CaverCork Posted October 29, 2015 Posted October 29, 2015 I have searched the Internet, volumes of curious lore, and the forum and have yet to find an answer to my question, which is this. Of what is the white to grayish white break powder in cheap Chinese shells composed? What I do know is it is not impact sensitive, has a very stable shelf life, and is extremely heat tolerant, which fits all of my safety criteria. I tested 0.5 grams today in my crucible and finally after several minutes with my propane burner at full throttle, it finally made a dull pop, similar to a like amount of good flash. It also makes a fair amount of smoke and when lit by fuse burns at close to slow flash speeds. This would make the compound a very good candidate for my micro blasting endeavors, but I would like to use it as an additive to other "more gassy" compounds to improve their speed and reduce the smoke. Excessive smoke in a cave environment is quite undesirable for obvious reasons. However, without knowing it's chemical makeup, it is quite unusable. As is well known here, some chemicals do not play well with others, and since I would be dragging this stuff through a cave, well, I'm sure you get the picture. Thanks in advance for any insight anyone may have.
taiwanluthiers Posted October 29, 2015 Posted October 29, 2015 knowing Chinese shells, probably lots of flash mixed with standard meal coated rice hulls.
CaverCork Posted October 29, 2015 Author Posted October 29, 2015 No rice hulls, just a fine whitish powder. Not hygroscopic, so I am assuming a perchlorate of some kind. Fuel unknown.
Nickmaslo Posted October 29, 2015 Posted October 29, 2015 It's most likely an H3 sort of burst or a booster like the Spanish Burst that Jopete mentions. A lot of times they substitute Chlorate for Perchlorate though. I wouldn't be suprised if they did.
CaverCork Posted October 29, 2015 Author Posted October 29, 2015 Considering the extremely high melting point, I would tend to say this is a perchlorate mixture. I a not familiar with hemp coal however. Is it relatively light colored? As I stated, this compound is a white to grayish white powder. The H3 sounds like a mixture I may have to try with Catalpa coal, which is mentioned a few times in the forum, but no one seems to have tried yet. But even then, it would still be very dark colored. I'm drawn to this mix for it's tolerance to all but flame, a real bonus when dragging it through tight crawlways far from civilization and daylight.
Nickmaslo Posted October 29, 2015 Posted October 29, 2015 There is a guy on FW that mentions using a KP prime with Dark Al, Sulfur and some Charcoal. Do you reasonably think they may have just taken the normal 75:15:10 BP mix and started to sub in more powerful ingredients. KP for KNo3, Dark Al for Charcoal, Sulfur for Charcoal and then maybe some Sulfur as well as a sensitizer?
Mumbles Posted October 29, 2015 Posted October 29, 2015 None of those mixtures could ever be confused as white or off-white. CaverCork, I think I mentioned last night that one possibility would be a whistle type mixture. The Chinese seem to be fond of terephthalate based mixtures at the moment. There could be some bright flake metals in there as well. Sulfur wouldn't affect the color much, but it does tend to lower ignition temperatures and increase sensitivity. It doesn't sound like this mixture has those properties.
CaverCork Posted October 29, 2015 Author Posted October 29, 2015 Quite right Mumbles. The sulfur would have melted in the crucible and been quite noticeable. Reading what little I can find on the substance, it is not something I would want to burn in an enclosed and fragile environment. I thought I noticed a bit of plastic smell right before deflagration occurred which would lend credence to your theory. But at least I can reuse it as burst powder since it keeps so well, so not all is lost. Thanks! And thank you Nick for the H3 idea. I'll have to mill some of my Catalpa and try that out.
FloridaCracker Posted November 6, 2015 Posted November 6, 2015 It is almost certainly perchlorate and potassium hydrogen phthalate which is their favored whistle fuel. If you still have some try packing some into a small diameter cardboard tube, leave a bit of empty space, and light with a piece of fuse. Shouldn't need much more than body weight to consolidate if you don't have a press. Should give at least a bit of a raspy whistle if I'm correct which I'm 95% sure I am.
CaverCork Posted November 10, 2015 Author Posted November 10, 2015 I'll try the whistle test. I have discovered the stuff will detonate. Good brisance and decent gas production. 0.5 grams dislodged my heavy steel crucible from the clamps and flung it across the yard, twice. I wasn't expecting that from a potassium product.
dusty56 Posted November 11, 2015 Posted November 11, 2015 I use a whistle mix burst charge that is an off white powder. I use KP and Potassium or Sodium Benzoate. Bleser mentions it in his Round Stars and Shells book. He says it can be on rice hulls or just sprinkled into the shell. When I fill a shell with stars I put the burst on the stars and close the shell. I use it in 3", 4" and 5" shells. It takes a lesser amount than black powder and is less sensitive than flash. Don't know if this is similar to what you found.
Recommended Posts