Introduction: Make a Water Leyden Jar

Here is another type of high voltage capacitors - a Salt Water Leyden Jar!

Don't know what a leyden jar is? No worries! Read here on Wikipedia!

The water leyden jar is easier to make than a normal leyden jar because putting foil tape perfectly on the inside of the container can be very difficult. If the foil tape job is messy, it can cause a lot of corona discharge, therefor draining its charge very quickly. So instead of having a hard time of perfectly putting foil tape on the inside of the container, just simply pour salted water in!

The leyden jar is a high voltage capacitor, high voltage capacitors are one of the most dangerous things you could ever use in electronics. A large charged leyden jar is potentially lethal if you touch its live terminals, and a small charged leyden jar can cause injury and it still be lethal in some ways.
So, I am not responsible what ever you do with this information and leyden jars.

Step 1: Get the Things!!

Okay, what you will need is...

  • Plastic or glass container
  • Water
  • Salt
  • Stainless steel nail
  • Aluminum foil (or even better, use AL foil tape if you have any!)
  • Tape (you won't need it if you are going to use foil tape)

Step 2: And the Tools...

Not many tools are needed to make a Leyden Jar.

  • Hammer
  • Hot glue (or anything to seal up the container to prevent water coming out)

I think that is just about it.

Step 3: Take the Sticky Stuff Off!

Before we start making a Leyden Jar, take all of that sticky stuff off! It can reduce the performance of the Leyden Jar, or even cause problems if you don't take the sticky tags off!

Step 4: The Construction of the Leyden Jar Begins...

Cut out a narrow sheet of foil about a centimeter or two shorter than the jar. Then wrap the foil around the jar, I used tape to hold the foil onto the jar. You can use glue if you want, but don't use flammable glue because of sparks, it is likely to catch on fire. There has been a report a leyden jar had exploded because the creator used flammable glue on the inside of the leyden jar.
After you wrapped the jar with foil, put some more tape on the top and the bottom of the jar to give the foil more protection from damage.

You can use something much much better than foil, use foil tape. You can just simply tape around the jar and not have a hard time wrapping the jar with foil and tape (or glue).

Step 5: The Wet and Salty Part...

Fill the jar with warm tap water. Then add a few teaspoons of table salt, and stir well!
After that, put the lid of the jar back on! Now it is a Leyden Jar!! (Well, almost.)

Step 6: Hammer in the Nail!


Hammer in the nail in the center of the lid, and leave the head of the nail about a centimeter away from the lid.

Step 7: Seal It.

After that, put some hot glue around the nail and the lid to stop the water coming out.

Step 8: Mission Almost Completed...

Attach a piece wire to the foil of the leyden jar.

Step 9: Completed!

There! You made a salted water leyden jar!

I also added a magnet and a ball to make it more "Leyden Jar" like.

I measured the capacitance of my leyden jar, and my meter reads 946pF, that is about 1nF! that is quite high for this small leyden jar!

Step 10: What to Use It For.

If you want to electrostaticly charge your Leyden Jar, read this site, it will show you how to make a simplest charger you can ever make.

Or even far more dangerous, treat it as a normal high voltage capacitor, you can use it as a capacitor bank for the tesla coil, or something like that.
I tested my leyden jar with high voltage power supply to see if it works. Never ever do that, unless you have good experiences with high voltage.

Step 11: My Set Up.

That is not my only leyden jar I made, I made many more, even leyden jars made out of wine bottles, but they did not turn out right, so, I threw them out..

I used my high voltage power supply (flyback transformer driver) to test the leyden jar I made, it works very well, and makes very bright sparks! I could probably use this as a Tesla Coil capacitor bank..

Well, I hoped you enjoyed this instructable!
If you have any questions, or need help, or found an error, or anything, make a comment! I like comments! :)


JoeG17 made it!(author)2017-06-11

What I would like to know how can you calculate the capacitance? Haven't got a meter.

evancyk made it!(author)2016-09-07

Hi, this is a really detailed instructable! I'd like to ask:

Could you please detail the way you charged up the jar? The link you've attached doesn't seem to be working. It'd be great to find a method where the charge is roughly the same every time.

How can you safely disassemble this without getting a shock? It seems dangerous to simply throw the whole thing away.

Any help would be much appreciated! Thanks so much

JoeG17 made it!(author)2017-06-11

Just take a short piece of insulated wire and touch the nail and the outer foil at the same time. It is then discharged. You can repeat just to make sure

YoloPeeps made it!(author)2017-01-02

Static is over a million volts. You could have 1,000,000,000,000,000 volts and 0.5 amps and you would not die.

JoeG17 made it!(author)2017-06-11

0.5 amps at THAT voltage is lethal. You should go to micro amperes.

rallekralle made it!(author)2017-03-16

i don't know about that, 0.5A is quite a lot at those kinds of voltages. i think you'd probably have to go down to less than 10mA at 10^(15) volts to survive.

but i'm no pro. so who knows.

wolf996 made it!(author)2012-10-27

It's Actually The Amperes That Kill Not Volts I Have Taken A Nasty Shock By A Million Volt Stun Gun

derekiswise made it!(author)2015-05-25

it is a combination of amps and volts that are able to kill. you have to have enough voltage that the charge is able to make it through the resistance of your body(skin. etc) but once you over that voltage (no, i dont know the exact value, it probably varies a lot) the amps do damage. in the future please dont make such a "blanket response" as it is a combination fo many factor that determine fatality. IN TheKingOfRandom's youtube channel there is a video where he grabs onto the live ends of a modified microwave oven transformer, he brought the voltage down to just 3 volt with it and although there was lots of amperage (he used it to weld steel washers) there wasnt enough voltage to go through the skin.

(I nearly killed myself while taking apart a 60cm crt tv that was just plugged in. i cut the cord going to the cathode ray tube and was knocked against the wall and temperarily blacked out.... fun..)

one.kender made it!(author)2015-09-06

I have always found this whole argument to be extremely ignorant...yet I see it everywhere. All you have to do
is look at ohm's law (V=IR) to realize that Voltage, current, and
resistance are related. Current, resistance, and voltage, it turns out,
are all just different aspects of the same thing--the flow of charge (or lack thereof) across a difference in potential. If you doubt this, set any of the values to zero and see what happens.
This is not enough information. It IS the flow of charge that causes burning and "clenching", but
that's only part of the picture. Next, you have to think about current
density (or energy) because a heat is easier displaced by larger objects across greater surface areas
and it's a concentration of heat that burns. Finally, we must think about the speed at
which that energy is displaced, or power. A
large, quick burst of energy does more damage than a smaller flow over a
longer period of time, even though the same amount of energy is
displaced. Again, heat is dissipated as it is being added as a function of In truth, it's not potential OR current that kills. It's not even energy, it's POWER.
Ohms don't kill, Voltage doesn't kill, and neither do Joules, WATTS KILL. Now all of this was somewhat over-simplified, but you should get the idea. There ARE other things
that come into play, too. Some organs are more susceptible to damage than
others. There are also differences between the way AC and DC affect
different parts of the body. Both of these make both the type of
electricity, the path it takes through the body, the frequency (if AC),
and the phase of that frequency with the heart and other bits (also for
AC only), and others but it is the power of the zap that does it, not
simply the potential or the current.

aclark17 made it!(author)2016-12-19

Preach it, brother!

aclark17 made it!(author)2016-12-19

It depends on AC or DC but I always think 35V just to be safe as I use AC quite often and the rule is about 50VAC. Just don't touch wires and you'll be fine lol

Spoonerdog123 made it!(author)2016-06-19

Here is my attempt at it! Hopefully the metal lid won't matter, I actually put some plastic tubing over the electrode wire so it can't touch the lid! Now I need to add some water and find a way to charge it up somehow :)

Thanks for a great instructible by the way, lots of fun making this!

Spoonerdog123 made it!(author)2016-06-19

Hi there!

Great instructible, but I'm wondering if there is any problem with using a glass jar with a metal lid? I can't see it causing any problem since the electrode is going to be touching the water and the glass is a good insulator but I though I should ask! Thanks!

FlareFolf made it!(author)2016-05-26

i made it but i made a really stupid mistake and used a jar with a metal lid x3

Squeal+boy made it!(author)2015-08-30

Even a fraction of a amp can kill you

gilligoon made it!(author)2016-04-13

Yep, a fraction as low as about 2/100.

rndmsfree made it!(author)2015-10-29

How long will a charge last in a reasonably well-built jar? Batteries will slowly drain over time. I assume these do too?

gilligoon made it!(author)2016-03-29

If you live anywhere that is ever humid (even deserts are humid at night) then there will be high leakage, you need a very dry environment for static experiments to work well.

jbrown146 made it!(author)2015-12-14

Realistically just about never.

DominickM7 made it!(author)2015-12-15

can a gkass jar be used

ItsNick made it!(author)2015-04-28

The nails have to touch the water? And can I wrap the outer layer with some tape for better looking?

ender_scythe made it!(author)2015-11-22

The nail has to touch the water and the foil has t contact the bottle, the foil has to be exposed.

jbrown146 made it!(author)2015-12-14

The foil does not need to be exposed as long as your wire can make contact with it. It would actually be slightly safer to cover the foil with electrical tape to insulate it a bit.

cmackenzie2 made it!(author)2014-12-12

is the tinfoil touching the inside of the jar ? or is it just on outside

GrimReeper9001. made it!(author)2015-03-04

Just the outside, the foil is used to "ground" the Leyden jar when it is ready to be used.

Kiteman made it!(author)2015-03-05

As your physics teacher should have told you, the charge is stored at the conductive surfaces - the charge flows when the surfaces are connected.

mrmolamola made it!(author)2015-01-05

Should the foil be wrapped all the way around the container?

GrimReeper9001. made it!(author)2015-03-04

Yes, it is more effective when you wrap the foil all the way around the container.

Chikpeas+Brother made it!(author)2014-03-31

Disclaimer aside, what damage could you really expect this to do to you?

GrimReeper9001. made it!(author)2015-03-04

My Physics class made some of these, and they had only 2oz. of salt water. When they are properly built and charged, the 2oz. Leyden jar produced enough charge that it actually traveled through the teacher's arm and he could feel it in his chest. If you were to make a large Leyden jar, say a 2 liter jar, then it could hold enough charge to do nerve damage or damage a pacemaker. They are more dangerous as the size grows.

ryan.sergas made it!(author)2014-12-22

Ohm my god, it works!

andersmolzen made it!(author)2014-09-04

The chain will live om!

impedance214 made it!(author)2009-09-29

do a 9v battery will work?

jwoo2023 made it!(author)2013-10-25

A way to charge the leyden jar is to get a tube of PVC piping, then get a tissue or cotton cloth then rub it till you can hear craclking, then put the pipe near the nail and repeat for as much as you want.

G.J.+Dyason made it!(author)2010-09-23

if you scale this down alot a 9V batery should work but the charge you'll be able to store will be REALLY tiny!

Plasmana made it!(author)2010-03-20


Pie+Ninja made it!(author)2010-01-08

Proabably not, that's a very low voltage.

jwoo2023 made it!(author)2013-10-25

Yay, it works!

dupes888 made it!(author)2013-08-22


knexpert1700 made it!(author)2012-05-28

Even though this is basicly a capacitor,you can buy a disposable camera (or get a free used on from where ever film is developed) and look up on instructables ''how to make a mini tazer'' and you will find a one where the tazer is like 1 square centimeter in size.This is about 400-500 volts and is only powered bye1 or 2 AA batteries and takes up to an hour but usually takes 20-25 minutes.
Have fun and be safe!(or not! :-))

knexpert1700 made it!(author)2012-05-28

What I said before when I said ''it takes up to an hour or 20-25'', I meant to make,not to charge!10 minutes if expert,25 minutes if s to intermediat,30 minutes if beginner,45 minutes-1 hour if no all. experiance at

Homepwner made it!(author)2012-02-04

I tried this with foil tape both on the inside and outside of the jar. It didn't work . Most likely because the adhesive acts as an insulator so the joints do not conduct. I wouldn't recommend using foil tape. I figured this would be a problem before the build but I thought I'd try anyway.

mdwfg made it!(author)2012-01-06

Dear plasmana i like your works but i wanted to tell you this:
energy can be created or destroyed if a positive and negative charge is created at same exact time or if a positive and negative charge is destroyed at the same exact time respectively.

Higgs+Boson made it!(author)2012-01-12

well I certainly hope this isn't true! If it was then our ideas of how the world work are completely wrong! Almost all theories of physics are based on thermodynamics.

MadScientist101 made it!(author)2011-07-21

I 'm not dissing your ible but i found that a tin foil lining gave me a 10x improvement in capacitence

cyberkeeper1 made it!(author)2012-01-09

thats only because there is not a layer of glue interfering with the conduit.

greymatter21 made it!(author)2010-04-26

nice  job!!!!!!!!!
1 question:what exactly would this be used for wen fully charged?

franzwa made it!(author)2010-05-02

tesla coil or some thing

freeza36 made it!(author)2012-01-06

or a trick taser ("touch this wire while holding the nail. it doesnt hurt, i swear")

Kryptonite made it!(author)2008-09-28

wtf is an nF or pF?

About This Instructable




Bio: ––––––––––––––––––––––– "Energy cannot be created nor destroyed!" –––––––––––––––––––––––
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