71 replies to this topic

[BrightStar]

Thanks Karl, the Blesser DVD sounds good. I must invest in more good literature at some stage... it can get expensive though.

I have been thinking about rolling some colour changing stars (once I'm somewhat better at it)... I understand that a 'changing relay' composition is used between the colours, giving the impression of all of the stars changing at once.

I've found two recipes for this:

Changing Relay #1 - Shimizu
Potassium perchlorate.............................35
Potassium nitrate.................................35
Hemp coal (or Paulownia coal).....................24
Soluble glutinous rice starch.....................6

Changing Relay #2 - Shimizu
Potassium perchlorate.............................81
Red gum...........................................13
Soluble glutinous rice starch.....................6

Assuming that I'm using #2, does anyone know if this would burn hot enough to directly ignite the central 6mm core of, say, Veline Red, or would I need an extra prime layer to allow the changing relay comp to ignite it?

Edited by BrightStar, 30 March 2007 - 12:25 AM.

[Wyvern]

With #2 i would say a prime would be necessary although i havnt used veline red, only the blue which does need quite a high temperature prime to ignite.

[TCblastmaster]

I have used shimizu#2 changing relay with considerable success.

On that occasion I went from a KClO4 organic fuelled composition to a hotter burning Veline comp.
The only prime I used between the core and the changing relay was a thin graduated prime of Veline to Shimizu of 2:1, 1:1 and 1:2. I didn't use a prime between changing relay and the organic colour comp as they use the same fuel and have similar flame temperatures.

The transition worked well with a definate gap between the more saturated but dimmer organic star and the sudden appearance of a smaller, brighter veline colour core.

Using this combination gave a good balance of light and colour intensity. Using Veline for both colours didn't work very well - despite the same light intensity the smaller size of the core made it appear dim by comparison.

I haven't tried any of the other "dark" relay compositions, though.

TC

[Gavin]

TC, what was the approx. diameter of the core, total thickness of graduated prime and thickness of changing relay?

Thanks,

Gavin

[TCblastmaster]

Hi Gavin,

Because the shell was a 4" spherical type, the stars were quite small. The cores were approximately 5mm, the graduated prime about 1mm, the changing relay 1mm, and the organic fuelled outer and its prime brought them up to about 13mm.

The rolling was done in stages, allowing the stars to dry in between, to avoid possible contamination of the colours.

As you can imagine the break was a little sparse but the effect quite elegant. A bigger shell with more stars would have been quite impressive.

TC

[Gavin]

Thanks TC, looks like I've been a bit heavy on the prime!

[madtrick]

For my stars, I use 6mm airsoft bb's. Unlike pepper corns they are perfectly round in size, light and cheap.
I would recommend!

[Pretty green flames]

For my stars, I use 6mm airsoft bb's. Unlike pepper corns they are perfectly round in size, light and cheap.
I would recommend!

Much too large and if you consider that the BB doesn't get consumed by the heat the BB's are gonna start falling out of the sky on the people watching on the ground, also it's not all that enviormentally friendly.

Small cut stars or dragons eggs (for example those taken from cracker balls) can also be used succesfully as cores.

[madtrick]

what do you mean, small cut stars? As for my mixture I currently use white star, do you mean compressing the powder then slicing?

Sorry I'm rather new to rolling stars.

[Pretty green flames]

what do you mean, small cut stars? As for my mixture I currently use white star, do you mean compressing the powder then slicing?

Sorry I'm rather new to rolling stars.

You make some cut stars by forming a slab of damp composition and cuttin out cubes. These should be fairly small (4x4x4mm for example), they are left to dry. When dry they are used as a core on which a round star will be rolled.

[madtrick]

Thanks, just wondering what the advantage is of rolling, apart from the shape of it. Does it produce a better effect than just cut or pressed stars on their own?

[Creepin_pyro]

The major advantage of rolling is that it enables colour changes. They are also generally more dense than cut stars, can be made (relatively) quickly in large batches, and have smoother burning characteristics than cut/pumped stars.

Edited by Creepin_pyro, 30 April 2007 - 04:25 PM.

[pymp]

The advantages include being able to do tons at once, and in a relatively short time. Also lets you do layered effects.

[KarlosH]

Hallo. I adding photos from my rolling stars on rape seeds. Composition contains synthetic shellac as binder in powder, magnalium, PVC, KP, Ba(NO3)2, charcoal. I making torro(slurry) and dry composition. I coating small seeds in smal bucket. When grains grow to 3 - 4mm, I give them to the bigger rotating bucket. I use separators for making uniform stars.
http://img03.picoodl...tem_a1b3103.jpg
http://img03.picoodl...rom_5fe5d98.jpg
http://img02.picoodl...rom_f3f40d3.jpg
http://img03.picoodl...tom_3a66436.jpg
http://img03.picoodl...nxm_6bca5d1.jpg

Edited by KarlosH, 02 May 2007 - 12:34 PM.

[sasman]

Oh!! I like those star screens? did you make them yourself..or purchase them?..If you purchased then can you tell me were?

Thanks