"Wave" formulas for color changing shells

[AdmiralDonSnider]

Many chinese shells feature a color change from a "wave" formula to bright color cores. I find the effect quite pleasing. Many examples of this type of effect are on youtube. Numerous commercial shells used in our displays are named e.g. "silver wave to green" or "golden wave to red". The effect is a quite fast burning aluminum mix changing to bright color that clicks on. With slower comps and more gentle breaks they also look good when they willow slightly.

 

I know Shimizu offers formulas of that exact name; admittedly I have not tried them so far.

 

What kind of compositions with what typical ingredients are we talking about here and what are formulas you would recommend for the initial "waving" comp? I think those are typically based on another metal than Ti or FeTi, I guess Al, which gives a brocade willow type effect, but is not so elegant and more short-lived.

Edited February 1, 2014 by AdmiralDonSnider

[Zumber]

Video..??

[nater]

The Shimizu Silver Wave includes the BP ingredients along with coarse aluminum, magnalium, antimony trisulphide and realgar.

 

I have seen plenty of commercial shells with that description to, but they seem to be describing a short duration of silver or gold before the transition to the final color. I think it is a distinct effect from Shimizu's comp. Do you have a video of the effect you are after? I wonder if any fast burning glitter or tremelon rolled in a thin layer would duplicate the commercial effect?

[LambentPyro]

Admiral, I would think it's Titanium based, no?

[pyrokid]

No it's aluminum.

Edited February 3, 2014 by pyrokid

[Carbon796]

It sounds like you may be after a silver / gold flitter, or wave.

 

Silver flitter

 

40% KP

60% bright AL -325 mesh

+6% dextrin

 

Silver wave

 

50% KP

15% dark Al

25% medium AL bright flake 70-150 mesh

10% coarse Al flake 10-12 mesh

+6% dextrin

 

Both are hard to light, use a hot prime or step prime. Used caution when mixing the silver wave, as its a boarder line flash mix untill you get the larger flake aluminums mixed in. You probably will not be able to roll this silver wave, but you could sub the coarse flake for some thing finer.

 

-Rich

Edited February 3, 2014 by Carbon796

[AzoMittle]

From UtahPyro's Pyrotechnic's Cookbook, pages 95-97:

 

Silver Wave

Source: Composition from Shimizu[1], page 220.
Comments: This composition produces a silver fire dust. A large silver fire dust flame of short duration is
obtained. When the ratio perchlorate to aluminum is changed to 35/65 a small flame with yellowish fire dust
of long duration is obtained.

Potassium perchlorate.....................................50
Aluminum (somewhat coarse flake)..................50
Soluble glutinous rice starch...........................+5%

 

Golden Wave #1

Source: Composition from Shimizu[1], page 221

Potassium nitrate........................................37
Aluminum (somewhat coarse flake).............47
Antimony trisulfide........................................9
Boric acid.....................................................1
Soluble glutinous rice starch........................6

 

Golden Wave #2

Source: Composition from Shimizu[1], page 221

Potassium nitrate...........................................37
Aluminum (somewhat coarse flake)...............47
Sulfur..............................................................9
Boric acid........................................................1
Soluble glutinous rice starch...........................6

 

Golden Wave #3

Source: Composition from Shimizu[1], page 221.
Comments: A somewhat reddish gold effect is obtained with this composition.

Potassium nitrate.........................................37
Aluminum (somewhat coarse flake)..............47
Realgar.........................................................9
Boric acid......................................................1
Soluble glutinous rice starch.........................6

 

Silver Wave Chrysanthenum

Source: Composition from Shimizu[1], page 222.
Comments: A fire dust with sparks from the metal powder is obtained. It looks as if red, yellow and green
twinkling fire particles were mixed together.
Preparation: The potassium nitrate, sulfur and pine charcoal are previously mixed densely as in the
manufacture of black powder.

Potassium nitrate......................................50
Sulfur......................................................17.5
Pine charcoal...........................................7.5
Aluminum (somewhat coarse flake)..........7.5
Magnalium................................................1.5
Antimony trisulfide....................................2.5
Realgar....................................................7.5
Soluble glutinous rice starch....................6.0

Edited February 3, 2014 by AzoMittle

[FlaMtnBkr]

I think you can use your favorite color as a core and then roll on your favorite streamer comp to the final size.

 

It is recommended to use a layer of 'dark' relay prime. This helps it look like they all click 'on' at the same time to the color you used.

[bigbuck]

found a silver wave formula by shimizu that I wanted to try as follows

potassium nitrate 50

sulfur 17.5

charcoal 7.5

aluminium 7.5

magnalium 1.5

antimony trisulfide 2.5

realgar 7.5

dextrin 6

I was curious if there is a sub for realgar? or another formula very similar to this one that does not contain realgar

[Mumbles]

My first inclination would be to replace with more Sb2S3. Realgar is kind of a special chemical. It gives a unique effect. Antimony trisulfide, and to a lesser extent sulfur, are not perfect substitutes but will give you the general idea.

[bigbuck]

dark or chinese needle? or either one

[Mumbles]

I'd go with whatever you have. For something like this, I'm not sure how much it matters. I usually only buy chinese needle.

[Sparx88]

Not sure if this is helpful but I started using variants of shimizus silver wave comps for this purpose and as a 1st step primer.

 

I use the 50/50 perc/dk alum with 4g dextrin and 8g sulfur added. One of my favorite changing stars start as win 19, to hardt green 5 to hardt white strobe using that wave comp between both effects. The changes of the dex and sulfur wakes it up nice and works well with thin layers of it. I have applied it on damp and dry core/stars. Works best on damp. just spray the dry with plain water and let them get tacky sticky first. You can also apply the next effect to the 1st fresh damp wave layer. I do them like this, create cores plus 1st layer of wave then 2nd effect, dry them or apply your primer if only 1 change. Then I wet them, add final layer wave, second effect then finish with primer.

Edited August 4, 2016 by Sparx88