Mario1 Posted September 4, 2009 Posted September 4, 2009 Ok so Im in the process of making a star mine. Im using about 25 tiger tail stars (44/44/12) ball milled for 4 hours. I used rubbing alcohol to make the stars and they are drying as I type this and should be done tomorrow. I already have my granulated lift powder ready(about 20-30 grams of it). I dont really know how much to use. I dont want to use too much and have it explode and I dont want it to be to little and not have the stars go into the air. Help is greatly appericated
Mumbles Posted September 4, 2009 Posted September 4, 2009 I use about 1/10th the mass of the stars. I also suggest a sabot to help with lifting. I use 2 end disks with some news paper in between. This goes between the lift and the stars, and helps to use the lift more efficiently. Also, you need a binder in those stars. If there is dextrin in there, it is not activated by the alcohol. If you use them as is, assuming you don't have an appropriate binder, you will probably get a nice fluffy cloud of sparks as all of your stars are pulverized.
Arthur Posted September 4, 2009 Posted September 4, 2009 The pro mines that I have used leave behind a card disc with a few holes punched in. This is a sabot, the lift gas pressure acts on the sabot to push the stars up, the heat of the lift acts through the holes to ignite all the stars.
Mumbles Posted September 4, 2009 Posted September 4, 2009 I've tried just a disk, and didn't get as good of results. One also has to cover all the holes to prevent any lift from migrating. The sabot is key to all of my mines. A disk helps, but the full lift sabot really throws them up there. Same lift, and same construction, and a 4" mine tossed the stars easily 50-100 feet higher in a tighter group. It really makes a difference with the firefly stars I was using.
Mario1 Posted September 4, 2009 Author Posted September 4, 2009 On the top of the lift powder I need to put a little paper disk with a couple holes in it? Ok thats easy, but my stars do not have dextrin in them. I dont have corn starch so Ill get some this weekend. And does the Dextrin have to be baked in the oven or can it be used right out of the box?
Mumbles Posted September 4, 2009 Posted September 4, 2009 Yes, it REALLY has to be baked. Liquid laundry starch will work as is, right out of the bottle as a binder.
Bonny Posted September 4, 2009 Posted September 4, 2009 To prevent the lift migrating into the stars, you can put a layer of tissue paper in between the disk with holes (or sabot), the tissue will burn away no problem. Also, to aid in star ignition, you can run the fuse to the stars rather than the lift, that way they get a head start burning before being blasted out of the tube. For lift,as Mumbles said 1/10 should be good, I go a bit higher using a coarse (2FA) powder. Personally I like the nice thump of the coarse powder vs the bang/crack of finer stuff.
lodcomm Posted September 4, 2009 Posted September 4, 2009 On the top of the lift powder I need to put a little paper disk with a couple holes in it? Ok thats easy, but my stars do not have dextrin in them. I dont have corn starch so Ill get some this weekend. And does the Dextrin have to be baked in the oven or can it be used right out of the box? It Looks like there was a bit of confusion is this post about cornstarch & dextrin.. Let me just put it all straight. Dextrin is an excellent binder for stars. You *do* have to bake corn starch to convert it into Dextrin. You *do not* bake Dextrin to use it as a binder, Dextrin is ready to use as is.. have fun. -t
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