Avoiding water

Hi all,

No I don't have rabies but my aversion to using nasty things like Potassium Dichromate is similar :-)

In my browsing of various exciting star formulae on Passfire I notice how many of the ones I like use Magnalium and also need water to dampen. Now some of these formula do not state a binder so I presume for most pumped/cut stars it would be possible to use an alcohol based binder so I can avoid the water completely?

I've got plenty of red gum and acetone but acetone evaporates so fast I wonder if there is a better solvent I can use? I use meths in my water mix to aid evaporation so wondered if meths can be used with MgAl or does it contain some water.

First rule of pyro -can it be cheaper!!! and water is the cheapest solvent Loadsa formulae use meths, water/meths mix, acetone etc. but water is the cheapest.

Some stars are pressed from dry powders in a machine, but the machine is heavy expensive and electric but for real production 1 - 5 thousand stars an hour isnt a bad rate especially as they are dry enough to firer.

Hi all,

No I don't have rabies but my aversion to using nasty things like Potassium Dichromate is similar :-)

In my browsing of various exciting star formulae on Passfire I notice how many of the ones I like use Magnalium and also need water to dampen. Now some of these formula do not state a binder so I presume for most pumped/cut stars it would be possible to use an alcohol based binder so I can avoid the water completely?

I've got plenty of red gum and acetone but acetone evaporates so fast I wonder if there is a better solvent I can use? I use meths in my water mix to aid evaporation so wondered if meths can be used with MgAl or does it contain some water.

That is the beauty of Magnalium,as it is far more stable than Mg .Even when using Mg i have never used dichromate but have just passivated the Mg using boiled linseed.

I have used 25/75 meths / water to bind magnalium formulas with good success,i would also imagine that yuo could use 50/50.

With regards to the formula with no binders, look at the composition and you'll see what you can use. If it's heavy on parlon, use acetone, red gum-alcohol and if there's no compatibility issues water. I still see the use of boric acid in MgAl comps and wonder why, as I've read this could make things worse!!

Edited by portfire, 25 September 2012 - 08:06 PM.

I've ruined or damaged several batches of glitters by wetting with boric acid solution before I figured it out. Now I don't use boric acid even in most glitters, unless the formula looks very likely to react. Magnalium occasionally has some issues, but I've found trying to dry them in a heated drying box is more often the cause, or at least exacerbates the problem.

I've bound dozens of magnalium fueled stars with water, and never had a problem. I generally use straight distilled water with a touch of alcohol to break the surface tension. I've always wanted to get a hardness tester, and test a bunch of binders and solvents to activate them and look at the results. I'm of the opinion that both red gum and parlon are inferior binders for differing reasons. I'd also like to see what the effect that alcohol in the water has on the final hardness of the stars.

Thanks for the advice all. Just on the whole topic of binders I still see a lot of formula with Shellac as a binder. Can you replace shellac with something like dextrin in most cases? I've seen a couple of nice Orange/Amber star formula and there's quite a lot of shellac so I presume it's acting as a fuel and may even aid the colour?