14 replies to this topic

[RegimentalPyro]

Hello,

I have been fortunate enough to manage to score a couple of kilo's of napthalene and am looking to try and play with this stinky stuff to try and create some awesome fireballs. The Naptha is in the form of some fairly course crystals and I figure it has to be powdered thoroughly first.

I'm thinking a bit of BP lift with some Ti sprinkled in (to ensure ignition) would be a good starting point (a bit like petrol fireballs) but would welcome some ideas of what quantities should be used. Any designs for fireball devices would be greatly appreciated.

Needless to say safety is always paramount. Has anybody had any bad experiences using this stuff?

As an aside has anybody got any experience using cork dust for fireballs? This video got me thinking.....

[digger]

I have done a few, no need to think too hard about them. It is pretty easy to ignite.

I would suggest for a small unit simply a thin walled cardboard tube, maybe 3" ID and 4" high with 250g of naphthalene in it. The choice is yours on the burst type as just about anything will ignite it as long as you don't go mental will 10g of flash. I guess a 1.5g flash break (in a 1/4" id tube) near the bottom of the tube will do the trick in my experience. I guess a more progressive burst would be a 5g BP maroon.

I have developed a new type of fireball burst using more environmentally friendly chemicals. PM me if you are interested in the composition.

D

Edited by digger, 28 May 2010 - 06:34 PM.

[dave]

i know i have seen mentioned several alternative fuels for fireballs.
starch powder, (cornflower), hexamine and accoides resin, powdered rubber , ashphatum (very good), fine cork dust, sawdust, can all produce some effect.

naphthalene on storage can tend to increase in crystal size due to the high vapour pressure and sublimation effects, it can also produce pounding headaches if care is not taken when grinding up.

if the effect is for indoor use i would think the starch / cornflour/ coffee whitener would be the way to go

dave321

[phildunford]

Might be worth a word with Pyromancer, as he does this sort of thing for a living...

[Arthur Brown]

Have you searched you tube? Lots on there.

[BrightStar]

Does anyone have any suggestions for readily available short, wide mortars for fireball use please?

I'd like to find something 5 - 6" diameter, about 7 - 8" tall that will safely withstand a 50g strung bound BP maroon lifting 500ml or so of fuel.

Edited by BrightStar, 31 May 2010 - 06:35 PM.

[digger]

Why do you need such a big maroon for so little fuel? a 50g string bound is a pretty powerful device, you would need a pretty strong mortar if it is not going to be blown to bits.

The method for fireballs that I have used is a 2mm-3mm thick very shallow steel cone (well thats what I have used on some sfx jobs).

What sort of fuel are you intending to use?

[Mumbles]

Oh yeah, thats an enormous amount of lift. I think the cremoras I've seen were about 100g of loose lift for probably 10-15lbs of fuel. The liquid fireballs I make are 50g of lift for like 2 gallons of fuel.

[BrightStar]

Yes, it's excessive, but it sure makes a good bang!

A sealed bag of fuel over a BP maroon does have the advantage that it's easy to set up and safely dismantle if needed. In theory there's also the option of using commercial maroons.

A small galvanised bucket fully buried does survive but ends up badly distorted. In the absence of welded steel troughs (where could I buy them?), I'm looking for similarly robust alternatives...

[digger]

Fair enough if you want a big bang.

I guess if you must go down the mortar route then a short length of schedule 160 pipe of an appropriate diameter would be just about indestructible, easy enough to have a pn100 blank welded on the end.

I would however guess that a 2g flash maroon (also available as a commercial sfx unit) would be more than up to the job for that amount of fuel and would still give a decent bang (much smaller too).

Edited by digger, 02 June 2010 - 11:26 PM.

[Pyro-centric]

I helped set up a job using 2 gallons of petrol and a commercial petrol lifter, (well several plus single gallon set ups too) may have been a number 2, sorry was a while back. We used a basic squared sided cone shaped mortar with a flat bottom, which took 2 guys to place (make sue you cut handle holes!!). The mortar managed to compress the field about 3 inch and filp it's self completely over. The mortars where built in house so if you know some one with a welder and, as i recall, 1/4 inch plate steel you can build one yourself. I would guide to over engineer the mortar. I once split an oil drum using a maroon! doh

Edited by Pyro-centric, 29 July 2012 - 10:20 AM.

[Guido Fawkes]

Take your battered steel bucket dig down an extra foot and bed the bucket into dry sand if its fully supported you won't bend it any more

[Mumbles]

I was mistaken before. It takes 225g-336g of BP to lift the cremoras.

I don't know how supportive dry sand will be. It has quite a bit of give with things buried in it. I've always been taught something compactable is best, and also to put something solid like large stones, railroad ties, etc under the mortar.

Edited by Mumbles, 16 June 2010 - 06:59 AM.

[digger]

I was mistaken before. It takes 225g-336g of BP to lift the cremoras.

I don't know how supportive dry sand will be. It has quite a bit of give with things buried in it. I've always been taught something compactable is best, and also to put something solid like large stones, railroad ties, etc under the mortar.

I would guess wet/damp sand is a very different story. It is very cohesive.

[Pyro-centric]

One other way to focus the Fire ball....the bottom of and old propane bottle, the big 47Kgs ones....but you need to be very careful ensuring the bottle is empty before cutting it. It has a pre-built stand on it and a nice curve.