The504 Posted May 23, 2012 Posted May 23, 2012 Hello all, I'm having problems with my lift charge in the mortar making process. I'm using whistle mix (70% potassium perchlorate & 30% sodium benzoate). The only thing it does is burn very very bright and does not combust what so ever. So my questions are 1. Am I doing something wrong? 2. What other compositions can I use the make a lift charge? 3. Is the whistle mix I'm currently using even realistic to use a lift charge?
Peret Posted May 23, 2012 Posted May 23, 2012 I do not think you should use whistle mix for lift. You've probably been quite lucky that it just burns - if it had been mixed properly and gone off with a bang it could have destroyed your mortar and injured you. Use only black powder. If you live in the US you can purchase it, otherwise you really ought to practice making your own, since you can't get far in pyro without it.
Seymour Posted May 23, 2012 Posted May 23, 2012 Whistle mix is not a good lift charge. While this is not the answer to why you are not having success with it burning, it is something you are doing wrong. To get good whistle there are three main things to make sure of, which while important in all mixtures, are more so than normal with whistle. 1. The Potassium perchlorate and Sodium benzoate must be very fine. Both should be silky-smooth powders which do not feel gritty between the fingers. 2. It has to be very well mixed. This can pose more of a challenge with whistle, because of the higher than average sensitivity and explosive power of it, and the fact that benzoate clogs screens. One of the most common ways is to use powders freshly milled or screened before mixing to get rid of all lumps. Then heavy hydrocarbons (waxes, oils) dissolved in lighter hydrocarbons are added, and the mix is stirred while "wet". Once mixed thoroughly (consider kneading the stuff for some time when it's a dough like consistency), it's spread out somewhere for the solvent to evaporate. 3. It's all dry. Many substances absorb some water from the air, and Sodium benzoate does this enough to have a serious impact on how well it works in pyrotechnics. I like to oven dry my Sodium nitrate prills, then ball mill it, and then just before making whistle, I like to oven dry both of them to be sure I'm working with crispy chemicals. The heavy hydrocarbon I mentioned earlier should help protect it from absorbing water again (as well as make it less dusty and a little less sensitive), though I still suggest keeping it in an airtight container, ideally with desiccant. I suggest using Black powder, which is so much the standard lift charge for fireworks that cases of other methods are very exceptional, such as Disney's compressed air, and Benzolift, a blend of BP with some whistle, which has had a bit of use in hobby circles. It's said to be unsuitable for medium to large effects, and some people consider it too dodgy for small ones too.
The504 Posted May 23, 2012 Author Posted May 23, 2012 Ok so I should just stick with BP as a lift charge. Can I do anything with the chems I have right now? Those would be Potassium Perclorate & Sodium benzoate.
Seymour Posted May 23, 2012 Posted May 23, 2012 Well, you can make whistle for whistles, rockets and as a burst mix, or more commonly just a booster to give a kick to the main BP burst charge. You may have read this, but it's worth repeating that Whistle mix is quite unsafe to ram like one can do with Black powder. Because of the fairly high shock sensitivity, especially considering the explosive damage it can do (why it's a poor lift), and you have to press whistle to consolidate it in tubes for whistles and rockets. For use as an explosive it is granulated, often just using something like wax as the binder. Before it dries, granulate it though a coarse screen. I've mentioned it as an explosive in the context of boosting shells, but it also finds use in salutes, breaking crossettes and in some cases (like some bombettes) as the only burst charge
The504 Posted May 23, 2012 Author Posted May 23, 2012 So I think I'm going to either mill or buy some BP.
Bcorso85 Posted May 27, 2012 Posted May 27, 2012 If you mill it use willow charcoal. Makes a great product. For me 10 grams will lift a 150 gram shell. Whislte mix is sometimes used with black powder to make benzolift. But stay away from that for now. It is very powerful and not really useful. Making b.p. is pretty cheap. Buying it can get very costly. In my local gun shops they don't even carry it anymore. Let alone finding the right size for large bore guns. Go to harbor freight and get a ball mill. They're half the price. If you pay more than the charge, its a rip off. Also get NON SPARKING GRINDING MEDIA. Lead or ceramic 1/2 inch (.550)! -325 potassium nitrate, air float willow charcoal, and sulfur. NOT SULFUR OF FLOWERS, BUT FLOUR.Any questions let us know. Check out Danny Creagans website.Good Luck,Benjamin
Arthur Posted May 27, 2012 Posted May 27, 2012 I've seen lots of shells launch and only one mortar failure, and that was when someone tried to use whistle as lift. Please research the masters -Lancaster, Shimizu, Fulcanelli etc read their books learn how they work. It will save your life and liberty if you do things safely. They all use BP as lift, and BP is older than most other compounds yet it's still well regarded. Before making devices please learn to make good BP.
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