27 replies to this topic

[leosedf]

This might be usefull

B.R.

[Potassium chlorate]

Very simple formula from my Swedish chemical supplier: 75 % Bi2O3, 15 % MgAl, 10 % CuO.

[phildunford]

Very simple formula from my Swedish chemical supplier: 75 % Bi2O3, 15 % MgAl, 10 % CuO.

This is one of Lancaster's formula. Bind with NC - very effective and reliable.

[pudi.dk]

I can't really get my eggs to work, they burn quickly with a sharp woosh, but don't CRACK as I'd like them to. I have tried 37,5 Bi2O3 - 37,5 MgAl - 25 CuO and above lancaster with 75 bi2O3. I think my binder is the problem. I have some NC dissolved in acetone to a honey consistancy and just add it untill it look "fine" and add more acetone if too thick. Is the amount of NC in the mix very strict? I need some help here.

-pudi

[phildunford]

As NC liquid is so hard to measure, I don't think I have ever been very accurate. I mix to a very thick liquid. When I put it on a glass plate it spreads out on its own, but very slowly - maybe thickness of emulsion paint...

Hope this helps

[al93535]

ahh screw it... n/m

Edited by al93535, 24 February 2009 - 02:13 AM.

[cooperman435]

I dry mine and weigh it by parts to get consistent results. I simply add Acetone and stir for a while to dissolve it properly.

[Potassium chlorate]

Don't you have those green crackling balls in your countries? There are 12-15 microstars in them.

[Vic]

I new this thread would come back and haunt me. In my original post I made a cock up on the blue star formula it was supposed to read as:

Potassium perchlorate 38
Ammonium perchlorate 29
Copper carbonate 14
Red gum 14
Dextrin 5

This taken from the "Chemistry of the Elements" and printed on Skylighter in there “Best blue fireworks stars”

With regards to the dragon eggs, the NC was already diluted to some extent with acetone when I received it, this was diluted further by myself 10:100 to get a 10% mix I ended up with a fairly thin consistency this was added to the crackle mix until I had soft wettish dough somewhat glistening then rolled between two thin laths and cut the same as cut stars. It was surprising how much NC was needed I think this is an important factor in their performance.

Dragon egg core stars, re they worth pursuing?

For me no, but elusive blue star yes.

[spanner]

Here’s an article that sheds some light on Dragons Eggs.

[Bonny]

I can't really get my eggs to work, they burn quickly with a sharp woosh, but don't CRACK as I'd like them to. I have tried 37,5 Bi2O3 - 37,5 MgAl - 25 CuO and above lancaster with 75 bi2O3. I think my binder is the problem. I have some NC dissolved in acetone to a honey consistancy and just add it untill it look "fine" and add more acetone if too thick. Is the amount of NC in the mix very strict? I need some help here.

-pudi

I use this 75 % Bi2O3, 15 % MgAl, 10 % CuO {+ 5%Al (atomised)} and it works well for me. The NC I use is ping pong balls dissolved in acetone. Try diluting your NC so it is more like thick paint, then add enough to get a thick dough. I have tried cutting with a noodle cutter passsfire style but it didn't work very well. I just run it through a 20 mesh screen. You have to work quickly, as it will dry fast. If needed add a bit of acetone. I have even spilled a large amount of acetone into the comp and just let it dry up while stirring with no ill effects.
Give the thinner NC a try and see how that works. What mesh of MgAl are you using? I've made them with 100mesh and 200 mesh. It was recommended to me to get the nest SINGLE pop rather than a few pops per egg to use 60mesh MgAl, but I haven't tried yet.

[pudi.dk]

Bonny, the only difference in the formula is the Al. I have only got 400 mesh not the soecified 200, but some coarser is on the way.
The MgAl i use is from KeteN who don't know **** about mesh size (I can eyeball the actual mesh better than he specifies it to be), it seems to be around 200 mesh.

[Bonny]

Bonny, the only difference in the formula is the Al. I have only got 400 mesh not the soecified 200, but some coarser is on the way.
The MgAl i use is from KeteN who don't know **** about mesh size (I can eyeball the actual mesh better than he specifies it to be), it seems to be around 200 mesh.

I've used 200 mesh and the eggs worked fine, I think they just popped quicker (less time heating up) than the 100 mesh. Not sure if they were the same as far as volume goes. I believe the Al is only added to produce a flash when they pop, but I could be wrong. I use 250mesh Al. My eggs often pop 2 or sometimes even 3 times per egg.
I test just be holding a lighter on them on the ground (takes a few seconds for them to heat up)..and put your safety glasses on

For priming I use the "veline style" prime by Pax, IIRC 2 layers (dried in between), then a dusting in greenmix or BP, but it depends on how you wnat to use them. In a hot mix matrix comet or star, a prime shouldn't be needed, where in a shell or mine you will need to prime.