How to Weld Aluminum with a Torch?

Having some skill in welding helps a person greatly in various ways. You may need to repair a wide range of metals occasionally, whether you are a professional welder or a DIY lover. Among them, aluminum is a common material to work on.

However, when it comes to welding aluminum, not everyone thinks of using a torch. There are more effective tools out there for the job. But they come at a high cost. You can simply do the same welding session using propane or oxy-acetylene torch and get an excellent result.

All you need to do is understand the principles, practice, and be careful during the projects. Today, we will elaborate on the welding process of aluminum using a torch step-by-step.

Equipment Needed to Gas Weld Aluminum

Torch- Obviously, you will need a torch. Whether you want to go for a propane torch or an oxy-acetylene torch depends on your preference and availability of the gases. The nozzle of the torch is where the flame will appear. Make sure that you are getting a quality torch that can heat the metal faster.

Brazing and Welding Rod- You will need brazing and a filler rod. Remember that they are made differently for each metal type. So, choose the ones only for aluminum.

Oxygen and Acetylene Gases- If you are going for an oxy-acetylene weld, you will need these gases. They come in cylinders with hoses to connect to the torch and valves to control the gas flow.

Preparing the Aluminum

You should make sure that the aluminum is ready for the weld. Follow these steps

Cut the aluminum at the correct shape and size that you will need using any workbench saw.
Chamfer the edge using a file. To clearly put it, the edge of the metal will have a lesser thickness than the middle, like a slope. Doing this will decrease the stress on the material during the weld.
Clean the aluminum using a wire brush. As metals may have dirt and grime on them, they should be cleaned before being used. Alternatively, you may use degreasing solvent if you don’t want to use a wire brush.
Clamp the pieces together at the proper position and angle that you want to weld.

Lighting Up an Oxy-Acetylene Torch

To oxy-acetylene weld, you will need to light up the torch properly by setting the right gas settings. Ignore these steps if you are using a propane torch.

Make sure the valves are turned off.
Hook up the hoses between the torch and gas cylinders tightly with a wrench.
Open the gas valves of each gas slowly. Don’t be fast, or it may cause accidents.
Use the regulator to set the correct gas flow. The acetylene will have a maximum flow, while the oxygen will be ¼ of the max flow.
Use a striker to light the torch.
Use the regulator to get a blue and small flame.

Welding Process

Now that everything is ready let’s move on to the welding part. Both oxy-acetylene and propane torch will require the same steps as below

Place the torch on the joint to heat it. Keep the brazing rod on the weld seam so that it can melt in contact with the heated aluminum workpiece.
Remember that the melting point of commercial aluminum is 1200-degree F while the filler rod has a melting point of 700-degree F. So, keep the heat in between these points. Your goal is to melt the brazing rod, not the workpiece itself.
Heat the places with a consistent pace and steadily.
The welding rod should be a few inches in front of the flame. As the rod melts, it will keep filling the joint, creating a metal pool. Make sure that it covers the seam from both sides. Do not overfill the joint.
Run the process along the seam at the same consistency. If the brazing rod doesn’t melt properly on any spot, you will need to heat that area a bit more.
Once you have finished the session, let it cool down and chip away any slag.
Make sure to close all the gas valves, if you are using an oxy-acetylene torch. Also, put the regulator to 0.

Frequently Asked Questions

What Filler Rod Should I Use to Weld Aluminum with a Torch?

You can find specially made aluminum filler rods for this project. 1100 or 3003 are good filler rods for aluminum welding with gas torches.

How Much Heat Should I Apply for Aluminum Gas Welding?

Keep the heat within 700-1200-degree F.

Final Note

It is true that the project ends as you cool the metal, but your practice should not end there. In fact, you should expect to get an imperfect result on your first few tries. It is because controlling the accurate heat supply on the weld is not easy to master quickly.

With enough practice, your welding outcome can get as excellent as using high-quality welding methods. And as the equipment is easy to come by, it is even more affordable to try repeatedly.

Last Updated on 2 years by Richard Boyer

Richard Boyer

Richard Boyer has been a professional welder for over 27 years of his life, and now he is a trainer and blogger providing critical information to anyone interested in welding. He is helping out both hobbyists, novice and professional welders to learn newer and better techniques. Read more about me

Click Here to Leave a Comment Below 0 comments