Some chlorate stars are hard to ignite.

[50AE]

Just to let you know, this NYE I had the chance to discover that some meal primed clorate stars are hard to ignite. So generalising chlorate comps as easy ignited is sometimes wrong.

 

The stars were 100% chlorate based as oxidizer, and they had:

 

1st comp:

-CaCO3 18%

-Shellac - about 6%

 

 

2nd comp

-SrCO3 18%

-Shellac - about 7%

 

So it seems shellac is harder to ignite than red gum, even when finelly ground, and the carbonates also play a goal in this. I just want to post this useful info, to prevent failure of other people.

[frosty90]

Yeah true. Redgum always seems to make chlroate easier to light. I tried a silver streamer of 50/50 chlorate and flake al, but nothing would light it. You could hold a torch on the star (pumped, so that probably contributed) for upto 10 seconds and it wouldnt light. Then I tried 50 chlorate 45 Al 5 redgum and it ignites very easily from just meal prime.

 

But shellac sub. 1 to 1 for red gum seems to give a better colour, and brighter flame. With an organic green comp say, it seems almost a requriement to use shellac rather than red gum: the difference is quite surprising!

[50AE]

Yes, it truly does seem to give a better color. There is no red gum supplier in my country, so I'm forced to use shellac anyway

[AdmiralDonSnider]

Barium chlorate stars are harder to ignite than potassium chlorate based ones, or ones using both oxidizers.

 

I found that similar appearing mixes can be quite different to light, e.g. a blue CuO based chlorate star vs. one based on CuOCl (I guess something else than the color producing agent made the difference). The former lit easily when unprimed while the latter did blow blind in similar shells.

[Bonny]

Just to let you know, this NYE I had the chance to discover that some meal primed clorate stars are hard to ignite. So generalising chlorate comps as easy ignited is sometimes wrong.

 

The stars were 100% chlorate based as oxidizer, and they had:

 

1st comp:

-CaCO3 18%

-Shellac - about 6%

 

 

2nd comp

-SrCO3 18%

-Shellac - about 7%

 

So it seems shellac is harder to ignite than red gum, even when finelly ground, and the carbonates also play a goal in this. I just want to post this useful info, to prevent failure of other people.

 

Maybe you should try dissolving the shellac in solvent before adding to the comp. Also, not sure if you do this, but freezing the shellac before grinding really helps it break up easier.

 

I made the following formula few times years ago, and did not have problems with ignition, even with no prime. The main issue was that the (overwetted) comp took weeks to dry.

 

Red star #3

Source:

Comments:

Preparation: Dissolve shellac in boiling ethanol, and add the other ingredients.

 

Potassium chlorate................................65

Strontium carbonate...............................15

Shellac...........................................20

[frosty90]

I found that similar appearing mixes can be quite different to light, e.g. a blue CuO based chlorate star vs. one based on CuOCl (I guess something else than the color producing agent made the difference). The former lit easily when unprimed while the latter did blow blind in similar shells.

 

Aha! There does seem to be something wierd about copper chloride or copper oxychloride! I have heard others mention this and I have experienced it myself several times:

 

Compo. with chlorate and copper chloride/oxychloride sometimes seems to burn with out a flame! You can sometimes light a star say on the ground, and it will ignite and burn away, but with no flame and leave alot of residue. Sometimes the blue flame will flick on and off. OIther times it will burn properly. Others, the star smoulders and glows red as it burns, but with no flame! Different stars from the same batch will behave differently. Good priming seems to stop the effect. I have had it happen in copper oxychloride blues, and I have heard others mention it in copper chloride blues. It is almost as if the star were still damp (even though it is dry, you can see the same effect with dry compo pressed into a tube like a lance.). I reckon thats what may have happend to your unprimed stars!