How to Solder ABC

Soldering is one of the skills that is good to learn in an early stage of your RC hobby career. Good soldering skills are needed for example when you’re changing connectors to a battery or when changing the motor. It’s good to start practising soldering as soon as possible so you’ll get the hang of it.

The basic idea of soldering is to solder together two pieces of metal using a filler metal. Both surfaces have to be higher in temperature than the melting point of the filler metal in order for the soldering to be successful. The temperature of the surfaces can be increased using the soldering iron (electric or gas). The surfaces are heated by pressing the hot tip of the iron on them. When the surfaces are hotter than the melting point of the filler metal, the filler metal will melt between the surfaces and create a connection.

Note: Good connections are extremely important for the flow of electricity. Badly soldered connections can result in loss of power and radio/functional disturbances.

Needed tools:

• Soldering iron, min. 25W + sponge / moist paper towel
• Filler metal
• Heat-resistant pad
• Pliers for cutting and pressing
• Heat-shrink tubing, wire and connectors if necessary

Note: Wires and connectors heat up during soldering, so it is good to have a pair of protective gloves handy.

Following the steps below will help you to develop a soldering routine

1. Heat up the soldering iron (depending on the iron this will take 5-15 min). The iron must be the right temperature before starting the process

2. Moisten the sponge. If you don’t have a sponge, a moist paper towel will also do the job just as well.

3. Prepare the surfaces to be soldered

-Peel 3-5mm of insulator off the wires
-Cut the needed length of heat-shrink tubing to protect the connections if necessary
- Check the markings of the connectors ( + and – or ABC) before soldering

Pro Tip: if you are soldering a plastic connector, it is good to put the opposite connector in place in order to avoid bends when the wires warm up.

4. Melt a bit of filler metal on the tip of the soldering iron and press the tip on the wire where the insulator is peeled off long enough for the filler metal to melt on it. Make sure there is metal filler around the wire
– you can recognize a well melted filler metal when you can see the individual wires underneath it.

5. Next, melt a bit of filler metal on the surface (e.g. connector) that needs to be connected.
- First, clean the tip of the soldering iron on the sponge or paper towel.
- Melt a piece of filler metal on the tip of the soldering iron and press the iron on the surface so that the melted metal will remain between the iron and the surface.
- When the melted filler metal “flows” onto the surface, you can add a little more of it.

6. Clean the tip of the iron on the sponge.
- At this point you can slip some heat-shrink tubing on the wire if necessary

7. Place the objects to be soldered on top of each other (or facing each other, or whichever way they are meant to be soldered) and press the connected surfaces lightly together. Melt a bit of filler metal on the tip of the iron, and use the iron on the connection or on the side of it so that a drop of melted filler metal will remain between the iron and the surface.

8. You’ll see when the filler metal melts on the wire and the surface. Wait until the metal is completely melted and you’ll notice it gets easier to press the wire against the surface. The wire is close enough when it touches the connected surface. You can now put away the iron and wait until the filler metal has completely solidified.
When the connection has cooled down, you can slip on the heat-shrink tubing and shrink it.

A well-made soldered connection is smooth.

Before you place the battery in a device, double-check that the connection is done correctly. Plus to plus, minus to minus, et cetera.