Be sure to always wear eye protection when soldering.
Getting involved with drones or any type of electric hobby means you’ll need to know how to solder wires, battery leads, ESCs, Aduino hardware, etc. With practice soldering is easy and it starts by assembling the proper tools. Here’s what I have and recommend:
- 45-60 watt soldering iron
- Soldering stand with clips
- 63-37 [or] 60-40 solder (tin-to-lead ratio)
- Desoldering braid; to clean up excess solder “blobs”
- Rosin flux; Optional when using Rosin Core solder
- Small kitchen sponge you can cut up
- X-acto knife
- Small wire cutters
First, all soldering for rc should be done with a soldering iron and not a soldering gun. An iron gives you way more precision due to the design of the tip which is meant to fit in small places and provide precision heat. And while you could get a soldering station they are often 2x to 3x times more expensive than your standard soldering iron. Yes, a soldering station has its own power supply, temperature adjustments, and won’t loose temperature as you solder, however most rc hobbyists will find that a good quality standard soldering iron will work for 90% of their needs.
Top tips for rc soldering:
- Clean and tin your soldering iron tip before each use.
- Tin all wire that’s going to be joined.
- If possible, twist the wires together before soldering for a good connection
- Don’t over tin wires or apply too much solder to the connection
Prep your space and inspect
For safety reasons always solder on a flat, fire resistant surface because you will drip solder at some point. Second, before you turn on the soldering iron, check the tip to be sure it is residue-free. If not, take a damp rag soaked with a little bit of rubbing alcohol and wipe clean the tip. Do not sand your soldering iron tip as this reduces its effectiveness to transfer heat. If any build-up of rust or corrosion is evident, replace the tip.
Solder type and tinning
Your soldering should be done with a soldering iron rated at approximately 45-60 watts and have a tip size of around 1/4″ or 5mm. Use 63-37 or 60-40 rosin-core solder (not acid-core). This tin-to-lead ratio provides rapid solid to liquid transition, has the best stress resistance, and is readily available in most hardware and electronics stores.
The soldering iron’s tip must be tinned before you begin. Tinning is a process where you coating a soldering irons tip with a thin layer of solder which aids in the transfer of heat between the tip and the surface you are soldering.
During the process of tinning and of soldering, frequently wipe the soldering iron’s tip off on the wet sponge to remove all flux residue. A clean and tinned soldering iron tip ensures good conduction of heat. If you store the soldering iron for a long period of time re-tin the tip to help the iron dissipate excess heat when not in use. This will save wear and tear on the heating element and extend the life of your soldering iron.
How to solder
After cutting and twisting the lead I add a drop of rosin flux. This helps the solder to flow better which creates stronger electrical connection.
Tin the wire by heating the wire with the soldering iron and touching the solder to the wire and not the iron’s tip.
Clean & prepare the surface that wire will be soldered on to. When necessary, use desoldering braid to remove excess solder from a surface.
Melt a small drop of solder on to the surface where the wire will be connected.
Now place the prepared wire on the surface of the solder and apply the iron’s tip to the wire, not to the surface where the wire will be attached. Remember that a bright silver solder connection is a sign of a strong joint whereas dull solder indicates a ‘cold connection’ – which is weak.