Maltese Ball Shells

[marks265]

Warthog

 

Take a chill pill, keep religion out of pyro, and listen to what others have to say. It really is no big deal unless you make it one. Either way you slice it nothing will change and the drama will continue. I also suggest you not compare to other boards because the conversation is here and not elsewhere. If you widen the bullshit the bigger you'll make your problem. I suggest you take a couple of weeks off from the boards and think about this. If not than I might add to the unpleasant fun you seemingly choose to enjoy.

 

Mark

[BJV]

Warthog

 

Take a chill pill, keep religion out of pyro, and listen to what others have to say. It really is no big deal unless you make it one. Either way you slice it nothing will change and the drama will continue. I also suggest you not compare to other boards because the conversation is here and not elsewhere. If you widen the bullshit the bigger you'll make your problem. I suggest you take a couple of weeks off from the boards and think about this. If not than I might add to the unpleasant fun you seemingly choose to enjoy.

 

Mark

 

+1

BJV

[dagabu]

+2

 

-dag

[stckmndn]

I wouldn't shoot with you. No way, no how.

 

And God hates you, too. He told me. Said you're angry.

 

 

 

 

[stckmndn]

You can ban me now. It's ok. I just don't like that guy.

[ExplosiveCoek]

@Seymour, it also depends on how long you mill those charcoal comps. If the charcoal is really airfloat, and your mix has been in the ball mill for several hours, then there will be more 'smaller charcoal particles' available then when you just roughly screen it and get bigger charcoal particles. Which tend to give a longer lasting tail. I'm always leaning towards the 'not so long milling' because I like the long hangtime of these charcoal streamers.

However, your mix does tend to speed up significantly. Almost burning as fast if you take the extra air that mumbles described into account. This is the way I look at it now.

 

What kind of priming, and what thickness of layers of each compound, would you suggest then? Right now I have to use a lot of prime on top of my stars in order to make them work, and I don't really like that.

I do agree that willow is one of the coolest burning pyro mixes you can have. Although it should burn hotter according to the fact that it's travelling through air and giving the willow a more fierce burning.

 

@Mumbles, I do think you and the other guys have a good point about the need of an oxygen negative prime. But what I'm wondering about is, why do you still need the meal layer? Is this layer for getting everything started when burning in the shell, so when the stars haven't been ejected yet? It's a bit of guessing here.

 

 

I've another good example that you guys are talking about the right point: I've been blowing blind tiger tail, which is basically burning 'half as fast' as meal if you compare the 75/44 ration of KNO3 and the 15/44 ratio of charcoal. Those stars have been successfully blown blind with a small layer on meal on top of them. However, when I've had glitter - which is basically meal for 60-70% - with a very thin layer meal on top of that, it always ignited! So maybe there is some sort of oxygen negative prime needed, but also not to much. Most of the time my meal streamers with 60-70 percent meal in there always ignited. This would make the theory that the usage of C6 would be ideal for a prime layer underneath the meal layer to get everything going. C6 is 55/75=73% of meal based on KNO3 and for charcoal it would be double the amount of charcoal. Which gives an average of about 60% burning compared to meal. Something like that would be ideal, in theory.

 

What do you guys think about this?

[fredhappy]

Explosive coek+ other searchers for the holy prime grail.....( me included)

 

For priming I have noticed it is easy to make the mistake of judging the amount of prime rolled on as an adequate amount. I have shot many blind stars whilst I thought they were very well primed.

 

In general a layer of 1 mm for streamers, and for coloured stars 1.5 mm is adequate. For coloured stars I first roll on 0.5 mm of very hot prime ( see formulae below) then I apply 1 mm of fencepost. Since I apply my prime with the toro method, it is very important that the last imcrement is just ordinary fast meal. Toro method tends to make very smooth stars, and it is very important to have a somewhat porose ( like sandpaper) first fire layer as the outer surface. I have blown blind some adequately thickly primed stars simply due to the surface being very smooth. So when I am finished and my priming layer has achieved the correct thickness, I stop the star roller and gently and sparcely sprinkle the wet stars with fast meal ( I do add 1.5% diatomeous earth for more sand like structure)

 

But this step has a danger of its own I have noticed. When you overdo the last amount of meal, I have experienced what I call the "sponge"effect. Too much meal with that last increment will draw the moisture out of the carefully applied prime layer and give problems with adhesion to the star surface. I have noticed that this problem solely happened to me with coloured stars, especially coloured stars with BaNo3. Streamers and willows did not gave me these issues.

 

The type of charcoal used for prime is also important. A Spanish pyrotecnician absolutely stressed that Willow or a likewise softcharcoal should be used in prime formulae's due to the higher porosity and slightly lower ignition temperature properties of this charcoal .

 

 

11 mm B70 to 6 mm strobe. ( left star)

The strobe stars have been primed with 1 mm of very hot prime, the B70 has a thin layer ( 0.3 mm ) of the same hotprime, and a 1.2 mm layer of fencepost. I have finished with a dusting of fast meal 75-15-10 with willow C,1.5% DE and 4% dextrine . These stars will ignite with high speed breaks .

 

As a mealprime I use fencepost, it is good. Personally I apply 0.3-0.5 mm hotprime on coloured stars and then the fencepost, just to be sure. I love BaNo3 coloured stars, but they are a bit hard to light I must say. I have had blind stars even with fencepost, but since I started using the last dusting with fast meal this problem has not occured again. Again, it is not only about thickness of the prime layer, but also about the porosity of the first fire layer( outer surface of primed star).

 

I mill my fencepost for about 30 minutes, but that is my personal approach.

 

11 mm glitter to 6 mm bright blue

 

What explosivecoek describes in regard to achieving good ignition with thinly primed glitters is something I have observed too. The stars in the picture above gave me 100% ignition rates, despite the obvious thin layer.

 

8 mm turquoise (BaNo3 +high amount Mg/Al. with 0.5 hotprime and 1 mm fencepost, finished off with meal.

 

Above picture gives an idea how thick the actual prime layer should be. I primed this batch according to industry standards. About 60 will fit in a 3"shell, and 100% ignition rates even with very hard breaks should be achieved.

 

It is important to measure the thickness of the prime layer. Guessing always leads to thin layers, at least it does with me. I use my screens to constantly measure how thick the stars are.

as a light-all hotprime I use this Spanish formulae:

 

KCLO4 45

KNO3 30

Sulphur 6

Red Gum 6

Willow 15

Mg/Al 15/18 (230 mesh)

Dextrine 5

 

It burns extremely fierce/hot , almost like thermite. The combination of KCLO4 and KNO3 should give you the best of both oxidisers. Lowered ignition temperature from the KNO3, and temperature from the KCLO4.

 

Always put another layer of meal/fencepost on top of this one.

 

The Chinese give specialized courses about the sole subject of how to apply prime, it is a most vital step to get the priming right.

 

There is nothing more frustrating than seeing that perfectly screened batch of coloured stars go blind, so I am safe to say that it is a big challenge to achieve 100% ignition when using hard breaks.

 

I hope this helps a bit.

 

note: when replying to this thread please keep it factual. No IMO posts or hypotheses, please just factual stuff or stuff you have observed yourself in regard to this subject and preferably with pictures/clips . Thanks guys!

Edited May 26, 2012 by fredhappy

[Potassiumchlorate]

I find priming to be a tricky thing. On Bleser's Mg stars, for instance, 0.1mm of KP prime with silicon is enough. On some chlorate stars you rather need 1mm. Theoretically the parlon stars should be harder to ignite.

[marks265]

I don't know that I buy into a lot of "special primes" for most of the stars I make with perchlorate and nitrates. I remember a 6" ball shell I made with ruby red stars. I was starting to experiment with the toro method for priming. I use exclusively fence post prime and a final PB 75-15-10 +5 for dextrin w/willow C (well milled). Nor do I step prime. Anyway, while experimenting I had really overdone the prime on these stars taking a 7/16" star and priming it to about 5/8" or so. I chose to break the shell with KP on hulls so it broke pretty hard and all the stars seemed to all light. I can only guess that the large amount of prime and the rough surface helped the stars survive the first part of their flight.

 

I am a firm believer in the rough surface for better ignitability, and more is better. All the stars that I roll get a final trip to the star roller when dried.

 

Part of my own personal voodoo when priming stars is to start with stars that have been dried then prime them with fence post. When that dries I finish with the BP prime.

 

There are do don'ts but a lot also comes from the manufacturer. Being consistent by writing down what you do, testing, and adjusting are the biggest things that a person can do. I see more new primes coming all the time when trying to solve an age old problem. I personally find one or two that work the best for MY process and stick to them and make them work. Otherwise I get wrapped up way too deep in figuring out other primes.

 

Of course special primes are needed when working with AP and other examples of chemical compatibility. The above covers most instances for a wide range of stars for me.

 

Mark

[fredhappy]

marks: I agree with you on need for the outer star surface to be rough/porose . Often it is only about thickness in regard to prime layers, but the outer layer plays an important part in initial ignition.

 

It is most important to keep notes and photograph/film everything you do . I weigh my stars prior to priming , and weigh the amount of prime needed to get to a certain size. I then put this data in a file so I can keep track . Consistent results is what you want with priming.

 

Also, it is true that every manufacturer has its own way of priming stars. I have been experimenting with the above formulae, and have gotten good results. What ever personal voodoo works for you and gets your stars ignited, it's all good. There are many ways to skin this cat.....

 

I predominantly use KP 7/1 on hulls as a break charge, and have found that to get that 100% ingnition rate the priming must be robust .

 

fred

Edited May 26, 2012 by fredhappy

[marks265]

The amazing world of pyro Fred! The points you made Fred are where a lot of people miss the boat.

 

Mark

[Potassiumchlorate]

I find pinball prime with +6% silicon to be excellent. Almost every star lights with it. You just have to make it thick enough. Maybe one could use some KNO₃ in it to make it cheaper and still have it performing as good, something like:

 

Potassium perchlorate 40-45

Potassium nitrate 30-35

Charcoal 15

Red gum 10

Silicon +6

Dextrin +5

 

This one is similar to Fred's composition.