How to cold solder to your Touch Board or Pi Cap to your sensors

How to cold solder to your Touch Board or Pi Cap to your sensors

Use Electric Paint to cold solder your board onto almost any material

Cold soldering is an excellent alternative to soldering and doesn't require a soldering iron or soldering station. Instead, all you need is some Electric Paint! This tutorial demonstrates how to cold solder with our electrodes stencil and the Touch Board and shows you how to cold solder onto other materials!

We also provide a template to easily print out the pitch of the Touch Board or Pi Cap's electrodes.

You will need:

  • 1 x Touch Board or Pi Cap
  • Electric Paint 10ml, 50ml or 1l

Step 1 Touch Board and Pi Cap electrode spacing

If you want to connect to a number of sensors printed or painted onto a surface, getting the spacing between the sensors is important. If you bridge between the two sensors (because your painted lines are too wide or mis-aligned) those sensors won't function. Don't worry! You won't break your board. It just won't register anything until the electrical connection between those two electrodes is broken. If you've smudged Electric Paint across the electrodes, no problem. Just clean with soap and water.

You can paint your own lines, but to make things easier, we have also designed a stencil, which you can download here. If you don't know how to prepare the stencil, you can follow our stencil tutorial to learn how to do this.

Once the stencil is ready, align your Touch Board or Pi Cap to the Electric Paint traces you have applied.

Step 2 Cold solder

To cold solder, all you have to do is carefully squeeze a droplet of Electric Paint into each electrode that you want to connect to the paint beneath. When you are done, leave the paint to dry. The Electric Paint will act as a conductor and as a glue. That's it, that's how you cold solder!

Be careful not to move the Touch Board while drying. Otherwise, you risk smudging the paint and shorting the electrodes. Shorting the electrodes will not break the board, but you will need to clean it before you can use it again.

Step 3 Cold soldering the Pi Cap

As the Pi Cap has the same pitch for the electrodes as the Touch Board, the above method also works for the Pi Cap. You can use it to make your own piano!

Step 4 Cold solder onto other materials

You can cold solder with Electric Paint to paper and onto other materials, for example, copper tape. This is useful for quick prototyping or when you need to securely attach your board to other conductors.