Introduction: Leyden Jar of DOOM!

About: Electronics engineer with allot of mechanical design expertise email I dont check here often for messages so email me if you have one
OK so you have built a large
Van de Graaff Generator
now you want to take it a step further and up the spark current.

A good way to do that is to use a leyden jar and build up a large charge in it and watch the powerful sparks fly.

This Leyden jar is made from a 5 gallon bucket and stores enough electricity to kill you.

I strongly recommend building a smaller one unless you know what your doing.

The leyden jar is a very old design dating back to the late 1700's
Its simply put a high voltage high capacity capacitor.

Built properly and treated like a loaded gun you too can make your own miniature lightning bolts.
Trust me when i tell you that a discharge from this device is loud enough to damage your hearing so wear hearing protection.

I have experimented with high voltage for many years this is one of the more dangerous projects I have completed so please be careful. I accept no responsibility for your injury or death.

Have fun and please be safe,
Zachary M.

Next up parts list.

Step 1: Parts and Tools Needed


5 gallon plastic bucket
Roll of aluminum foil
copper pipe 1/2" diameter or larger
small piece of copper sheet
round door knob
spray glue (i used contact cement)

Drill with bits
masking tape

Step 2: Ready the Bucket

Remove the handle with the pliers and clean the bucket inside and out with alcohol.

Next you will want to make a perfectly level line around the bucket about 10" from the bottom.

I stacked some books next to the bucket and held a sharpie on them and turned the bucket around wile marking a perfectly level line.

Step 3: Tape It Up...and Spray

Tape along the line you just made.

now spray the out side of the bucket with a few coats of contact cement.

On a smaller leyden jar i would recommend aluminum duct tape, but you have a huge surface area to cover on this one.

let the glue dry...

Step 4: Put on the Metal

I started with the center of the bottom and pushed the metal into every crevice I could.

I also resprayed the bottom over the metal and put on another coat for a little more durability.

next do the side getting out all the wrinkles as you go along. If you used the thickest aluminum foil one coat is fine.

just coat up to the tape line. I let mine over lap and I cut along the tape with a sharp knife to make a perfect edge.

Step 5: Mark and Tape the Inside of the Bucket

Next I measured down the bucket to the top of the foil and made a mark on my ruler.

then I taped a piece of plastic to the ruler on that mark to make a makeshift gauge.

I then used it to mark the inside of the bucket. Simply but it up against the lip of the bucket and mark below the end of the ruler.

Step 6: Tape the Inside and Spray It

Tape off the inside and spray it as you did the outside.

Step 7: Foil the Inside

I started with the bottom and then glued strips up the sides.

I also cut off the excess and made sure the edge was sharp and level.

You can over lap the foil just spay the glue on the foil and let dry then apply.

Step 8: Center Post

I wanted a good connection with the center post so I cut the pipe so that it ends about eight inches above the rim of the bucket and soldered a piece of copper sheet 4" square on one end.

Step 9: Center Post Installed

set the center post in place and glue it down with strips of foil.

Make sure its as close to center as you can get it.

Step 10: Put on the Lid, Opperation

Now simply drill a hole in the center of the lid and put it on the bucket.

Secure the door knob to the tip of the post and its done.

I will be looking for a better ball for it and will post the changes later.

Now that you have built it simply connect the doorknob to a VDG and charge up!

For a big spark connect another door knob to a pole that is connected to the outside of the leyden jar.

It will be the negative side and the center post the positive.

To discharge it without hurting your self, make a set of discharge tongs from the old bucket handle and put them on the end of a fiberglass pole. Then short out the outside of the bucket to the center node. Yes a large spark will occur.Touch the outside of the bucket first so as to not burn holes in the aluminum.

I will add a video when I get my test stand done.

Thanks for looking and please be safe.
Zachary M.