Sciencemadness Discussion Board

Light bulb flasks

Hawkguy - 9-8-2015 at 20:26

Tried using a lightbulb as a RBF after seeing a video by Rudolf Maker, where he uses them to boil water and make coffee. I cleaned out the inside, smoothened the hole's rim, and added a bung with a bent glass tube in the top. I heated it over a flame, and did a minor distillation of some homemade alcohol. Surprisingly, it held up well in the heat, and the only problem I noticed was the bung material degrading from the alcohol. I found this experiment interesting, and I can definitely recommend this use of lightbulbs for novelty hobbyists and home chemists in the ghetto phase, provided, of course, that even heating is utilized and all bulbs are inspected for cracks.

j_sum1 - 9-8-2015 at 20:42

I have seen a nice siphon coffee maker made with light bulbs. Heated of course with a light-bulb spirit burner. There are numerous hacks that can be done with light bulbs. (When did they start to be called globes anyway?) The chief problem seems to me to be the difficulty in holding them securely. You really do need a decent stand and clamps that can hold them if you want to do anything with them.

I no longer throw out any light bulbs. I keep them for whatever they contain -- which is a surprising amount. Cracking a bulb under water into a zip seal plastic bag will give a small amount of inert gas. You can use a peristaltic aquarium dosing pump to feed that into ampoules or wherever it is needed.

Depending on the bulb they may contain the following useful items
W
Mo
Ar
N2/Ar

Hawkguy - 10-8-2015 at 08:58

I've recovered the tungsten easily, but what component is the Molybdenum found in?

To hold the bulbs in place, I made a 'spring' out of thick wire that screwed into the threads. The wire then led to a stand. This setup was strong enough to hold the bulb while full of water, and could easily be screwedor unscrewed.

battoussai114 - 10-8-2015 at 09:53

Quote: Originally posted by Hawkguy  
I've recovered the tungsten easily, but what component is the Molybdenum found in?

To hold the bulbs in place, I made a 'spring' out of thick wire that screwed into the threads. The wire then led to a stand. This setup was strong enough to hold the bulb while full of water, and could easily be screwedor unscrewed.

I'd guess it may be used in place of tungsten depending on the bulb.

Texium - 10-8-2015 at 09:58

Quote: Originally posted by battoussai114  
Quote: Originally posted by Hawkguy  
I've recovered the tungsten easily, but what component is the Molybdenum found in?

To hold the bulbs in place, I made a 'spring' out of thick wire that screwed into the threads. The wire then led to a stand. This setup was strong enough to hold the bulb while full of water, and could easily be screwedor unscrewed.

I'd guess it may be used in place of tungsten depending on the bulb.
It's supposedly used for the support wires that hold up the tungsten filament, although I don't think it's been confirmed yet that molybdenum is used for this purpose in all incandescent bulbs.

kecskesajt - 10-8-2015 at 10:52

Found this out earlier.Wanted to make wood alcohol but only got a bunch of tar :(
Also,good for waping glycerine and make good clouds.Like a hookah.But be careful,at some temperatures,it makes your throat scratch.

skip - 10-8-2015 at 20:31

like to add that while light bulb type chemistry is fun, it can be dangerous . Lye will do a light bulb in under heat and the bulb can fracture. I would only try to boil water in one at best. Just buy some proper gear mate.






l

kecskesajt - 10-8-2015 at 21:06

Never melt anything in a RBF.

NedsHead - 10-8-2015 at 23:51

I've thought about using old metal halide bulbs as RBF's and high pressure sodium bulbs for boiling stuff, they're made to handle a fair amount of thermal abuse and shouldn't be hard to get a supply of used bulbs from a hydro shop for free.
Can probably pull a strong vacuum on them too

byko3y - 11-8-2015 at 01:23

In my country round bottom flasks are dirt cheap, like 1$ for 250 ml one. Where should I live to have problems obtaining the simple flask? Australia?

NedsHead - 11-8-2015 at 01:51

A Chinese 250ml RBF costs about $20 in Australia + shipping, glassware is becoming increasingly difficult to buy throughout Australia and outright banned in some states.
It's never a bad idea to have a backup plan as these kinds of laws generally become worse not better, but for me it's about repurposing and up-cycling things readily available in my immediate area

[Edited on 11-8-2015 by NedsHead]

byko3y - 11-8-2015 at 03:27

So the laws are the reason, and not recycling, because glass is something that is easier to make from scratch than recycle.
I'm wondering how chemical industry in australia works. Is there any chemical industry in australia? Analytical labs? Because the main shield for amateur chemisters is industry - regular people need chemicals and devices, otherwise a lot ofpeople will become criminals and the whole regulation will become pointless, just like banning alcohol.

j_sum1 - 11-8-2015 at 03:56

I think NedsHead has slightly overstated the legal situation here in Australia. There is a recent thread on the matter which... well, doesn't make things clearer since the laws are pretty loose and open to interpretation (deliberately). But it does state the lie of the land a bit better than he depicts.
http://www.sciencemadness.org/talk/viewthread.php?tid=63146

Basically, nothing is illegal to own unless it is demonstrably drug related. Some things are de-facto restricted to buy and sell but that is a voluntary code of conduct based on documentation put out by the Federal Police. The movement of glassware is watched both through customs and local sales. Anything suspicious and the police pay a visit to check out.

The fact remains that glassware can be expensive for the amateur. But it can be purchased. Importing from China seems to be the most cost-effective means. Just don't be surprised if a chap in a blue uniform turns up wanting a chat.

As for professional labs, I really don't know. I am sure they import just the same as the rest of us.

NedsHead - 11-8-2015 at 04:38

Yeah You're right j_sum1 I'm a little jaded from the 3 years I spent in QLD, I've seen this country at its worst and would hate to see other states follow suit.
Glassware isn't outright banned its just controlled by varying degrees of difficulty to obtain (EUD's) and varying degrees of punishment/harassment for owning.

j_sum1 - 11-8-2015 at 04:51

Well, I'm in QLD and just made a big glassware order...
Let's see what happens. (Actually, I think I am covered pretty well. But if the police do knock, they can darned well make an entry into my lab journal for posterity's sake.)

Hawkguy - 11-8-2015 at 13:51

I'm getting a pack of two 100ml Pyrex RBFs (24 40) for $98 (CAD) off Cole Parmer. Feels like a rip off but I feel like the quality won't be bad.

aga - 11-8-2015 at 14:08

They'll be a lot better and thicker than some old light bulbs for your intended purpose(s).

Hawkguy - 11-8-2015 at 19:02

I guess. But 50 bucks each seems fucked, plus $20 shipping. I thought 30 would be more reasonable.