Swede Posted September 24, 2008 Posted September 24, 2008 Agreed, that had to be the lamest "safe and sound" POS I've ever seen. I think a kid would have more fun with a book of matches. Not that I'd hand a little kid some matches, but it was spectacularly whimpy. I take it all back. I'm guessing if you were four or five years old, that thing would be cool. But otherwise...
Richtee Posted September 24, 2008 Posted September 24, 2008 My god, I almost died laughing... I kept waiting...and waiting...for SOMETHING to happen. Sigh. My screensaver kicked in.
tentacles Posted September 24, 2008 Posted September 24, 2008 Swede: No way! I got to have firecrackers when I was 5, that shit would have sucked ass for me.
mormanman Posted September 24, 2008 Posted September 24, 2008 I was 4 when I got my first box of assorted fireworks. It was for my Birthday and I was a happy camper.
asilentbob Posted September 24, 2008 Posted September 24, 2008 Have you ever wondered what happens when you leave corn starch/flour in the oven and forget about it when trying to make dextrin? Looks to me like you might have in-advertently invented the next generation of high temperature insulating expanding foams. Kinda like this: Great Stuff! Expanding foam insulation Except like fragile... But if its all charcoal and air its gotta be a pretty decent insulation... I have my first organic chem II exam later today (its 2am now.)... and I'm not ready... :[ On the positive note Thursdays are like my Fridays right now... so weekend soon . I'm considering selling my radio scanner and getting a metal lathe / mill combo machine... something around $450-600... My budget could possibly be higher if I persuaded my dad to pitch in. Harbor Freight has some nice looking ones:http://www.harborfreight.com/cpi/ctaf/Disp...temnumber=39743http://ww2.harborfreight.com/cpi/ctaf/Disp...temnumber=46199Just want one for prototyping random things out of aluminum and brass mostly. Also our normal drill press is really basic... and c-clamps cant hold shit down very well the way it is made. Meaning cutting holes in metal gets like 5x more dangerous and challenging than it should be. On the flip side... If I go off to college somewhere I'm not going to have a garage to actually use the machine :[ Got a Texas club firework shoot in something like 2 weeks from now. Supposed to be the best one in a long time. 76 pyro magazine guys are supposed to be there taking pics for an upcoming article and to help try to get more members, which we REALLY need to keep paying for all the costs it takes to do this kinda club shoot in Texas. I have been thinking of trying my hand at crossetts for a ring of crossetts shell or something since I liked the last one so much... But man... after PGI I'm completely out of filler and the prospect of making more without the convenience of a roller is daunting. I think I'll be able to find the time for some starmines or something at the least.
tentacles Posted September 24, 2008 Posted September 24, 2008 (edited) Bob: Beware, combo machines make neither a good lathe, nor a good mill. Buy a much bigger machine than you'd normally want, and it might work for you. Can't you stick a tire on your ball mill and roll in that? I made some very pretty BP hulls the other day in mine. What's everyone's opinion on rolling a dab of whistle mix on top of bp hulls instead of adding whistle break to the shell? If you got the amount right, it would scale up to bigger shells easily. Edited September 24, 2008 by tentacles
flying fish Posted September 24, 2008 Posted September 24, 2008 I kept waiting...and waiting...for SOMETHING to happen. Sigh. My screensaver kicked in.Well...SOMEONE has to give safety instructions to the incompetent.
shagaKahn Posted October 1, 2008 Posted October 1, 2008 Got some 300 mesh Al powder and I'm thinking of ball-milling it to a smaller size. Have searched here for reference to ball-milling metals and can't really find any details of anyone actually doing it. Seem to recall mention of blenderizing Al foil and then ball milling it to dust but can't recall the forum where this was discussed. Any tips, warnings, discouragements? Grinding media will be Alumina, and I've read the warnings about pyrophoricity--though someone's suggestion to open the jar periodically to let in fresh air seemed like the exact opposite of what you should do. They must use ball mills to create fine aluminum powders, right--otherwise where would they come from? Thanx for the width,s
oskarchem Posted October 1, 2008 Posted October 1, 2008 I've heard from someone, but I have no idea if it's true; I THINK that the fine Al powder is distilled. But I'm not really sure so let's wait for confirmation.
FrankRizzo Posted October 1, 2008 Posted October 1, 2008 Flake powders are hammer-milled from foils to the desired particle size. Atomized powders are made by spraying a jet of inert gas at a stream of molten metal, and sorting the resulting spheres of metal.
jacob Posted October 1, 2008 Posted October 1, 2008 shaga, Let me share what Lloyd Sponenburgh had to say about milling metals, from his book, Ball Milling Theory And Practice. On milling metals: "I must say I do not recommend milling metals in this mil (a hobby sized mill). That's something better suited to very large commercial mills. Powdered aluminum and magnesium are quite inexpensive compared with the time and trouble you'll go through to mill your own flake. People who mill their own flake usually start with shredded foil or atomized metal, use tungsten carbide or high-alumina media, and use a suspending fluid like mineral spirits or denatured alcohol to keep the particles from re-welding during milling. This is just not a task well suited to the amateur, and I don't recomend it.The suspending fluid might leak from the jars, causing a fire or explosion hazard. the milling takes *forever*-- it takes about ten times as long to get from twenty micron particles to six micron particles as it did to go from foil chunks to twenty microns. Additionally, the amateur has no effective way to grade the material after grinding. No--this is one material you ought to buy, rather than make...in my opinion."
Mumbles Posted October 1, 2008 Posted October 1, 2008 Frank, are you sure you didn't mean a stamp mill?
tentacles Posted October 1, 2008 Posted October 1, 2008 Crap, I had a reply typed up, and this shitty satellite internet here lost it. Anyways, the one metal you CAN mill reasonably, is MgAl. Do this in a jar+media reserved for this purpose only. It WILL become pyrophoric if you mill it too finely. When it starts looking grey rather than silver, it's probably a good time to stop. Believe me, at that point it is PLENTY reactive.
mike_au Posted October 2, 2008 Posted October 2, 2008 I've read the warnings about pyrophoricity--though someone's suggestion to open the jar periodically to let in fresh air seemed like the exact opposite of what you should do. The way I understand it is: Aluminium, when exposed to air will form a thin layer of Aluminium oxide which protects the inner metal. This oxidation reaction is, of course, exothermic. When you are milling you are constantly increasing the total exposed surface area. This newly exposed Al will initially form the protective layer as normal, until all of the O2 in the jar is consumed. Any Al which is exposed after the O2 has been consumed can't form a protective layer. When you open the jar O2 is allowed in and all of a sudden it can oxidize. If you do it every few hours or so then only a small amount of unprotected Al exists and relatively little heat is generated each time. If you let it run for a few weeks non-stop then a far larger amount of unprotected Al will exist and when the oxide layer forms on the surface of all of that Al all at once, a significant amount of heat is formed which can ignite the powder. I've never actually tried this and I may be well off the mark, but that is the impression I got as to why you need to open the jar periodically and/or expose the newly milled powder to air very slowly.
shagaKahn Posted October 2, 2008 Posted October 2, 2008 Thanx Tentacles--that does make sense put the way you put it. (A small amount of slight oxidation beats hell out of a sudden rapid oxidation event). Clearly this is a task to be very careful with. Again thanx for your lucid response,s
ITCHI Posted October 2, 2008 Posted October 2, 2008 Crap, I had a reply typed up, and this shitty satellite internet here lost it. Anyways, the one metal you CAN mill reasonably, is MgAl. Do this in a jar+media reserved for this purpose only. It WILL become pyrophoric if you mill it too finely. When it starts looking grey rather than silver, it's probably a good time to stop. Believe me, at that point it is PLENTY reactive.What kind of downloads speeds do you get with your satellite internet connection?
shagaKahn Posted October 2, 2008 Posted October 2, 2008 The way I understand it is: When you open the jar O2 is allowed in and all of a sudden it can oxidize. If you do it every few hours or so then only a small amount of unprotected Al exists and relatively little heat is generated each time. If you let it run for a few weeks non-stop then a far larger amount of unprotected Al will exist and when the oxide layer forms on the surface of all of that Al all at once, a significant amount of heat is formed which can ignite the powder. Woops, that thanx was s'posed to go to you, mike. And hey thanx to you too, Jacob, for the heads up about milling metal powders. Just got this pretty sweet price ($5/lb) so I thought I'd give it a shot. But maybe I can use this atomized 300 mesh to make exploding targets or something . . .
Mumbles Posted October 2, 2008 Posted October 2, 2008 Or perhaps something actually involving pure pyrotechnics like glitters.
shagaKahn Posted October 2, 2008 Posted October 2, 2008 Right on mumbs. Coincidence must be the mother of invention 'cause I just came across Alan Yates' formula for D1 Glitter--and another recipe in which this atomized 300 mesh will substitute for titanium in Willow Diadem Stars. 'Course I've got five pounds of the stuff. I know: MINES. Lots and lots of mines. . .
Mumbles Posted October 2, 2008 Posted October 2, 2008 Did you get that from Dale on ebay? If so, it's good stuff. I love it. I have 15lbs of it. I am however wary of substituting such a fine mesh Al into a diadem and having it still preform the same. I've seen weirder things though, so it's definitely possible. I've made a few glitters that give long delayed sparks, but they never seem to have the, for lack of a better word, texture of a good brocade.
tentacles Posted October 2, 2008 Posted October 2, 2008 What kind of downloads speeds do you get with your satellite internet connection? It's at work, generally I've seen up to 100k/s, but more often it's about 60. When it works, which is to say, not during the daytime.. or in the winter (sun's at a bad angle to the dish).. or on cloudy/overcast days. It certainly beats dialup, but it's no cable modem. Upload speeds aren't bad, and the lag is serviceable for browsing.
shagaKahn Posted October 3, 2008 Posted October 3, 2008 Did you get that from Dale on ebay? If so, it's good stuff. I love it. I have 15lbs of it. Jeez I guess nothing gets past the mumbs. (Yeah it's his stuff; kool guy to do business with--and I love that he has such wacko listings. Like giant weather balloons).
TheSidewinder Posted October 3, 2008 Posted October 3, 2008 Then PM me the winning Powerball numbers for tomorrow night.
flying fish Posted October 5, 2008 Posted October 5, 2008 (edited) Edit: Problem solved with the phone - I just sent the split comet video to my email address instead and it worked (to my utter surprise)! Now a new problem...How much am I going to get charged for uploading the video? $4000? Edit: Ok, Now that I got the video on youtube: And I realise how awful the quality is (not to mention the sound for some reason didn't upload), I better not be charged an arm and a leg for the data transfer! Edited October 5, 2008 by flying fish
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