11 replies to this topic

[Sparky]

Hi all

 

can anyone give me some advice on some very basic petrol fireball type effects please?

 

I have 4 inch tubes so I was thinking plastic food bags with petrol but not sure of the BP to fuel ratio. Please keep in mind that the BP is home made and not as fast as commercial. For shells I usually use about 1.5 times as much.

 

Thanks

 

Sparky

[icarus]

petrol is often too hot and quick burning dilute it with kerosene or white spirit or diesel fuel.Also the lift charge often fails to ignite the fuel so always add a few small primed stars much the same as a mine

[starseeker]

Hi Bob,

 

For our 4inch petrol lifters i used 40g of B.p and 1 ltr of petrol,

 

As you probably know the B.p is enclosed in a plastic bag which is wrapped in tape to provide some containment and the fuel is suspended in the mouth of the mortar ,double bagged and the bags taped around the top of the mortar and then foil covering this.

 

We have fired a few like this with no problem with ignition.

[Sam Miller]

I agree with Starseeker. This method is the best and works a charm, I've used it several times and it has never failed

[starseeker]

For a comparison of how much B.P to use,i would use 35g of my powder to lift a 4inch shell.

[Sparky]

Thanks guys, I'll give that a shot. I presume you use food / freezer bags or similar for the fuel?

[Mumbles]

Knock off JP-4 jet fuel works well for lampares.  It's a 50-50 mix of petrol and kerosine.  I've never tried it for fireball effects, but it's worth a shot I suppose.  I've also used what a friend calls "dragon juice", which is meant to be used in his version of mortar based liquid fueled fireballs that he calls Dragon's Breath.  It's 70% petrol, 20% diesel, and 10% methanol or 80-10-10 depending on when you asked.  You can find videos of these devices on youtube.  I've used about 40g BP for 4" fireballs (2L), 60g for 5"(4-5L), and 80g for 6" (8-10L).  The seemingly convenient trend stops there as 8" (~25L) needs about 240g. 

[starseeker]

Hi Bob,

 

I use the better quality sandwich bags as i thought the fuel might melt the thin ones!

[bangkokpyro]

This is a good way to make a big loud and hot fireball that produces a great smoke ring every time.

 

Use a 3 or 4 inch mortar tube (fiberglass works fine for 3 and 4 inch, make sure first it is leakproof) Fill the first 2 inches with water then  fill to within 2 inches of the top of the tube with a mix of Petrol and Diesel  85/15 or 80/20 works just fine.

For lift charge approx 60 gms of 2FA for a 4 inch and 45gms for a 3 inch is placed in a double plastic bag along with 2 e matches ( test to make sure the e matches are good ).

Twist the neck of the bag around a few times and bend it over against the sides of the bag. Now wrap tightly with some good quality black PVC electrical tape. First cover the bag surface in one direction then again at right angles to the first wrap so none of the plastic bag is visible and it has 2 layers of tape all over. You now have a ball of B.P with 2 matches poking out. You don't need more tape the B.P does not need to be confined well to work

 

The bag can be placed into the mortar up to an hour before firing.....Putting the 2 inches of water in the mortar first ensures the tape is not softened by the Petrol/Diesel mix. Give yourself a good 30 foot of scabwire to connect to your firing device....you don't want to next to this if it goes off unexpectedly !

2 matches ensure ignition.....it's no fun having to empty out the mortar if it fails to fire.

2 inches of water and 2 inches empty at the top of the tube will ensure no petrol ends up burning on the ground.

If you're worried about the mix not igniting add a pinch of Titanium to the B.P.

 

http://youtu.be/irWSLaSvcw0

 

http://youtu.be/vX7L-0689dA

Edited by bangkokpyro, 09 January 2014 - 11:03 AM.

[Sparky]

Thanks Paul!

Love that last video of the long lasting smoke ring. Nice stable atmosphere helped there I imagine. I think on the audio I hear you mention Uric acid but maybe I'm hearing things.

That ring had me wondering what the locals made of it, imagine seeing it once it had formed, you'd really not have a clue what it was!

[bangkokpyro]

Uric Acid no.  That was me mumbling....."if you put pure Gasoline in it, it doesn't make a ring like that"

The ring lasted well over 10 minutes and I can well imagine a few people on the farms around my workshop wondered just what it was

[Sparky]

Ha! Uric Acid - Pure Gasoline in It - my old ears!