Manekinen has come up with this home-brew spot welder that’s powered by a guitar amp transformer. It produces 2.6V at 1kA and can make clean spot welds between two pieces of steel up to .75 mm thick.

The device is enclosed in an old computer power supply box and has safeguards built into the electronics. A limit switch gives a delay before the welder turns on so the user can get his/her pieces in place. Also, a potentiometer varies the time of each weld between one and four seconds depending on the material being used. A BT138 Triac closes the primary circuit but Manekinen suggests using something more rugged for the job. There are more detailed instructions on the project at his site if you want to try it yourself.

[via Hacked Gadgets]

Michael Colombo

Michael Colombo

In addition to being an online editor for MAKE Magazine, Michael Colombo works in fabrication, electronics, sound design, music production and performance (Yes. All that.) In the past he has also been a childrens’ educator and entertainer, and holds a Masters degree from NYU’s Interactive Telecommunications Program.

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  • Mike McAdam

    Pretty cool, but I’ve got a spot welder that I’d like to convert into a Super Reverb. Got any ideas?

  • KillbotFactoryOutlet (@Killbot_Factory)

    Sorry, but it looks like the Technics SU-V670 is not a guitar amp – it’s a stereo amp. Still cool, tho.

    • Michael Colombo

      Correct Killbot. My mistake.

  • Brandon A Boyer

    Neat little project. You should try to find a way to increase the electrode force. That will improve the quality of the welds while shortening then necessary weld time.

  • guitar

    This is pretty much spot on with my view of things. I would mostly agree and think you wouldn’t get an argument with others.

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  • Kevin Smith

    Great tips and techniques for spot welding fro guitar amp transformer.

    Spot Welding Process