mm in length (This is much bigger then your average fountain). And drop some powdered clay to the bottom.


How thick and what material the tube should be?
And whats with the clay?How big should be the nozzle or the opening at the top .
Can it made from another material?

[Chaz]

About a week ago I made a 2 coloured fountain, first silver, then gold. It was quite a cool effect:

Video Here

The silver was:

Fountain #4
Source: Shimizu[1], page 127

Black powder, finely powdered.....................70
Pine charcoal.....................................4
Metal powder......................................26 (I used aluminium)


And the gold was:

Fountain #3
Source: rec.pyrotechnics. Posted by Tom Perigrin <tip@lead.aichem.arizona.edu

Potassium nitrate.................................50
Charcoal..........................................10
Sulfur............................................15
Iron..............................................25

Edited by Chaz, 12 May 2004 - 10:33 PM.

[zanes]

chaz-

what was the metal powder in the silver one- was it alu?

Anyway, do alu fountains produce silver/white sparks because the alu melts at lower temperatures than iron, meaning they also get white ho at lower temps? No doubt there is some really technical reason, but it was just a theory me and my dad came up with the other day.

[Chaz]

I've edited my post. I used aluminium, it works really nicely.

[Phoenix]

Zanes said,

Anyway, do alu fountains produce silver/white sparks because the alu melts at lower temperatures than iron, meaning they also get white ho at lower temps? No doubt there is some really technical reason, but it was just a theory me and my dad came up with the other day

The colour of the spark is due to it's temperature - the hotter, the brighter. Low temperatures produce dim red or orange (charcoal), higher temperatures produce bright yellow (iron) and even higher temperatures produce brighter white or silver (aluminium, titanium). So it's partly due to the tmeperature at which the substance burns (obviously aluminium burning hotter than charcoal) but I think another reason for aluminium's brightness is the nature of the oxide. Aluminium oxide remains solid, and as it is very hot, it glows white. On the other hand, carbon dioxide is of course a gas a room temperature, never mind pyro spark temperature, so it cannot glow in this way.

Chaz, nice work on the fountain :-). What were the dimensions (tube ID, choke diameter etc), and what sort of aluminium did you use?. It seemed like the aluminium part was "coughing" a little. I found that happens when the BP content is less than 75%, but if it is kept over that then a smoother burn results. It looked good anyway though.

[Chaz]

Yeah all of my fountains do that for some reason, they cough and splutter.

The tubes are 18mm ID, and the walls are about 2mm. I should have made them thicker, because the mix nearly burnt through the tube. I did another fountain more recently, just Aluminium, and it did just about burn through the tube at the end (video here).

The choke was 4mm as far as I can remember. The plugs were just dowel, but the choke didnt seem to errode from the heat because the fountain didnt start getting shorter.

Today I came up with the idea of attaching a fountain firmly to a flat wooden disc, and putting a small hole in the centre of the disc, then nailing it to a wall. If the fountain has enough thrust then it'll make the disc spin around like a cathrine wheel. Could be a nice effect...


EDIT: I know this'll be too basic for 95% of the people here, but I wrote a tutorial on making fountains, incase anyone would like a bit of guidance for their first fountain. Click here.

Edited by Chaz, 29 May 2004 - 01:47 PM.

[Phoenix]

That's quite a narrow choke for that size of fountain. It might burn more smoothly with a 9mm choke, and you still ought to get plenty of height from it. I don't know whether wooden nozzles would affect how it burns, but if using a larger choke doesn't help you could try a clay nozzle to see if it's that.

That aluminium fountain looked great. Were the sparks really that bright? They looked blue on the video (on my screen, at least). My aluminium fountains have been pretty crappy, with the alumnium mostly just burning yellow or gold. I usually use iron, since I get better results from that. I'll have to try some 325 mesh spherical, since people seem to get nicer results from that than I do with my home brew flake Al.

[Charged]

Thanks for the fountain tytorial.Now i got things pretty clear.

[BigG]

Plenty of remarks on this procedure.

First, you don?t use wood for nozzle. It?s a nice novelty, but it?s asking for trouble. Most cuts will leave a bit a space between the outer lip and the wooden plug; wood also burn, and the sides will give up at some point. Wood was not used for plugs from the early age of fireworks. Clay is the natural choice, and is also cheaper.

Second, the comment ?that the length of the tube is not important? of course is wrong, especially with the composition in the tutorial. Metal powder comes in different sizes. If you were to use aluminium mesh 20 on this fountain, chances you would not go through 5 cm before getting a blow through. Even aluminium 200 mesh will probably chook the fountain 25 cm in ? while aluminium 350 mesh will last much longer.

Last, the relation between the nozzle side and the tube id is important ? and the article ignores it completely.

[Chaz]

Well thanks everyone for the ideas. I tried out that catherine wheel, video here.

Picture of the device here. The block on the left is to balance out the weight of fountain on the other side. I should have made the block larger, because it wasnt until some of the fuel had burned, evening out the weight, that it actually balanced and so started to spin. I added the duct tape because I didnt want the mix to burn a hole in the side of the tube, but it just caught on fire. I used hot-melt glue to attach the fountain to the board (yes, I was careful keeping boiling hot glue away from anything flammable) and the heat from it being on fire eventually melted it off into a sticky mess, but that was a good 20 seconds after the fountain had finished.

I could have used two fountains on either side in opposite directions, that would solve the balance problem and make it spin even faster, but I wanted to keep it simple at first and see if I could actually get it to even act like a catherine wheel.


I'll make another one some time soon, this time I'll just use BP with about 4% aluminium added to give it a silver effect. I just use BP in my rockets and they seem to have plenty of thrust. I might even use a clay nozzle since BigG insists I should. :-)

Edited by Chaz, 30 May 2004 - 11:09 AM.