pyrodoc Posted February 6, 2017 Posted February 6, 2017 Hi allWhat all raw material are required for manufacturing cold fountain.Any good references which can also help.
pyrodoc Posted February 6, 2017 Author Posted February 6, 2017 Hello Lloyd,How RU doing sir? Any good references or videos as a pointer.
pyrodoc Posted February 6, 2017 Author Posted February 6, 2017 How much is the percentage of metal with nitrocotton? Any diagram, I heard that nozzle is not made with nitro cotton
lloyd Posted February 6, 2017 Posted February 6, 2017 (edited) Doc, there are a few fairly 'experimental' pieces out there about how to make them. But when I want to see how a good one is made, I buy and disassemble some of the German indoor units. I don't have any to peer at right now... but those have no nozzles. There's quite little metal in them and it appears that the nitrocotton is dampened with alcohol with just the merest trace of an NC solvent, such that it 'takes a set' when compressed and dried, but is not dissolved, and does not lose its 'cottony' character (although quite heavily compressed). The core looks and feels much like the texture of a (new) woman's tampon. And yeah... I'm familiar with those -- we carried them and also menstrual pads as emergency 'battle dressings' for heavy bleeding. Eh... they had DOD wrappers and stamps, but you could tell exactly what they were. Lloyd Edited February 6, 2017 by lloyd
dave321 Posted February 6, 2017 Posted February 6, 2017 a well pyrotechnist in the uk who died a few years ago,once told me mica particles produce a cold spark maybe mica nc would work ?
schroedinger Posted February 7, 2017 Posted February 7, 2017 don't know what mica is. But for the so called ice-sparkles you need to use a fuel based on nc. The reason for this is that you don't want smoke. Also you want want the germans call "Kollodiumwolle" it is NC with less then 12,2 % Nitrogen content. This can be prepared with sulfuric acid and an nitrate or 65% nitric acid, in a single nitration bath. No reworking besides stabilization. Don't use the trinitrate (common propellant powder), it is way more powerfull, burns hotter and to fast. The sparks get created by a metal, where the content is between 4-10%. "Mischmetal" like Lloyd mentioned is an Alloy specially designed for this and gives sparks a little more on the blue side. Also fine Ti flake in up to 150 my can be used. All in all, be very carefull with these divices, they are quite sensitive. If you fail to compress them propper and use to much comp, it can happen, that the whole comp burns up in one flash with quite some power. For pressing dampen with isopropyl alcohol. Binder content will normally be no more then 2%
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