NeighborJ Posted January 9, 2017 Share Posted January 9, 2017 Just riffling thru comp lists and they popped out at me and left me with lots of question marks?????? Has anyone tried them? If so how did they work? Would they work for burst or only salutes? It appears they use sulfates for the oxidizers so would they need some sort of hi temp initiation comp? Sorry lots of questions. Link to comment Share on other sites More sharing options...
LiamPyro Posted January 11, 2017 Share Posted January 11, 2017 Care to list any of the formulas? Sulfates tend to form hydrates, which (I would assume) would mean you'd have to get them into their anhydrous form. Storage would be a pain in the ass if this is the case, depending on how hygroscopic the given sulfate is. Sounds more like a novelty than anything else. Would be interesting to know where the name "negative explosive" comes from. Maybe they subtract your fingers. Link to comment Share on other sites More sharing options...
Mumbles Posted January 11, 2017 Share Posted January 11, 2017 Negative explosives are a term that Shimizu applies to essentially flash compositions with non-traditional oxidizers. Things like carbonates or sulfates, which do not decompose on heating to yield oxygen. To make them work, you need a very strong reductant like aluminum or magnesium. They're notably less loud and powerful than ones with conventional oxidizers. There's a blurb about them in Lancaster on pp 148-149. I've made some similar compositions. They're fine. Nothing special. I don't really remember much about them as far as how easy they are to ignite or anything. Shimizu mentions that they can be used as lifting charges with about 12% of the explosive powder of black powder. In another publication he mentions you need about 2x to 2.5x as much to equal the sound of a conventional flash powder. Link to comment Share on other sites More sharing options...
OldMarine Posted January 11, 2017 Share Posted January 11, 2017 Negative explosives are a term that Shimizu applies to essentially flash compositions with non-traditional oxidizers. Things like carbonates or sulfates, which do not decompose on heating to yield oxygen. To make them work, you need a very strong reductant like aluminum or magnesium. They're notably less loud and powerful than ones with conventional oxidizers. There's a blurb about them in Lancaster on pp 148-149. I've made some similar compositions. They're fine. Nothing special. I don't really remember much about them as far as how easy they are to ignite or anything. Shimizu mentions that they can be used as lifting charges with about 12% of the explosive powder of black powder. In another publication he mentions you need about 2x to 2.5x as much to equal the sound of a conventional flash powder. Mumbles, your description begs the question: Why use it? Link to comment Share on other sites More sharing options...
NeighborJ Posted January 11, 2017 Author Share Posted January 11, 2017 It's safer than flash And only one of the comps is associated with the 12% of BP note- it's the one using the hydrous sulfate. It doesn't mention the anhydrous power but there is quite a number of these comps including colored explosives. I'd be interested in using them in larger bottom shots where fillers are normally used. Link to comment Share on other sites More sharing options...
NeighborJ Posted January 11, 2017 Author Share Posted January 11, 2017 White explosive: 50 Mg-80mesh, 50 Mg sulfate heptahydrate Negative explosive: 60-Mg 60mesh, 40-Mg sulfate anhydrous. Shimizu green negative explosive: 50-Mg80mesh, 25-Mg sulfate heptahydrate, 25-Barium sulfate, 10-parlon. Note: comps are to be mixed with a thick NC laquer and granulated. I have everything to make this stuff but I never got creative with Mg mesh size and airfloat is all I have. Will this still work and should it be coated in dichromate, or will the NC binder be enough of a barrier? Link to comment Share on other sites More sharing options...
Mumbles Posted January 11, 2017 Share Posted January 11, 2017 Bigger bottom shots use fillers? That's news to me. Just because some people inappropriately do it, doesn't mean it's right or traditional. Also, the 60:40 mixture with anhydrous magnesium sulfate is the one noted to be 12% the power of BP. Link to comment Share on other sites More sharing options...
NeighborJ Posted January 11, 2017 Author Share Posted January 11, 2017 Are you suggesting that I not even try it? With NC as the binder it would seem that the power would come almost solely from the binder? I couldn't imagine the sulfate adding much to that reaction and still only adding up to 12%. Link to comment Share on other sites More sharing options...
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