bangkokpyro

I've recently made coloured smoke shells from cornflour mixed with food colouring. These were 4 inch canister shells containing around 400 gms and burst with a 10 gm flash bag. The cornflour did not ignite just produced a cloud of colour.

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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

A previous mention of these rockets included that they were fired for gambling, how far/high or long a time. Perhaps one of the forum members in that area would care to explain something about the cultural reasons behind the rockets. However these pics showed blue tube which says "water main pipe" to me, previous mentions of these rockets included the mention of the bodies being made from hollowed out logs

 

These rockets are made and launched to bring on the rain during the month of May each year, the most famous rocket festival is at Yasathorn in the north east of Thailand and is held during the second week of May each year but down in the south west of the country in Sakgeow province rockets ranging in size from 7 Kg to 1000 Kg are launched at big and small festivals throughout the months of May, June and July.

50 years or so ago these rockets would have been made using bamboo with layers of cloth bound around the outsides to give them strength but now all rockets are made from blue PVC water pipe. The smaller rockets (10kg) use 2 inch ID pipe while the 1 ton size utilizes a 12 inch pipe. In the countryside around Sakgeow groups of enthusiasts get together on weekends to launch mostly smaller sizes and yes they gamble on the longest time from launch to the rocket returning to earth.

The tubes are filled with a mix of Potassium Nitrate and charcoal (no Sulphur) and the mix is very coarse, if you take a small pile of the mixed comp and ignite it on the ground it hardly burns. Crude hydraulic presses are used to press the increments into the pipe and the PVC tube is held inside a sand filled steel pipe while being pressed. 'sticks' are bamboo poles that have been heat treated to keep them from warping and to make them hard. The nozzle is formed with an increment of clay as well as a hardwood plug.

Flight times range from 2 to 5 minutes and some reach an altitude of over 3000 mts. Most spent rockets return to earth 3 or 4 miles from the launch site and the stick/tube is balanced so that the rocket decends horizontaly rather than coming down nose first (this gives a longer flight time).

The rockets are ignited with a crude 'electrical match' a small wad of iron wool is attached on opposite sides to 2 wires then put into a small thumb sized plastic bag of B.P. The bag is taped to the end of a thin bamboo stick and inserted 2/3 of the way up the rockets core ( all these rockets are cored) the 'e match' wires are then bought into contact with a 12 volt car battery to ignite the rocket.

You can't beat an Allpax gasket cutter for making end discs. It will cut through 1/8 thick cardboard with ease. You can adjust it to cut any size of disc and once you get into the hang of using you can cut hundreds of discs in an hour.

You can often find them second hand on ebay.

 

This formula by Gary Smith make a nice Aqua star
in %

Barium Nitrate 40
Potassium Perchlorate 15
Parlon 15
Copper 2 Oxide 15
Magnalium 325 mesh 12
Red Gum 3

Bind with Acetone for cut stars or add an additional 5% dextrin and bind with water if you want to roll them. Prime with something like fencepost prime.

http://www.popularme...ut...ws#slide-1

This later article portrays the PGI in a better light I think.

I have to say that the diference between 33.3/66.6% FP and 70/30 is negliable and both are as sensative realistically.

Mgal Is more sensative and powefull as it has sharper edges than ali (like for like particle sizes) so swapping to ali would be better yep.

Bangs are part of the display but JUST bangs are just a recipie for trouble :-(

My God! talk about massacring the English language.

Mg/Al is not more sensitive and powerful than Aluminium because it has sharp edges. It is more sensitive because it is an alloy containing 50% Magnesium which is more sensitive than plain Aluminium.
Aluminiums used in flash powder are generally flake shaped particles and as such are not sharp unlike granular material. It is the large surface are of the particles that give it it's sensitivity.

Olly.
Is flash powder a 'high explosive ? No and as such does not detonate but this is academic really as even a few grams of any kind of flash will in the right circumstances remove your fingers with ease;
Just a hundred grams will kill you if ignited in an unconfined pile in front of you. No flash powder is safe. 70/30 Perchlorate and Aluminium is probably the 'least dangerous' and exotic mixtures containing
Magnesium, Sulphur, Permanganate, Antimony etc will one day lead you to disaster.

Making bangs is a small part of pyrotechnics and perhaps the easiest way to get hurt or bring unwanted attention to yourself. Far more gratifying and difficult is being able to make other devices
such as fountains wheels, shells, mines etc to a high standard.
My advise would be that if you have to ask the kind of questions that you did in your post you should not be even thinking about making flash powder.
Get some books or look up some information on the internet before you attempt anything else. When you can make a 'hot' Black Powder and put it to use in various devices then maybe
you would be ready to use flash powder wisely in a crossette shell or as a booster in a small shells etc.
A good place to find some safe reliable information would be somewhere like skylighter.com which has a wealth of step by step articles on how to make a multitude of devices safely.

The Accident if one can describe such blatent disregard for safety procedures as an accident was caused by a low breaking shell raining down burning stars and debris on a nearby fabric tent full of shells and other devices.
The tent load of stuff went up causing a massive explosion and the fallout set fire to a load of nearby houses (mostly wooden).
I believe there were 4 dead and approx 50 injured. A couple of dozen houses were burnt to the ground
Min safe distances for specific calibre guns were not observed and they were firing 12 nch shells within 100 feet of spectators.
This sort of madness is common here where firework display operators are not licenced, trained or endowed with enough brains to even spell the word safety.
Sadly the victims families will end up with a few hundred quid compensation, no enqury , no outcry, no change to the way these events are planned and organized.