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h0lx
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That's why I have a dry extinguisher beside my lab entrance
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Jdurg
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| Quote: | Originally posted by h0lx
That's why I have a dry extinguisher beside my lab entrance
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Smart man. 
\"A real fart is beefy, has a density greater than or equal to the air surrounding it, consists of the unmistakable scent of broccoli, and usually
requires wiping afterwards.\"
http://maddox.xmission.com. |
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h0lx
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I made a pic of the turnings too. the wooden object is a matchstick, so you get an idea, of how big they are(nah, actually it was for scraping them
together, but it serves 2 purposes then). I hope the image is not too big
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photoguy
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I use flash powder in my traditional wooden box camera photos. I used to buy the stuff for years, but became impatient when the price soar in the late
90's due to legal issues. Now I just make my own... plain and simple.
I have used the following:
Permanganate based flash w/ MagAl + Sulphur:
These powders seem to be best if no Perchlorate can be found. But -permanganate flash compositions tend to be bar-none the MOST dangerous type around!
Always gives me the best results for photography.
KNitrate/MagAl:
pretty good to.... but the intensity of the flash is usually too bright - and burn time is too long to be of real use, unless I keep my fstop very
high - say f11+
--- commercial stuff:
Always the best - perchlorate/Al or perchlorate/MagAl- same results as permanganate.
[Edited on 25-12-2006 by photoguy]
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Sauron
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Glycerine is oxidized by KMnO4 in finely divided form, to acrolein, acrylic aldehyde, which is an important industrial feedstock, that is also a
proven human carcinogen.
The structure given several posts above is incorrect as the hydroxyl groups were eliminated. There's a double bond at one end of the three carbon
chain and an aldehyde function at the other. It's a very famous rxn. I think I first did this in my garage when I was maybe 13-14, now about 42 years
ago.
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Aqua_Fortis_100%
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| Quote: | Mensagem original enviada por photoguy
I use flash powder in my traditional wooden box camera photos. I used to buy the stuff for years, but became impatient when the price soar in the late
90's due to legal issues. Now I just make my own... plain and simple.
I have used the following:
Permanganate based flash w/ MagAl + Sulphur:
These powders seem to be best if no Perchlorate can be found. But -permanganate flash compositions tend to be bar-none the MOST dangerous type around!
Always gives me the best results for photography.
KNitrate/MagAl:
pretty good to.... but the intensity of the flash is usually too bright - and burn time is too long to be of real use, unless I keep my fstop very
high - say f11+
--- commercial stuff:
Always the best - perchlorate/Al or perchlorate/MagAl- same results as permanganate.
[Edited on 25-12-2006 by photoguy] |
could be this Magnalium/nitrate/S flash more stable and storage than Al/nitrate/S or Mg/nitrate/S ???
(I remember read here which in an experiment from Garage Chemist, he not observed reaction of Magnalium and NaOH solution(even hot solution!), then i
think which this MagAl probably will be resistant against alcalines products formed from nitrate and the metal..even maybe without formate this...
Additionally ,coated MagAl powder can be better than MagAl without coating..)
[sorry about my very poor english...]
"The secret of freedom lies in educating people, whereas the secret of tyranny is in keeping them ignorant."
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Zinc
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2 days ago I lighted a small amount of NaNO3/Al flash powder (I used Al powder extracted from paint). It burned slower than the NaNO3/Al/S flash
powder.
What is the best ratio for the NaNO3/Al flash powder?
I have read that the best ratio is 50:50 by weight. Is that true?
Also is the NaNO3/Al flash powder safer than the NaNO3/Al/S flash powder?
[Edited on 12-1-2007 by Zinc]
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quicksilver
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Just my opinion but....There is no "best ratio" it depends on what you want to accompish. 50/50 Sounds like too much fuel. (Perhaps start at 70/30)
Remember, all metals powders may contain variety in their sizes. So your Al may have some material that is smaller and more volitile than you know:
take advantage of that! Take the container and tap it or shake it. The smaller material will settle on the bottem. Use that. It may be sub-sieve in
size while other larger material will be on the top of the container. But what is also important may be that there may be an issue with temp
sensitivity. For that, a material to lower the ignition temp may help (S or Sb2S3) like you did before! Safety is an issue that is best met by working
with ALL deflagrants as if they were so very sensitive that any exposure to ignition is totally avoided. Treat it all like it will flash over the
same. Don't look for a formula that lets you get comfortable! The more wary you stay; the safer you stay. Always assume that you have a very
dangerous material in any deflagerant. All energetic materials are as dangerous or as safe as the handeling them are met with. Armstrong's can be
worked with if it is whetted. BP has caused serious accidents from it's dust in the air being exposed to static. Remember the ammonium perchlorate
accidents in Nevada or the ammonium nitrate accident in texas City. Those were generally "safe" materials. Looking for a "safe" formula is not the
best idea due to an underlying feeling that it can be handled in a more casual way. Check out the PGII's safety issues with general construction
protocals; it will set you mind at ease. Following them you tailor your methods to the material to an extent but maintain certain standards all the
time. That way when you work with a material, you target what you want, not what you feel you need to compromise to use.....JMO
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nitro-genes
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I suppose you used dark german aluminium or equivalent? Straight KNO3 or NaNO3 doesn't even ignite with atomized or even flake Al in my experience,
even with dark aluminium the reaction is very slow without any sulfur. So, depending on your aluminium powder, it can be very safe without any sulfur.
Just like with gunpowder, it is mainly the hot sulfur vapours that run very fast trough the mix, speeding up the reaction and lowering the ignition
temperature...
Personally I prefer 50/50 KNO3/Al, because of NaNO3's hychroscopicity. I use flake Al, which makes the mixture unable to ignite by flame, but
sensitive to a small detonator. The 50/50 mix has a very bright flash (not as bright as NaNO3 though), and an extremely low pitched report. Great new
year's charges!
[Edited on 12-1-2007 by nitro-genes]
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Zinc
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How about Na2Al2O4 and Al?
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DeAdFX
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Sodium Aluminate is just a mixture of Aluminum oxide and Sodium oxide. That thermic mixture isn't going to do much if anything at all.
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Zinc
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I have tried the BaSO4/Al (3:2) flash powder(I have heared that this is a powerful mixture). I used Al extracted from paint so it contained some
residual organic material and I added a small amount of sulfur (to sensitse the mixture). First I tried to light it with a propane/butane torch but
it didn't ignite. Then I tried to ignite it wit magnesium ribbon but it also didn't ignite.
Does anyone know why?
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h0lx
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has anybody tought of using Oxygen rich explosives for oxidisers in flash? HNE would make quite an energetic mixture with Mg or such IMO.
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chemoleo
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Zinc, I've always meant to try this particular mixture, BaSO4/Al. First of all, did you make stoichiometric calculations? What grade was your BaSO4,
how fine is the Al? Both need to be very fine.
Then, from my experience with CaSO4/Al, you need *excessive* ignition power. That is, several sparklers tied together, placed into a pressed mixture
of BaSO4/Al.
If it doesn't work still, add a small amount (i.e. 10% of the total weight) of powdered sulfur, and increase the amount of Al accordingly i.e. to form
Al2S3. This should serve, similar to the SiO2/Al thermite, as an energetic additive that keeps the reaction going.
Never Stop to Begin, and Never Begin to Stop...
Tolerance is good. But not with the intolerant! (Wilhelm Busch)
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CWAnalyst
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Flash Powder
Hello fellas,
try to use BaSO4 with less than Bassanite water content as it renders the mix very difficult to ignite.
As a starter powdered Fe/KMnO4 will work.
regards
CWAnalyst
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Zinc
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| Quote: | Originally posted by chemoleo
First of all, did you make stoichiometric calculations?
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I mixed it with the ratio 3 parts of BaSO4 and 2 poars of Al
and I added a small amount of sulfur.
| Quote: | Originally posted by chemoleo
What grade was your BaSO4, how fine is the Al? Both need to be very fine.
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The BaSO4 was dried in the oven for 2 hours at 150 degres celsius and powdered with a mortar and pastelle for a few minutes. The Al was extracted from
paint so it contained some residual organic material.
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Bert
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| Quote: | Originally posted by Zinc
I have tried the BaSO4/Al (3:2) flash powder(I have heared that this is a powerful mixture). I used Al extracted from paint so it contained some
residual organic material and I added a small amount of sulfur (to sensitse the mixture). First I tried to light it with a propane/butane torch but
it didn't ignite. Then I tried to ignite it wit magnesium ribbon but it also didn't ignite.
Does anyone know why? |
If you haven't read this re-post on E&W, you might wish to do so.The Few, The Proud, The Sulfates
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photoguy
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...interesting! Never tried BaSO4/Al before... doubt it would be a powderful as Permanganate flash.
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Zinc
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| Quote: | Originally posted by photoguy
doubt it would be a powderful as Permanganate flash. |
But it is safer.
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quicksilver
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That was a great article. I remember Haarmann
from rec.pyrotechnics, etc. I received that from PGII also and really liked it. (& it was no suprise that NBK had a tantrum when the guy didn't
used "% additional"). The issues of particle size also influences ignition in
tough to ignite materials.
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Zinc
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Yesterday I tried to light a mixture of KClO3 and Al powder. The Al (analitical grade) was in the form of airfloat and shiny flakes. The KClO3 was
20-30 years old. I tried to light it with a propane/butane torch. It did not burn.
The KClO3 melted and decomposed.
Does anyne know why?
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Bert
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Try it again with a SMALL batch, adding a bit of Sulfur. Chlorate and Aluminum by themselves do not make a good flash.
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quicksilver
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Fuel / oxidizer mixes need to be intimate and the particulates need to be SMALL. The particulate at sub-sieve size (single digit micron size) is
optimum. Crush the materials individually then mix them very completely. IF your fuel is small enough you should have good results. However the term
"analitical grade" doesn't specify the size. IF you use 90 mesh flake Al you won't get the results that you would if you used paint-grade Al that was
ball-milled down to dark. Niether would it be best if the KCLO3 was lumpy, etc.
I have seen Alcan 813 flake ball milled to some of the best dark Al in less than 24 hours using tank / tractor ball bearings in a ball mill. Likewise
I have seen spherical aluminum ball milled to a flake that was sub-sieve. Both worked as well as ANY of the dark German Alumiinums. Eckart's sub-sieve
Al is a very special aluminum. Eckart is a pigment manufacturer! They make their own Al with a process similar to that in that they shave and crush
non-coated Al down to single-micron size and then tumble it so the smallest sizes sink to the bottom of the containers. Sraining it from there they
keep the smallest particulate material for silver inks. In any batch of any particulate the smallest sizes eventually sink to the bottom of a
container that has been subjected to bumping, etc. You can obtain differing sizes yourself using that technique.
Brittle material like Mg is shipped in limited size containers for that reason. DOT has regulations that maintain the "shaving" phenomenon from
happening in large drums by limiting size. In materials like Zirconium that is very important. I once had a container of brittle material (Ti) that
was subjected to shaving via being left in a truck and the bottom most layer was certainly sub-sieve in size.
Particulate size and intimacy of mix are the most important factors in making fuel / oxidizer mixes. Whetting mix- techniques using etoh is very
effective for F/O materials and in fact is the only way that some people/companies mix pyrotechnics (industrially). The standard mil flare of
teflon/magniesum is always mixed with a fluid of thin NC laquer. That gets that particles close together and maintains them. Seperation is much more
difficult if the particles are in a binder, of course.
[Edited on 1-2-2007 by quicksilver]
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Zinc
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| Quote: | Originally posted by Bert
Try it again with a SMALL batch, adding a bit of Sulfur. |
I do not have KClO3 any more.
Tooday I ignited a small amount of KBrO3/Al/charcoal.
I belive that it didn't burn fast because the chemicals were not fine enough.
Does anyone have expirience with potassium bromate flash powders?
If yes please post some information.
[Edited on 4-2-2007 by Zinc]
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woelen
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I make KBrO3 from KBr quite easily, at high purity, and it is a nice chem for conveniently making bromine, but for flash purposes it simply is too
sensitive. KClO3/reductor mixes already are quite risky, this is even worse with KBrO3/reductor mixes. Too violent and too friction sensitive. If you
value your hands and don't want a similar experience I had with K3CrO8/P/Al, then be VERY careful.
KBrO3 does make flash, but for practical purposes I think it is not useful.
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