Brilliant core by Shimizu

Looking for a very bright and fastburning star, I found this one In The Art Science And techinque:

Barium Nitrate 66%
Al (fine fake) 27
Boric Acid 1
Soluble rice starch 6

I have looked through Shimizu?s and Lancaster?s books on boric acid and, this is probably stupid, but do I aply the acid to the Al like Potassium Dichromate? I would take my best guess and saying NO. The Boric acid kicks in when I dampen the comp. right?
OK. Is this formula tested by anyone? Is it likely to heat up --> is it "safe"? I put my trust to the Boric acid. And ceep to small mixtures.

And one more thing. The rice starch can be substituted using dextrine? I have done this before in other comps. and I don?t really see why this is unwise to do.

Reading further Shimizu says:
"The stars burn so quickly they move, as if they were swimming round by rocket action when the core is ignited in a unstable way."

I will test this comp to make some go getters. Not using tubes if possible. I just love when chemicals and compositions has multiple ways of usage!

Boric acid is best when dissolved into the water that will be used to dampen the comp, this allows for best distribution. I always weigh my solvent, so if you do the same you can add the necessary percentage of your boric acid to this and dump the whole mix straight into your mixed comp.

The rice starch can be substituted using dextrine?

Rice starch and dextrin are interchangeable. The way I take it, If you can get SGRS use it, as it has every advantage over dextrin; price and availability excluded.

Barium Nitrate 66%
Al (fine fake) 27
Boric Acid 1
Soluble rice starch 6

This comp is also known as a flash comp as It is supposed to burn fast.
If this self propelled effect is what you want, than these can be used straight as cores as it is the uneven ignition of the core that gives it its thrust.
This core also has a brilliant prime who's purpose is to itself flash over the core igniting all sides evenly making it flash rather than fly itself around.

Brilliant Core Coating Composition.
Kcl04 33
BaN03 34
Al(fine Flake) 10
Red Gum 8
Sb2s3 9
Boric acid 1
SGRS 5

I was so sure I was going to get a hold of some BaN03 I had everything all planned out and this was going to be my first project, so sad, tell me how she goes!

Marcus

Thanks a lot!

I will mainly use this star as briliant core, but I just love go getters!

SGRS is not available around here. But maby somewere I have not looked.

I will be sure to post a reply in the future. But Im not abel to make a shell untill summer . But some test stars will be made next week probably.

Thanks

The Boric acid is there because Al comps like this can start to react with alkaline byproducts, the Boric acid is there to stop this. Therefore it needs to be well distributed in the mix. Dicromate coatings put a protective film over the metal and in these cases the metal needs to be treated first and then dried.

OK thanks!

Dicromate coatings put a protective film over the metal and in these cases the metal needs to be treated first and then dried.

Interesting! I know Shimizu wrote about this but I must have missed this.

Looking for a very bright and fastburning star, I found this one In The Art Science And techinque:

Barium Nitrate 66%
Al (fine fake) 27
Boric Acid 1
Soluble rice starch 6

I have looked through Shimizu?s and Lancaster?s books on boric acid and, this is probably stupid, but do I aply the acid to the Al like Potassium Dichromate? I would take my best guess and saying NO. The Boric acid kicks in when I dampen the comp. right?
OK. Is this formula tested by anyone? Is it likely to heat up --> is it "safe"? I put my trust to the Boric acid. And ceep to small mixtures.

And one more thing. The rice starch can be substituted using dextrine? I have done this before in other comps. and I don?t really see why this is unwise to do.

Reading further Shimizu says:
"The stars burn so quickly they move, as if they were swimming round by rocket action when the core is ignited in a unstable way."

I will test this comp to make some go getters. Not using tubes if possible. I just love when chemicals and compositions has multiple ways of usage!

Hey there Ben,

The boric acid can be done either way, however gettting exactly 1 part / % into the comp, when mixing it with Water will be variable since you don't always know how much water it will take to dampen the comp. I'd be more concerned with the Barium as to the safety aspect, not nearly so of the PH of the comp. Use a minimum amount of water when dampening, and 33% Alcohol, to lessen the possible Nitrate/AL reaction. Nitrile Gloves (the Purple ones) are alot more impervious to chemicals in general, so try and use them when working with known water soluble (Skin) chemicals. I have found that Potassium Nitrate seems to be alot more reactive than Barium anyway, so I Usually don't even bother with it (Boric acid), but thats just me, your result's may vary, No Warranty expressed or implied, Etc. Etc.

Have fun,

Regards, Stay Green,

Bear

The boric acid can be done either way, however gettting exactly 1 part / % into the comp, when mixing it with Water will be variable since you don't always know how much water it will take to dampen the comp.

You use 1% of the comps weight, not amount of water you use to dampen the comp. Now if this % of Boric acid is added to the water and all the water is added to the comp how can this vary?

In general I have herd 8% solvent is good for glitters and anywhere up to 15% solvent for most all other comps. If you know how much comp you mixed (I don't know why you shouldn't) you take your desired percentage for the right comp, do the math and you should get the weight of solvent for your specific mix.

I may have missed something here but I have put some thought into it and am open to corrections.

Marcus

You could just weigh the wet comp and then add the boric acid

I havent even read this but 'weigh the wet comp' might aswell 'weigh the water'. Please find me correct.

I?m going to make something like 50g this first time and use small portions of it to test different things. And measureing the % of boric acid each t?me is not as easy and practical as haveing the acid in the comp from the start.

Thanks for the help!
I will have some results next week probably. Now I?m going to get rid of some old 2,7" HDPE mortars that I don?t use because of the unusual size. :-/

You could just weigh the wet comp and then add the boric acid

But the goal was to disolve the boric acid in the water.
Plus, if you do this you will end up with more than 1% boric acid because you are adding the weight of the water.

I got mixed up when I read this the first time.

gettting exactly 1 part / % into the comp, when mixing it with Water will be variable since you don't always know how much water it will take to dampen the comp

% of BA used doesn't have to do with the amount of water, It's a given percent of your COMPS weight. I mentioned weight of solvent beacuse I DO Know how much solvent I use when mixing. I only said this beacuse it makes it easier on me to be able to dump all my BA into my water and all my water into my comp.

And measureing the % of boric acid each t?me is not as easy and practical as haveing the acid in the comp from the start.

Im sure that works out just fine too. After I get stuck using a certain practice I don't put much second thought into it.

But the goal was to disolve the boric acid in the water.
Plus, if you do this you will end up with more than 1% boric acid because you are adding the weight of the water.

From previous posts I was under the impression you wanted to account for the water, I may have read it incorrectly. In that case, just add the Boric Acid to the dry mix and then add water.

Stuart

Remember that the water / solvent isn't actually a component of the formula, as it will evaporate. So you should'nt take into consideration the weight / volume etc of the solvent. You should of course follow any guidelines as to how much solvent is needed to manipulate the dry mix.

I cant find any info on how much water is needed in Shimizu?s book. Probably not very important. Not to much or to little.

Remember that the water / solvent isn't actually a component of the formula, as it will evaporate. So you should'nt take into consideration the weight / volume etc of the solvent. You should of course follow any guidelines as to how much solvent is needed to manipulate the dry mix.

That's what I am saying.

"Amount of BA used doesn't have anything to do with the amount of water, BA is a given percentage of your COMPS weight. I mentioned weight of solvent because I DO Know how much solvent I use when mixing. I only said this because it makes it easier on me to be able to dump all my BA into my water and all my water into my comp."

I cant find any info on how much water is needed in Shimizu?s book. Probably not very important. Not to much or to little.

Enough to activate your solvent.
Again 12-15% for water and alcohol bound stars has worked for me, It also depends whether the stars are being cut or pumped.
One exemption I can think of is glitter comps using flakeAL because to much will kill the glitter effect; I use 8%.