FlaMtnBkr Posted April 12, 2015 Posted April 12, 2015 What do you mean by burn violently? Is that the prime burning off? Can you see it glow red? Does it make flashes of light but no noise? Need more info and a video would help us pin point the problem.
j3cub Posted April 14, 2015 Posted April 14, 2015 Turns out that the -200 +325 mesh MgAl that I used was straight Mg. Fortunately it was only a 100g test batch as this was my first attempt. Made a new batch with the MgAl and they are working great.
stix Posted April 15, 2015 Author Posted April 15, 2015 Turns out that the -200 +325 mesh MgAl that I used was straight Mg. Fortunately it was only a 100g test batch as this was my first attempt. Made a new batch with the MgAl and they are working great. Good to hear that the original formula posted works. Any chance of a video? I might have a crack (pardon the pun) at making it this weekend Cheers.
Ubehage Posted April 16, 2015 Posted April 16, 2015 (edited) Good to hear that the original formula posted works. Any chance of a video? I might have a crack (pardon the pun) at making it this weekend Cheers.I made a batch of this as well, using 70mesh MgAl, and cut them into about 1 cubic-centimeter stars.When unprimed, they do pop loudly. But only about half the star; the rest of the star becomes a dud and flies away.But when primed, each star will give 2-3-4 loud pops each.(Note, that each pop will propell the star in a random direction. Stay away from flammable buildings) I'm having a blast with these (pun intended) Does anyone know if Titanium can be safely added to the mixture? And what would be better - sponges or powder? Edited April 16, 2015 by Ubehage
FlaMtnBkr Posted April 16, 2015 Posted April 16, 2015 10 mm cubes are way too big for these. I bet you are losing more unreacted comp than you think. Try making 3 mm cubes and see how you like them. You can add 5-10% additional titanium to add sparks. I don't think the type matters as long as it's the right size. Something in the 40-100 mesh range is about right. 1
Ubehage Posted April 17, 2015 Posted April 17, 2015 10 mm cubes are way too big for these. I bet you are losing more unreacted comp than you think. Try making 3 mm cubes and see how you like them. I just made a batch, and pushed it through a 4mm-screen. (That's the only screen I got, at this moment - besides kitchen sieves). I feel like these stars are popping much-much faster, almost instantly, and not nearly as loud as the bigger stars.They still give a few pops each, which to me seems like the reaction is exactly the same - just smaller scaled. Could this be poorly mixed, or is this what I should expect?
FlaMtnBkr Posted April 18, 2015 Posted April 18, 2015 If they are still popping a few times each I would say your MgAl is a bit too fine. If you can get some coarser metal and replace all or part of what you are currently using. You should be able to make 2.5mm eggs that will pop once and sound like a .22 or louder. Lighting good eggs at arms length will make your closest ear ring. A fast pop and multiple pops is a sign the metal is too fine. Any time I've made them like this and too big a corner pops off a couple times and most goes to waste. I've never tried making even bigger stars to see how they react but I imagine it would be similar. You can keep making them that way but I think you will be more happy if you invest in some different, more coarse metal. You will be able to make a lot more eggs with the same amount of comp and they will likely be louder. Or if you have a really fine sieve you can try to take out some of the fine stuff and set it aside. Just hate to see you not get many eggs since bismuth is so expensive when you should get many thousands from a lb of bismuth. 2
Ubehage Posted April 18, 2015 Posted April 18, 2015 If they are still popping a few times each I would say your MgAl is a bit too fine. If you can get some coarser metal and replace all or part of what you are currently using. You should be able to make 2.5mm eggs that will pop once and sound like a .22 or louder. Lighting good eggs at arms length will make your closest ear ring. A fast pop and multiple pops is a sign the metal is too fine. Any time I've made them like this and too big a corner pops off a couple times and most goes to waste. I've never tried making even bigger stars to see how they react but I imagine it would be similar. You can keep making them that way but I think you will be more happy if you invest in some different, more coarse metal. You will be able to make a lot more eggs with the same amount of comp and they will likely be louder. Or if you have a really fine sieve you can try to take out some of the fine stuff and set it aside. Just hate to see you not get many eggs since bismuth is so expensive when you should get many thousands from a lb of bismuth.70mesh MgAl is the coarsest I can get.I can get both Mg and Al a bit more coarse. Will it be the same if I just mix these 2, or do they have to be one alloy? (I propably didn't use the right words there, but I hope you get my pointe )
FlaMtnBkr Posted April 18, 2015 Posted April 18, 2015 It has to be an alloy. What mesh are you using now?
Ubehage Posted April 18, 2015 Posted April 18, 2015 I'm using 70 mesh.70, 150 and 200 are the ones I can get. I'm in the EU, if you know any resellers.
Mumbles Posted April 19, 2015 Posted April 19, 2015 I've had similar problems to you Ubehage. One of the things I found was that the amount of NC lacquer is important. More is better. It seems each variety of NC is a little different. I suspect things will be different between single vs. double base powders, vs ping pong balls, vs. good NC lint, etc. With the 10% NC lacquer (in acetone) I had, I had to make the composition into sort of a soup and dry it out in order to get enough NC in the eggs for a proper crackle. It does seem that denser eggs tend to behave better too. 2
stix Posted April 21, 2015 Author Posted April 21, 2015 I finally got around to making some on the weekend - with reasonable results. I made various sizes ranging from around 1mm up to 4mm. I didn't use prime, just a jet lighter. Starting off with 1mm, these popped after about 1 sec with a reasonably loud crack. I moved up to the 2 - 3mm ones and they 'multiple popped' which I liked but not the effect I was after. The larger 4mm+ ones did the same multiple pops, sometimes leaving unburnt granules. Unfortunately I can't be exactly sure of the mesh of my MgAl. According to my supplier it's "mixed granularity" which in my limited experience doesn't seem right with what I'm looking at. It resembles portland cement, or course wheat flour. Possibly 200mesh? certainly no "mixed granularity" that I can see. I only made a 20gram mix and the comp itself was easy to make, so I don't believe that I screwed it up. My method was pretty much as mumbles posted above. I made a slurry of +10% (dry weight single base) with a generous amount of acetone - after about 1hr it was dissolved and smooth so I added the other pre-screened components. It took a further 1hr or so of mixing and leaving until it could be formed into a dough and cut. Much easier than making charcoal stars. Overall I'm reasonably happy with the results. They are still usable which is good. I'm impressed that such a small thing can give such a crack! This was the other formula that I might try: 75.0% bismuth trioxide10.0% black copper(II) oxide15.0% magnalium (-200 mesh) +5% Al+10% NCL Quite a big difference with that formula, although I'd be inclined to perhaps drop the Al?? Cheers.
FlaMtnBkr Posted April 21, 2015 Posted April 21, 2015 Did you add enough of the 10% NCL to make an almost soup? It's almost better to make a 25% mixture so you don't have to let so much acetone evaporate to get plenty of NC in the mix. Since they are working I don't think this is an issue, just curious. With multiple pops really the only thing you can do is use some coarser MgAl to get a single pop egg. If they smolder too long there are a couple things you can do to get them working. You can try a different formula and it might behave differently with your metal? I've never tried it but I wonder if a few percent of a carbonate might slow it down enough to get a single pop? Could be worth trying if MgAl is hard for you to get.
stix Posted April 22, 2015 Author Posted April 22, 2015 Did you add enough of the 10% NCL to make an almost soup? It's almost better to make a 25% mixture so you don't have to let so much acetone evaporate to get plenty of NC in the mix. Since they are working I don't think this is an issue, just curious. With multiple pops really the only thing you can do is use some coarser MgAl to get a single pop egg. If they smolder too long there are a couple things you can do to get them working. You can try a different formula and it might behave differently with your metal? I've never tried it but I wonder if a few percent of a carbonate might slow it down enough to get a single pop? Could be worth trying if MgAl is hard for you to get. Thanks FlaMtnBkr, There's an important thing to point out. In my original formula I referred to +10% Nitrocellulose Lacquer (NCL) - It should have read +10% Nitrocellulose (NC) - my error, but I don't think that was an issue for me because I did add exactly 10% Nitrocellulose. (I call it a lacquer when it's dissolved in acetone in the slurry state) I made a slurry from +10% (dry weight - single base smokeless powder) with a generous amount of acetone - after about 1hr it was dissolved and smooth so I added the other pre-screened components. That way, I was sure there was exactly +10% of NC - otherwise, how could you properly measure how much NC was there if you were measuring the NC as a "wet lacquer" - it would be depend on the consistency - or am I missing something? I don't have an issue with them smouldering too long - if anything too fast. The smaller eggs smoulder for around 1sec which works ok - the larger ones don't smoulder for much longer either, they just burst apart with multiple cracks - not too bad, but not right. I'll try the other formula I have and see how things go - then work it from there. Cheers.
stix Posted May 4, 2015 Author Posted May 4, 2015 (edited) Ok, so I've tried the other formula: 75% bismuth trioxide10% black copper(II) oxide15% magnalium +5% Al (200 mesh)+10% NCL Well, the new formula works much better for me. The old formula cracked like a big kids very loud cap gun, not bad - but this is different. I lit a small 1mm cube and almost shat myself!!! not the .22 rifle standard yet, but enough to make me decide not to light anymore, or bigger pieces until I can do it in some open spaces. I'm very satisfied with this and it's going to be a very usable DE formula for me. The only improvement I can see is maybe using Pb3O4 instead of Bi2O3 and adding Ti, if I can get some. I'm still a bit confused though - I have read and re-read various formulas and methods, and a few times it states adding the NCL by volume. Volume? how can you be accurate when the viscosity of the lacquer can vary and the dry ingredients could be tamped or loose? [EDIT] I still have to work on the priming - so I'm not really done yet. Anyway, thanks for everyone's input. Much appreciated. Cheers. Edited May 4, 2015 by stix
Ubehage Posted May 4, 2015 Posted May 4, 2015 Ok, so I've tried the other formula: 75% bismuth trioxide10% black copper(II) oxide15% magnalium +5% Al (200 mesh)+10% NCL Well, the new formula works much better for me. The old formula cracked like a big kids very loud cap gun, not bad - but this is different. I lit a small 1mm cube and almost shat myself!!! not the .22 rifle standard yet, but enough to make me decide not to light anymore, or bigger pieces until I can do it in some open spaces. I'm very satisfied with this and it's going to be a very usable DE formula for me. The only improvement I can see is maybe using Pb3O4 instead of Bi2O3 and adding Ti, if I can get some. I'm still a bit confused though - I have read and re-read various formulas and methods, and a few times it states adding the NCL by volume. Volume? how can you be accurate when the viscosity of the lacquer can vary and the dry ingredients could be tamped or loose? [EDIT] I still have to work on the priming - so I'm not really done yet. Anyway, thanks for everyone's input. Much appreciated. Cheers.I might try this. I have some red Lead, that I don't think I will use for much else. The added NCL is actually just NC.+10% NC, means that you take 10% (by weight) NC, and make it into a lacquer. Then use that.
FlaMtnBkr Posted May 6, 2015 Posted May 6, 2015 I think volume is usually called out because as long as there is enough NC they work well so you just have to get enough in. Most people have a mixed up container of NCL and it's usually around 10% so enough volume is called for to get enough in. Most people don't take the necessary amount of NC and then make lacquer to add to one batch which would be the best way to get the exact right amount in. Just an assumption as to why it's done that way.
stix Posted May 6, 2015 Author Posted May 6, 2015 . . . The added NCL is actually just NC.+10% NC, means that you take 10% (by weight) NC, and make it into a lacquer. Then use that. Thanks Ube's - yes I know! and that's exactly how I do it. I think I mentioned it in posts #38 and #40. Anyway, I couldn't help myself so the next day I lit another small piece - even smaller than the last one (less than 1mm cubed I think?) this time, I saw it 'smoulder' for a second, and then BANG!! a bigger bang the previous test. I guess that the acetone had not completely evaporated when I did the first test. I'll have to try the 2mm+ eggs in a proper environment (open spaces) - looking forward to it. Then I'll try them in a pumped matrix star/comet with a glitter formula using my star gun to begin with. Cheers. 1
stix Posted May 6, 2015 Author Posted May 6, 2015 I think volume is usually called out because as long as there is enough NC they work well so you just have to get enough in. Most people have a mixed up container of NCL and it's usually around 10% so enough volume is called for to get enough in. Most people don't take the necessary amount of NC and then make lacquer to add to one batch which would be the best way to get the exact right amount in. Just an assumption as to why it's done that way. Fair enough, thanks. But like I said, if the dry ingredients are tamped or loose and the slurry is different, then how can you be consistent? Perhaps the method of making DE's isn't as critical as has been suggested - perhaps the important point is to keep your method the same and then adjust accordingly and check for the 'smouldering' stage. I'm happy to stick with the weight method, seems a bit more precise and you know where you are at. For me it's working well at the moment, but I haven't dared to light the bigger pieces yet - then I'll see (hear) if they sound BIG like a .22 or split off into smaller pieces. Cheers.
Rocketier Posted May 6, 2015 Posted May 6, 2015 (edited) I think that the disadvantage of premixing the NC with the composition is that you always end up with cut stars. If that's what you need fine offcoarse. I prefer the rolling methode I showed in previous posts. You will endup with nice round eggs easy to roll up into other creations. I spray in the NC with nosespray or hairspray evaporizers with enough solvent. At the end there will be enough NC in the eggs. The NC is the binder in the starcompo so if there is not enough the star will not pickup composition. So when you continu with spraying the sticky NC will pickup and your star will grow. It will be one loud bang on each star. Edited May 6, 2015 by Rocketier
Ubehage Posted May 6, 2015 Posted May 6, 2015 ... I think that the disadvantage of premixing the NC with the composition is that you always end up with cut stars. ...Actually, I found that pushing it through a coarse screen, is much easier and more consistent than cutting the stars.After priming, they all become nice round-ish; which has so far been good enough for me. I also tried priming a batch 'till they became all round. They work perfectly, but some BP is "wasted" on thickening the surface.
FlaMtnBkr Posted May 7, 2015 Posted May 7, 2015 Ubehage- does the screen slicing leave the screen really dirty? Will it be destined to be a DE slicing screen or can it be cleaned up? After slicing, have you tried taking the pieces and roll them in circles on a hard surface to try and make them round as well as compact them a bit? I have only cut them so far which is a bit of a pain but makes nice eggs. I think I know how a company makes them, but it takes a machine that would cost a couple hundred dollars and I'm not positive. I know they made 5# batches in about 15 minutes. But I don't need 5# batches and have no idea if it will work with smaller? I would be curious to see if other types of microstars could be made? If it did that would be more incentive to build the machine.
Ubehage Posted May 7, 2015 Posted May 7, 2015 Ubehage- does the screen slicing leave the screen really dirty? Will it be destined to be a DE slicing screen or can it be cleaned up? After slicing, have you tried taking the pieces and roll them in circles on a hard surface to try and make them round as well as compact them a bit? The screen is quite easy to clean.I let it dry completely, then brush it with a steel-brush. All the composition and lacquer just breaks off very easy. No, I haven't tried modifying the shape of them yet.
Rocketier Posted May 7, 2015 Posted May 7, 2015 (edited) I have seen that methode on one of Ned Gorski's video's. I made use of this method a couple of years ago. But end up with microstars sometime pop more than one time. Fun Though but I prefer the nice round ones. My rolling method.I think when you produce them with the screen method it might be possible to put them in the starroller respray them with pure aceton to get them round. Edited May 7, 2015 by Rocketier 1
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