Step #1: Obligatory Safety Warning
This project involves working closely with open flame, so be sure to take all the necessary safety precautions. Always closely monitor a fire and never leave it unattended. Keep a responsible adult nearby with a fire extinguishing tool. Make every effort to keep the fire contained and away from other flammable objects. Avoid loose clothing and hair. Be careful to avoid burning yourself, especially when handling objects that are on fire or have been heated by the fire. When possible wear fire resistant gloves.
Seriously, I am not responsible if you set your house on fire.
Step #4: Find Some Scrap Metal to Use as a Soldering Iron
- When soldering on a circuit board, you can't heat the board directly with an open flame, so you need to use something as a soldering iron. You can probably find a suitable piece of metal laying around.
- Steel is a good material to use for this. It is strong, it retains heat fairly well, and it is very common. Copper can work, but copper cools off much more quickly than steel. If you use copper you will need to work quickly.
- Here are some examples of objects that can work: Steel wire (at least 14-gauge); nails; screw driver; bolts; multi-tool; rebar
- The thicker an object is, the more heat it will take to get it to the appropriate temperature. So for small heat sources such as candles and lighters, use thinner soldering irons. For larger heat sources, you can use larger soldering irons.
Step #6: Create a Soldering Iron to Use with Large Heat Sources Such as Open Fires
- If you are working with a larger heat source such as a fire place or a camp fire, then you need to do a few things differently. First, you will need to take many more safety precautions. Wear fire resistant gloves and, whenever possible, use metal tongs or pliers when handling the heated soldering tool.
- A wood fire is much hotter than a candle or a lighter, so you will want to use a tool that lets you work at a safe distance. To do this you can either use a long wire or you can attach your soldering tool to the end of a non-combustible rod such as a piece of steel rebar.
- An open fire provides a lot more heat than a lighter, but it is much more difficult to precisely control. So you will probably want your soldering tool to be made of thicker metal. This will help it to catch and retain more heat. If you are using a wire as your soldering tool, you can make the tip thicker by folding the end of the wire over several times.
- How and where you heat the solder tool will depend on the kind of fire you are working with. Hot coals will generally be a more steady heat source than leaping flames, but you will need a lot of glowing coals to heat your soldering tool. You will probably have to use some trial and error until you get a feel for what works. To make it easier, start with a larger fire. This will give you a larger and longer lasting coal bed to work with.
- After you have heated your tool, move it quickly to the object that you want to solder. Be careful! Once the soldering tool is no longer able to melt the solder, move it back to the fire to reheat it.