This is an experiment and there may be flaws but that is all part of the learning process.
I used a Bacardi bottle for the bulb but any glass bottle will do,
This in not a LED instructable. This is a direct response to the death of the incandescent bulb.
I harvested a tungsten filament from a 40 W bulb since I did not have a local source for tungsten wire,
The build is 40 W and I love the glow. I t has been running for a couple of weeks now with no problems. I tested the bulb with a constant run of over 24 hours in the shop'
There is a slight discoloration of the bottle near the filament (the glass turned blue) but the light is bright and constant...
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Signing UpStep 1: Materials
A bottle
A wiring solution.
Some brass rod and screws
Some wood for a base
The ability to braze
High Temp Silicone
glass drill
a vacuum pump
Free will
And some imagination
other materials will be required as presented.














































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This is an awesome instructable!
Don't know how pure, but it's sure better than plain air.
It is intended to keep the high heat from causing a reaction between the tungsten and other elements like oxygen, burning it up.
One might try sealing a burning piece of something (or other chemical reaction) inside to consume all oxygen creating a non-reactive environment.
I admit: I didnt read all the comments, but i thought of something:
You evacuate the bottle. Why not fill it with an inert gas? like CO2?
Longer lasting (Vacuum will not be hold forever) and simpler to create (since CO2 is heavier than air, simply pour it in the bottle and let the Air escape upwards & out of the bottle). Also a CO2-Cartridge is cheaper than a vacuum-pump (if you have to buy one).
My 0.02$ :)
A refrigerator compressor can be used as a vacuum pump, good enough who knows.
Old vacuum tubes used to use a getter, this was a ( i think ) a second filament that was deliberately burned out to consume remaining gas, perhaps you could add one.
Nicrhrome wire from a toaster might make a filament.
For quite a time edison used carbon filaments. He made them from bamboo that he carbonized by heating.
Refrigerator compressors produce good vacuum but I amnot sure if they can get as good as the 2 stage ones like I used. if you have to buy a compressor, for roughly the same price you can get a decent vacuum pump.
I inadvertently included a getter in this build as part of the filament wires. zirconium is used on the filament leads. check out my second bottle light...
I use nichrome wires in my glow lamps. They may be too thick to produce more light than heat.
I was reading about incandescent bulbs the other day and was surprised by how many factors contribute to the life of the bulb.
I am sure that was some interesting reading, I spent many hours myself in search of proper methods and answers..
I definitely learned a lot from this. A low pressure inert gas will be needed.
My 6cfm pump is rated down to 50 microns and I have seen as low as 12 on newer refrigerator systems. tested with an inficon pilot gauge. the bottle would do 100 but leaks were evident overnight.
more work is needed on this one but I am pleased with the results so far.
A high quality vacuum is extraordinarily difficult to achieve and maintain on Earth.
I'd say 72 hrs of burn is pretty good.
I like the tungsten deposits on the glass. It looks great.
What would happen if you placed a piece of aluminum tape on one side of the bottle and put a + or - charge to it? Could you steer the tungsten deposits toward one side?
How about a third electrode inside the bottle.
Home brew tube rectifiers anyone? Sweet!!
http://www.graphitesupplies.com/servlet/the-914/Copper,-Graphite,-EDM,-Casting,/Detail
It's expensive ($75), but at 100 meters you could make about 600 light bulbs.
I was also thinking about using the neck as the entrance point for the filament and leads. This would cut down the number of points that need to be sealed. I realize that would also make for a tight fit with the hardware.
There is a source of inexpensive wire on eBay that is located in Canada but definitely not local.
good luck with your project.
http://www.aliexpress.com/wholesale/wholesale-tungsten-wire.html
This place sounds like an electrical hardware store online(not had a chance to really check it out as of this writing, but saved the addy). If that's the case, I'll be spending lots of money at this place. LOL :)
The dark band might be the result of tungsten evaporation/condensation. You may also have some water vapor in the bottle. I don't know how you would remove all water vapor, honestly. Wikipedia claims that store-bought bulbs use zirconium to remove oxygen when the water is split by the high temperature. If water vapor is the problem, then the blue compound might be tungsten pentoxide. It might also be tungsten hexachloride, which might (???) have been introduced by a chlorine-containing brazing flux or chlorine-based cleaner. This is pure speculation though - I'm not a chemist, so I don't know the feasibility of creating these compounds in situ.
I think you could simplify this considerably by using Helium as an inert gas. It's lighter than everything but hydrogen, so you could invert the bottle and fill it from the neck. The helium will displace the air from the bottle. Then, just put the electrodes in through the neck and attach it to the base upside down, or hang it right side up.
Finally, if you look at the filament under a magnifying glass, you will see that it's tightly coiled to increase surface area and efficiency. There's no way you're going to be to replicate that at home. I think your approach to getting a filament from a store-bought bulb is probably the best one.
This is just blue-skying, but you might also be able to scavenge one from a "burnt out" higher wattage bulb. Grab the biggest piece of the broken filament and try stringing it between your electrodes. Of course, I could get off my butt and try it myself, but it's much easier for me to suggest that you try it in your very cool and beautiful creation.
I thought of putting the electrics through the neck but the cord hanging out the top presented a problem with aesthetics. I will be making the top stopper more covert so that it can be hidden beneath the bottle cap. The bottle shown was a proof of concept and more work is needed to make it pretty.
Final washing in extremely hot water then inverting the bottle to dry gets rid of most of the water. Running in a deep vacuum for a half hour tends to boil off the remaining moisture. My pump is a two stage oil bath type capable of producing a deep vacuum.
The discoloration must be from contaminates in the silicone or from the brazing process or as you mentioned from the filament itself..
Thank you again for your input.
Most people don't realize that true helium is a bear to store,
even in tanks. It is so small of a molecule that even steel
walls are "porous" to it, to some extent.
BTW, don't even bother with department store "helium" tanks.
That is NOT true Helium, but "Ballon Gas", a MIX of normal
air and helium most people use to inflate balloons.
That's why over a few days your balloons will slowly deflate to a
"medium inflation", and sink to the ground. The helium in the
mix has left the balloon, leaving only normal air.
In our case, trying balloon gas MAY expose the filament to oxygen!
In reality though, the Helium will leave your glass within days,
leaving only whatever other gasses they used to dilute the mix.
This may or may not include Oxygen.
TRUE "pure" Helium MAY work. The partial pressure will descend
until it is similar to the outside pressure. (I'm not sure what happens
after that...) But it is very expensive to buy. You're probably better
off (cost wise) with other, cheaper, more commonly available
welding "oxygen displacing" gasses, like Nitrogen or Argon.
- Keith
Still looking for an answer for the bluing though. I will try some different methods to isolate the source...