[dave]

just came across this in my web surfing.

no personal experience with this composition, but its based around an old rocket comp.

instead of blackpowder to ignite fireballs in a mortar, it seems they use ZINKIT
ZINC 75%
SULPHUR 25%

http://www.pyronobel.../en/sfx/?id=123

zinkit is described on their site under safety information

video on above link

dave

[seymour]

I do have some experience with this composition, and while I've never used it as fireball lift, I can definitely see how it'd work.

With fine Zn it goes "thump" and you get a voluminous, thick smoke cloud. This is how I expect they are doing it. I used about ten micron Zinc flake for this.

With much coarser Zinc, a pile on the ground erupts in to a pretty greenish fireball on it's own. Not lift suitable.

I expect they're using it primarily as a smoke generator, since you need to use so much more material to lift it, and you get more smoke out of it per gram than BP I would hazard to guess.

The Zinc may add some effect to the flame too, but considering the dirtiness of the classic fuel fireball, I doubt it'd be anything but negligible.

[icarus]

This is a very similar composition to that used in zinc sulphur rockets it is a low impetus fuel that often has a thin foil diaphragm on the end to build up pressure .Many months ago I queried as to whether Zn/S mixes as rocket propellants were subject to the restrictions imposed by M.S.E.R for amateur experimentation as it is not a fuel +oxidiser mix. but as a propellant it is covered by the 100g exemption rule , This mix is a superb safe alternative to B P which I have often found will fail to ignite fireballs due to its short burn duration .When using BP a few micro stars had to be added to increase ignition reliability Ive used Zn/S for rocket motors but until reading this post had not tried it for fire balls .Do try a single layer of Al foil gaffer taped over the end of the fireball mortar tube - it keeps it watertight and gives a bigger pop +improved thrust