mabuse00 Posted September 10, 2010 Share Posted September 10, 2010 Hi, recently I tried Kyle Kepley's Emerald green and Hardts Green Star #5, as well as Conkling Blue #1. Just did some ground tests (vulcans) and found them pretty hard to light.Dextrin bound Blackpowder was not really satisfactory. I needed pretty thick, long burning layers to ensure ignition. I don't think i could handle it that way with real stars. What kind of prime do you recommend for these compositions, when used for cut stars?I prefer something that is sensitive enough to work without two-step-priming... Link to comment Share on other sites More sharing options...
Fred Posted September 10, 2010 Share Posted September 10, 2010 (edited) As a prime for stars like emerald green and ruby red you can use green mix with 5% dextrine and 5% up to 10% metal like silicon, magnalium or aluminum with good success. Edited September 10, 2010 by Fred Link to comment Share on other sites More sharing options...
jrin0630 Posted September 10, 2010 Share Posted September 10, 2010 I agree with Fred. I've have very good success priming Kepley's Emerald Green with a mixture that is 60% green mix. Just BP ingrediants screened together. Plus 30% fast BP plus 5% German Dark Al and 5% Dex. I put a thick layer (like 1/16") of this first and just a final dusting of straight BP. Works very well. Link to comment Share on other sites More sharing options...
mabuse00 Posted September 11, 2010 Author Share Posted September 11, 2010 Thank you, i'll try 5% dark 5µ aluminium. Can you also recommend sth. for the Hardt Silver Star 1? Hardt Silver Star #1Potassium chlorate 59Aluminium (bright) 26Red gum 7.5Dextrin 7.5 I want to use 100µ Alu for this composition, with is pretty inert.And it contains KClO3, BP contains sulphur. Link to comment Share on other sites More sharing options...
WSM Posted September 13, 2010 Share Posted September 13, 2010 What kind of prime do you recommend for these compositions, when used for cut stars?I prefer something that is sensitive enough to work without two-step-priming... Very hot, easy to ignite and layered thick. The materials to use should include a large amount of charcoal powder (10%-20%) and probably a metallic or metaloid component; let alone an excellent binder. Other than these, look through what you have on hand and experiment, experiment, experiment. WSM Link to comment Share on other sites More sharing options...
vh718 Posted September 14, 2010 Share Posted September 14, 2010 Hi, recently I tried Kyle Kepley's Emerald green and Hardts Green Star #5, as well as Conkling Blue #1. Just did some ground tests (vulcans) and found them pretty hard to light.Dextrin bound Blackpowder was not really satisfactory. I needed pretty thick, long burning layers to ensure ignition. I don't think i could handle it that way with real stars. What kind of prime do you recommend for these compositions, when used for cut stars?I prefer something that is sensitive enough to work without two-step-priming... i would use meal with 5% MgAl or silicon then just dust with green mix Link to comment Share on other sites More sharing options...
AdmiralDonSnider Posted September 14, 2010 Share Posted September 14, 2010 The primes you suggested for Ruby and Emerald are suitable, BUT: make sure you use a generous layer! Even 30% silicon won´t do the job when the layer is only 0,5mm - I tried that in a shell and it failed. Step-priming is much more reliable, but can be inconvenient with cut stars. Concerning the chlorate silver: I found that such comps burn frightingly fast. Use large stars. I personally don´t hesitate to use scratch mix/BP prime for chlorate stars; this is different from having sulphur and chlorate in one comp. But other people do. Link to comment Share on other sites More sharing options...
mabuse00 Posted September 17, 2010 Author Share Posted September 17, 2010 Hi, thanks for your advice. Did not tests yet. Concerning the real difficult cases:As i understand, 2-step-priming with veline superprime seems to be the best variant, but i want to evade it: I dont have potassium dichromate und i dont have proper woodmeal. I sure could produce some, but i don't have the equipment to filter out the right particle size. Searching the web brought this here: Name: Veline styleSource: PaxPotassium Perchlorate 62 Charcoal Airfloat 22 Magnalium, granular, -200 mesh 7 Dextrin 4 Aluminum, flake, dark, American dark. -325 mesh 3 Copper(II) Oxide, black 2 Ever tried that composition? Can it compete with the original Veline Superprime mix? Link to comment Share on other sites More sharing options...
Peret Posted September 18, 2010 Share Posted September 18, 2010 Ever tried that composition? Can it compete with the original Veline Superprime mix? Only by trying it can you answer that. My initial comment is a good prime should be a low gas mixture with a hot sticky residue and this doesn't look much like one. The Al/CuO component is a hot thermite, but not a slaggy one (Veline uses iron oxide). On the other hand, I haven't been entirely happy with Veline Superprime made to recipe. The prime never fails to burn and always lights perchlorate compositions, but it doesn't do a good job with barium nitrate stars (green or white) even when laid on thick. I got better results by replacing the magnalium with silicon, which also tames the initial bright white flare, but I'm still looking for a reliable prime for barium nitrate. For wood meal, try yellow corn meal. Link to comment Share on other sites More sharing options...
mabuse00 Posted September 19, 2010 Author Share Posted September 19, 2010 yellow corn meal Thank you for that hint. That stuff seems to be rather unusual in the german kitchen. Maybe I can get it in some heath food shop... Does anyone have experience with MDF Dust? What about the dichromate, i don't have any and I wont get it in the next time. What will happen if i leave it out? I guess a little oxydation of the magnalium will not hurt...? Link to comment Share on other sites More sharing options...
Peret Posted September 19, 2010 Share Posted September 19, 2010 Thank you for that hint. That stuff seems to be rather unusual in the german kitchen. Maybe I can get it in some heath food shop... Does anyone have experience with MDF Dust? What about the dichromate, i don't have any and I wont get it in the next time. What will happen if i leave it out? I guess a little oxydation of the magnalium will not hurt...? Cornmeal is a very common grocery item in America. It is hard and gritty with the consistency of sand and is often used to dust the bottom of pizza dough so that it doesn't stick to the oven bottom. It's not quite equivalent to wood meal because it softens when it gets wet, but you don't mix prime wet. I think the dichromate in Veline is used as a catalyst to make it ignite easier, not to protect the magnalium. As I don't suffer from chromophobia I've never tried making the prime without it, so I can't say how much difference it makes. Link to comment Share on other sites More sharing options...
mabuse00 Posted September 21, 2010 Author Share Posted September 21, 2010 Thank you. I'll try it when i find it. Link to comment Share on other sites More sharing options...
WSM Posted October 3, 2010 Share Posted October 3, 2010 I know a professional who had success using the same composition for burst and prime on the stars. This is a very attractive option. Also the suggestion to apply the prime thick can't be overstated. High charcoal percentages (~20%) help the fast moving stars hold a spark till they slow down enough to ignite. A rough surface on the stars increase the surface area available to be ignited, too (this it why some people add wood flour or grainy components to their prime). A metal component really helps by adding extra heat to the prime function. Glassy components (like silicates or borates) help by making the combustion products of the prime hot and sticky, throwing lots of hot spots on the other shell components to increase ignition points. Adding catalysts like dichromate help but aren't always neccessary if other methods are used. A lot of people avoid dichromates because of the toxicity. WSM Link to comment Share on other sites More sharing options...
mabuse00 Posted October 8, 2010 Author Share Posted October 8, 2010 (edited) Hi, today I found that corn stuff - our big local grocerer had it. There are 2 different types. One is pale yellow and has the consistency of normal flour. Not airfloat, but very fine. Looks like this here:http://www.skywarrio...gross/950_3.jpg The other has a stronger yellow colour and is rather coarse, a consistency like breadcrumbs, little finer. It's sold as (base material for) "Polenta". Like this here:http://theblissfulch.../09/polenta.jpg Seems to be the right stuff...? Or better take the first?What do you think? Edited October 8, 2010 by mabuse00 Link to comment Share on other sites More sharing options...
Updup Posted October 8, 2010 Share Posted October 8, 2010 Hi, today I found that corn stuff - our big local grocerer had it. There are 2 different types. One is pale yellow and has the consistency of normal flour. Not airfloat, but very fine. Looks like this here:http://www.skywarrio...gross/950_3.jpg The other has a stronger yellow colour and is rather coarse, a consistency like breadcrumbs, little finer. It's sold as (base material for) "Polenta". Like this here:http://theblissfulch.../09/polenta.jpg Seems to be the right stuff...? Or better take the first?What do you think? The first one you mentiond is corn flour, and the second is corn meal... I think you'll want the second one. Link to comment Share on other sites More sharing options...
Peret Posted October 9, 2010 Share Posted October 9, 2010 The first one you mentiond is corn flour, and the second is corn meal... I think you'll want the second one. Yep, the second one, the coarse corn meal. If you bought both, spread out the fine corn flour on a large baking tray and bake it at 200C (400F) for two hours to make dextrin. Link to comment Share on other sites More sharing options...
mabuse00 Posted October 13, 2010 Author Share Posted October 13, 2010 Thanks for your advice. I'm going to try that polenta stuff. Link to comment Share on other sites More sharing options...
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