10 replies to this topic

[icarus]

a dutch pyrotechnic article briefly mentions making a flexible fuse by combining flash powder and silicon sealant then exuding the mix through a syringe onto polythene sheet. Once dry a flexible fuse cord is formed . He states using black powder instead of flash did not work . I tried dow and corning silicon with both permanganate based flash and kNO3/Mg flash without success . I then tried an acrylic sealant 151 no joy. For my last attempt I used liquid latex , this failed with nitrate base flash and reacted badly with permanganate flash attempting to cook my remote stirrer by heating up then spontaneously igniting. Has anyone any information on formulation of this fuse?? .I. am using an electric syringe drive from an infusion unit to exude flash/silicon mix onto a strip of poly dragged slowly under syringe I will make a fuse machine once i have a suitable formulation. Were my syringe to explode i lose £15.00 but no fingers .Permanganate flash is one of the compositions i would like to totally avoid if possible its very production can seldom be justified .

[Charlie]

Information on this fuse can be found @ http://www.frogfot.com/pyro.html

[icarus]

many thanks for the link I will try the formulations listed and post the results

[pyrotrev]

Both those mixes sound potentially very hazardous! If it were me I would try something like whistle (with some extra KClO4 to oxidise the silicone) mixed with silicone, maybe with some Al bright flake or silicon powder to up the temperature and give better ignition.

[icarus]

i agree they are not my mixtures of choice but im mixing in an old open topped dental amalgam mixer with remote turn on/off . The sticky silicon sealant with a small amount of acetone added seems to desensitise the flash type compounds a 1 kg weight dropped down a 2m tube end diameter 22mm cast iron base failed to detonate or ignite the mix. I exude the mix using an old infusion unit that drives a syringe drilled out to 3mm outlet i will try perc based compositions ,

PRELIMINARY RESULTS
KMnO4 5 S 1 dow corning silicon sealant 2 as exuded and dryed appeared to burn with a disappointing smoky yellow flame when wrapped in a thick covering of masking tape however this mix proved to be an excellent viable fuse. Smoke blows out with a gentle hiss it is not extiguished by high wind or passing through 1 cm deep 3mm dia bentonite hole approx speed is 5S per cm . Before encapsulation this was a very flexible fuse so i am going to dip in nc laquer and re test This would be a superb core to pass through a visco machine to produce slow fuse. further results to follow

[leosedf]

I made some pieces some time a go with instructions from frogfot. Not made anymore cause they are obsolete.

[icarus]

the flame/ result looks same as i got. The fuse is very good once confined by for example a tape outer it changes from a flame to a gentle hissing smoke emitting burn that passes through a long bentonite plug without going out.It would make an excellent core to put through a home made visco type fuse machine. I havent had chance to try other formulations yet . Please post if you try other formulations

[leosedf]

Well... I would avoid those comps, one has KMnO4 and the other chlorate.

[MMMMMM Pyro]

Hi,

Well I'm assuming that this fuse is to be made by those that are unable to get any Visco?

Whats wrong with blackmatch? Ill grant that its not perfectly reliable but it is gonna be a damn sight safer than using ClO3- or MnO4- with say a sulphur containing B.P. rocket.

Regardless of the compoundss being bound up in the Silicone there is always a chance.

[icarus]

i could buy better fireworks than the ones i make , ive made black match, sticky match , flash paper , improvised string fuses etc. i agree visco is brilliant especially in wet conditions or underwater use. It would have been interesting to load a mastic cartridge so i could squirt a fuse into place i enjoy the manufacturing side of the hobby. The ends of the fuse could be sealed with nitrocellulose laquer before insertion into a firework to stop cross contamination/ premature ignition

[banga]

i could buy better fireworks than the ones i make , ive made black match, sticky match , flash paper , improvised string fuses etc. i agree visco is brilliant especially in wet conditions or underwater use. It would have been interesting to load a mastic cartridge so i could squirt a fuse into place i enjoy the manufacturing side of the hobby. The ends of the fuse could be sealed with nitrocellulose laquer before insertion into a firework to stop cross contamination/ premature ignition

I can't get hold of visco either, so I use heat shrink over my fuse. Works really good you can bend it and move it around how ever you like, the speed of the fuse depends on your mix. Just make your fuse, insert it into the heat shrink and air heat it, good to go.