Mumbles Posted May 9, 2010 Posted May 9, 2010 There is a combination of things going on here. There is the` tetramine complex, which the more I think about it, the less I think it's valid. Only ammonia can for copper amine complexes, not ammonium ions (no lone pair with which to bind). Though there is defined hydrolysis reaction. The real issue comes from the use of soluble copper salts in combination with metals, treated or not. Copper solutions are quite corrosive to most metals, including magnesium, magnalium, and aluminum.
Cookieman Posted May 31, 2010 Author Posted May 31, 2010 The standard red twinkler formula using 70 mesh Mg. Hard to tell but I think it's around 4 Hz. Blinding!- Edit- added green with same mesh Mg, still wet with acetone though Here is a 1/2"x1/2" Yellow AP strobe that I just finished. What do you think these stars would look better in a starmine or aerial shell? Shimizu\'s yellow AP strobe star.avi
swervedriver Posted May 31, 2010 Posted May 31, 2010 (edited) Looks good cookieman, they'd look good in either a mine or shell. If they burn as fast as the reds I made, 1/2" might burn before falling to the ground in a 3 inch mine. These are eight 3/8" red stars in a 3/4" mortar. I'm having trouble getting them to light quickly enough. This ignition timing problem I'm having might not look to good in a shell- http://www.youtube.com/watch?v=LEUka2MairQ Edited May 31, 2010 by swervedriver
PyroMan LTU Posted May 31, 2010 Posted May 31, 2010 Some very nice strobes there guys! I have some mg an AP. But can I bind with NC and use uncoted mg? And I dont have sulphates, I thought I could make some with sulfuric acid and metal carbonates.. But is it safe to use this material knowing that it may have some acid remainings?
FREAKYDUTCHMEN Posted May 31, 2010 Posted May 31, 2010 Yes you can bind with solvent and NC lacquer, without coating the Mg. You can also bind with alcohol and resin, this way it is easier to roll.
Mumbles Posted May 31, 2010 Posted May 31, 2010 The reaction between sulfuric acid and the carbonates is reasonably slow, as neither the carbonates or sulfates are all that soluble. It can be done though, I'd just dilute the acid to prevent splattering. If you are really worried about any remaining acid, a few percent of the carbonate can be added to the composition. Even when binding with NC, I still prefer to coat the Mg. NC isn't as good of a seal against moisture as some think. It will be fine for a while, but long term storage could be an issue eventually.
swervedriver Posted May 31, 2010 Posted May 31, 2010 Yes you can bind with solvent and NC lacquer, without coating the Mg. You can also bind with alcohol and resin, this way it is easier to roll. Freakdeakydutchman, could you share what resin you are using with alcohol? Not red gum I'm guessing. Also, NC lacquer is enough to protect magnesium from ammonium perchlorate in your experience? Or do you mean nitrate based comps?
Cookieman Posted June 1, 2010 Author Posted June 1, 2010 Guys,need some help here. I did something really stupid and now I don't know what to do. I filled a 6"shell with strobe stars and used my meal coated hulls for burst. I already pasted the shell. Do I have a ticking time bomb here? should I take the shell apart or try to fire it and hope the stars ignite?
Mumbles Posted June 1, 2010 Posted June 1, 2010 Well, your stars (and possibly burst) are toast no matter what. I'd say fire anyway, preferably soon. As long as your stars are well primed, I think you'll be okay for a while.
Cookieman Posted June 1, 2010 Author Posted June 1, 2010 Well, your stars (and possibly burst) are toast no matter what. I'd say fire anyway, preferably soon. As long as your stars are well primed, I think you'll be okay for a while. The stars all well primed,but my next shoot is July 1st. Do you think it's to long? What will happen if the nitrate burst comes in contact with the AP?
Mumbles Posted June 1, 2010 Posted June 1, 2010 The bad thing that can happen is there is a double decomposition to form potassium perchlorate and ammonium nitrate. Ammonium nitrate sucks water in from the air like a sponge, and would turn your stars to mush. Even though there should be very minimal air in a pasted shell, weirder things have happened. The Ammonium nitrate can soak into the burst, and just make it also kind of a mess. I wouldn't be too worried, but you can take it apart if you think it will be a problem. If you do, leaving the stars out in the air for a few days will tell if they got contaminated. When I prime my AP stars, I add a NC bound layer of KP based prime, then a NC bound layer of BP to prime. Doing this I've never had any problems even with KNO3 based burst.
Ventsi Posted June 1, 2010 Posted June 1, 2010 (edited) Guys,need some help here. I did something really stupid and now I don't know what to do. I filled a 6"shell with strobe stars and used my meal coated hulls for burst. I already pasted the shell. Do I have a ticking time bomb here? should I take the shell apart or try to fire it and hope the stars ignite? Are you thinking about the nitrate switcharoo that goes on between AP and KNO3? If so, you're looking at a water balloon more than a bomb. You should be fine if you plan to fire the shell soon. I'd say put it in a bag of rice so no water can get in. The problem we face when the rxn between the two chemicals occurs is that we end up with KClO4 and NH4NO3, the latter being extremely hygroscopic and causing the stars to absorb water until they resemble a plump blueberry. So when you fire your shell, it might just fall back down, or blueberries might rain from the sky. Or it could be just fine... Edited June 1, 2010 by Ventsi
Cookieman Posted June 1, 2010 Author Posted June 1, 2010 OK thanks for your help guys, I think I'll wait it out until the 1st and hopefully it ignites the stars.
FREAKYDUTCHMEN Posted June 1, 2010 Posted June 1, 2010 Freakdeakydutchman, could you share what resin you are using with alcohol? Not red gum I'm guessing. Also, NC lacquer is enough to protect magnesium from ammonium perchlorate in your experience? Or do you mean nitrate based comps? Phenolic resin, it's used very often in the commercial manufacturing of stars. It's just a matter of keeping moisture away from the magnesium. It was told me by a pro, and it seems to work (of course).
Cookieman Posted June 1, 2010 Author Posted June 1, 2010 Phenolic resin, it's used very often in the commercial manufacturing of stars. It's just a matter of keeping moisture away from the magnesium. It was told me by a pro, and it seems to work (of course). Thanks for that one Freakydutchmen, I will try it next time. I really hate working with potassium dichromate.
Cookieman Posted June 2, 2010 Author Posted June 2, 2010 Phenolic resin, it's used very often in the commercial manufacturing of stars. It's just a matter of keeping moisture away from the magnesium. It was told me by a pro, and it seems to work (of course). Is this a good price for Phenolic resin?My link
FREAKYDUTCHMEN Posted June 3, 2010 Posted June 3, 2010 Looks like a good deal if it's pure resin. Mine is a little bit different, I have it in chunks.
swervedriver Posted June 3, 2010 Posted June 3, 2010 So, you dissolve a chunk in alcohol and spray, or grind to a powder and mix a percentage in the composition? It seems that powder is impossible to source on a small scale.
FREAKYDUTCHMEN Posted June 3, 2010 Posted June 3, 2010 You need powder, and pure alc in your spray bottle. Powder can be cleaned with just water (ballmill or coffee grinder), NO ALCOHOL!.The roller drum (wall) must be cleaned with pure alcohol.
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