Using Sodium Bicarbonate in Glitter comp

[Sparx88]

I'm out on a limb on this...is the purpose of Sodium Bicarbonate in glitter formulas to react and foam when water is added to the mix and create litle air bubbles in the star so the star can go to pieces while burning and create the glitter effect?

[nwpyro]

No, I am pretty sure it's primarily to slow down the stars burn so that it lasts longer and can form larger molten droplets.

 

With higher bicarbonate you can make smaller stars that last longer, but are not as brilliant.

[Niladmirari]

create litle air bubbles

For this need (NH4)2CO3

 

Function NaHCO3 - create slag (delay burning) and gold color.

[Sparx88]

Ok, so thats whats happening now so I suppose they are working ok. I just noticed that if I even overwet the comp a little it will kinda proof up like making pizza dough. I hate not having a video camera again.

[Mumbles]

If they're actually poofing up, it means they're reacting. This is something you want to avoid. The nitrate degrades the aluminum in basic environments producing either ammonia or H2S. I do however notice that my overwet stars get more rounded because they don't cut quite as cleanly. This is fine.

[nwpyro]

Mumbles, is there a way to completely prevent the nitrate from degrading the aluminum by using a stronger acid than Boric Acid? Maybe adding a small amount sulfuric acid to the water your wetting the comp with? Like 2-5% would lower the PH significantly, and not leave much sulfuric acid in the comp once dry.

 

However, these stars would have to stay a mile away from chlorate... Ha! Maybe HCL would be a better idea as it can completely evaporate.

Edited May 26, 2014 by nwpyro

[schroedinger]

No, you can't use a strong acid as they can attack aluminium in strong acidic enviroment

[Mumbles]

They'll also react with oxalates or carbonates present in your composition.

 

Boric acid is kind of a weird acid, but actually perfect for our uses. It doesn't produce H+ like most acids. It instead absorbs OH-, which has the effect of lowering the pH.

[Sparx88]

Ok, sounds like I need to add a little bit more boric until I get the reaction to stop. I'm using these little 2 oz bottles and don't have anything to measure ml. Should be close to 2% now.

[psyco_1322]

Usually just adding 1% of the powder to the comp is sufficient to stop anything. Are you sure you grabbed the baking soda, not the baking powder?

[Sparx88]

It's baking soda, arm and hammer ofcourse. It may be I was'nt even at 1% because I was guessing by just a little sprinkle and shaking to mix. I was adding it to the water and then use the water to wet the mix. I figured to little is better than too much because you can always add but you can't take away. Or something like that anyway

Edited May 27, 2014 by Sparx88

[spitfire]

The purpose of Sodium Bicarbonate in glitters is to act as a phlegmatising agent. To slow 2nd (spritzel) reactions down. If your wet star comp creates bubbles, something is going terribly wrong. Dangerous at least.