Shimizu's Strobe Stars

[Cookieman]

Hi guys, I need some help with strobe stars. I want to make Shimizu's red, green, and orange strobe stars. His formula calls for 60 mesh Magnesium(treated with potassium Bichromate) and I can only get my hands on 200 mesh. My question is, if I use the 200 mesh,how will this effect the strobing? or is it to fine? Also, for orange can I substitute the Calcium Sulfate with Calcium Carbonate?

[Ralph]

using 200mesh magnesium will make it shimmer at best if not just a continuous burn you need the 60 as for the replacing the sulphate for the carbonates I dont see it working.

[Arthur]

Calcium will give the same flame colour, but sulphate can be an oxidiser which carbonate cannot. In one comp, the method included a caution that the frequency depended on the mesh size and it worked from 20 to 100 mesh (20 being slow and 100 faster) SO I'd guess that both substitutions could be a bad thing for you getting the comp to work as you hoped.

[Mumbles]

using 200mesh magnesium will make it shimmer at best if not just a continuous burn you need the 60 as for the replacing the sulphate for the carbonates I dont see it working.

 

Well, obviously someone has never made a strobe in his life.

 

With proper tuning, -200 or -325 MgAl can be made into decent strobes. Even 1-3 Hz strobes.

[Ralph]

Well, obviously someone has never made a strobe in his life.

 

With proper tuning, -200 or -325 MgAl can be made into decent strobes. Even 1-3 Hz strobes.

 

not an AP strobe but i have made plenty of Barium nitrate MgAl ones

[xetap]

for orange can I substitute the Calcium Sulfate with Calcium Carbonate?

You can try the white comp w/the added calcium carbonate, but I wouldn't expect miracles.

 

A sulfate/sulfur is a necessary ingredient in a strobe, in any event.

Edited April 9, 2010 by xetap

[swervedriver]

On a different note, treating 200 or 325 mesh and getting it back to 200 or 325 mesh size may be a challenge. It sure would be for me. I've treated -70+100 mesh Mg with K Dichromate and it is tough to get back to even 70 mesh size after drying. I've never tried smaller than 100 mesh though, I could be wrong.

 

edit- or is that +70-100? I always mix the +- up

Edited April 9, 2010 by swervedriver

[Cookieman]

Thanks alot for your help guys!!! If there is no substitute for Calcium Sulfate, I guess the orange strobes have to wait. My Supplier doesn't have any.

[Mumbles]

Do they not sell plaster in your neighborhood? Plaster is calcium carbonate.

[xetap]

Actually plaster of paris is calcium sulfate hemihydrate. Throw some in the oven to dry, and then use it.

 

Just don't grab ANY plaster- there are several types that do not contain pure calcium sulfate and are made w/lime, cement, etc.

Edited April 10, 2010 by xetap

[Cookieman]

Do they not sell plaster in your neighborhood? Plaster is calcium carbonate.

 

 

Yes they do,Lowes,Home Depot I guess. So all I have to do is buy some plaster of Paris and dry it in the oven to get Calcium Sulphate?

[Mumbles]

I was trying to think about the hydration thing. I don't know if it would be better to dehydrate it, leave it as is, or let it become fully hydrated. It's reaction with water is exothermic, and I wouldn't want to have any accidental ignitions or heating up. Then again, I wouldn't want any water around the metals either.

[xetap]

I've used plaster of paris after a cursory drying in the oven in "negative" comps w/no problems- though I don't store comps of any kind for any real length of time.

 

Where I believe there'd more likely be a problem is w/the dihydrate (gypsum), at least more so than w/the p of p- it having more water in it from the get go.

 

As far as drying p of p out to the anhydrous state- this makes a desiccant- which surely will absorb any atmospheric water, or water from a binder. As will p of p. Using a non-water binder like NC lacquer that's called for by Shimizu is the solution to this.

[swervedriver]

The standard red twinkler formula using 70 mesh Mg. Hard to tell but I think it's around 4 Hz. Blinding!-

 

http://www.youtube.com/watch?v=RcxSclzetSU

 

 

Edit- added green with same mesh Mg, still wet with acetone though

 

 

http://www.youtube.com/watch?v=rOSz_G-0CpQ

Edited April 24, 2010 by swervedriver

[Cookieman]

Nice strobe stars swervedriver. Just coated some mag. with Dichromate.Do you bind this comp. with N/C laquer? Also is BP meal a good prime for AP strobe comps.Also, are Shimizu's strobe comps. good for pressing in rocket motors. Sorry for all the questions,but I would like to have the knowledge before I start anything and waste good chems.

[Mumbles]

BP would not be a good prime. Ammonium Perchlorate and the nitrate in BP don't get along well, even if the star is bound with NC. You'll want to use some sort of barrier prime at least that is free from nitrates and chlorates. Apply that with NC lacquer too, and then you can put a dusting of meal over the top.

[Cookieman]

BP would not be a good prime. Ammonium Perchlorate and the nitrate in BP don't get along well, even if the star is bound with NC. You'll want to use some sort of barrier prime at least that is free from nitrates and chlorates. Apply that with NC lacquer too, and then you can put a dusting of meal over the top.

[Cookieman]

OK thanks, how does Shimizu's Ignition Comp. for twinklers work?

 

Potassium perchlorate 74%

Rosin(BL combustion agent)

or Accroides Resin 12

Hemp coal or paulownia coal 6

Aluminium(fine flake) 3

Potassium bichromate 5

 

[swervedriver]

OK thanks, how does Shimizu's Ignition Comp. for twinklers work?

 

 

I used that prime you listed above in a NC bound slurry then an NC bound BP on top of that. I haven't tried them in a shell, but here's what a star gun test looked like-

 

http://www.youtube.com/watch?v=u98fCyVFG2E

[dagabu]

Those were very pretty Swerve!

 

Can you post a short tutorial on making them?

 

D

[Cookieman]

I used that prime you listed above in a NC bound slurry then an NC bound BP on top of that. I haven't tried them in a shell, but here's what a star gun test looked like-

 

 

 

The strobing was beautifull!!! what size were those stars?

[swervedriver]

Yeah, those were small stars in the vid cookieman, 5mm cut cubes. They were sized for use as star cores in 3/8-1/2" rolled stars.

 

Dagabu, yeah they are neat heh. I just followed shimizu's recipe. The Mg was treated with the dichromate process. I milled the AP and K dichromate together for a few hours to a talc fine powder. The comp was screened together and bound with a 25% weight/part of 10% NC lacquer in a ziplock baggie, then cut into 3/16 and 3/8" stars. After drying for a day they went into the roller and got a heavy layer of the strobe igniter prime until fairly round. Then dried again and coated with a final layer of green mix bound with NC.

 

Probably the most time consuming stars I've ever made, at least they dry fast. I

 

 

Question- I've come across a blue strobe composition that was credited to shimizu that uses copper sulfate, but I understand copper and AP are not compatible?

[dagabu]

Uh, Mumbles? Help?

 

Sorry Swerve, chemistry is not my strength.

 

From Skylighter:

 

Ammonium Perchlorate Blues

 

According to Weingart and many other sources, ammonium perchlorate and common copper salts produce the best blue firework stars. This is because ammonium perchlorate has a lower melting point and burns cooler than chlorate and perchlorate. The safest copper to add to this kind of formulation is copper carbonate. Care should be taken not to add finely divided metals, [such as] magnesium or aluminum to such compositions. "Corrosion of aluminum powder is accelerated by the presence of copper or mercury." (Weingart 59). In addition, it is always best to use distilled water for such firework star compositions when adding water as the solvent. It should be noted that care should be taken when storing ammonium perchlorate firework stars. Moisture can cause decomposition.

[swervedriver]

Doh, nevermind, just a brain fart, lol. I must've been thinking of something else, chlorates maybe. I've made AP blue stars using both copper oxide and copper carbonate.

 

Anyway, the strobes are bright. I recommend giving them a try.

[Ralph]

Doh, nevermind, just a brain fart, lol. I must've been thinking of something else, chlorates maybe. I've made AP blue stars using both copper oxide and copper carbonate.

 

Anyway, the strobes are bright. I recommend giving them a try.

 

No I think you may have been right I think AP when mixed with copper (I think it needs to elemental copper or soluble compounds of it) can form copper tetramine complexes which are primaries