How To Make An Electrical Arc Furnace

How to hack flashlight batteries and a fire brick, into a desktop arc reaction chamber. …For hobby metal melting, and for science!

Some quick links to a few of the materials I used:

[✓] Lantern battery:
[✓] Forstner Bit:
[✓] 3/8 Drill bit:

Endcard Links:

Micro Welder:
Laser Blowgun:
Magic Mud:
Matchbox Rockets:

See What Else I’m Up To:


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Risk of electric shock, fire hazards, and toxic fumes depending on what material you’re working with. Dust from refractory brick should never be inhaled, as it can damage lungs and cause long term respiratory challenges. This project can reach temperatures in excess of 3,000ºF (1,648ºC) which is well beyond the melting point of hobbyists. Caution, care and expert planning are required to mitigate risks. Have fun, but always think ahead, and remember that every project you try is at your own risk.

Music By: Scott & Brendo (“Photographs” – Instrumental)

Project Inspired By:

This project was originally inspired by Theo Grey and his book, “Mad Science”. After seeing the concept, I couldn’t find any information anywhere on the internet or in libraries about arc furnace experiments, so I set out on my own to achieve these results.

Project History & More Info:

If you’re wondering where you can get fire brick locally, try a quick Google search for “refractory materials” in your city. I called a couple of companies near me and asked if they’d sell to the general public. All of them said yes.

If you can’t find anything locally, try searching major hardwares stores online. They usually have inventory online that they don’t carry in the stores.

The insulating fire bricks I got were the 3” x 4.5” x 9” Alumina-Silicate Brick variety. I got a box of 10 for $33, effectively making them around $3.30 each. I went one step further and designed the furnace so that 2 of them could be made from one brick, cutting the cost in half, making each furnace a pro-rated $1.65 each!

They’re extremely lightweight, and capable of withstanding the temperatures used in steel working, but soft enough you can cut and carve them with kitchen utensils if you need to.

In reading and studying history a bit, I learned that some of the earliest forms of light were made using carbon arc lighting. Large amounts of electricity were pumped through carbon rods, making a bright arc and providing light.

To scavenge carbon electrodes, I took a lesson from NurdRage ( a couple of years ago I saw his video on what could be scavenged from a carbon-zinc lantern battery ( It’s useful to know what common everyday materials are made of, and these heavy duty batteries are containers packed with carbon rods, zinc metal, and manganese dioxide. I tucked the information in the back of my mind until now.

In this project I tried melting the zinc casings from the lantern batteries, and casting them into a small ingot, formed with a mini muffin tray. Be cautious of the zinc oxide fumes produced. I haven’t personally suffered any ill effects from working with it, but some people claim it can give flu like symptoms, or a fever if inhaled in large quantities.

Zinc has a relatively low melting point 787.2°F (419.5°C), so the Arc Furnace is able to melt each casing into liquid zinc in around 5-10 seconds. That’s amazing!

I don’t have an exact purpose for the zinc yet, but it’s an easy metal to work with, easy to cast, and great to have on hand for a future projects. It’s also one of the main metals used for making a simple carbon-zinc battery.

The black stuff pulled out of the battery casings is manganese dioxide. It’s a useful chemical for experiments with hydrogen peroxide, so it’s worth hanging onto.

Although I haven’t verified it, I believe any stick welder can be used to power the mini arc furnace, and for most hobbyists, that would definitely be the easier and safer way to go. I just don’t own a welder, so I used the one I made instead. You can see how to make it here:

The longest I’ve run the unit continuously is around 3-4 minutes, and the electrodes get so hot at that point they can seriously burn your hands, or melt your gloves. I wouldn’t recommend running it any longer than that.



22 responses to “How To Make An Electrical Arc Furnace”

  1. smooky Avatar

    I did same as your video 🙂 But with a flame torch

  2. cb Avatar

    “You could carve them with kitchen utensils”
    pulls out big saw

  3. F K Avatar

    What do you do with the slag?

  4. Neil Williams Avatar

    What a bell end

  5. DARTH Potatosoru Avatar

    i want to see titanium in there. i dont think my country allows this. but itd be cool if theyd allowed it.

  6. forhad ahmed Avatar

    A mentor with style….

  7. Marte Houdesheldt Avatar

    instead of using battery carbons go to the local welding supply and ask for gouging carbons. the come in different sizes and lengths

  8. Guildev Montski Avatar

    4 years later and still waiting for the manganese dioxide reuse

  9. nimra razzaq Avatar

    Electricity bill 1000000 $$$

  10. German Sokolov Avatar

    Can you just buy graphite electrods insted ?

  11. steven Walker Avatar

    Do I have a problem if I had all of these parts in my room

  12. Greg Glasgow Avatar

    Love to learn this stuff.

  13. Khai Do Avatar

    They lied to me! I bet I could make a giant homemade battery and connect them all to a charger! 3:13

  14. Sabrina Flipse Avatar

    is the arc blinding? should i wear shaded glasses? like for welding?

  15. Darria Kassandra Avatar

    i did nothing after seeing this video

  16. Alexis Guerrero Ramos Avatar

    I don't know if anyone can tell me what the power source was for it?

  17. Bashfulvideos Avatar

    Surely, that arc is damaging to eyes…

  18. Nathan EverLast Avatar

    Can you melt granite

  19. Sawyer Nugent Avatar

    Mix all the metal ingots and make something with it

  20. bruh Avatar

    Is there other way to do the without using the microwave parts I do own a arc welder which I rather not damage

  21. Zak Thackwray Avatar

    Mmmm dangerous and manly science !

  22. No.1 BTS Stan Avatar

    I'm still a student and I've got to say your videos are really motivating

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