22 replies to this topic

[Caramanos2000]

pyrogear.net I tried locally but nothing. Also at mcmaster.com

[paul]

Regarding the 1mm hole (which is REALLY small) I´d go with pre-cutted small pieces of the thinnest visco available which is the one used in commercial firecrackers, ignited on the outside of the cannon.

Another way is to prepare a 1mm black match. It´s not that hard to get it working but you have to use fast meal and then incorporate the bp slurry into every last fibre of the thin yarn to get a reliable fuse.

[RegimentalPyro]

Have you considered using a carbide cannon?

For those that don't know about these, water is added to Calcium Carbide which causes it to evolve acetylene. This is then ignited using a spark plug to produce a very meaty bang indeed.

There are lots of sites on t'internet which sell these......I don't really consider them pyrotechnic devices but they have their uses.

[hst45]

But one last question that refers to ignitors.
---for my smallest cannons, I need a electrical igniter that will fit in 1mm hole.---

Wow, that's tiny. Could you could fill the "flash" hole with, well, flash, and tape the igniter on top? I suppose really fine grained BP dust could be made to work also. Pauls idea of blackmatch thread seems promising, but I'm not sure that it might not be stiff enough to push into the hole without bending and binding up.

[StevenRS]

I really like the idea of the small fuse, as I have some of that. It will also not allow them all to go off at the same instant, but at slightly different times. I will also try the idea of very thin black match or filling it with flash powder, and see which is more consistent.

About the Calcium Carbide, I thought about it, but the calcium hydroxide left over doesn't like metal, and it produced a kinda "hollow" blast, I really don't know how to describe it, but I didn't like it, not mention there was not enough smoke.(I like smoke .)

I shot some 6 round volleys out of my 1 inchers, and it was crazy. They only use 1 gram of Bp each, but they shoot a huge cloud of smoke, and the blast shook windows 200yds away.

I am, however, disappointed in the muzzle flash. Any ideas? Something I could put right in front of the Bp charge? (hopefully easily findable and not a liquid).

Thanks for all the help,
Steven.

Edited by StevenRS, 09 April 2007 - 07:51 PM.

[Caramanos2000]

Try flour, cofee
creamer or Magnesium.

Edited by Caramanos2000, 09 April 2007 - 07:38 PM.

[StevenRS]

I fired the big one for the first time!! It was amazing!! My video camera is on the fritz, so no video, but I will eventually get one. I had enough recoil to shatter the heavy wood frame, and dig another 3" into the ground. The percussion was so immense, I swear I saw light distortion around it.

I also was wondering about sulfurless Bp. I have heard it actually burns faster, and with a bigger flash, but with less gas produced, and less corrosive solids(but more in solids overall).
Does anyone have experience with this Bp variant? I just ran out of my good sulfur, and I have only cheap 90% stuff.

[pyroguitarman]

What are the laws on cannons in the UK? p.s I'm not sure about sulphur free BP, but a standard mix is 70.5 KNO3 : 29.5 charcoal.