PyroJoe Posted May 5, 2006 Posted May 5, 2006 I FINALLY succesfully rolled 2lbs worth of blue stars!! I tried rolling stars in a wok, then with my dads cement mixer and both times the stars became heavily spiked very early. This time I used my dad's cement mixer once again and went easy on the water. They are only cores at the moment, about 3/16" in diameter. I used the smallest lead shot, #8 or 9. They are very uniform in size too. Im going to let them dry over night then mix up more composition and roll them all to 1/4" and prime them. I should have around 3.5 pounds of blue stars ready for the 4th! Next I will probably roll a couple pounds of some red and green stars as well. Ohhh I can't wait for the 4th of july. Last year I didn't get anything made in time, so it was mostly consumer fireworks all night. Not this time though!
Douchermann Posted May 5, 2006 Posted May 5, 2006 Quarter inch is pretty small, but its good for 2-inch shells. A good ratio for star diamter is just 1/8 the diameter of the aerial shell. 2inch - 1/4" star (2 / 8 = 0.25)4inch - 1/2" star (4 / 8 = 0.5)8inch - 1" star16inch - 2" star and so on. The 16inch seems a little big though, the rest seem appropriate.
PyroJoe Posted May 5, 2006 Posted May 5, 2006 They will probably be 3/8" actually, im using them for a lot of 3" shells. They are smaller though because the blue comp I use burns quite slow in star form and they usually fall to the ground if they are bigger than that. Im just scared that my prime won't work when I do finish them, then I'll have wasted 3lbs of stars! Everybody in the aerial shell thread says that perchlorate primes ignite these stars fine, so I should be ok. I'm having flash backs of last year when I made a pound of cut stars that were useless due to crappy prime!
MNPyro Posted May 5, 2006 Posted May 5, 2006 Why not make a very small "batch" of prime, and test a few stars from a star gun? That way, not only can you tell the performance of the stars, but can test to make sure the prime works. And if not, then you didn't waste all of the stars.
PyroJoe Posted May 5, 2006 Posted May 5, 2006 I just rolled another 800 grams of powder onto the cores. I didn't realize once the stars start to get bigger they easily consume mass amounts of powder! Each core is probably just under 1/4". It sucks because I have ran out of red gum for my blue that I was using! I took a handful of the cores and rolled some prime onto them, they are drying right now, so I can see how well the prime works. Now im going to probably seperate the stars and start rolling some red on one half and maybe some tigertail on the other half to get them to the size I want.
al93535 Posted May 6, 2006 Posted May 6, 2006 Quarter inch is pretty small, but its good for 2-inch shells. A good ratio for star diamter is just 1/8 the diameter of the aerial shell. 2inch - 1/4" star (2 / 8 = 0.25)4inch - 1/2" star (4 / 8 = 0.5)8inch - 1" star16inch - 2" star and so on. The 16inch seems a little big though, the rest seem appropriate.1/4" stars for a 2" shell seem about right. But for a 4" shell a 1/2" star seems a bit large to me. I use 1/2" color stars in my 6" shells. A 1/2" charcoal streamer may be good for a 4" but you won't be able to fit as many and it will make the break look a bit empty. Here is a table which gives good starting sizes:Cut Star Size vs Shell Size Shell Size ----------- Cut Color Stars ----------- Cut Tailed 3" ----------- 1/4" or smaller ---------- 1/4" - 3/8" 4" ---------- 1/4" - 3/8" ---------- 3/8" - 1/2" 5" ---------- 3/8" - 1/2" ---------- 1/2" - 5/8" 6" --------- 3/8" - 1/2" ---------- 1/2" - 5/8" or 3/4" 8" ---------- 1/2" or larger --------- 5/8" or larger
Douchermann Posted May 6, 2006 Posted May 6, 2006 The ammount of extra space for lift charge if you use a 3/8" star as opposed to a 1/2" star is only ~4.1529cubic centimeters. So imagine a graduated cylinder filed up to the 4ml mark with break charge. Not that much of a difference really. I guess its your opinion though, I'm not going to tell you to use 1/2" stars now. I've found that every perchlorate prime I have tried needs an additional couple layers of green mix on it to ignite the prime. I know this is slightly off topic, but how hot does the average blackpowder burn?
al93535 Posted May 6, 2006 Posted May 6, 2006 Davis states: One gram of the 'Powder in the state in which it was normally used, that is, while containing 1.058 per cent of moisture, produced 718.1 calories and 271.3 cc. of permanent gas measured at O' and 760 mm. One gram of the completely desiccated powder gave 725.7 calories and 274.2 cc. These results indicate by calculation that the explosion of the powder produces a temperature of about 3880. I agree that a perclorate primes benefits from a green mix prime. I always use a BP prime 50/50 green mix/milled BP over my perc primes. And by an empty break I mean a lower number of burning stars. A 4" shell with 150 smaller stars looks fuller then a 4" shell with 100 bigger stars.
Douchermann Posted May 7, 2006 Posted May 7, 2006 And by an empty break I mean a lower number of burning stars. A 4" shell with 150 smaller stars looks fuller then a 4" shell with 100 bigger stars. Ah okay, then yes I'll agree with that. Thanks for the info on the blackpowder.
justanotherpyro Posted May 14, 2006 Posted May 14, 2006 I roll stars via the wok method and I was curious if there are any techniques that will help keep the composition build up in the wok to a minimum. When I roll stars I have to scrape a lot off of the wok and then press them. It would be nice to eliminate this extra step or at least minimize it. I just tried a batch of red and it rolled like shit. It spiked really bad. I think I may give up on the wok method and build a star roller.
FrankRizzo Posted May 15, 2006 Posted May 15, 2006 I roll stars via the wok method and I was curious if there are any techniques that will help keep the composition build up in the wok to a minimum. When I roll stars I have to scrape a lot off of the wok and then press them. It would be nice to eliminate this extra step or at least minimize it. I just tried a batch of red and it rolled like shit. It spiked really bad. I think I may give up on the wok method and build a star roller. For small amounts of stars, it's better to take the stars out of the roller and apply the solvent when they're in a stainless mesh kitchen sieve, tossing 'em around as you spritz to give them an even coating. Dump some comp into the roller and then dump the damp stars back in on top of it. Wetting them outside the roller ensures that the overspray doesn't end up on the star roller (wok, etc.) and collect patches of comp.
justanotherpyro Posted June 13, 2006 Posted June 13, 2006 After much duress and a little bit of a hint from the old APC forum I figured out what I was doing wrong, and hopefully it can save someone else the heartache. The stars I was rolling ( Al's red star comp ) needed to be wet to the point of looking like rabbit crap. Also, the sprayer makes all the difference in the world in its ability to get them wet. Don't wet all at once, go slowly to keep them from clumping and get them to the rabbit crap stage. My sprayer is a regular squirt bottle that shoots more of a stream. It would really wet a few stars but they get all of the other ones wet. What causes spiking in general is that the stars are getting wet unevenly. Fixing this isn't achieved by a lot of spraying then adding a bunch of comp. Making sure they are all the exact same wetness prevents spiking. Hopefully this helps someone.
FrankRizzo Posted June 13, 2006 Posted June 13, 2006 Right. Some other factors do come into play when dealing with spiking problems (charcoal mesh, shrinking comps, etc.), but uniform wetting will help your stars build at roughly even rates as well. Spray bottles that only shoot a stream are not useful for rolling stars. You want a sprayer that will spray a fine mist in a fairly uniform pattern. I've used nasal spray bottles with good success when just starting to build up the comp on the cores. You'll want to take out the tube in the nasal spray bottle so that it will dispense when squeezed upside down. The really small spray bottles that Wal-Mart sells in the travel-sized section of the cosmetics department also work very well.
justanotherpyro Posted June 13, 2006 Posted June 13, 2006 Using the fine mister was my main problem. The stars would start out very round but before they got to BB size they would start to spike. The fine mist would not equally coat them when they got much larger than the original lead shot, instead it would coat the roller with water and make the comp stick to the roller. My squirt type bottle works very well, for me at least. even at 1/4 inch size I never would completely pull the trigger, just barely even squeeze it. So I guess it is best to just experiment and find a squirt bottle that will get them all equally wet and continue to do so as the stars grow in size.
PyroJoe Posted June 15, 2006 Posted June 15, 2006 I just got done making a 100 gram batch of Mag green cut stars. Here is the formula I used: Bleser Mg #8Barium Nitrate 55Magnesium 18PVC 15Parlon 12 I used about a 60/40 acetone and alcohol mix to wet the stars and cut them. They have been drying for a day now. They seem dry, I can light them and they burn great (very beautiful bright green I might add) but they are very weak. I can easily smash them between my fingers. Does anybody have experience with binding stars with parlon and acetone? Should I use more acetone in my solution? Also, after my stars are dry wouold it be ok to add a meal/dextrin prime on the outside using water to coat them? I heard the parlon protects the magnesium from water once the stars are dry, but I just want to make sure.
Pyroman2 Posted June 15, 2006 Posted June 15, 2006 I do this stars with only PVC (I don't have parlon) and I use THF as binder and I also cut them. They are very hard and I can't crash them on the hands...I prime them BP with 5 dextrin (25% alc. as solvent) , because PVC protect Mg and they are good.( I use 60/20/20g ratio ) Regards
PyroJoe Posted June 16, 2006 Posted June 16, 2006 Where do you get your THF? I've been reading up and it doesn't seem to be available in hardware stores, unless it is in some type of PVC solvent. If I can't get THF maybe ill try some MEK mixed in with it or something.
Pyroman2 Posted June 16, 2006 Posted June 16, 2006 I buy it in chemical's store (Poland).. Some ethers can be good (you have to try.. ) I also hear about "PCV primer" (contain THF), this is use as solvent for pvc-glue etc(but unfortunately, also in Poland.. but I searched this and I can't get it). Maybe You should try use NC lacquer, I alternate them when I press flares on this comp (because mix with THF is gooey).sorry for my english
PyroJoe Posted June 19, 2006 Posted June 19, 2006 I just went to lowe's today and purchased some materials to begin my 4th of July arsenal I was looking at the PVC primers and it looked pretty expensive until I saw a big 32oz. can of it for $8. It contains Acetone, THF, Mek, and one other chemical. I just tried some more green stars with the PVC primer and I can already tell that the stars are going to be rock hard! I could tell the new solvent melted both the parlon and the PVC very easily. Thanks for the tip pyroman.
PyroJoe Posted June 27, 2006 Posted June 27, 2006 Ahhhhhh, I am VERY sad/mad at the moment. I just rolled a prime layer a couple days ago on my 2 lbs. of 1/4" rolled stars. Well, I used the perchrlorate prime, then a crappy 3 hour milled black powder on top of that. Usually I would use green mix that ignites much easier than crappy milled stuff. Well... my stars will not ignite now. The crappy layer of black powder will not take fire easily. Every star gun test I have done has failed. So, to try and correct this problem I added a green mix prime on top of the crappy BP to get it to ignite. Well now the green mix ignites and just burns around the star but does not ignite the star!!! So again, I put ANOTHER layer of green mix with 10% german dark aluminum. Same thing, the outside layer burns till it gets to the crappy BP powder layer and stops. Does anybody have any tips, or am I just in a hole now? What could I put on the outside of this star to get it to ignite??? I primed about 100 of these stars earlier with the perc. prime, then green mix and they took fire fine. Now that ive put a 3 layers of different primes on the outside, im not sure if I'll be able to recover the stars! I am so mad because this will screw up about 15 3" shells I had planned for the 4th.
ADP9 Posted June 30, 2006 Posted June 30, 2006 On the topic of star rollers, I've used the wok method but it tends to be tedious and tiring to say the least. Does anyone have an opinion on where I should start for the construction of a star roller? I've read about the Nasker roller but don't know much about it. Comparisons would be great. I would also be interested in what works best for you guys.
psymon Posted June 30, 2006 Posted June 30, 2006 I would try getting a very small drill and drilling a hole through each of the stars. Then use my hottest and best prime and coat the stars again. The hole should take the fire inside the star and if the star is any good, it should ignite. Try that or you could drill the hole and then put a bit of visco inside the star. Its worth trying. I had a batch like this and ended up using it in fountain comps - then I thought of this idea. Its worth a try.
brainfever Posted June 30, 2006 Posted June 30, 2006 Remove all primes untill the crappy BP by burning it off (it never lights you said so it should be safe) and then you might want to try putting them in the ball mill without media to let them "rub off" the crappy BP ... Crappy BP should have rough edges so it should come of rather easy. Chech every minute or something. If this should fail or yourtest batch of stars did not survive the ballmill treatment, I can only suggest taking a sharp knife to them and scratch a good patch of the crappy BP of each star, and prime again with good prime. ADP9, making a star roller is pretty elementary ... try some search engines.When I make mine, I'll put at least 1 picture of it on my site
hst45 Posted June 30, 2006 Posted June 30, 2006 Perhaps you could roll the stars gently between two sheets of sandpaper. I'm thinking that one sheet on a flat surface face-up, then a few stars, then a sheet face down. Gently move the sandpaper back and forth to try to scratch off the crappy BP. I would definatly use gloves and try this outside with just a dozen or so stars just in case the friction causes ignition of the Mg.
PyroJoe Posted June 30, 2006 Posted June 30, 2006 I ended up rolling tiger tail on the outside of the stars. I rolled a nice thick layer so they change from tiger tail to blue rather fast, but now they light just fine! On top of the tigertail I added a fast meal prime. It's such a relief! If anyone has problems like I did just roll a heavy charcoal content composition on the outside! Thanks for all the sugestions anyway, I was starting to consider the sand paper idea.
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