37 replies to this topic

[dannytsg]

Thank. I found the skylighter tutorial so that helps quite a lot.

[Mortartube]

You might find this page generally useful. Your fountain will obviously be a lot smaller than the beast that is the "Clarks giant steel fountain", but many of the principles will be the same. http://www.brianredm...s/projects.html

[dannytsg]

Yes thanks for that.

[dannytsg]

http://www.pyrodb.or...tion=browse-all

 

Another good reference site. Thanks for that.

[dannytsg]

Just as a further question. If I leave the fountain unchoked is there any chance of it going bang instead of fizz?

 

Worried about testing such a thing and it not doing as intended especially in my back garden or the like where it would draw unnecessary attention if it went boom.

[helix]

The main causes of a fountain going bang are either the composition not being consolidated properly or the nozzle clogging up.

 

If you don't have a nozzle then chances are the spray height will be somewhat disappointing - you would normally have a nozzle unless its a rain formula or coloured fire/ traffic light type effort.  

 

The nozzle sometimes clogs up with comps. containing aluminium  but if you are starting with charcoal gerbs then you should be ok - just start with a fairly large nozzle.

[Arthur Brown]

If the powder core is properly rammed to a hard dense solid then there is little chance of making a banger, if the powder cracks then it might bang.

 

A gerbe without a nozzle will be weak and low, a gerbe with too small a nozzle will tend to bang. you need to find a fair size of nozzle to come between a wimp fountain and a big banger, Start with a nozzle about bore/2.

[starseeker]

For your peace of mind if you start with a nozzle less fountain and when this performs correctly then add a nozzle to your next one.

[dannytsg]

Well I gave it a try tonight. I made the tube myself, plugged it off one end and filled it using some BP+Al mix. I didn't ram it home as I didn't have the correct dowel size so it was just packed as best I could. I fitted it with Visco and nozzle which was 1/2 the diameter.

Here is the video:



It started off well but then slowed somewhat. I guess I need to really ram the composition next time to get a more consistent burn but I am happy for a first try.

[Deano 1]

Good start.

But don't forget, if you've got metals in there, don't ram it, it needs to be pressed.

 

 

Dean

[Arthur Brown]

For a first try that is superb. You can now try to choke it a little til you get a fair height and a slightly noisy burn without the bang!

 

Remember that BP mixes can be rammed with a drift and a mallet, but once you add metal powder you should only use a press. Pressing is more steady and you get good compacting without the impact of ramming with a mallet. There is a tiny risk of spontaneous combustion if you ram a comp with metal powder, pressing is safer.

[Crazy Cat]

Hi all,
I am now looking to progress to experimenting with fountains and flares. I wanted to get some collective ideas of which formulas are the simplest and still give good effect.
Any suggestions of compositions?

Many resources here, http://getanewgun.com/

Good e-book to read: http://getanewgun.co...f_Fireworks.pdf

[dannytsg]

Thanks. I will give it another go later on and try and press the powder evenly this time.

[Mortartube]

Did the tube burn through at the side, that is a possible cause of it dying down, or it may just need a choke to keep up the pressure. A good start. The addition of metals can raise the temperature. If you ever get on to Barium Nitrate and Aluminium mixes, some of those produce tremendous heat and need very thick walled tubes.

 

Keep up the good work.

[dannytsg]

Can I also just ask what difference pressing the powder makes compared to just loose filling the tube? Is it just to do with more fuel for the effect?