silver stars

[MadMat]

I tried a comp for silver stars I found at pyrodata.com. It was:

 

35 potassium perchlorate

65 aluminum (flake)

5 dextrin

One of the things that caught my attention about this comp was it's simplicity. I used bright flake aluminum and it produced beautiful stars, that were very brilliant and sparkly. Unfortunately, the stars are not very hard and I know they wouldn't hold up to the break charge. I assume the stearin coating on my bright flake aluminum is causing the problem. I am wondering if increasing the dextrin would help, or if I should try a different binder, such as n/c lacquer. Any suggestions?

[OldMarine]

I wouldn't think NC would work well for binding at that % and more would probably slow the burn way down. I'd try subbing SGRS or even try phenolic first.

That is a very simple white! Let us know what you figure out please.

[MadMat]

I wouldn't worry about slowing down the burn rate on this comp; it is a bit on the fast side for my liking anyways. I guess I'm just going to have to experiment a little. Maybe some of that experimentation will include replacing some of the bright flake with flitter aluminum as well. Yes, it is a simple comp.... just the way I like it!

Edited November 12, 2016 by MadMat

[Maserface]

Some bright streamer formulas have as high as 8% dextrin, and others require dampening with freshly prepared wheat paste (in addition to the dextrin in the mix). The use of wheat paste helps hold the composition together when its wet, and the dextrin gives the stars their dry strength.

[MadMat]

For everyone's information the star comp I'm talking about is shimizu silver wave #2.

[MadMat]

I ground up and 40 mesh screened my crumbly stars and added dextrin up to 8% and recut them. They are now nice and hard! The extra dextrin doesn't seem to have affected them anything noticeable.

Edited December 1, 2016 by MadMat

[NeighborJ]

6-8% dex is often what I use for comets when I want to break them hard and no I haven't had any noticeable change in the effects. I had issues with using SGRS when pumping silver wave stars not too long ago and mumbles suggested that I use the wheat starch to help hold the stars together better with less moisture. I bought the starch but never used it yet. I think I will try adding it to a few batches of pumped stars to see how it may help. Edited December 1, 2016 by NeighborJ

[chuckufarley]

J,

 

Do you use the wheat starch along with the SGRS? Or to replace the SGRS?

[NeighborJ]

It is used along with the SGRS to change its wet consolidation properties. I'll need to look up the post to see what quantities to use.

[MadMat]

Hmm I might try the wheat starch in the future but, by simply upping the dextrin to 8%, I'm getting stars that are quite hard when dry.

[Mumbles]

Just to clarify, it's wheat paste not wheat starch.

 

I don't know that I've ever used it with SGRS, but it works for dextrin. Wetting the star or comet comp with a thin wheat paste helps counteract some of the greasiness of the aluminum and give better wet adhesion. I use like 10 parts water to 1 part dried wheat paste. It's available in some locations as powdered wall paper paste, but avoid the vinyl based stuff. You could also make your own by boiling flour in water in about the same ratios.

[dynomike1]

I was wondering when that would come up. Back in the day we used to use flower and water for hanging wall paper. I just pumped some crossetts with Tiger tall and Ti using Phenolic and you can throw them against the wall. Beware they wont light with visco, so that means they are hard to light. they have to be primed. Also phenolic speeds the burn rate up some. I use BP+Silicone and pulverine for prime.

[MadMat]

Opps! I meant to say wheat paste. what I didn't know was you made it that thin. I did notice that it took considerably more effort and time to incorporate the water/alcohol (80/20) into the comp before cutting them. I assume it was the stearin coating on the aluminum that exacerbated this problem (one of the reasons I used a 80/20 alcohol/water to wet the comp., but I digress). If wheat paste will help with this that would be great. As far as igniting these stars, they don't seem that hard to light, but I use a two step prime on almost everything these days; first a hot prime 71 perchlorate, 14 charcoal 9 red gum, 5 Mg/Al, 3 dextrin, 4 silicon. Then bp.

Edited December 1, 2016 by MadMat

[MeowMix]

I've been reserved about this formula because of how close to flash it seems (That might sound stupid, I dunno)

Would you prepare this the same way as other star comps?

(Weigh, shake mix in container, screen, repeat)

[MadMat]

Meow, There are no worries about this formula acting like flash. First off, it uses bright flake aluminum which, even in the proper ratio, would be slower than flash. Secondly, the ratios are almost exactly the opposite of flash.

[Sparx88]

Meow, There are no worries about this formula acting like flash. First off, it uses bright flake aluminum which, even in the proper ratio, would be slower than flash. Secondly, the ratios are almost exactly the opposite of flash.

 

 

I second that. There are 4 versions Shimizu Silver Wave I know of. I use the 50/50 perc to alum ratio. I control the speed by simply more dextrin "slower" as already stated and the use of 5413 to speed it up. Using b,c,or d versions instead of course will do this to slow it. Also I use a 50/50 blend of 325mesh bright flake and Eckart 41813/g flake. Larger flakes don't do so well for a bright intense white/silver star/comets so that's where the 325mesh comes in. I hope this is some use for you.

 

Shimizu Silver Wave comps. VV

 

http://pyrosource.wikia.com/wiki/Silver_Stars