Introduction: DIY Soldering Iron From a Pencil

About: Hacks, builds, experiments.

It's surprisingly easy to convert a pencil into a temporary soldering iron.

Graphite heats up to soldering temperature when the right amount of current passes through it, so simply connecting two wires to the tip and applying a voltage is enough to melt solder!

Supplies

  • HB pencil
  • Craft knife
  • USB cable
  • 5V USB charger
  • Pliers or wire strippers
  • Tape or heat shrink tubing
  • (Optional) Thin copper tubing (inner diameter slightly bigger than the diameter of the graphite in the pencil)

Step 1: Watch the Video!

Some things here are awkward to explain in words, so the video makes it much easier to see exactly what to do, especially for the subtle things. If you like it, please like and subscribe to help support the channel and see future builds!

Step 2: Pencil Prep.

Get a HB pencil and use a blade to cut a groove all the way around the wood, about an inch from the top.

Use this to carve away the pencil upwards, using the blade (see video) until all that's left is the graphite (see images).

Step 3: Wire Grooves

On the exposed graphite, use a blade to (gently) carve two grooves all the way around, about half an inch apart.

These are where the wires are going to wrap around.

Step 4: Wire Prep

Using any regular USB cable, cut off the non-USB end, and use pliers or wire strippers to remove a few inches of the insulation.

You should see two wires, one red, one black.

Remove about an inch of each of their insulation.

Then just twist them until they're tight.

Step 5: Connecting the Wires

Wrap one of the wires (either one) around one of the grooves of the graphite (from Step 3) and pinch and twist the pencil around so there is a firm connection between the wire and the graphite.

Do the same with the other wire.

Use tape or heat shrink tubing to attach the wires to the side of the pencil.

Using a blade, sharpen the tip (gently - if the tip snaps, you're back to square one!)

Step 6: The Power Source

After putting on safety glasses, grab a 5V, 2A USB charger (only these can be used but fortunately, they're the most common) and plug in the pencil.

After a while, it will heat up to soldering temperature.

You can see from the video that the tip of the pencil gets so hot that it can easily melt through thick plastic and 3D-printed parts, which is very useful for making holes.

It can also seal plastic bags, but this is kind of hit or miss.

Now, the last (optional) step is the replaceable tip.

Step 7: (Optional, But Highly Recommended) the Replaceable Tip

Using a small copper tube, cut a small piece off the end using pliers.

The cool thing about this is, when you cut it, it naturally sticks together at one side, forming a perfect replaceable tip!

Simply place this on the tip of the pencil and you're good to go!

If you enjoyed this Instructable, please consider following and subscribing to my YouTube (Made You Make)!