Strobe/flasher help

[loaded4bear]

Hi Guys:

 

I'm fairly new at this and would like some help with strobe/flasher comps and technique. I have my star roller working well and have sucessfully made simple star color transitions for 3" and 4" ball shells. I would like work up a TT with a strobe/flasher finish. No problem with the TT but info on the web is kinda scarce on strobe efx. Could you all share some of your expirtise, formulas, and anything special that I need to know before I fire up the roller (ok bad choice of words!). I have also seen a crackling-sparkling effect at the end of the burst. Would love some help with that as well. Thanks. This is a great forum.

[PyroCube]

It`s not that difficult so make white strobe stars, I used this forumla with success:

 

Barium Nitrate .................51

Potassium Nitrate ............7

Sulfur ..............................19

Magnalium ......................18 (60 to 100 Mesh)

Dextrin ............................5

 

Just make them not too big, the burning time is quite long. For TT to white strobe I recommend about

6mm star diameter. A hot prime is also very useful, BP with silicon should do well.

 

 

Greets

Edited February 15, 2013 by PyroCube

[loaded4bear]

Awesome. Thanks, that is one I can try. I even have those components. I have 3 different magalums - I never seem to have the right mesh size. Do you guys screen out what you don't need or will that damage a screen. I want to try Wilkonur 20 that calls for 200 mesh Magalum. I have 200-325 mesh (from HCS). What do you think?

[psyco_1322]

Awesome. Thanks, that is one I can try. I even have those components. I have 3 different magalums - I never seem to have the right mesh size. Do you guys screen out what you don't need or will that damage a screen. I want to try Wilkonur 20 that calls for 200 mesh Magalum. I have 200-325 mesh (from HCS). What do you think?

 

Any Mg/Al 200-325 mesh will work.

[dynomike1]

I just got through making some Blessers White Strobe, easiest comp that i have made so far.

[Bcorso85]

Strobe stars are rolled just like any other comps you've made so far. The differnt sizes in the metal will change the speed of the flashing core. If you use a strobe formula that uses aluminum as a fuel, the kind of aluminum and mesh is very important. As in sperodial, dark, firefly or sperical. Like in the formula "Yankees Flashing Stars."

 

The crackling sparkling effect you are reffering to is called "Dragon Eggs," and there are a few differnt formulas to make these. Some, as in the older and chaeper ones use lead tetradioxide, which is extremely toxix red lead. The safer more expensive version is made with bismout trioxide, or bismouth subcarbonate. Those two chemicals are very expensize for very little. after you combine the ingredients in the formula, you then dissolve smokeless black powder (Available at your local gun shop) in acetone and make a thin gravy. This dissolved Nitrocellulose acts as the binder, and moisture, because dextrin and other water bound binders dont usually work. They are then primed well because they are VERY hard to ignite. These need to be handled with care, because their effect is a small explosion. An accidental ignition on a 100 gram batch is a larger explosion. Not that I doubt your experience or safety precautions.

[Seymour]

It`s not that difficult so make white strobe stars, I used this forumla with success:

 

Barium Nitrate .................51

Potassium Nitrate ............7

Sulfur ..............................19

Magnalium ......................18 (60 to 100 Mesh)

Dextrin ............................5

 

Just make them not too big, the burning time is quite long. For TT to white strobe I recommend about

6mm star diameter. A hot prime is also very useful, BP with silicon should do well.

 

Thats exactly the same MgAl size i had best results with using that formula (Blessers White Strobe). Finer stuff gave me shimmering effect, though I know it works for other people. I'll also second the fact that strobe stars need to be small, so they burn up in the air, and because larger stars don't strobe so well. Again, you get that shimmer.

 

The crackling sparkling effect you are reffering to is called "Dragon Eggs," and there are a few differnt formulas to make these.

 

Technically I'd have to say that crackling effects are called Dragon eggs. Crackling-Sparking effects are called Dragon Flowers.

 

Loaded4bear, there are a few methods, but by and large you still have to make dragon eggs, and then coat them in another composition that contains the sparks and smolders. I have posted my methods for dragon flowers on the forum several times in some detail including all the formulas that I've used, and so have a few others. Search the keywords "dragon flowers".

 

Some, as in the older and chaeper ones use lead tetradioxide, which is extremely toxix red lead. The safer more expensive version is made with bismout trioxide, or bismouth subcarbonate. Those two chemicals are very expensize for very little. after you combine the ingredients in the formula, you then dissolve smokeless black powder (Available at your local gun shop) in acetone and make a thin gravy. This dissolved Nitrocellulose acts as the binder, and moisture, because dextrin and other water bound binders dont usually work. They are then primed well because they are VERY hard to ignite. These need to be handled with care, because their effect is a small explosion. An accidental ignition on a 100 gram batch is a larger explosion. Not that I doubt your experience or safety precautions.

 

Also CuO is included in many, of not the majority of crackle compositions. I've had much better success with compositions with a high CuO content, both in Lead tetraoxide and Bismuth trioxide formulas. While the lead and bismuth oxides are pricier than most chemicals, and dense (thus appearing much less than they are), you get so much effect out of it you still get a lot from each dollar in my opinion.

 

Priming requirements vary enormously depending on the particular formula and particle size. The worst I've seen needed a hot prime such as required by a contemporary perchlorate based colour star. The best will work with a BP prime and light very easily, often with no prime. I'd say there is a trend for bismuth ones to light easier, but it really depends.

 

Smokeless black powder.

 

Likely this is a typo, but I feel obliged to point out mistakes on here. People think they are truths. Black powder is already taken as a name. Smokeless powder is often died dark colours. I've never seen any that I'd call black, but it probably exists. I don't think it can be called "smokeless black powder".

 

I'd like to point out that any form of stabilized (just not that dodgy homemade stuff someone made and never purified) nitrocellulose is great, though for many people gun stuff is the easiest option. For others it might be varnish grade NC, or even solid stuff that's not mixed with NG and pressed in to ammunition specific pellets.

 

I also disagree that water based binders such as dextrin usually don't work, In my experience they usually do. I've heard people say that NC is usually used to prevent nitrates getting in and ruining the effect. A wax coat has been suggested as an alternative for when nitrates leaching in is a likelihood, which is often, but not always. I've never had this affect me, and while I've read some dissent of this theory, including crackle formulas that contain KNO3, It makes more sense than any other theory as to why using nitrocellulose in these things is nearly universal. Its also worth noting that other than Nitro and water based binders, there are all the other binders not water based.

 

I've used Dextrin to bind Bismuth trioxide dragon eggs three times myself, and on one occasion I admit I had issues. I abandoned the process of cutting the batch after wetting the lot, having only made a few stars (which were fine). Later on once I re-wet the mass it got a bit strange, faintly warm with a strange but mild smell. Something was going on. The second coming of this batch was definitely affected by the reaction, and a single egg (these were big, 3mm cubes or so) would glow and... suspense... nothing. However a ten gram pile glowed for ages before going off really loud.

 

Twenty grams went off just as loud as ten grams, and scattered the other ten grams unlit. Similar things happen with 'good' eggs, except they go bang sooner, thus the 'glowing wave' has not gone so far. This is why there is a limit of about 2mm across for most crackle compositions to go bang in a single pop, with enough tweaking, larger still, but not by a lot.

 

This is why 100g is not necessarily a larger explosion. Primed they're all going to ignite and go off in a bit of a crackling inferno, but not really an explosion. Unprimed, some crackle does ignite surrounding crackle in the explosion (where at worst it is like primed eggs), though just as often, the explosion does not light surrounding eggs, just scattering them. This can be seen in larger dragon eggs. Some formulas multipop if made too big (unless multipop is what you want), though many others make one small explosion that scatters most of the egg unlit, wasted, if the egg is too large.

 

It's still explosives, and I expect that they are more sensitive than a lot of mixes, but I think that the fact that they cause small explosions before they can propagate much is almost a safety feature.

 

Bcorso85 I know I'm criticizing your post a fair bit, but I'm just being a bit OCD. I don't mean to criticize you personally.

Edited February 16, 2013 by Seymour

[loaded4bear]

I guess I really shouldn't be calling what I am looking for a "strobe". The shot that I am looking for burst with a basic color but when the stars reach the end of their travel open up slightly into almost stationary small sparkling/shimmering white clouds. A very short duration. I'll look around for a video. Seymour, thanks for the dragon details. I'll check other posts to see if I want to attempt that one. Basically what I am looking for is a dense sparkling way to "finish" the shot.

[loaded4bear]

Oh, I forgot - can someone post the formula for yankee flashers. I googled it and came up will zilch.

[Mumbles]

It's probably due to the spelling of his name.

 

http://www.amateurpyro.com/forums/topic/2866-yankies-flash-stars/

[loaded4bear]

I knew I should have stayed awake in spelling class......hehe