braddsn Posted January 3, 2015 Posted January 3, 2015 Hey guys...I have a question about priming stars. I use a step prime method using KP hot prime first, then a layer of BP+MgAl+Silicon over the top of it. None of my stars are chlorate stars. Do I need to let my stars dry before priming them? Or just prime them wet? And, since my prime is a 2 step system, should I also dry between the 2 prime steps or just put them both on wet? Thanks!! Also for what it's worth, I shot my first 6" shell on NYE, and unfortunately didn't film it. The shell was impressive, and the break was HUGE.. but one thing I noticed.. when it broke, I could distinctly see the prime burning first, then turned to purple (the stars were purple). There was a good solid 1 second of orange color from the prime, then they changed to purple, almost like a color changing star. I am not necessarily complaining, because all the stars lit. But, I tend to be picky.. and ideally, I would like the stars to start out purple. Am I priming too much? Thanks for any input.
Bobosan Posted January 3, 2015 Posted January 3, 2015 Sounds like the Mg/Al and silicon is what you are seeing. I have noticed the same when testing stars with this prime. Have you tried just the KP prime by itself? Also may want to look at the monocapa prime Jopetes has posted here.
enanthate Posted January 3, 2015 Posted January 3, 2015 How much prime do you use? If you watched it burn for a second, it's clearly too much..The BP + silicon might ignite the stars alone, have you tried that? If I understand correctly, steppriming can be done while the stars are wet. I tend to let my stars dry before priming, then add all primelayers in one job. I use about 1mm pinball prime (sometimes less), and 1mm BP+si.My ignitionrate sucks tho, so I probably shouldn't speak about priming. Had alot of blind stars falling on NYE. I fired a 6" as well, with N1 stars. Great success! The glitter hang for about 10 seconds.The 4" shells looks bigger actually, since the 6" went so darn high up. It really went way too high, and the break looked very small. Makes the 4" look huge in comparison.
mabuse00 Posted January 3, 2015 Posted January 3, 2015 Do I need to let my stars dry before priming them? Or just prime them wet? Depends. Personally i do mostly pumped stars, and because I can arrange them like bricks at the canister's walls, I prefer them to keep the shape at least a little. So I dry them first. For the sake of priming, one should rather prime them wet, also between the two prime layers. The idea is to have a transition between the layers as smooth as possible, without sudden jumps. So that the layers can mix with each other. Am I priming too much?Just try to use less If you do not like the prime to burn visibly, try to swap all MgAl for silicon, IMHO silicon does not produce any light.
dynomike1 Posted January 4, 2015 Posted January 4, 2015 You could go to fence post then bp+ silicon prime, i haven't had a problem yet with that. It's also like a dark relay. Note when doing a color change with green to red say as an example, use a relay in between or it will wash the green out. 1
dynomike1 Posted January 4, 2015 Posted January 4, 2015 Brad have you tried the red yet? I have made 2 batches and for some reason they are still crumbley.
braddsn Posted January 4, 2015 Author Posted January 4, 2015 Bobosan, you think like I do! I have been pondering the same thing... I am going to try a few batches of stars with just the KP hot prime and see what happens. I will let you know. Mike, the red I finally settled on is the following: KCl04 - 68, Strontium-13, Red Gum - 14, Dextrin - 5. It's a Skylighter formula. It gives me a good bright deep red, and I have had no problems with it. And they are easy to light. I will film one soon. I wish all colors were as easy as red.
dynomike1 Posted January 4, 2015 Posted January 4, 2015 Come to find out the red i am using are harder to dry for some reason. These are the first ones i have rolled this time of year.
GalFisk Posted January 4, 2015 Posted January 4, 2015 Are they strontium nitrate red? The nitrate can be hard to dry. Some say it's hygroscopic, others say that it is contamination by strontium chloride that makes it so.
braddsn Posted January 5, 2015 Author Posted January 5, 2015 Mike, I had a similar problem with a SN based star recently, tangerine color. They stayed wet for a few days. Even after being in the dehydrator for a few hours. It has something to do with the Nitrate I bet. You might want to consider a Strontium Carbonate based star. I will say however, that they eventually did try.. just took like a week with a fan on em. Strange.
TYRONEEZEKIEL Posted January 5, 2015 Posted January 5, 2015 I genuinely believe that all priming problems with very few exceptions can be solved with the monocapa prime. I struggled for a very long time with blind stars. I tried every prime under the sun. There were 2 factors that contributed to my almost immediate success. 1. Monocapa prime 2. Building a drying chamber A good dry star with just a layer or 2 of monocapa will light just about anything you throw at it. It's a very fierce prime that takes fire very well. You don't need a thick layer, so that solves your 'color changing' issue
dagabu Posted January 5, 2015 Posted January 5, 2015 I genuinely believe that all priming problems with very few exceptions can be solved with the monocapa prime. I struggled for a very long time with blind stars. I tried every prime under the sun. There were 2 factors that contributed to my almost immediate success. 1. Monocapa prime2. Building a drying chamber A good dry star with just a layer or 2 of monocapa will light just about anything you throw at it. It's a very fierce prime that takes fire very well. You don't need a thick layer, so that solves your 'color changing' issue Do you still top it off with a BP layer?
enanthate Posted January 5, 2015 Posted January 5, 2015 Will give that a try tyron, thanks. Been struggling with blind stars myself.Can I use red iron oxide instead of black?
dynomike1 Posted January 6, 2015 Posted January 6, 2015 They been drying in my shop for a month and didn't dry so i forced dried them, then they just crumbled. I wonder if by staying damp that long did something to the Dextrin?
Bobosan Posted January 6, 2015 Posted January 6, 2015 Will give that a try tyron, thanks. Been struggling with blind stars myself.Can I use red iron oxide instead of black? Yes. I've made monocapa with red iron oxide and it works the same.
TYRONEEZEKIEL Posted January 6, 2015 Posted January 6, 2015 Yes. Use any iron oxide except yellow. I imagine the water in yellow iron oxide would be detrimental. I use red myself worth no problems. You do not need a final BP prime. This prime is essentially BP prime cut with a flash/thermite hybrid. The outside of these stars are quite rough and really does the trick. I don't think I'll use any other prime.
JOPETES Posted January 6, 2015 Posted January 6, 2015 Never forget this: the monolayer always have to use charcoal lighter, willow, poplar, hemp, raft, etc .. and similarly if a final layer of black powder is used. Light charcoal greatly favors the lighting of the stars at high speed, ie for aerial shells that break with great force. to break the aerial shells at high speed with a 100% fiafilidad use on the star first monolayer thickness 0.5mm and a final layer of 1mm to 1.2mm. good luck to all.
JOPETES Posted January 6, 2015 Posted January 6, 2015 I mean the final layer of black powder from 1mm to 1.2mm. I apologize for not specified either.
enanthate Posted January 6, 2015 Posted January 6, 2015 (edited) Jopetes, that sounds like a great tip. I have allways beeb using pine C, and even the tiger tails arent very easy to ignite with a lighter.Fired 2 3" couple of weeks ago with TT stars and 2,5g SLOWflash booster, and they blew 100% blind. Couldnt believe it. Wonder if soft charcoal lets me use more flash as well? Edit: Is Vine good for primes? Edited January 6, 2015 by enanthate
FlaMtnBkr Posted January 7, 2015 Posted January 7, 2015 It sounds like he is suggesting hot/fast charcoal and my experience is vine isn't very hot charcoal. I've read most others agree with this though there is literature saying it's hot. So there may be some stuff, somewhere, that makes faster BP.
jessoman Posted January 7, 2015 Posted January 7, 2015 (edited) Well the italians all make their vine charcoal work. I'm lead to believe they tune the BP ratios a bit to suit. I'm glad JOPETES recommended to use a BP prime with the monocapa here. I learnt the hard way that it is required. I read everywhere that no BP layer was necessary, considering the reaction I found it hard to believe. Did some star gun tests and they worked without bp layer. Did a few shells, without layer- some blind stars. So I will ALWAYS throw a nice layer over the top of monocapa.Ignition issues all amended by bp over the top.Hard is it to just chuck some on anyway ? Edited January 7, 2015 by jessoman
Bobosan Posted January 8, 2015 Posted January 8, 2015 jesso,That was also my experience trying to ignite some parlon blue stars. The monocapa lit from the gun with light lift charge but blew blind when I really pushed them hard. Added the BP prime over the monocapa and they stayed lit.
Bobosan Posted January 21, 2015 Posted January 21, 2015 This thread has info on monocapa prime. http://www.amateurpyro.com/forums/topic/6544-formulas-priming-and-technical-pyrotechnics/
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