Colour Changes

[frosty90]

Hi all,

 

I would like to make some stars that change from some sort of streamer, like C6, to colour. I remember reading somewhere that a 'dark' composition is used between the layers, to give the illusion of smooth simultaneous change on all stars at once. Is this really needed for something like c6 to a colour? (I know it will work with out it, but what I mean is do you think it is worth the extra effort for the effect?) Also, how does one formulate a dark composition? Like one that burns fairly rapidly but doesnt give off much light? I dont have too many exotic chemicals either.

 

Cheers,

Jesse

[Ralph]

when I do TT to colour i never put a dark relay and it always seems to change at about the same time i personally don't think its worth the effort

[xetap]

Should you want to experiment, here's a formula that comes from a well known practitioner:

 

"Here's a slightly modified Glüsatz I've used for delayed lighting of stars. It requires no CMC - which most other formulae contain - and coats onto stars nicely when rolling.

 

"The burn rate of this particular formula is roughly 30 seconds per inch, so a uniformly-applied 1/16" layer would burn almost 2 seconds. It really works, lights very easily, and barely glows, even in the dark. Oh, yes- and it lights almost everything except high metal content stars, which might require a prime layer between the delay and the star. LLoyd"

 

In parts.

Barium nitrate...75.5

AF charcoal......10

Sulfur.................10

Cab-O-Sil............1

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

Use to coat stars for delayed lighting. Burns with no flame envelope at all. Do prime them. Glusatz, being barium nitrate based, is a little harder to light than black powder. A 'weak powder' prime is adequate. LLoyd

 

The original Glusatz formula:

Barium nitrate...75.5

Charcoal AF...10

Sulfur...10

Meal powder...3

Cab-O-Sil...1

CMC...0.5 (or 0.75 dextrin)

Distilled H2O...+6

Edited March 7, 2010 by xetap

[explomaan]

Barium nitrate...75.5

AF charcoal......10

Sulfur.................10

Cab-O-Sil............1

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

Use to coat stars for delayed lighting. Burns with no flame envelope at all. Do prime them. Glusatz, being barium nitrate based, is a little harder to light than black powder. A 'weak powder' prime is adequate. LLoyd

 

Sorry for this bump but I would really like to know this:

What is the function of Cab-O-Sil in this formule and could it be left out? I would like to try this dark star relay but I don't have Cab-O-Sil and it contains only 1 part of it. How visible are the common relay compositions?:

 

Changing Relay #1

Source: Shimizu[1], page 187

Comments: This type of composition is put between two color layers in a star to create the illusion that all the stars change their color clearly and simultaneously in spite of slight deviations in manufacture.

Preparation:

 

Potassium perchlorate.............................35

Potassium nitrate.................................35

Hemp coal (or Paulownia coal).....................24

Soluble glutinous rice starch.....................6

 

Changing Relay #2

Source: Shimizu[1], page 187

Comments: This type of composition is put between two color layers in a star to create the illusion that all the stars change their color clearly and simultaneously in spite of slight deviations in manufacture.

Preparation:

 

Potassium perchlorate.............................81

Red gum...........................................13

Soluble glutinous rice starch.....................6

Edited August 10, 2010 by explomaan

[Twotails]

Not having made this composition(but looking at I SHOULD have tried it on my last stars, oh well, next time) I would guess the cab-o-sil makes the layer "fluffy", Im thinking it may be possable(if thats the case, that the Cab-o-Sil serves no other function) to substitute fine wood dust, or another Chemical or compound used to fluff up a prime.

[Algenco]

isn't cab-0-sil fumed silica? If so wouldn't it deposit molten glass droplets similar to silicon?

[Mumbles]

Honestly, without any metal in there, I don't know if you could get the temperatures needed to melt the cab-o-sil. BP based primes get away with it by actually burning silicon to generate molten SiO2. I'd think it'd be just a fluffing agent. Woodmeal is used in some other light obscuring formulas, so it should work, as should leaving anything out all together.

 

In my limited experience, the formulas are completely unnoticeable when going between two different star compositions. However if you want a dark opening, you may see a dim orange glow or charcoal tail particularly at high speeds.