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Chemistry Alchemist
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Make shift Glassware
Im curious, what home equipment could be used as chemical glass ware?
i got a suggestion from someone that a empty liight bulb can be used as a round bottom glask? is the glass stable enough for direct heating with a
liquid inside? is there a chance for shattering?
anyother things that can substitute more expensive stuff?
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hissingnoise
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Quote: | i got a suggestion from someone that a empty liight bulb can be used as a round bottom glask? |
Holy shit! Light bulbs?
Things down there in Oz must be really seriously fucked-up . . .
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Endimion17
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Quote: Originally posted by Chemistry Alchemist | Im curious, what home equipment could be used as chemical glass ware?
i got a suggestion from someone that a empty liight bulb can be used as a round bottom glask? is the glass stable enough for direct heating with a
liquid inside? is there a chance for shattering?
anyother things that can substitute more expensive stuff? |
Yes, light bulbs can be used as round bottom flasks.
They're great for things like dry distillation. Disposable, durable, inert.
For example, you can make lots of copper sulphide if you stuff the copper wire inside and add excess sulphur, and then bury the bulb in hot coal. Not
the neck, though. After half an hour, sulphur is gone and you're left with a nice, crumbly compound. No muss, no fuss.
But where did you get the idea that flasks can be heated in flame? Laboratory glassware (unless special, like quartz) is heated over a hot plate, and
if your source of heat is flame, asbestos/ceramic plate is used. Or water/oil/lead/sand baths, depending on the temperature you want to reach.
Sometimes 2-3 layers of iron wire gauze is a good idea, too.
Naked flame - never.
In addition to lightbulbs, you can use fluorescent light tubing for some less demanding tasks. For example, it can be carefully heated to around 300
°C if wrapped in the gauze. It tends to melt easily, though.
It's very easy to prepare a large glass tube from a fluorescent light.
[Edited on 1-10-2011 by Endimion17]
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Wizzard
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Glass soda bottles are also very handy- They can withstand a vacuum with ease, and also high pressure- Any glass container made for carbonated soda
MUST be 100% safe at a minimum 150PSI.
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bbartlog
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Quote: | where did you get the idea that flasks can be heated in flame? |
I heat RBF with direct flame and have not had problems. Granted I position the flask just above (not in) the actual glowing flame. And I have seen
other examples of people doing the same, see e.g. garage chemist's synthesis of heptachloropropane, here: http://www.sciencemadness.org/talk/viewthread.php?tid=14584#... .
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Endimion17
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It's simply not done like that. Every organic chemist would cringe to see a flask being heated with a naked flame.
"Never" is an interesting word, especially when you do lots of organic experiments and deal with ether and acetone refluxes all the time.
I'd never put my safety in the hands of "never".
Just because lots of people does something the wrong way, that doesn't make it right.
Open flame heating and fancy glassware don't go together. Simple rule.
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Chemistry Alchemist
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Quote: Originally posted by hissingnoise | Quote: | i got a suggestion from someone that a empty liight bulb can be used as a round bottom glask? |
Holy shit! Light bulbs?
Things down there in Oz must be really seriously fucked-up . . .
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There are alot of restrictions in australia, "Home Chemistry" easly refurs to drug labs and australia says no so they are stricked with there
imporation of chemicals and glassware :/ my next door neighbours house blew up from hydrogen build up while they tried making drugs
[Edited on 2-10-2011 by Chemistry Alchemist]
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Chemistry Alchemist
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I got the idea from those alcohol burners you get, i wasnt talking about a direct blowtorch flame, i was thinking of like a Bunsen burner flame...
Is there a way you would flatten the bottom of the bulb to make a flat bottom flask?
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Blasty
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Quote: Originally posted by Chemistry Alchemist | Im curious, what home equipment could be used as chemical glass ware?
i got a suggestion from someone that a empty liight bulb can be used as a round bottom glask? is the glass stable enough for direct heating with a
liquid inside? is there a chance for shattering?
anyother things that can substitute more expensive stuff? |
I have used commercial glass bottles, like those used for Snapple iced teas and lemonades, as flasks for carrying out basic reactions a bunch of
times. They are cheap, easily available and economize on the actual more expensive bona fide flasks. The only catch is that if a particular experiment
requires heat, you have to do it by gradually heating in a sand-bath. They won't take the thermal shock of a direct flame like borosilicate glass can.
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Blasty
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Quote: Originally posted by Endimion17 |
It's simply not done like that. Every organic chemist would cringe to see a flask being heated with a naked flame.
"Never" is an interesting word, especially when you do lots of organic experiments and deal with ether and acetone refluxes all the time.
I'd never put my safety in the hands of "never".
Just because lots of people does something the wrong way, that doesn't make it right.
Open flame heating and fancy glassware don't go together. Simple rule. |
The reason why it's not done in organic chemistry is pretty much self-evident: look at some of the chemicals you yourself mentioned... volatile &
flammable + open flame = recipe for an accident!
But in inorganic chemistry it can be done, as long as no flammable materials are being dealt with (preparation of nitric acid from a mixture of sodium
nitrate and sulfuric acid, for example.) Borosilicate glassware, specially the round bottomed pieces, can take the thermal shock very well (at first
the flame should be yellow, though, not an air/gas mix blue flame at the full blast of the burner! Even the best round borosilicate glass pieces can
crack with such a brutally sudden thermal shock.)
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Mildronate
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Light bulbs its not seriously. I sometimes use 3L and 1L jars for experiments, because jars are cheap and big, but when i need to heat something i
use real glasware.
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Endimion17
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Quote: Originally posted by Chemistry Alchemist | I got the idea from those alcohol burners you get, i wasnt talking about a direct blowtorch flame, i was thinking of like a Bunsen burner flame...
Is there a way you would flatten the bottom of the bulb to make a flat bottom flask? |
Same thing. Borosilicate glass is never heated (unless you're a flameworker, lol) in a naked flame.
It is possible to flatten it, but it's tricky, as wrinkles can form. Use a propane blowtorch and practice. That's the best advice I can give to you.
Quote: Originally posted by Blasty | The reason why it's not done in organic chemistry is pretty much self-evident: look at some of the chemicals you yourself mentioned... volatile &
flammable + open flame = recipe for an accident!
But in inorganic chemistry it can be done, as long as no flammable materials are being dealt with (preparation of nitric acid from a mixture of sodium
nitrate and sulfuric acid, for example.) Borosilicate glassware, specially the round bottomed pieces, can take the thermal shock very well (at first
the flame should be yellow, though, not an air/gas mix blue flame at the full blast of the burner! Even the best round borosilicate glass pieces can
crack with such a brutally sudden thermal shock.) |
My opinion comes from:
1) more than a decade of working with such glassware
2) flameworker's advices
3) literature
4) laboratory technicians and college staff with decades of experience
I'm not saying that borosilicate glass will burst if heated in an open flame. If that was happening all the time, flameworkers wouldn't
exist, would they?
The point is that localized, great temperature differentials (flame!) cause stresses in the glass structure.
First time nothing. Second time nothing. Third time nothing. Fourth time CRACK. Not neccessarily at fourth heating, of course. It can happen at tenth,
but why playing a Russian roulette?
Improper heating reduces its lifetime. It's simple as that.
That's why glassware (especially NB borosilicate, expensive glassware) is heated in mantles, heating coils, baths etc.
I'l admit it, I heat cheap glassware above the visible naked flame. Test tubes (it not like I'm gonna set a sand bath every time I do it), already
damaged flasks, tubes... It's not a problem. But when I see naked flame being used on glassware with standard tapers, I cringe and immediately form a
not so good opinion about the one doing it. Call it a prejudice, I don't care.
[Edited on 2-10-2011 by Endimion17]
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Chemistry Alchemist
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Yeah, I'm planning on getting a oxytorch used for welding copper but for my pyrotechnics, can't do anything till I get that tho thanks
[Edited on 2-10-2011 by Chemistry Alchemist]
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Mildronate
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You can make rounbotommed from glass pipe, also can make test tubes from pipe, liebig cooler, some pipets just need to practice, but why you cant buy
glassware?
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Steve_hi
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Ground glass Distillation improvistion
I bought a 14/20 distillation flask and condensor it was expensive and I'm afraid of breaking it I also have a leibig and graham condensor that use
rubber stopper. Today I turned some nylon shaft to fit into my 50ml flask and my leibig condensor and put O-rings in them these are only nitrile
O-rings but I will buy some vitron O-ring which can withstand nitric acid the piping I used was aluminum because I saw on Nurdrage that aluminum is
impervious to attack by nitric acid I distilled some water to test for leaks everything seems to be ok.
I want to do this for my my 250ml and 500ml flasks as well but I am thinking of either buying stainless steel or teflon shaft if it exists. Can you
give me your opinions on whether you think this is a bad idea or should I go with it. Any imput will be appreciated
[img]C:\Users\Steve\Pictures\2011-10-02\21.jpg[/img]
[img]C:\Users\Steve\Pictures\2011-10-02\22.jpg[/img]
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Chemistry Alchemist
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my parents dont want to buy my glassware :/ and its hard where i live...
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Neil
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Can't be harder then welding copper
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bquirky
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seriously.. don't waste your time with a light-globe just buy the frigging flask and save yourself the mess and cuts
G1115-100 GG17 BOROSILICATE BOILING FLASK ROUND BOTTOM
100ml WITH LONG NECK AND ROUND BOTTOM $4.62
from
http://www.wiltronics.com.au/catalogue/161274/science/flasks...
lightglobes
52 Watt = 75 Watt GLS Halogen Replacement Light Globe (4 Pack) $19.95
from http://lightingpro.com.au/catalog/index.php?cPath=26_120
infact since our green Nazi Overloads have outlawed friggin light globes we will probably soon have to make light globes out of round bottom flasks
!!!
[Edited on 4-10-2011 by bquirky]
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Endimion17
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Quote: Originally posted by bquirky | ...
infact since our green Nazi Overloads have outlawed friggin light globes we will probably soon have to make light globes out of round bottom flasks
!!! |
I can see it coming. A whole "hidden biosphere" of development, starting with a mix of 18th century technology and 20th century scrap.
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hissingnoise
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"End User Declaration required for individuals purchasing this product" on a 500ml flask?
WTF!!!
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Chemistry Alchemist
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yeah, on some of the important adapters for a simple distillation also says that ><
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dann2
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Don't admit its for to make a bulb.......
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hissingnoise
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It's for an art installation, guv!
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Endimion17
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Actually, the "art installation" excuse works, at least here. Try that, you've got nothing to loose.
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Panache
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You can say whatever you like on an EUD, they are simply a means of tracking the distribution of an item to a individual. If you have no nefarious
intent there is no problem. They are also not legally required as they are part of a cooperative code of conduct framework the suppliers choose or
choose not to adhere to.
As a cooperative means they are effective,police consort with the suppliers rather than tediously (and ineffectively) antagonize them. From the
outside the system appears onerous and invasive, but it's actually an excellent system, it does not stop or slow any transaction, rather just makes it
accountable.
I can already feel the warmth from the flames in your replies, lol.
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