How to Build a Simple ARC Welder.




Introduction: How to Build a Simple ARC Welder.

120v transformer
6 Gauge wire or other thick insulated wire
A hack saw, grinder or chisel
Rubber mallet
120v wire
120v switch
Pliers or wire strippers
Metal box

Estimated build time: 35 min

A short video:

Step 1: Find a Transformer

You will need a large transformer, about 4" by 2" by 4". These are found in microwaves, electric mowers Etc.

Step 2: Remove the Base

Use a hacksaw, grinder, or chisel to break one of the welds holding the base to the body. Remove the base.

Step 3: Remove the Coils

Remove the main and secondary coil. You will need to larger wired one, so be careful. The smaller wired and mid coils are unnecessary.

Step 4: Reinstall Main Coil

You will now reinstall the main coil onto the transformer. Simply slip it back on, and push it to the bottom. Sometimes the use of a rubber mallet is required. This is ok, just be sure to not injure to coil.

Step 5: Install a 6 Gauge Wire

Find a 6 gauge wire, or any (insulated) wire or bundle that will fit snugly around the center "pillar" of the transformer. You will wind this once.

Step 6: Re-Assemble

Use epoxy, a welder, Jb welds or even duct tape to reattach the base.

Step 7: Add a Switch

Find a 120v power cord that is Un-needed. Cut it to a desired length, and make sure to not cut the plug off. This will be needed to plug into the wall.

Splice the wires, and find 2 connectors that will fit on the coil leads. Once your wire is spliced, take one of the leads and chop it to about a foot. DO NOT CUT THE GREEN ONE. IT IS THE GROUND. It does not matter which of the others is cut.

Attach the shorter wire to a terminal on a 120v switch. Take the piece you chopped of and add it to the other terminal of the switch.

Attach the clips that fit on the transformer to the wires.

Step 8: Mount It

Mount the switch in an electrical box, and the transformer on a piece of wood.

Step 9: Attach Conducters

Attach a conductor to each end of the coil of 6 gauge wire that is running through the transformer. I used 2 welding rods.

Step 10: Try It!

Put in some rubber gloves, check for bad connections and turn it on! It will buzz, and when the leads coming off the 6 gauge wire touch, they will spark fantastically and easlyelt coins and nails.

Follow me on Instagram!

I take no responsibility for any injuries caused by this post or in direct relation to it. Have fun!!

Be the First to Share


    • Pocket-Sized Speed Challenge

      Pocket-Sized Speed Challenge
    • Super-Size Speed Challenge

      Super-Size Speed Challenge
    • Metalworking Contest

      Metalworking Contest

    7 Discussions


    3 years ago

    Amazing - there are 9 different transformers in this one instructable. And none of them are wired the same way...


    6 years ago

    I designed it then looked it up to make sure I was not going to zap myself. I did see his video and it is almost identical, but it's not a copy

    Timothy M
    Timothy M

    6 years ago

    Did you design this yourself? Because it's identical to the one that King of Random made...


    6 years ago on Introduction

    Yah I picked up on that too........... that's that Boston lady stasterisk.


    6 years ago

    The last picture of your Instructable belongs to another project. Did you ask permission to use the picture?


    6 years ago

    A schematic was more usefull.