10 replies to this topic

[Potassium chlorate]

I have been into more "advanced" pyrotechnics for little less than two years, i.e. since I joined this board. With that I mean shell and rocket building.

Still haven't found out my ideal star compositions, though. I know that metallic fueled stars emit much more light than organic ones. My ideal coloured star (except for the blue ones) would be either:

1. Colour donor, potassium chlorate, magnesium or magnalium, shellac or red gum, parlon. The parlon would also serve as a binder and would be absolutely necessary if magnesium was to be used.

2. Colour donor, potassium perchlorate, magnesium or magnalium, red gum, parlon. 5% respectively of sulfur and airfloat charcoal as additional fuels for the perc. Parlon as a binder here too.

NC laquer as a solvent for the parlon.

Only problem is that parlon stars are hard to make. They take extremely long time to roll and are either too sticky, dry or wet for easy pumping or cutting.

Suggestions? Should I use only organic fuels instead? Because metal powders make up half of the problem with parlon, when it comes to the stickiness and problem to pump and aren't absolutely necessary, especially not with chlorates. Or should I keep it as it is and bind with dextrine or SGRS? Or is there a comfortable method binding with parlon?

I think I have asked something about this before, but didn't get much feedback.

[BrightStar]

The question seems to be confusing two issues here. Metallic / Organic stars versus Aqueous / Solvent bound stars.

Yes, magnesium stars need to be bound with a solvent method, often using parlon as the binder. Magnalium and aluminium stars can also be bound this way or with water and dextrine or SGRS.

If you see a colour formula that includes parlon with dextrin, you can assume it should be bound with water. You are however free to modify it by removing the dextrin and perhaps adding an extra couple of percent parlon. It can then be bound using a solvent such as acetone.

The choice as to which to use depends on your preference. Solvents are expensive and present a flammable vapour hazard but allow you to make stars that dry very quickly and can be primed the same day. This can be an advantage for the amateur, particularly when using strontium nitrate stars that can otherwise take weeks to dry.

I'm not sure why you would use NC laquer with parlon. Acetone (or acetone + methyl-ethyl-ketone for more working time) should do just fine.

Edited by BrightStar, 22 September 2010 - 02:04 PM.

[Potassium chlorate]

No, I'm not confusing anything. I would like my stars parlon-bound and metallic-fueled. These stars are ecxcellent when succesfully made. The tricky thing is to make them in a succesful way, like the examples I gave above.

And of course I know that I can remove a water soluble binder and put in an aceton or alcohol soluble instead. that was kind of the point.

Though, the easiest way to bind such stars would be with dextrine or SGRS. It's a hell rolling stars with parlon and cutting or pumping them make a bad shape and/or makes the parlon become thousands of small sticky strings, but rolling them with a water soluble binder makes the use of magnalium compulsory and makes the drying time very long, plus the fact that chemicals like strontium nitrate might be hard to dry completely this way due to their hygroscopic nature.

I have found out that metallic fuel in parlon stars make them even harder to pump or cut, hence the question of abandoning metallic fuels and just making organic stars.

Edited by Pyroswede, 22 September 2010 - 01:20 PM.

[BrightStar]

Ok, thanks for clarifying your question. I wasn't quite sure what you meant at first.

I suspect that the 'stringies' are fairly inevitable with parlon / acetone binding. One tip I have heard though is to add a small fraction (maybe 15%) Coleman Fuel (purified gasoline) to the mix as a lubricant. This apparently makes cutting and pumping much easier.

It's interesting that you find the metal content makes the problem worse. Intuitively, I would have thought the opposite to be the case.

Have you tried making parlon bound stars with a star plate? I'd be intrested to know how it turned out.

Edited by BrightStar, 22 September 2010 - 01:47 PM.

[Potassium chlorate]

I don't own a star plate, alas.

Metals actually make stars easier to pump if they're dextrine or SGRS bound. So for compositions like zink spreader stars or silver stars, where you don't use parlon anyway, pumping and binding with a water soluble binder is perfect.

[digger]

interesting. I don't know what to add to this. But.... There are many great formula out there. The best colour saturation I have seen is with the nitrate based formula such as the independence colours are excellent (parlon binding should be possible). On the other end of the cost scale AP based formula offer some great colours too. Pot Perc and Pot chlorate colours are ok, but in my experience the carbonates usually (but not always) add a chalkiness to the flame.

I guess you pays yer money and takes yer pick.

[starseeker]

i think the trick is when rolling parlon bound stars using acetone is to spray the solvent quite sparingly to avoid the sticky mess,i rolled some mag red the other day and did not find it much more tricky than rolling with water,alchohol.

[Potassium chlorate]

i think the trick is when rolling parlon bound stars using acetone is to spray the solvent quite sparingly to avoid the sticky mess,i rolled some mag red the other day and did not find it much more tricky than rolling with water,alchohol.

That's what I tried last year. But I'll give it a new try. The stars tend to "grow" slower with acetone/parlon than with the other solvents/binders, though.

[digger]

i think the trick is when rolling parlon bound stars using acetone is to spray the solvent quite sparingly to avoid the sticky mess,i rolled some mag red the other day and did not find it much more tricky than rolling with water,alchohol.

How do you deal with the issue of the solvent vapours? Are you hand rolling or machine (Ex rated motor I assume)

[seymour]

Other than Coleman fuel, I've found that adding alcohol to the Acetone helps reduce the parlon "stringiness".

When I use Parlon as a binder, I almost always cut them. Make a patty with the dampened mix, and let it dry a bit. It becomes much less sticky, and you can easily cut them in to perfect squares with a sharp knife.

I prime these and use as is, or I use them as cores for larger stars, and usually I roll the rest using water based binders (Gum Arabic for me, but not a good idea with your chlorate stars).

I've rolled and pumped using Parlon as a binder, and while possible, I find that it's not worth it.

Yes, water does make Magnalium preferable (though treating Mg makes it last fairly well with water), but MgAl is perfectly good. As an obsessed pyro, I do sympathise with your desire to use Mg for that bit of improvement, but is it always worth the effort?

The best colour saturation I have seen is with the nitrate based formula such as the independence colours are excellent (parlon binding should be possible).

I agree! For red, and especially green anyway. A bit hard for blue.

A good green for me usually consists mostly of Barium nitrate, with lots of parlon and MgAl. Other chemicals will be in smallish quantities. Parlon binding is definitely possible.

[Potassium chlorate]

I know that one of the best pyro amateurs in Sweden use a mix of acetone and alcohol when binding with parlon, so maybe I should try that.

This far I haven't been able to make "perfect" squares when cutting parlon bound star mix, though I might give it a try with an addition of alcohol.

I might be skipping the idea of "improving" barium chlorate stars with metal and parlon anyway. The barium chlorate/shellac is fantastic as it is.

Though my red stars is a different thing. I always use strontium nitrate, since it gives the best red (except for strontium chlorate, which I don't have), but it's hygroscopicity might be a problem. The only way if not binding with parlon there is to dry them throroughly after rolling and then keeping them in airtight containers until directly before loading a shell with them and then using the shell within very few days.