Introduction: Homemade Lightbulb

Picture of Homemade Lightbulb

Ever looked at a lightbulb and thought that doesn't look too complicated, I bet I could make one? With this Instructable you can!

This lightbulb is made entirely out of simple, mostly household materials requiring very little in special equipment. The basic construction includes a glass jar filled with CO2 and a graphite filament(Pencil Lead). This makes it a carbon filament bulb analogous to those made by Edison before tungsten became the norm.

Step 1: Supplies

Picture of Supplies

Materials Needed:

  • Jar and Lid
  • Pencil Lead
  • Maleable Wire
  • Heat-Shrink Tubing
  • 4 Machine Screws(I used 10-32 1/2")
  • 4 Nuts
  • 2 Acorn Nuts
  • JB Weld
  • Silicone
  • CO2 Canister
  • Short Length of Piano Wire

Tools Needed:

  • Drill and Bits
  • Wire Cutters
  • Needle-Nose Pliers
  • Vise-Grips
  • Scissors
  • Penknife
  • Screw Driver
  • Candle/Matches/Lighter
  • Air Nozzle(Only Unusual Tool Needed)
  • Oven
  • Voltage Source
  • Wire Leads
  • Multimeter(Optional)

Step 2: Hollow-Out the Screws

Picture of Hollow-Out the Screws

Drill a 3/32" hole through the center of each screw.

Two of these will become vents for filling the jar with CO2 and two will be for holding the wire hangers.

This is much easier if you first drill a hole in a piece of scrap wood to hold the screw in place. You may want to purchase extra screws because keeping the drill straight and centered is difficult and you will mess up at least once.

Step 3: Prepare the Lid

Picture of Prepare the Lid

Drill 4 holes in the lid arranged with equal spacing as in the photo.

Use a penknife to score the area around each hole on both sides of the lid. This will allow the epoxy to adhere better.

Step 4: The Hangers

Picture of The Hangers

Cut two lengths of wire approximately 10" long.

Clamp the wire in the vise grips with about 1.5" sticking out on one side.

Hold the length of piano wire against the vise grips such that it is perpendicular to the wire.

Use the needle-nose pliers to twist the wire around the piano wire.

Repeat for the second hanger.

Note: For my malleable wire I used 19 gauge stainless steel, though any solid core wire of similar gauge should work.

Step 5: The Hangers Cont.

Picture of The Hangers Cont.

Release the vise-grips and remove the piano wire, there should now be a nice coil to hold the filament.

Take a piece of pencil lead and place it in the coil. It will be quite loose.

Using the needle-nose pliers, gently adjust the coil so that it tightly holds the pencil lead. Only make small adjustments at a time.

Cut any extra length off the end of the coil.

Repeat for the second wire.

Bend the two wires such that they will hold the pencil lead vertically in the center and so the long leads align with the holes in the lid.

Step 6: Insulate the Hangers

Picture of Insulate the Hangers

Cut a 1" length of heat-shrink tubing.

Place it on the wire hanger at the area where it will go through the lid, about 4.5" from the bottom of the longer lead.

Apply heat to shrink and adhere the tubing to the hanger. A candle is the easiest way to apply heat though a lighter or even matches will work as well.

Repeat for the second hanger.

Step 7: Attaching Screws

Picture of Attaching Screws

Mix a small amount of JB Weld and apply to the outside of the heat-shrink tubing.

With the head facing down, carefully place the screw over the tubing and JB Weld. The epoxy needs to fill the hole in the screw as this needs to be an airtight seal. Also be sure that the screw is straight on the wire hanger.

Repeat for the second hanger.

Step 8: Mounting on the Lid

Picture of Mounting on the Lid

Mix a small amount of JB Weld and apply to the underside of the screw head.

Push the screw through the hole in the lid with the head facing down(inside the jar).

Tighten the nut on the opposite side of the lid.

Again be sure the epoxy fills any gap as this needs to be airtight.

Repeat for both vent-screws and hanger-screws.

Let the epoxy fully harden for at least a few hours.

Check for a good seal by tightening the lid on the jar and blowing into one of the vents while holding your finger over the other.

Step 9: Final Adjustments

Picture of Final Adjustments

After the JB Weld has hardened place a piece of pencil lead in the hangers to test fit and make any final adjustments to the hangers' positions.

Remove the pencil lead and thoroughly wash(with detergent) and dry the hangers, underside of the lid, and inside of the jar. The interior of the bulb needs to be free of any contaminants that will burn and cause discoloration.

If you have some latex gloves you should use them for the final assembly, otherwise thoroughly wash your hands as well.

Place a new, fresh piece of lead in the hangers being careful not to handle it too much.

Tightly screw the lid onto the jar.

Note: I used 0.7mm lead, though 0.5mm, and even 0.3mm should work as well. In fact the thinner lead will have a higher resistance and should make a brighter bulb.

Step 10: Prepare to Charge

Picture of Prepare to Charge

Place your assembled jar in the oven at 180 degrees. It will only need a few minutes to heat up.

While your jar is heating, apply a small amount of silicone to the inside of each acorn nut.

Step 11: Gas Charging

Picture of Gas Charging

This step should be completed quickly so it may be worthwhile to practice.

Remove the jar from the oven and place on the table.

Use your air nozzle to blow CO2 into the jar via one of the vents. Do this for close to a minute. The cold CO2 should fill the jar while the hot oxygen-containing air will be forced out of the second vent.

While continuing to blow CO2 into the jar, screw an acorn nut onto the open vent.

Remove the air nozzle from the vent and quickly screw an acorn nut onto it.

Tighten both acorn nuts to ensure a good seal.

Note: This is the only step that requires an unusual tool, the air nozzle. I got mine a few years ago at Office Depot. It is meant to be an air duster, however regular canister air dusters will not work. They are often filled with flammable gases such as propane and if you use one you will be creating a bomb, not a light bulb.

EDIT: As suggested by many in the comments, dry ice could be used as an alternative to a CO2 canister. Without heating first, place a small piece of dry ice in the jar and let it sublime into CO2 which will displace the air. After the dry ice has completely sublimed close and seal the vents. Do not seal the jar with dry ice still inside because it will continue to sublime and creative positive pressure which may become a safety hazard. I have not tried this yet, but plan to soon.

Step 12: First Test

Picture of First Test

Connect your bulb to a voltage source.

When the bulb is first turned on it will smoke a little as it burns the small amount of oxygen left in the jar. Run it for about 30 seconds and then let it cool and the smoke settle.

12 - 24V should be perfect so long as it can provide a high amount of current. I used two 6V NiMH batteries connecting in series.

Optionally, use a multimeter to measure the resistance of the bulb and with V=IR find out how much current your bulb will pull.

However, as graphite heats up its resistance decreases so the resistance you measure before turning on the bulb will be higher than it will be when on. This is one of the reasons we now use tungsten filaments because tungsten's resistance increases with temperature.

Step 13: Completion

Picture of Completion

The bulb is now completed!

If you are running it from batteries be vigilant that you do not overheat your batteries.

Unfortunately it is not very bright so don't count on replacing your household lighting with it. You can try increasing the voltage to increase brightness, though be careful as the higher voltage you use the higher the current will be.


عبداللها40 (author)2018-01-08

جميل جدا

Altoidian (author)2016-10-30

I like it. The dry ice method seems the most practical for filling the jar with CO2. It is easily available and you don't need any other devices. I would probably use a small bubble cup valve since no real pressure is involved. This valve is very similar or exactly like a beer or wine making bubble air lock valve.

See here:

Just let the dry ice sublimate completely ...and then seal the hole where the "J' tube comes out of the jar lid. Another great source of pure CO2 is club soda. Hooking up a bottle of the carbonated water to the jar with vinyl tubing would be easy enough. Just let the gas in and flow out through alternate hole that is similarly sealed as a one way valve. CO2 is heavier than air and will not be easily displaced once the jar is filled even if all you have is a small hole in the top of the jar lid. once the CO2 is flushed in, just seal the hole with JB weld or even solder.

I enjoyed your easy to follow explanation and detailed list of supplies and tools. Great job.

unbottled19208306 (author)2016-07-28

Using a brake bleeder vacuum pump to extract all the air out will help a lot with the smoke.

unbottled19208306 (author)2016-07-28

Using a brake bleeder vacuum pump to extract all the air out will help a lot with the smoke.

unbottled19208306 (author)2016-07-28

Using a brake bleeder vacuum pump to extract all the air out will help a lot with the smoke.

rheza.rijaya (author)2016-02-23

i ever read a that book there is steps to make a using candle inside the jar to remove the oxygen (remember how fire made)

KROKKENOSTER (author)2014-07-19

Returning to the roots! Scantelcorps if you want to make a diode or a triode the vacuum in the container must be as high as possible! The tubes made in factories use mercury vacuum pumps to get a super vacuum Oil pumps were also used. To get rid of the last atoms , a getter with magnesium is built during assembly in the container or bulb which get heated and this absorb the last atoms. If you would look at a glass tube then you would see a silvery patch on the inside. If the bulb get cracked then this silver turn milky white showing that the vacuum inside got destroyed.During WW2 Germans made tubes inside liquor bottles! They were not so effective as the vacuum obtained was too small but they worked!

Drake411 (author)KROKKENOSTER2015-06-17

I would like to ask a chemist about this because it occurred to me some time ago that CO2 is absorbed by lime and Portland cement. I wonder if a small chunk of CO2 absorbing chemical could be anchored to the inside, the bottle heated to reduce pressure then sealed. Finally the lime would hopefully absorb the last of the CO2 over time creating the desired vacuum. I've lost the paper but I think sulfuric acid absorbs certain gases. Hence my need for a chemist. The "getter" with magnesium in your comment really interests me. Any search terms that you can suggest would be very helpful. Since most of the gases they used were inert with no chemical activity I am glad to hear there may be an absorber that will bump up the vacuum of my less than perfect vacuum pump alternatives.

Thanks for that Krokkenoster. Agreed that a vacuum is required in a radio tube as opposed to CO2. Gasses tend to absorb electrons rather than allow current flows across to the plate.

My suggestion was a bit tongue-in-cheek because I have serious doubts about the ability of the carbon filament to even develop a sizable space charge to begin with. Interesting to speculate and experiment with though.

kschmidt2 (author)2015-01-14

a thought for an easier way to get CO2 in and oxygen out would be to get a tub of water, after sealing the jar, take the two screws off that you used to feed the CO2 in and the oxygen out, but instead of heating it, stick the vents in water, the jar is upside down, so no water can get in, then, in one screw hole, pump CO2 in, and the oxygen will be replaced by the CO2 and it'll come out of the other hole, in theory anyway, I think this'd work better with a lighter than air inert gas, like Helium. If I'm not mistaken helium, being a noble gas is not flammable, and should do the trick, but I could be wrong.

josuchav (author)2014-09-17

So, I see a lot of repeated comments, but couldn't find an answer to this question (which was asked before). What if I want to plug it into my wall outlet?

Assuming: a good gasket, using a bucket filled with inert gas so all the parts are in an inert bath as mentioned above, and potentially encasing the entire outside of the top in a slab of epoxy to help prevent leakage,

would it be doable to plug it into the wall?

JM1999 (author)2014-09-08

Do you still have to shake the jar well?

Nice replication of a household piece!

SphericDirection (author)2014-09-05

Magnificent, I'll certainly be having a go at this one. I love making things with a historic inspiration.

TickMagnet (author)2014-08-20

Some may consider it cheating but if you want to use tungsten to make your bulb just take the filament out of a store bought light bulb. If you want to try it old school Edison burned strips of bamboo to make his carbon filaments. I think a plumber's torch and some bamboo skewers split into strips would work fine. You would have to experiment to try bamboo.

diy_bloke (author)2014-07-31

Although i dont see much practical use, i think it is fantastic!!!

And I may make one, just because it is possible.!!

Would look great in some steampunk contraption

Applerust made it! (author)2014-07-28

I changed a few things but used some ideas from your instructable. First off, graphite didn't work out very well at all. I got it to light up but it was very dim and burned out fairly quickly. Getting inert gas in the jar was a bit of a pain. I could not find anything to put co2 in there with. So, I made an attachment for some co2 cartridges. The attachment worked but there was so much pressure from the co2 canister that it held the valve open on the end and there was no closing it. A ball valve in the mix would have worked better. Tried dry ice but the jb weld took something like 7-8 hours to dry instead of 4 so the dry ice was no longer around for use. In the end I went with some wine saver from a local wine store. The wine saver is "Private Preserve" and it's made up of argon, carbon dioxide, and nitrogen. All three inert. As far as looks go and money go, I strongly suggest against worrying about inert gas and against using graphite unless it's for a science project and you need to use these specifically.

I wanted to build this as a costume prop. So, how it looked was more important that how it was made. I cheated.

I used nichrome wire instead. First I used 30 gauge but that was a little dim for how I wanted it to look. In the end I went with coiled 34 gauge nichrome wire. I also used a smaller jar. Nichrome is cheap and this thin of a gauge lights up nicely. You don't have to worry about getting burned once the filament is inside the jar. I tested this. Since heat rises, the top of the jar (however it's oriented) is the part that will get the hottest and even that part doesn't get too hot. You can still touch it and not get burned. At least, this is true in my case, with this specific jar. A thinner walled glass jar may allow you to be burned with this setup. So, if you try this, be careful.

Thanks for the inspiration!

KJ4ZVQ (author)2014-07-20

You could try using something called kanthal wire as the filiment. its a resistive alloy wire used in heating elements and Ecigs/vaporizers. I know I've built coils that have burnt white-hot in open air.

mrwolfe (author)KJ4ZVQ2014-07-28

Is that nichrome? Nichrome wire should work well.

alcurb (author)2014-07-10

In a post-apocalyptic planet, this is a good start. Obtaining CO2 cartridges in such a world might be difficult since that is something that is not usually carried around by common folk. However, using something chemically reactive that produces CO2 is a consideration (e.g., fizzy tablets + H2O). Create the gas in a soda bottle and then feed the gas into the bulb jar. If you find that the resulting gas is too humid, you can feed the gas into an intermediate bottle containing salt or silica desiccant bags to dry the gas before feeding it into the bulb jar.

As a side note, a person I know locally had made a rarified-gas bulb from a high voltage supply, rubber tubing, ink roller, strong clip, and a glass cylinder blown fuse (filament gone). He connected the HV power supply to both ends of the blown fuse. The one end cap of the fuse had a small hole drilled into it. That end was connected to the rubber tubing. The other end of the rubber tubing was left open to air. The idea is to create a vacuum inside the the fuse body. So with the ink roller he kneaded the air inside the tubing away from the fuse body all while the the power is applied to the end caps of the fuse. The gas inside the fuse began to glow as a blue-violet light. Again, this was experimentally fun, but not very practical because of the small amount of light it produced. The clip in the parts list was used as a crude one-way valve for the rubber tubing. As you knead the tubing the clip allows the air to be squeezed out but it doesn't allow the air to come back in. Not perfect because there is always some leakage, but it worked nevertheless. I can't remember how high the voltage was coming out of the power supply, but it didn't arc in free-air when moving the output terminals closer together, about 5mm apart. Would that put it in the 5kV range?

To those who want to try the gas bulb, please always assume that the High Voltage power supply WILL KILL YOU. Even if that might not be true, treating HV with respect like that may help you get in the habit of taking these safety precautions. One rule I learned long ago in electronics class, when handling a live HV circuit, always keep one hand in your pocket to reduce the likelihood off accidentally conducting current across your chest and stopping your heart.

alcurb (author)alcurb2014-07-15

I was thinking a little bit about using CO2 as a displacement gas to get rid of the O2, but as suggested by another user, an inert gas such as argon would be a better choice. Evacuate the container then refill with argon. I have read that applying heat to CO2, as with the filament, may cause the gas molecules to disassociate, and since there is always going to be a bit of water molecules in the gas, it may produce carbon monoxide, carbon and oxygen. Helium might be more readily accessible (and cheaper) than argon as it is the gas of choice for flying party balloons. However, helium is tricky because it doesn't settle down as the other heavy gasses.

mrwolfe (author)alcurb2014-07-28

So Turn the jar upside down to purge! The helium will float to the top and displace the air.

Kante Tech (author)alcurb2014-07-16

I dont know why but I automatically thought about Zombies.

Mr.Fishers3 (author)alcurb2014-07-10

Oh man, now you've got me wanting to do build a gas lamp!!!

Also, I considered the chemical reaction route but chose not to because of the impracticality though it should work.

tomc53 (author)Mr.Fishers32014-07-10

Actually, as someone mentioned above, a tea-light would convert the oxygen to carbon dioxide, handling both point at once. The only gotcha is to burn the candle near the top so that it would not go out until all of the O2 + C became CO2. Give it a try - Put a candle into an open jar and light it - it will go out as the CO2 sinks to ghe bottom and displaces the O2. (Old Chem Teacher trick.)

PKM (author)tomc532014-07-11

I think the chemical reaction would give you the best results of the simple methods. Yes, a burning candle will convert oxygen to CO2 but only while there's enough oxygen to support combustion. At a certain point there will be some oxygen remaining in the jar but not enough to keep the candle flame alive. The vinegar/baking soda reaction generates CO2, which if done carefully could well displace almost all the oxygen in the jar.

Gerrick-Designs (author)2014-07-26

This is pretty sweet, nice job!

If im not mistaken tho, and i could be, I believe according to ohms law, current and voltage are directly and oppositely proportioned. So by increasing your voltage you should effectively decrease your current draw. This is why a lot of commercial buildings run lighting at 277v not 120, allowing you to run almost double the lighting load at a reduced current draw.

Perhaps its different for resistive loads, I cant actually remember.

mrwolfe (author)Gerrick-Designs2014-07-27

I'm with you, Gerrick, this is seriously cool!

Regarding Ohms law though, current and voltage are usually proportional, with resistance being the constant of proportionality. The formula for Ohm's law is V=IR, which can be rewritten as I=V/R or R=V/I, so that if resistance is constant (which is mostly the case) increasing the voltage will result in an increase in current. The power drawn by the circuit is equal to the voltage times the current P=VI, which can be rearranged into different forms:


What I think you are referring to is the practice of delivering power using higher voltages to reduce current draw. Lets say you want to deliver 100 Watts. You could use a voltage of 10 Volts and a lamp with a resistance of 1 Ohm, in which case the current drawn will be 10 Amps. Or you could use a voltage of 100 Volts and a lamp resistance of 100 Ohms. The power will be the same - 100 Watts - but now the current is only 1 Amp. You could go as far as you like (1,000 Volts, 10,000 Ohms, 0.1 Amps - 10,000 Volts, 1 Megohm, 10 milliAmps - still 100 Watts), but you do start to run into problems containing the higher voltages.

The problem with low voltages is that high currents require thick cables to carry them. Not so much of a problem for a few light bulbs, but if you need to power a city you need to carry megawatts which is why electricity is carried across the country at high voltages (150,000V for example). You are right about commercial buildings - large buildings with lots of lighting need Kilowatts of power so higher

electro18 (author)2014-07-24

Awesome Idea !

Applerust (author)2014-07-23

Can you be a bit more specific with the "air nozzle" tool? What's it specifically called? What's it look like? I have no idea where to find one of these.

Applerust (author)Applerust2014-07-24

Is this the thing I need?

saeledbetts made it! (author)2014-07-24

Look at it glow!

MoTinkerGNome (author)2014-07-23

Hmmmm I have some Tungsten wire left over from a hot foam cutter project that never got finished. I may have found next weekends project for the boy and I. Make a light bulb....

British Badger (author)2014-07-22

Ive voted for you in all 3 compation

Jack Moran (author)2014-07-13

You have my vote!

Gary Viveiros (author)Jack Moran2014-07-21

The good thing about halogen lights is that they burn hotter than normal filaments because the non-reactive gas circulates, drawing the excessive heat away from the filament and to the quartz-glass surround which can handle the heat (unless water droplets or a stray sawdust particle lands on it).

scantelcorps (author)2014-07-10

Nice! have you considered trying to add a third electrode configured as a plate hanging near the filament to see if you can demonstrate a diode? And, if you are successful with that, maybe a screen grid control element will allow the construction of an amplifier! My oh my. Just think of the applications that might be possible then!

ncaruso1 (author)scantelcorps2014-07-11

gas in envelope ->

KROKKENOSTER (author)ncaruso12014-07-19

Ncaruso Thyratrons as far as I know, were used as switches in industrial pulsed welding applications as well as regulators for chargers. If you know the operation af a "THYRISTOR" then you will discover that "Thyristor" is a combination of thyratron and transistor How's that for a technical history lesson! I lived through it!

monoverde (author)scantelcorps2014-07-10

baby food jar amplifiers?

scantelcorps (author)monoverde2014-07-10

Sure! Amplifiers, oscillators, transmitters, super hetero-dyne radio, color TV.... it staggers the mind. Might even invent a flip-flop and build a small computing device. From there, why not hook them all up world-wide into a kind of network?

DIY-Guy (author)2014-07-18

I was wondering if there's a possibility of shorting all those drilled screws with wires, because they are all connected to the same metal lid? Should any extra steps be taken to prevent shorting out?

Applerust (author)2014-07-16

What else could be used as a filament other than graphite, cotton string coated with graphite, and tungsten? Anything?

Mr.Fishers3 (author)Applerust2014-07-16

Anything that will provide small resistance and heat-up/glow under electrical load. Unfortunately besides carbon, the other options consist mostly of rare metals such as tungsten.

Kante Tech (author)2014-07-16

Would adding a booster circuit affect how bright the lightbulb is? For example using a Joule Thief.

Mr.Fishers3 (author)Kante Tech2014-07-16

Yes it would, if your booster could sustain enough current output. Just running at 12V was pulling about 5A. The more you increase the voltage, the more current it will pull. Adding a booster will even further increase the current pull on the battery, since it is basically trading current for voltage.

ZaneEricB (author)2014-07-14

Would argon gas be able to be used as well or only CO2? I am not sure of the science behind the CO2.... but just thought Argon could replace the air inside...thoughts?

Uncle Kudzu (author)2014-07-09

OK, that's entirely too cool. So would it just burn up/out without CO2?

Algag (author)Uncle Kudzu2014-07-10

Im thinking that to remove the oxygen you could:
A) Burn a tea candle in the container. If you left a pin hole in the chamber, the combination of heat and an increase in the # of gaseous particles would raise the pressure and it would push the extra out (or you could deal with a bit more pressure).

B) Fill it with propane. I know, I know, propane is flammable. But considering no one is going to light their house with these it should be fine. You are using the propane to displace the oxygen, which it also needs to burn.

Mr.Fishers3 (author)Algag2014-07-10

While true that you're using the propane to displace the oxygen, I wouldn't use it unless you were very very certain that you had displaced 99.99% of the oxygen. And even with just the CO2 I used it still smokes a bit showing that there was still some oxygen leftover.

Mr.Fishers3 (author)Mr.Fishers32014-07-10

Actually I just checked, and the explosive limit for propane is 10%, so in theory it should be safe. But I'd still be extremely cautious.

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