dixiedog Posted March 19, 2006 Share Posted March 19, 2006 Hey ya'll,Iv'e been messing around with tube inserts like you may find in cakes and stuff. Iv'e read a little bit on it. My question is... Should I try to achieve a good hard break like a display shell or should I just assume its going to blow out at one end or the other? I'm rolling my on tubes. Should I keep them thin and not worry about it or roll them thick and plug them good. I'd like to make some tube type shells that are lively and entertaining. I guess I want to be a Micro guy. I'm working with tubes between 1/2 and 1 inch diameter.I'd like to hear your ideas or even a good book on the subject. Link to comment Share on other sites More sharing options...
Chris Posted March 19, 2006 Share Posted March 19, 2006 Don't worry if you breaks arn't symmetrical etc since It's hard to achieve with small shells. However, they shouldn't blow out one end either. If you make the tubes with right proportions, you should get fairly nice small breaks. Just be sure that secure the end plugs, or whatever you are using, firmly so the burst will tear through the wall instead of the plug. Many commercial class 1.3 cake inserts contain a very small amount of flash together with BP burst. I'm sure this would aid your cause. Also, you could triangle-fold the tube ends instead of plugging them. Best is to experiment and do some ground testing with the inserts to sort out what works best. Link to comment Share on other sites More sharing options...
aquaman Posted March 19, 2006 Share Posted March 19, 2006 Dixidog the best thing about pyrotechinics is trial and error. Test different shells and see which one your liking best. Just make sure you remember how you made the one you like. Link to comment Share on other sites More sharing options...
dragonman586 Posted March 19, 2006 Share Posted March 19, 2006 I do small shells. For making them around 1/2" use 2 to 3 turns of pregummed kraft paper that is reinforced with fiberglass(this stuff can be brought from staples in the shipping asile). For 3/4" shells 3-4 turns is reccomended by me. If you use some decently rolled tubes with some nice cardboard end discs you should get some nice breaks. Link to comment Share on other sites More sharing options...
Mumbles Posted March 20, 2006 Share Posted March 20, 2006 I've made some smaller shells. They were 1 1/4" ID, but still, some of the concepts should carry down. For burst I used granulated BP and some flash powder. I used very small amounts of flash powder, but it did make the burst more symetrical. To get over the problem of blowing out the ends I spiked some vertical stripes in it. I think I used about 8. I never tried it, but fiberglass strapping tape may also help. I'd use 1 strip completely around vertically, and a second strip completely around vertically at a 90 degree angle to the first. It would look like an X from the top. I don't know if it will work, but it is something to try. Link to comment Share on other sites More sharing options...
dragonman586 Posted March 20, 2006 Share Posted March 20, 2006 How much flash would you say you used? 1 10th of a gram? Also would it be wise to add boric acid or would it be a useless action brought on by paranoia? Link to comment Share on other sites More sharing options...
Mumbles Posted March 20, 2006 Share Posted March 20, 2006 I always just did it by volume. Judging from the relative density of it, I would say roughly .1-.2g per shell. I never used boric acid personally. The KNO3 is bound into the BP grains, and the amount of Aluminum is small and spread out. If I did use .1g, that is only .03g. The amount of heat produced from that wouldn't be able to light anything. Link to comment Share on other sites More sharing options...
dixiedog Posted March 23, 2006 Author Share Posted March 23, 2006 Hey When you talk about granulated powder for burst, what size? Will black powder thats been wetted and pressed through a screen like lift powder work ok? I just used meal powder the last few times. Its a very good meal. I just Don't see how you could get a much bigger size powder around inside them small shells. Also could I assume that whislte should work as good as flash in the smaller shells? Does the flash or whislte need to be added somewhere around the middle of the shell.... Like powder,then flash,then finish with powder. Thanks for the input Link to comment Share on other sites More sharing options...
dragonman586 Posted March 23, 2006 Share Posted March 23, 2006 Yea the stuff passed through screens will work. That is what I personally use. Link to comment Share on other sites More sharing options...
Mumbles Posted March 23, 2006 Share Posted March 23, 2006 I mentioned it somewhere else, but I only use a certain fraction from passing it through a 16 mesh window screen. Wet and granulate through the screen. Let it dry, and pass through the screen again. Everything that stays on top you can use for lift, but you want the stuff that falls through. Sometimes I put it on a baking sheet with low walls. I slide it around to produce a granule size gradient. I usually don't use the very fine powder at one end. Pretty much if I can see the individual granules, it is good to go. I take out some of the bigger stuff too sometimes. All in all, if you just use what passes the screen after granulating and wetting, you will be fine. Link to comment Share on other sites More sharing options...
d4j0n Posted April 14, 2006 Share Posted April 14, 2006 When you talk of all this screening, is there any dextrin or binder involved? Link to comment Share on other sites More sharing options...
justanotherpyro Posted April 14, 2006 Share Posted April 14, 2006 It would make sense that dextrin would be helpful to keep the individual grains intact right? Standard 5% dextrin works well to make the granules really hard and resistant to breaking down into a finer powder. I would say its not terribly important though. There have been times I have made 200-300 grams of lift and spaced adding dextrin, but the lift still performed nicely. Link to comment Share on other sites More sharing options...
Mumbles Posted April 14, 2006 Share Posted April 14, 2006 I use dextrin. It keeps more of the stuff in granule form. For lift or break it's not extremely vital. However I can definatly tell the difference when coating composition on rice hulls. I space the last time, and ended up with compsition that falls off when you even touch it. I made a shell with it, we'll have to see how it works. Link to comment Share on other sites More sharing options...
Pyrohawk Posted April 14, 2006 Share Posted April 14, 2006 I have made lots of small shells. I just fill it up with Whistle Powder to fill the remaining space. If it's still got a little air space its no big deal. Your not going to get nice symetrical breaks with small shells so there's no point worrying about it. I made a nice little 3" shell of shells loaded with 8 smaller shells, I think they were about 3/4". It worked excellently. Link to comment Share on other sites More sharing options...
realfirewurx Posted April 16, 2006 Share Posted April 16, 2006 I made 5 of these this morning all were nice and worked well but the breaks were weak still really fun tho.(I used granulated bp for lift and also for my break.) Link to comment Share on other sites More sharing options...
dixiedog Posted April 16, 2006 Author Share Posted April 16, 2006 Do you add the whistle mix after the stars and just kinda shake down? Can you say that flash or whistle will be about the same as far as the burst goes? Iv'e been trying a combination of BP and whistle somwhere in the center of the shell/insert. They seem ok, but I know they can be better. I haven't tried just flash or just whistle... yet. Link to comment Share on other sites More sharing options...
realfirewurx Posted April 19, 2006 Share Posted April 19, 2006 When your doing small cake shots its realy just mix it up and try to get the stars on the outside since the shot is so small. (I would rather use whistle mix than flash ) try just whistle Link to comment Share on other sites More sharing options...
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