42 replies to this topic

[Kevin J]

A couple of weeks ago I made a *small* test shell with three of the above mentioned KNO3/sugar tubes. They were about 1cm diameter and 4cm long with a core running about two thirds of their length. It was a cannister shell with a diameter of about 1.5 inches with three of the inserts and a brake charge of meal powder at the bottom and some around them also. I primed the inserts with a piece of black match in the core of each.
It got to a decent altitude but I think it broke downwards because all of the inserts headed for the ground pretty fast and hit still burning. two of them seemed to go straight and the other one corkscrewd.
This may be worth more experimentation, but I think that I would need a very weak break, mabye just enough to actually break the shell and let the inserts do the flying. I think a higher lift is also in order.

[koobee]

When the shell breaks softly it helps accent the inserts, that way when it soflty pops the inserts will have more hang time and their effect will be noticed much more. So yes, go for a softer break.

[phildunford]

Dan williams describes the possibility of using the 'thermalite type fuse' he describes on his website with a few wraps of tape as go-getter inserts. I've never got round to making this as it uses what is described as a 'vinyl resin' to make a flexible binder for the fuse. Never found a UK equivalent for this. Anyone tried it or found a suitable substitute?

[pyrotrev]

Dan williams describes the possibility of using the 'thermalite type fuse' he describes on his website with a few wraps of tape as go-getter inserts. I've never got round to making this as it uses what is described as a 'vinyl resin' to make a flexible binder for the fuse. Never found a UK equivalent for this. Anyone tried it or found a suitable substitute?

I don't know of any fuse that's big enough to simulate the action of a proper go-getter - remember these things are normally 10mm+ ID filled with a pokey colour mixture . However I've noticed whilst fireproofing fusing for displays that slow PIC becomes self propelling if tightly wrapped in foil tape. This effect is of the scale of "fish" though, not go-getters.

Edited by pyrotrev, 20 March 2006 - 12:01 PM.

[BrightStar]

I made up a 3-inch ball shell the other day with green flying fish fuse inserts mixed in with BP on corn cob burst.

The fish fuse was cut into 1-inch strips, one end primed in BP/dextrine wet slurry, the other in PVA glue. Ignition was fine and there was plenty of green light in the sky, but at 400ft the fish didn't seem to fly very far...

As I was making the shell, I suddenly realised I didn't have a clue as to the composition in the green flying fish. It seems likely that there may be chlorates in there (perhaps barium chlorate).... I hope not ammonium compounds...

Does anyone have some examples of formulae? Is it safe to use flying fish fuse with a BP prime / burst in this way? (It seems that everyone does...) How can I find out if my fuse is full of chlorate???

[alany]

The good-old sulfuric acid test will fast tell you if you have significant amounts of chlorates in any comp. If you want a safer and more sensitive method you'll need aniline or indigo carmine.

[BrightStar]

Thanks Alan - most helpful. I'm currently lacking the reagents (but am working on it...). Is this a test you could maybe do yourself on behalf of the forum? Any type of chlorate contamination worries me - I religiously avoid working with ClO3...

Your web site is fantastic by the way - I discovered it 6 moths ago and must have spent dozens of hours reading your electronics and pyro work. I'm probably to blame for your bandwidth charges on all those videos

[alany]

I'd do the test, but I'm on the other side of the planet

I'm glad you like my site. I've been *really* busy with work of late, and haven't done a lot of pyro or my of anything else but work really... Hopefully that will soon change.

[BrightStar]

Does anyone have any experience making black powder exploding serpents for use in 3" can shells please? New Year is getting near and I'm hoping to try the effect.

Presumably they are some sort of end-burner with a slowish fuel mix and a flash header. Do they need a nozzle? What sort of ID / length works best? Any tried and tested fuel mixes? How do I ensure ignition when the shell bursts? Can they be used in ground mines as well?

Lots of questions, so thanks in advance...

Edited by BrightStar, 10 December 2006 - 07:19 AM.

[Mumbles]

I can't say I have any experience, but I do have books. I would suggest making some straight serpents before adding flash, but I would imagine that is how it would be done for exploding ones.

Degn in the Westech Fireworks Manual essentially just rolls a thin hard tube and fills with the comp. No core, no nozzle. The tube is 1/4" ID, 2.5" long and 4 turns thick, which what seems to be 70lb paper. One end primed, and the other dipped in sodium silicate to protect from fire. I have however seen serpent tooling. Basically it's a star pump that puts a core in it. After they are dry they are then pasted like one would do with comets or crossettes leaving the core end upen.

My best advice would be to make a combonation of the two. press it into a tube, and add a small core. I'd make the tube probably 1/4" or 3/8". 5-10mm, but cut the length to 1.5" or so. I see no reason they couldn't be used in mines. As for priming, BP priming would be fine, add some blackmatch if you feel worried. Degn uses tissue priming, which is rather outdated. BP slurry with granulated bp on top would be more than adequate I would imagine.

The formula Degn gives is as follows:

Meal 7
KNO3 2
C 1
Sulfur 1
Fe filings 3

[parabolic]

Hay folks, Iam also intrested in the 'flying fish fuse shells',
Iam not yet at the stage to fire anything yet but have all the parts I need , so until I get the chance I cant play with any ideas,, but if anyone is intrested---- I made my self a star gun the other day and was trying a few stars out, when I suddenly thought about firing a piece of the 1/4" time fuse to see what effect it had,

so.. I cut about a 1" length of time fuse, charged the star gun and inserted the timefuse on top, lit the gun and "woosh.." out came the time fuse to about 50 ft and was being self propelled and spinning quite powerfuly.
Id love to try this in a shell with perhaps 10-20 pieces of this time fuse, I reckon it will need the primming at one end and PVA glue on the other side like BrightStar suggested..

would you like to try this brightstar next time? and let us know how it goes?

Para

Edited by parabolic, 23 December 2006 - 07:33 PM.

[BrightStar]

would you like to try this brightstar next time? and let us know how it goes?

The flying fish fuse is quite easy to use and reliable - BP prime one end, PVA on the other. I'm making a few 2" can shells this evening:



For larger shells though the effect is not so effective - the burst is just too far away. That's why the serpent inserts will be good...

[parabolic]

could you try my time fuse idea as well?, I think it would be seen from bigger bursts because the time fuse has such a tail when it burns and because the fuse is so much bigger?

I hope your shells work ok, hope your gona video them!

cheers bud

para

actually ive just started to prime some pieces now Iam gona give it a go myself

Edited by parabolic, 24 December 2006 - 08:53 PM.