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PhoenixRising

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Looking at how fast you posted back I would say the acetone has barely had time to escape. Contrary to popular belief, not all of the acetone evaporates in a couple of hours. Most comps are usable in a couple hours, but do require a couple more days to fully cure. I learned this while making different crackle comps. (re-reading I see that you tried to light it before pressing, my apologies)

Also, these don't necessarily light readily. They more or less 'smolder' and flash, like a giant glob of glitter. Most comps will give you a "fair" idea of what they are when burned on the ground, but glitter and strobes especially need to be flying through the air. Shoot some from a stargun tonight! Any prime will work, BP with redgum/alcohol and maybe a pinch of mg/al should do fine.

Those might be a little bit big for strobe stars, be very careful if you decide to shoot them as they can very likely come down to the ground. I'm sure you know the drill. You may find that they burn so slow that you will have to cut them or screen slice. Strobes are one of the slowest burning comps out there.

Put up some video if you get a chance, we're all in this experiment together! No shame in failure.

Matter of fact I'll upload another fail comet for fun. :)

Edited by PhoenixRising
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For what it's worth, dichromate water might be incompatible with the strobe comp you posted. Incompatible in a being rendered useless, not in a dangerous way. Strontium and barium chromates are very insoluble in water, and will likely tie up the protective ions.

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I guess i forgot to mention this because that was what we were talking about . I used just enough water to make the comp stick together.

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I just noticed the stars smell like a women getting a permanent.

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Thanks for that bit of info about the dichromate, I did not think about that. Thankfully I already don't use the stuff!

 

Took me a minute to reply, was at the dentist this morning..... no appointment type visit... (ouch).

 

If one wanted to, would treating the mg/al with dichromate beforehand be possible? I still don't do that, but others may be interested.

 

Dyno, can you please show us a picture of the stars? Thanks buddy!

Edited by PhoenixRising
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Part of the advantage to dichromate coating is that some of it stays in the surface coating. This is how it retains some self-healing ability. Strontium and barium carbonate will basically suck this out. It shouldn't harm the passivization though. There are some anecdotal stories about this effect if you ask Mike Swisher. In my opinion, this shouldn't be a problem unless you're using ammonium perchlorate too.

 

Actually, if you really want my opinion, I wouldn't worry about a reaction between strontium or barium nitrate and MgAl. Dichromate doesn't hurt though.

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Thanks for the info, remember reading that there was a couple of exceptions to using dichromate but never quite remembered. Heck, you'd be hard pressed to find me even using boric acid. If I were doing larger batches of aluminum-heavy comps then I suppose it would be of some practical use.

 

Okay, well back to the drawing-board here..... it's 'prime-time'.. to figure out which primer to use. Something slow.... possibly containing the same oxidizer as the strobe itself? Also, noting the meshes used next time is in order.

Edited by PhoenixRising
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Dam i just primed them yesterday, but they were gray

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I have been told that MgAl doesn't pose a risk of reacting with water and therefor doesn't need coating of Dichromate.
That has always been my approach to wetting MgAl-comps, and I have never had reason to suspect otherwise :) That being said, I haven't tried this particular glitter yet, though.

Edited by Ubehage
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I tested one while ago and i am going to have to change my prime. There kinda hard to light.

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I have been told that MgAl doesn't pose a risk of reacting with water and therefor doesn't need coating of Dichromate.

That has always been my approach to wetting MgAl-comps, and I have never had reason to suspect otherwise :) That being said, I haven't tried this particular glitter yet, though.

 

Your source may have accidentally given you bad information.

 

I've had more than a few batches of Mg/Al comps have a reaction because they were too wet.

 

For what it's worth, it usually happens with charcoal heavy comps. I've had it happen with both Potassium and Sodium NItrate glitter comps.

 

Siimply decreasing the amount of water used remedied the problem. 10 percent moisture and below seems to be okay as long as no extra heat is applied during the drying process.

Edited by PhoenixRising
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Well at least the prime lit. I think i didnt have enough prime on it.

Edited by dynomike1
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I've only really had trouble when using a combination of nitrate, MgAl, and a strong base like sodium oxalate or occasionally sodium bicarbonate. This is exacerbated by heat. That might be a case to use dichromate wetting water, though limiting the water and avoiding forced heating can avoid some problems too. Generally if I'm using a sodium yellow I wont be using barium or strontium nitrate in conjunction. The one notable exception is the orange I like, independence tangerine. It has both strontium nitrate, sodium oxalate, and MgAl. This one definitely puffs up like a balloon if you try to force dry it. Strontium nitrate and sodium oxalate should be incompatible too, forming sodium nitrate and strontium oxalate, but I have yet to have any trouble with the star yet. Go figure.

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I had trouble getting the red nitrate strobe to light

Red glitter coming tonight

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3" shell ready to go.

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I guess my stars wasn't as dry as i thought. Only 4 of them lit, but they flashed.

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I did notice that the more they dried they started loosing color. The last time i checked they were pink. So the next night i built a star mine and they looked like C-6, so i guess water does have an effect on them.

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Considering your strobes never worked from the get-go, and you provided little to no information on construction, etc, it's hard to surmise your problem.

 

Taking a break from this for a little bit due to other projects getting in the way.

 

I've got more stuff to share but will wait until it can all be put together, as to be actually useful. ;)

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I have never heard of a KClO4 strobe composition. Can you provide some starting point for a formulation?

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  • 1 month later...

 

Your source may have accidentally given you bad information.

 

I've had more than a few batches of Mg/Al comps have a reaction because they were too wet.

 

For what it's worth, it usually happens with charcoal heavy comps. I've had it happen with both Potassium and Sodium NItrate glitter comps.

 

Siimply decreasing the amount of water used remedied the problem. 10 percent moisture and below seems to be okay as long as no extra heat is applied during the drying process.

 

I was told here that for glitters in general, you should never use more than 7% water. For some reason, too much water destroys glitter.

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You're absolutely right 'hage, in most cases anything more than 7 percent will cause a reaction.

 

However, if a comp has more than, say, 20 percent charcoal, it's sometimes okay to use a few extra percent of moisture. Still, you need to monitor it carefully by weighing it.

 

It is my opinion that all glitters have 'some' reaction while wet, but it's the matter of how long it stays wet that will determine how bad the reaction is.

 

Think of a patina on a carbon-steel knife. You can briefly expose the blade to water/salts and it will only stain the blade. Leave it wet and it rusts.

 

This is also why I condone (as well as others, but for different reasons I think) mixing the moisture in very well without the metals first, then add the metals after.

 

After I add the metals (Mg/Al or Aluminum) I will then "fluff" the mixture a lot, to get a lot of air into the mix, Mixing it and fluffing it for about a minute straight.

 

In my opinion the combination of air and moisture will help force a thin layer of patina on the metal, which helps protect it from further, worse, reaction.

 

In practice, controlling your moisture from the get-go is the best way to ensure success. My 'patina theory' may be a bunch of bologna, but it's what I do.

Edited by PhoenixRising
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