Rolled Dragon Eggs

[TYRONEEZEKIEL]

So I have lately had a great interest in using round Dragon Eggs as star cores to roll on. Last month I bought a box of crackler balls from the fireworks stand and took them apart to use as star cores. They are all spherical little guys and make beautiful cores. So this being said, I know that it is possible to do this.

 

Here is where the problems come up. All the DE formulas that are commonly listed usually bind with NC lacquer and must be cut for obvious reasons. This comp wont roll well as there is no real way to spray NC lacquer in an atomized fashion. Besides that would just be awfully messy anyway.

 

So fellas, do you have any ideas as what I could do to handle this?

 

If it is any help at all, My current stars burn, then have a quick delay as the core starts to glow then a nice pop. From time to time they sound like small crackers. I notice the identical smell that comes from cap guns or the clacker balls that you bang together. What comp is this?

[LambentPyro]

I do the same thing and they make great crackles in a 3" shell. If you split one open (be careful), if it has a green color, it is Bismuth Trioxide or Subcarbonate. If its red, than its lead.

 

It's a good point though as it doesn't look like NC lacquer was used, and the black coating on top that turns red hot when lit is a BP prime.

 

It could even be Phosphorous based!

[TYRONEEZEKIEL]

Could a standard DE comp be bound without NC laquer? Would a generic +5 dx work? However another obstacle is most comps call for pretty coarse mgal. That being said, I do have 3 micron mgal. I wonder if it will make usable dragon eggs with dextrin. Mumbles, if you read this, what does your chemistry background have to say about this option?

[TYRONEEZEKIEL]

I was checking on the web and came across this site someone brought this formula along and I am interested. It looks to be just a dextrin bound copper based thermite comp.

 

32% CuO

60% MgAl

8 % Dextrin

 

Has anyone ever used a comp like this before? Also, I would only roll them to 2mm or so. So should I try to roll them from base powder? Or could I just roll them on my normal tiny lead shot, then roll color over?

[pyrojig]

Most likely no phosphorous is used due to expense. The common DE is a cut or riced comp that is sifted to size, then rolled round with green mix bp. I have had great luck rolling comps with a 3% Nitrocellulose/ acetone sprayed with a atomized sprayer. This works best for comps where cross-contamination is a issue ( and water being a carrier ). Most all comps "DE" are bismuth salt based, at least sold in the states due to regulations etc. The cracker(sulfur) smell is from the prime burning on the DE.

NC is a important item needed for the DE to perform correct and get that loud pop( making rolling a bad choice due to not enough getting into the comp). There are other comps called dragon flowers that can use the thermite effect to do a similar flower. These do more of a soft multi pop. The choice of magnal mesh size is critical to the effect. Too fine will cause the star to either multi pop, or maybe just burn with a puff. The larger mesh makes the effect delay longer but louder and less pops. Usually one loud bang. I have had great luck with 36- mesh for a long delayed , crazy loud single bang.

Edited August 19, 2013 by pyrojig

[Pyrophury]

I recently had another go a rolling core-less red lead based microstars, using 2% phenolic resin as the binder and alcohol as the solvent.

 

I started by pushing some of the red lead composition, dampened with alcohol to clay like consistency, through a 20 mesh screen. The resulting extruded 'worms' were allowed to dry for a few hours before being rubbed through the screen a second time to break them up, fines and dust were separated with a 40 mesh.

 

I started with 1 tsp of the 20 - 40 mesh granules in the roller and misted them with alcohol, I found I had to use quite a lot of alcohol before they would begin to pick up the dry composition, which was sprinkled on in small increments. I continued until I noticed a few larger microstars forming, then began to separate by carefully scooping up the stars while the roller was still going, and holding a 6" round 10 mesh screen inside my star roller with the other hand, I screened off all the smaller stars back into the roller.

 

I repeated this process of spraying and sprinkling 3 increments, then screening out the stars that had grown to about 2mm, about 30-50 at a time. After about 90 minutes and using up 50g of composition, I had a small pile of about 1000 2mm microstars weighing roughly 15g.

 

http://s24.postimg.org/kxn0hiu1x/Rolled_DE.jpg

 

It's quite a time consuming, inefficient method. The main problem was over-spray leading to the building up of composition on the sides of the star roller, and new cores were always forming faster than the larger ones were growing. The results were OK, not as consistent as I'd of liked...

 

http://youtu.be/SqjEkvbum1g

 

Priming is still an issue that I'm working on, they require a very hot prime, but most of what I've tried so far just burns off without igniting the microstar. I tried something different that looks promising, but it's a gamble priming all these stars that took so long to make.