red stars

[MadMat]

I recently had a conversation with someone (I'll withhold the name in case he was completely wrong). this person told me that it is possible, and he has done it in the past, to bind metal fueled red stars with dextrin. The formulas I'm talking about are usually parlon bound. Is this actually workable? Two comps come to mind; ruby red:

50 strontium nitrate

8 potassium perchlorate

18 parlon

12 magnalium

5 charcoal

5 sulfur

2 red gum

5 dextrin

 

or independence red:

50 strontium nitrate

18 magnalium

16 parlon

10 red gum

5 dextrin

[dagabu]

I have made comets (sorry, no stars) with parlon and dextrin as the binder with no issues. They are a PITA to dry though. I only use 3% max of dex in anything I do so my experience will not be the same.

 

BTW- That top one has three binders, red gum, parlon and dextrin. Denatured alcohol would be my choice and leave out the dex.

[MadMat]

I know some of you are going to ask why I don't want to use acetone and the parlon for binding. My reason is that I want to try to get as near perfect cubes as possible when I cut them. Every time I cut rubber stars they seem to deform a bit. I have tried different techniques (i.e. less or more solvent, Very sharp knives ect) but still have some deformation of the cube. I am attempting to do shaped burst patterns, and nice cubes make stacking the stars in the shell much easier.

Dagabu, in my experience, red gum is a fairly weak binder. I have tried using it in the past and had problems with things being easily crumbled.

Edited May 25, 2016 by MadMat

[fredjr]

The parlon binding method is NOT the standard binding method for either of those. Both where meant to be dextrin bound. Pretty much any formula that has dextrin is meant to be bound with it...

Edited May 25, 2016 by fredjr

[BengalFlair]

I have made stars with dextrin as binders for independence red with no problem. Gum arabic and sgrs also work great for me. I use very fine red gum and parlon with water activated binders.

[MadMat]

I have to disagree Fred, dextrin can and is used as an adjunct fuel in some cases. The formulas I posted are meant to be parlon bound.

Edited May 25, 2016 by MadMat

[Merlin]

My two cents and that's what it's worth. Parlon would act as a chlorine donor in both comps and the red gum a binder/ fuel with dextrin the primary binder all of this depending on the wetting agent. Edited May 25, 2016 by Merlin

[AzoMittle]

Why wouldn't you be able to use dextrin.............?

 

I normally bind all of my stars with 2-3% SGRS (including in my reds) unless there is a reason not to.

 

You can try it but I'll bet every dollar in my pocket that they will still deform on you. If you want perfectly shaped stars you'll want to switch to either pumping them or rolling them, rolling them will take more practice but you can make color changing stars that way too.

 

edit: Oh, if you are worried about using the dextrin with metals because of water content, you should be and shouldn't be. Look into how to coat magnesium, there are a few ways and I personally like the dichromate method but to each his own.

Edited May 25, 2016 by AzoMittle

[fredjr]

You can disagree if you like, but you would be wrong. Both of those where in use long before the parlon binding method became popular. If you were on passfire when parlon binding method was first being discussed you would know that "rubber" star formulas were being modified by removing the dextrin because it was no longer needed for binding. Search the passfire formula database for either and you will find originals with dextrin and modified rubber ie. parlon bound versions. Note the originals state the stars are very hygroscopic. When parlon bound they are sealed and are not hygroscopic...

Edited May 25, 2016 by fredjr

[MadMat]

Well I guess I'm not too old to learn something new (or old depending on how you look at it)

Edited May 25, 2016 by MadMat

[lloyd]

I had an outage of Internet service that prevented me from posting when I wished to, about an hour ago:

 

 

I have made (or supervised making) (yes, actually) tens of thousands of pounds of parlon-chlorinated, dextrin-bound stars -- both in wet-rolled and dry-pressed varieties. We used both a traditional star roller and also "Tablet presses" to make stars; and the fomulae did not vary, at all!

 

There is NO deficit in using dex in most stars. A few minor special formulae might be injured by it, but not most.

 

LLoyd

[lloyd]

ACtually... I lied! Our tablet-pressed stars also required a mere 1/2% of a lubricant (like magnesium stearate) to keep the molds from galling. But other than that, no changes, and CERTAINLY nothing that would change the character of the star.

 

LLoyd

[MadMat]

Thanks for the input guys! Some of your comments have invoked a few more questions; Would I really need to worry about
"coating" magnalium if I use a water-based binder? None of my stars are stored for very long at all. Secondly, I have been checking into the possibility of rolling stars. I've read and watched videos on rolling stars, and think I've got a decent handle on the process, but (this is for the more experienced people... Lloyd perhaps ) Is there any tips or suggestions that may well be omitted in what I have read or watched?

Edited May 25, 2016 by MadMat

[Mumbles]

There's no problem binding strontium nitrate based stars with water and dextrin. They might take a little longer to dry, but it can be done. In my opinion, the hygroscopic nature of strontium nitrate is exaggerated. Less pure forms tend to be more hygroscopic though. It pales in comparison to Lloyd's experience, but I've made 10's of pounds of that particular formula almost all water bound. It may be related to water, but I found the strontium nitrate versions to burn slower than the comparable barium nitrate greens. Worked out perfect for double petal shells though.

 

I wouldn't worry too much about coating metals and the like. The only time it really becomes necessary is when utilizing ammonium perchlorate, or using iron/steel. Other things can attack them, but there are easier steps that can be taken to prevent/stop the reaction from happening. Heat can be a factor, so I tend to allow my metal based stars to dry at ambient conditions for a while before finishing them off with a heated dry box. Once dry, most stars and compositions are stable almost indefinitely. It's when they're wet that reactions are a concern. Storing them for a week or a decade wont matter much if they're dry. There are a few exceptions (steel/iron and naphthalene stars), but most common things are fine.

 

If you care, there are 3 tricks to cutting perfect cubes. #1 a well compacted star patty. Good compaction allows for less water, and thus less drooping and deforming #2 a sharp, thin knife. #3 often a thin layer of prime on the knife or star patty. This serves the same purpose as using flour on the counter when working bread dough. Keeps it from sticking. https://youtu.be/VH9s0YFEbdo?t=4m34s

 

For what it's worth, if you're looking for patterned shell breaks, I would only use round stars. Cut stars, and to a lesser extent pumped stars, can fly erratically due to their shape. About the best tip is that practice makes perfect. Larger batches are also easier. It is honestly easiest to show someone in person. Describing some of the intricacies is actually rather difficult.

[MadMat]

Thanks Mumbles. I haven't had any problems with getting well shaped cubes when cutting water based bound stars, just with the rubber stars. I have tried the prime coating on the knife/patty hoping it would do exactly as you said, but for some reason it never acted like flour on dough for me and just created problems. I now prime my stars after they are dry. I am hoping to start rolling stars in the near future, but for now I'm just experimenting (screwing around?) with shaped bursts. I guess it's just an excuse to shoot off more shells

Edited May 25, 2016 by MadMat

[lloyd]

Mad,

Most any 'stable' formula may be rolled, cut, pressed, or even "tablet pressed" (which is a different regime, entirely).

 

You needn't worry about almost any formula that has been published in the literature, as it most assuredly has been processed "wet"... which is the usual way. Any formula that cannot withstand that would ordinarily be revealed as such in its documentation.

 

LLoyd