To weld aluminum with an oxy-acetylene torch, set your gas to 4 lbs of oxygen and acetylene, and achieve a soft neutral flame.
Warm the workpiece gradually. Use a 4043 filler rod, dipped in aluminum treatment powder if available, to dab along the weld. Allow it to cool before cleaning with a wire brush, chipping hammer, or chemical treatment.
How To Weld Aluminum With An Oxy Acetylene Torch – Step-by-Step
Time needed: 1 hour and 30 minutes
You do not necessarily need a full TIG welding setup to weld aluminum. If you have an oxy-acetylene torch and some 4043 rods, you have everything you need to weld aluminum. Follow this step-by-step guide to weld aluminum with an oxy-acetylene torch.
- Set Up The Torch
Before you start, make sure you have all the safety equipment you will need. This includes, but is not limited to, a welding helmet.
Set the torch up with around 4 lbs of oxygen and acetylene and light it. Achieve a soft, neutral flame if the aluminum is thin. You may want a slightly hotter flame for thicker aluminum.
- Prepare The Workpiece
Clean and dry the workpiece before starting, particularly around the welding area. The area to be welded should be as free from contaminants as possible, and ideally should be ground to a shine.
Lay the workpiece out on the welding table, preferably on a jig. Leave a small gap for the filler to get through. Clamp if necessary.
Warm the workpiece as you would if you were TIG welding. Do this in a few passes to avoid building up too much heat too quickly in one spot.
- Use The Filler Rod
Grab a suitable filler rod for the aluminum you are welding. In most cases, a 4043 rod will be a good choice.
There are a variety of coatings available that you can dip your filler rod into to help fight the oxidization of the aluminum during the weld. While not strictly necessary, having one of these to hand can make a cleaner weld.
Bring the torch to the start of the weld and introduce the filler rod. Start the pool, then weld by dabbing along the seam.
- Allow To Cool
Once the weld has finished, allow it to cool before you clean it up.
If you have any oxidization on the weld, you may have to chip and clean it off. Some post-weld powders and treatments will do this quickly if you have a lot of welding to do, but for single pieces, you can usually get by with a wire brush or a chipping hammer.
If you want to see this process in action, check out this video: https://youtu.be/o8BGko__DlA
We hope this guide has helped you to weld aluminum with an oxy-acetylene torch. As this process has shown, you do not necessarily need a TIG welding machine to effectively weld aluminum.
If you have any questions or comments about this guide or oxy-acetylene welding techniques in general, please feel free to leave them in the comments section below.