MgAl particle size

[Merlin]

What effect does the particle size of MgAL have on star formulations? I have a quantity of -325 MgAL but not -200 or -230 etc. Can -325 but substituted for example in the following.

 

0.18 Potassium perchlorate

0.45 Barium nitrate

0.10 Red gum

0.09 Parlon

0.14 Magnalium, 230-mesh

0.04 Dextrin

[OldMarine]

The smaller the MgAl mesh, the quicker the star burns is what I've been told. I know this is true with strobes.

[mabuse00]

Absolutely no problem. They will burn faster.

 

With 200mesh a lot of stars show a very slight tail of magnalium sparks, with the 325 they wont, what some might consider a slight advantage.

[Merlin]

Thanks guys! Upon further pillaging I came across some-200 to -325. This year I am going by the book- no more shortcuts. I think when we see a really great shell it is either because someone is going by the book or because they wrote the book.

[Fulmen]

The effect will depend on the type of star. For a straight metal-fueled star you can expect increased burn rate and a cleaner burn. But for other stars like strobes, glitter, dragons eggs etc. the effect can be much more significant.

 

As for changing comps to suit your supplies i think it's ok as long as you don't over-do it. You can never duplicate someone else work perfectly, so some tweaking must be expected. A slight change like this isn't going to skew the result entirely. But your reasoning is sound, there is often countless hours of experimentation behind a published recipe.

[braddsn]

The finer the MgAl, the faster and brighter the star will burn. Of course we want brighter right? BUT...... with brighter it also burns faster, so we find a nice middle ground which is 200-325. Another thing to note: If you use MgAl larger than 200, then the star not only burns slower, but becomes more difficult to light. I made a batch of white flitter comets once with 80 mesh MgAl. I did it because I was out of -230 and the 80 was all I had laying around. I thought it would only affect the burn rate. I was WRONG. I could not get enough prime on them to get them to light consistently. It was a waste of comp. So I recommend following the recommended mesh sizes in the formulas. I use 200-325 for nearly everything.