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Quince
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My parents are on the other side of the continent. I'm a graduate student renting a place. I measured the reagents using a scale accurate to
0.1 g. "Can't light it...can't find it" has nothing to do with basic chemistry, so I don't see where that bit of patronizing
is coming from. And by the way, the word is spelled "boring" with no 'e'.
[Edited on 4-3-2005 by Quince]
\"One of the surest signs of Conrad\'s genius is that women dislike his books.\" --George Orwell
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Bert
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Mood: " I think we are all going to die. I think that love is an illusion. We are flawed, my darling".
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You can't light thermite. You can't find basic OTC chemicals. I'm not trying to be patronizing, everyone had to start somewhere. But
for some reason, 30 odd years ago when I was 14 I made and ignited thermite on my first try. And a bit of basic searching on sulfates with metallic
fuels would have answered the other thread you started. If you're a grad student- It isn't in chemistry. English lit perhaps?
(edit)
Just looked at the rest of your 108 posts here since you joined 1/31/05. Apparently you have allready found roguesci. Also quite evidently, you ask
LOTS of questions without searching thoroughly.
[Edited on 4-3-2005 by Bert]
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Saerynide
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There is no need to chastise Quince for what he said. Just because someone couldn't light thermite on the first try, it doesn't somehow
make them inferior to someone else who could.
And so what, if he's not a chem student? It's not like everyone here is, and you dont have to be to be if you only enjoy it as a hobby.
"Microsoft reserves the right at all times to monitor communications on the Service and disclose any information Microsoft deems necessary to...
satisfy any applicable law, regulation or legal process"
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Quince
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| Quote: | Originally posted by Bert
English lit perhaps? |
Ha, you must think you are so witty! Computer science, actually. But as I value quality literature and other art, I say you are quite arrogant to
insult non-scientific academic disciplines.
\"One of the surest signs of Conrad\'s genius is that women dislike his books.\" --George Orwell
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uber luminal
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I think its great that Quince has found an interest in chemistry. (even if its starting with smoke and fire types of reactions). I also think its
great that he hasnt given up trying to do things. Not all learning has to be done from the ground up, especialy if you allready have a standing
elsewhere else.
Quince, I would try making a little bit more than the 10? 20? gram mixtures that you have been trying.
I usually make a test batch by starting with 27g of Al and add the metal by ratio from there. Mix the load, then divide it back up into 2 or 3
seperate loads.
-edit- Also, back with the Al foil/blender. I can't think of why the Al would have turned grey. was it like a light grey? or a dull dirt looking
grey? I really doubt the Al foil was oxidized in the proccess of blending it. the next question I have is, how small are the pieces? The best results
Iv had (aside from buying good stuff on ebay), have been from Al filings. If all else fails you could take a trusty large grain file to the bottom of
a few Al cans (or whatever source you have)
[Edited on 5-3-2005 by uber luminal]
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Quince
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I have many other hobbies (electronics, physics, philosophy, piano, organ, books, hiking, cognac, women), which means sometimes I have to take
shortcuts and decrease the DIY part in order to have time for all of them. I prefer generalizm over specialism. For me knowing nothing about
everything beats knowing everything about nothing.
I've had just one chemistry class in my life (back in highschool), so I can't be expected to know anything when I'm getting started.
Searching helps to some extent, but given that chemicals can be written in multiple ways makes it easy to miss results, just as difficulties in
knowing the most likely way something was worded makes finding relevant results also a problem.
[Edited on 5-3-2005 by Quince]
\"One of the surest signs of Conrad\'s genius is that women dislike his books.\" --George Orwell
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chemoleo
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Quince, despite the sympathy vote, you aren't off the hook.
Indeed you ask many questions that have been debated to death elsewhere (like that vacuum destillation one). 110 posts, where more than 2/3 is on
stuff that's been debated elsewhere is NOT good.
When people tell you half a teaspoon is WAY too small an amount then accept it. There are people who have tried this many many times.
The trouble is with thermites, the reaction needs to 'catch fire', i.e. the heat it produces must be enough to propagate. With small amounts
such as yours it has barely a chance to propagate. Neither do you know the quality of your oxide (and that of the Al for that matter). 1cm of a
sparkler piece is WAY too little as well. The sparkler (or several tied together) should stick INTO the mix (either end works). Further, it always
helps pressing the thermite, to get it into more immediate contact with the igniter. But half a teaspoon, with homemade material... I'd be
surprised actually if you got it to work.
I really suggest you take some time off posting, and start reading the threads here (and EW). Noone else seems to ask such questions, so who ought to
do the reading?
I am very tempted to close this thread, it's veering off way into the practical trivial, and all the important bits have been said. Take that as
a warning...
So back on topic now chaps!
Never Stop to Begin, and Never Begin to Stop...
Tolerance is good. But not with the intolerant! (Wilhelm Busch)
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I am a fish
undersea enforcer
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| Quote: | | Originally posted by Quince Searching helps to some extent, but given that chemicals can be written in multiple ways makes it easy to miss
results, just as difficulties in knowing the most likely way something was worded makes finding relevant results also a problem.
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Then perform multiple searches. When searching through previous topics, I usually make several searches, to avoid missing anything out.
1f `/0u (4|\\| |234d 7|-|15, `/0u |234||`/ |\\|33d 70 937 0u7 /\\/\\0|23.
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Bert
Super Administrator
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I will try to make this an informative and useful post, rather than a criticism.
1. Tiny samples of thermite (1 gram? 2 gram?) are difficult to weigh properly. 10 milligrams is a large error in a one gram sample. Make AT LEAST an
ounce, then you will also be able to do something fun like welding or puncturing a piece of steel with your thermite.
2. As a mass decreases in size, the ratio of surface area to volume increases to the extent that a reaction may lose heat by radiation from the
surface too fast to self sustain. Once again, a larger sample is the answer.
3. I lit my first sample by means of a step prime. A cone shaped well was made in the top center of a pile of thermite, and filled with succeeding
layers of composition made with varying proportions of a crude black powder mix with thermite- i.e., bottom layer was 75%: 25% thermite : black
powder, middle layer was 50 : 50, top layer was 25 : 75.
This allowed use of a firecracker fuse to ignite the sample. This is a common technique in pyrotechnics, which may be applied to rolled stars as well.
The use in the crude BP igniter of a somewhat higher proportion of Sulfur to charcoal than normal for propellant uses may also be of benefit.
Additionally: the photo of a clearly highly exothermic reaction being carried out on a textile surface shows some lack of forethought. When igniting
a sample of thermite you should be aware that the reaction may progress with explosive swiftness, heating air trapped in the powder so swiftly it
expands quickly enough to blow molten iron all over the area. Similarly, small amounts of water trapped in any nearby material, such as wood, sand or
porous ceramic will guarantee a steam explosion. This also will occur if thermite is ignited on a cement or plaster surface as the water chemically
bound in the cement or plaster WILL be released as steam.
Granted a safe place to perform such an experiment, I would proceed thus: Take clean sand, previously baked dry in an oven and make a ring on the
(dry, clean) steel target to be welded or punctured sufficient in size to retain the liquid Iron in the area desired. This may be accomplished by
taking a drinking cup of the appropriate size and setting it on the target, piling sand around it and carefully picking it up. Fill the cavity in
the sand with the mix. DEEPER is better than WIDER Ideally, a cone shaped charge will concentrate the molten iron on a small bare area of the
target at the bottom of the cone for the maximum spot heating effect. A "V" shaped trench in sand over the juncture of two steel plates may
be used for welding them- In all cases, make sure that whatever is under the plate will either retain the weld material safely, or allow the molten
iron to run away safely if a puncture is the intended effect. Do it on bare concrete and you may be eating molten iron and glass.
[Edited on 5-3-2005 by Bert]
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