The Art of the Solder Joint
3. How to actually do the soldering!
First, strip about inch of insulation from the ends of the wires you want to connect. Then, “tin” the wires by heating them with the soldering iron and applying a small amount of solder. This coats the exposed wire with solder, making it easier to create a strong connection.
Now, bring the tinned wires together in the desired configuration. If you’re joining two wires end-to-end, you can twist them together for extra strength. If you’re connecting a wire to a circuit board, insert it into the appropriate hole.
Heat the connection point with the soldering iron, making sure to touch both wires simultaneously. Apply solder to the heated joint, allowing it to flow and melt around the wires. You want to see a smooth, shiny connection, not a blobby mess. Remove the soldering iron and let the joint cool undisturbed. Avoid blowing on it to cool it quicker, as this can create a weak joint.
Once the solder has cooled completely, inspect the joint. It should be shiny and smooth, with no cracks or gaps. If the joint looks dull or crumbly, it’s likely a “cold solder joint” and needs to be redone. Simply reheat the joint and apply more solder. If you have too much solder you can use a desoldering pump to remove it. After this step, the joint should be smooth and shiny.