Arthur Posted January 2, 2010 Posted January 2, 2010 I'm planning to make a nice falling willow as a finale to a show on 3rd April, so given the drying times for big stars I thought I'd ask some questions and invite comment! (in other words do my design for me!) OK the mortars stop at 6" so that is the limit (they are HDPE) 6" hemis Stars Tiger tail or D1 Glitter 3/4" pumped in two layers - more stars less break! Break BP on rice krispies Two timefuses (chinese time fuse) cut to 5 seconds in 1/4" tubes to the middle. No booster Lift 1/16th mass, FA The tubes are a metre long outside so will be a yard inside after plugging. Targetsa soft falling willow with good hang and glitter stopping just above ground level. Comments welcome
firetech Posted January 2, 2010 Posted January 2, 2010 Your shell should work fine without a booster. However you might want to roll your break in dry slow flash like 2/1/1. You'll end up with a bigger spread.
dagabu Posted January 2, 2010 Posted January 2, 2010 I'm planning to make a nice falling willow as a finale to a show on 3rd April, so given the drying times for big stars I thought I'd ask some questions and invite comment! (in other words do my design for me!) You are much smarter then I am! The D1 glitter is a quick dryer compared to TT and Willow. One word of caution on true willow, it takes months yo dry and still some (there must be a dozen guys so far) pyros still have never made a single batch that work as advertised. I abandoned the willow quest this fall and went with TT. They were fine but didn't have the incredible hang time of the willow. I would make up some batches with various amounts of oxidizer (more rather then less) in them and find the point where they light and stay lit all the way down. These cant be tested on the ground, they need a lot of air to burn effectively. If you do get a good willow star please share with the rest of us. D
Miech Posted January 2, 2010 Posted January 2, 2010 For a longer burning time you can pump your stars, and wrap them in a layer of paper with wheat paste, leaving the top and bottom exposed. For an even longer burning time, also cover one of the exposed sides.
Arthur Posted January 2, 2010 Author Posted January 2, 2010 The secret of good dry big stars is to make them six or more months in advance! Or keep thm in a warm dry place for a few months. The only way of getting a large star quickly is to use a catalysed resin as both binder and fuel.
Arthur Posted January 2, 2010 Author Posted January 2, 2010 Would it be possible to add flitter to Tiger Tail, only say 1%, or would it need coating?
dagabu Posted January 2, 2010 Posted January 2, 2010 Would it be possible to add flitter to Tiger Tail, only say 1%, or would it need coating? I assume you mean Al? No, most of the time it is shown that it is the hot Aluminum's that react and of those, you can spread them out if the reaction starts to cool them down. If you press or pump comets, just keep in mind what the signs are and don't dry them inside where they can start a bigger fire. You will see almost all reactions complete around 4 hours so if you make it that far you are generally in the clear. The secret is the water. Don't use tap water or WalMart distilled, go by a gallon of a brand name, for whatever reason, distilled water keeps reactions down in all comps. Mumbles, why is that? The first sign is the ammonia smell, heat is the second, smoke the third, fire the last. I have made D1 using all different Aluminum's and found 5413 super to react but the finest tin man flake wont. I say go ahead and do a 100g batch and see what you think. The winter is great for making these, the Al cant get a reaction going even with the hottest Al due to the -20° F temps we get at night. D
Bonny Posted January 3, 2010 Posted January 3, 2010 I've never had any issues with D1 stars using tap water (in up to 30C temps)...maybe mine is pretty pure? To add to the hangtime, maybe try a TT with a portion of the charcoal added after milling. Try a coarser maybe 40-80 mesh.You couls also use Slow Gold as it creates a very long hanging effect.
Mumbles Posted January 3, 2010 Posted January 3, 2010 Your post actually got me thinking before you asked about it. I really have no idea why they only react within the first few hours, and not over the several week drying times. After, say 48 hours, all of the excess water may just be absorbed into the charcoal or molecules or what have you, and just not be out in the open where it can react with the aluminum.
dagabu Posted January 3, 2010 Posted January 3, 2010 Your post actually got me thinking before you asked about it. I really have no idea why they only react within the first few hours, and not over the several week drying times. After, say 48 hours, all of the excess water may just be absorbed into the charcoal or molecules or what have you, and just not be out in the open where it can react with the aluminum. I am not really sure either but if you have been following the thread on PF, you will see that my answer was based on both my experiences with fresh rolled D1 star cores and some others experiences. I just got 8 different aluminums from my supplier and I am going to try each of them with a D1 comp (I really like D1, so I'm a noob) and measure the reaction with my tap water and do a spread sheet on the results. I also have an ounce of very fine Ti powder held in water... What the heck do you do with that stuff? Isn't it dangerous? It was a gift or a curse, not sure which yet. D
pianomistro Posted January 3, 2010 Posted January 3, 2010 I am not really sure either but if you have been following the thread on PF, you will see that my answer was based on both my experiences with fresh rolled D1 star cores and some others experiences. I just got 8 different aluminums from my supplier and I am going to try each of them with a D1 comp (I really like D1, so I'm a noob) and measure the reaction with my tap water and do a spread sheet on the results. I also have an ounce of very fine Ti powder held in water... What the heck do you do with that stuff? Isn't it dangerous? It was a gift or a curse, not sure which yet. D Liking D1 doesn't make you a noob... at least I don't think so. I love the comp personally. The only thing I think about using D1 as a willow effect is the burn speed of it. I'm not sure that 3/4" pumped stars will burn the 700 feet that they need to to reach the ground. I made a willow comp with lampblack a few years back, and made a 4" shell with 1" stars. This comp burnt MUCH slower than D1, and they just barely made it to the ground from 450 feet. I think you would be better off with 1" stars, if not 1-1/4". Someone said earlier that wrapping them and possibly sealing one end may increase the burn time, and I would do that on a 1" star, and you just may get the results you're looking for. Star gunning them wouldn't even give you a good estimate, unless of course you shoot them off a cliff. For 700 feet, you're probably looking for about a 10-11 second burn time.
Arthur Posted January 3, 2010 Author Posted January 3, 2010 I am not really sure either but if you have been following the thread on PF,.. snip.............D PF is............?
Ventsi Posted January 3, 2010 Posted January 3, 2010 I also have an ounce of very fine Ti powder held in water... What the heck do you do with that stuff? Isn't it dangerous? It was a gift or a curse, not sure which yet. D Ouch! I've got myself a pound of the stuff on accident! -325 sponge right?All I've used mine for is rolled shots flash and a prime that I dipped a few hundred sparklers in because I was bored. I tried it in all kinds of slow charoal streamers, but all it does is burn up in a sizzling bright white head.
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