Chlorate + Metal fuels

[AdmiralDonSnider]

I know I´m probably confessing my ignorance by asking this, but what are the practical reasons/dangers why combinations of chlorates and metal fuels such as MgAl or Al are avoided (you can´t say they´re eliminated, because there are some formulas out there employing both)?

 

While chlorate stars show some very desirable characteristics in ignitability, burn speed, hue, it´s also true that bright colors such as metal fuelled greens or reds are not possible when MgAl is eliminated in the formulas.

 

So please give me some hints (referring to facts not myths) why e.g. chlorate+magnalium has to be avoided at all costs. Thank you!

[50AE]

Just more sensitive than perchlorate mixtures. Greater care should be applied. I personally try to avoid mixing chlorates with high reactive metal fuels, such as fine Al, MgAl or Mg. I do make bright Al/KClO3 flash though, and some metallic chlorate stars, which are very beautiful.

I think that everything should be ok if you treat the compositions with care. KClO3 with very reactive fuel flash should be avoided though. I like the bright Al one, because this kind of al is stearing coated, so it's less reactive and does much less friction.

[ausgoty]

I know I´m probably confessing my ignorance by asking this, but what are the practical reasons/dangers why combinations of chlorates and metal fuels such as MgAl or Al are avoided (you can´t say they´re eliminated, because there are some formulas out there employing both)?

 

While chlorate stars show some very desirable characteristics in ignitability, burn speed, hue, it´s also true that bright colors such as metal fuelled greens or reds are not possible when MgAl is eliminated in the formulas.

 

So please give me some hints (referring to facts not myths) why e.g. chlorate+magnalium has to be avoided at all costs. Thank you!

 

I wasn't aware there was any incompatibility with chlorate/MgAl. Have been making metal fueled stars with chlorate for while now and have not experienced any problems at all.

 

I have had reactions with KNO3/MgAl (yes forgot the boric acid) but he chlorate/MgAl mixtures I have made seem to be fine and stable.

 

Of course all chlorate mixtures are friction sensitive and should never be mixed with Sulpher (along with many/any other sulpherous compounds).

 

I consider it to be quite safe if the propper precautions are followed. If you choose to use chlorate, just be very careful, It has the potential to be very nasty if mis-treated.

[Ralph]

I wasn't aware there was any incompatibility with chlorate/MgAl. Have been making metal fueled stars with chlorate for while now and have not experienced any problems at all.

 

I have had reactions with KNO3/MgAl (yes forgot the boric acid) but he chlorate/MgAl mixtures I have made seem to be fine and stable.

 

 

 

 

I think chlorate metal mixtures are not permitted by law in most countries to prevent sensitive chlorate flash from being used (just what I think) I have used them with out noticing any negative reaction at all ( warm solution of chlorate with Mg reacts about the same as with NaCl) but if you have ever had chlorate metal stars go "supper critical" you certainly will have gotten a shock

 

Don't want to sound like a scratched record but adding boric acid to MgAl comps makes them more dangerous than without and also MgAl nitrate comps suffer from the Al nitrate reaction even more than just Al and nitrates

[frosty90]

Shimizus book has a table of friction/shock sensitivity tests showing that perchlorate is more sensitive with flake aluminium than chlorate is, and plenty are happy to use perchlorate with metal and think nothing of it. Chlorate and fine magnalium is very sensitive though, and brissant. Much worse than aluminium alone from what Ive seen.

 

While chlorate stars show some very desirable characteristics in ignitability, burn speed, hue, it´s also true that bright colors such as metal fuelled greens or reds are not possible when MgAl is eliminated in the formulas.

 

A really good easy metal fueled green/red that doesnt use chlorate or perc is:

 

60 Ba or Sr Nitrate

20 Magnalium/flake Al

20 Parlon

bind with acetone

 

Its very bright and the colour is very good. The only downside is they are a little fast when using magnalium.The magnalium version burns very very fierce, the flake al one less so, but if you use bright flake, it leaves a small yellowish spark trail. Magnesium works very nicely too, but bright flake Al is cheaper and works nearly as well!

Edited November 7, 2010 by frosty90

[ExplosiveCoek]

I made that formula wit flake Al to and it really sucks compared to other comps with MgAl in it. Also it's quite difficult to ignite to. Definitely not word trying IMHO.

[AdmiralDonSnider]

Thanks for the inputs so far.

 

The main reasons for me using chlorate colors are burn speed and ease of ignition.

 

One aesthetic requirement for round shells (which you can affirm or deny) is a relatively low break density, compared to e.g. canister shells which usually have very dense bursts. Perchlorate colors usually do burn a lot longer than their chlorate counterparts and thus the star size has to be reduced when perchlorate stars are used in round shells. This means that the star count becomes higher and makes a much denser burst than desired.

 

Ease of ignition is another advantage of chlorate stars. Perchlorate colors, especially the metal fuelled types, can be hard to ignite and require step-priming for best results.

 

Given one desires using e.g. Velines formulas with chlorate, what kind of formula adjustments do you propose?

[50AE]

Alkali metal and some alkali earth metal sulfates are ok to mix with chlorates, because the sulfur is completely oxidized. Copper sulfate should not though, it's hygroscopic, soluble copper salt and acidic in solution.

I have a favorite chlorate silver streamer comp, which I've modified to make it burn slower. I replaced the red gum with shellac, and removed the KNO3, added slightly more Al.

Edited November 7, 2010 by 50AE

[billofca]

I made that formula wit flake Al to and it really sucks compared to other comps with MgAl in it. Also it's quite difficult to ignite to. Definitely not word trying IMHO.

 

I would tend to agree with you on this. The aluminum oxide decomposes to wash out the color towards white. Pure magnesium is used to produce brilliant deep "electric" colors because there is no oxide to decompose. Can be made in this formula with out fear of spontaneous combustion because acetone is used for binding. (Don't use water = bad reaction and heating of magnesium to possible combustion). If water is ever used with magnesium, the magnesium must first be coated with a protective layer. In the "old" days, this was done by roasting magnesium powder in an iron pot with linseed oil. Now days it's done with potassium dichromate (see Shimuzu's book). Potassium dichromate is a very nasty chemical that can ulcerate your nose membranes, and is a carcinogen. Definitely not for the beginner.

[frosty90]

True the green isnt as good with al as it is with magnalium or magnesium, it is a little yellowish, but when you can't get an easy supply of every chemical/metal cheaply/readily, they are quite decent: http://www.youtube.com/watch?v=94UeUCzk0h8