How to make a 12 V tin soldering iron

In most of the electronic projects we do, soldering is necessary to keep the connections secure. The type of solder used for these projects is tin solder, in case we don't have a soldering iron at hand, we can make our own 12V tin soldering iron. Today, we will look at how to make a 12V tin soldering iron.


- A diesel spark plug.

- A 5mm screwdriver.

- One 16mm terminal block or plug.

- 5 cm of 9mm internal diameter copper tube.

- 1 m of 1.5mm parallel cable.

- 2 alligator clips.

- 12 V power supply.

Assembling our soldering iron

First, we cut off the screwdriver, leaving the handle and about 2 cm of the tool. Then, remove the plastic part of the screwdriver to turn it into a double screwdriver stud.

The next step is to insert the screwdriver shank halfway into the stud and screw it in, then insert the threaded part of the spark plug and the positive side of the wire into the other half of the stud and tighten.

Now, we wind the negative part of the cable to the spark plug ground and then, we place the crocodile connectors at the other end of the parallel cable, to be able to connect to the 12 V power supply. At the end of this process, our tin soldering iron is ready and working. Now it is time to test it and enjoy our tin soldering iron.

Below is a video that explains in a simple way the assembly of this tin soldering iron.

3 thoughts on “Cómo hacer un soldador de estaño de 12 V”

  1. hello, what would happen if i don't use the alligator clips and i put a common plug and connect it directly to a 12v source?
    or instead of the crocodile clips I use a 12v transformer to be able to connect it to the wall of the house, could it be done?
    Does the spark plug need to be diesel? Does it work with a different type of spark plug?

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