How to Use a Soldering Torch

A yellow soldering torch with a flame.
What You'll Need
Soldering torch
Ceramic tile
Fire brick or heat resistant pad
Overhead lamp
Gloves, goggles and apron
Metal acid cleaning solution
An old pot for the acid cleaning solution
Copper tweezers
Torch igniter
Wire cutters to cut the solder
Jar of water (to cool pieces after soldering)

Soldering enables you to join two metal segments into one piece, using a torch and a softer metal as the adhesive. Before you start a soldering project, it’s important to set up a well-ventilated, clean work space. The following important tips will help to ensure that your soldering project is a success.

Step 1 - Organize a Safe Work Space

Place your tile on the surface of your work space. Put your fire brick on top of the tile. Place your torch and tools on the space around the tile. Take any items that might be flammable out of the area where you are working. If it’s not possible to remove a flammable item, be sure to use a heat shield to protect it from the heat of your soldering torch. Place your overhead light so that it shines over your work space. Put on your gloves, goggles, and apron.

Step 2 – Sand the Metal Edges

Use your sandpaper to smooth the edges of the two metals you would like to join. Be sure not to overly file the edges. You will get a stronger bond if the edges of the metals are slightly rough. It's also crucial to make sure that the two edges are joined as closely as possible so that there are no gaps between them.

Step 3 – Clean the Metals

Clean the two metal pieces you're using. Carefully immerse them in the acid cleaning liquid to get rid of any impurities that could weaken the bond between the two metal pieces.

Step 4 – Apply the Flux

A close-up image of flux used for metalworking.

Apply a generous amount of flux to the joint you are soldering. Be sure the flux is applied sufficiently to the entire bonding area. The flux will increase the solder flow and remove oxidation from the metals.

Step 5 – Secure the Metal Pieces

If necessary, position the two pieces into a vice so that they cannot move when you begin to use the soldering torch.

Step 6 – Remove Moisture From the Metal Surface

Make sure there is no moisture on the surface of the metals you are joining. The soldering process can create a dangerously hot steam if the torch heats any moisture in the metal. Moisture can also weaken the bond between the two metals.

Step 7 – Get Your Torch Ready

Attach the head to your soldering iron tank. Open the valve. When you hear the hissing sound of the gas, turn on your torch. Your flame should be around two inches. If necessary, make adjustments to the valve.

Step 8 – Heat the Metal Surface

Metalworking with a soldering torch.

Use the torch to heat the joint between the two metals. Move the torch closer to the joint area. Begin by applying the heat onto the metal a small distance away from the joint. Carefully move the flame, applying an even amount of heat to the area.

Step 9 – Apply Heat to the Joint

Once the areas outside of the joint have been properly heated, apply the flame directly to the top part of the joint area. Make sure the flux is flowing and is no longer bubbling. After the top part of the joint is complete, continue with the bottom of the joint. The heat from the torch should force the solder into the joint. This will ensure a strong bond. If more solder is needed, it can be applied at this time.

Step 10 – Turn off the Torch

Remove the torch from the joint area and turn off the heat. Inspect your joint for a clean, strong bond.

Step 11 – Clean the Metal Joint

Apply water to the joint area to cool the metals. Clean all areas of the joint to remove any flux residue from the metal surfaces. Smooth the joint with your filing tool or sandpaper.