7 Reasons Why You Shouldn't Use Propane for Welding

welder setting up plasma cutter

Welding Buddy Experts

August 11, 2022
propane welding

While propane welding may seem logical, it's not an ideal option for welding. You are better off sticking with an oxy-acetylene torch kit for your welding projects.

Here are the reasons why you should avoid using propane for welding. So if you're considering using propane for your next welding project, read on – and reconsider!

1. Propane is not as hot as other welding gasses.

The main reason why you shouldn't use propane for welding is that it's not hot enough. To weld properly, you need gas that can reach extremely high temperatures – and propane just doesn't cut it.

Propane can only reach a maximum temperature of around 2,500 °F. That's not hot enough to weld steel. For comparison, oxy-acetylene torches can reach temperatures up to 6,300 °F – more than twice as hot as propane!

2. Propane can cause welds to be porous and weak.

Another reason to avoid using propane welding torches is that it can cause welds to be porous and weak. This is because propane doesn't burn as hot as other oxy-acetylene, so it doesn't create as strong of a weld.

If you're looking for a gas that will give you strong, durable welds, propane is not the way to go. Instead, stick with an oxy-acetylene torch if you want quality welds that will last.

3. Propane makes brittle welds.

In addition to causing welds to be porous and weak, propane can also make them brittle. This is because propane doesn't provide enough heat to weld metals properly, leading to incomplete fusion and a lack of strength in the weld.

Brittle welds mean that the welds are more likely to break under stress, so it's not ideal to use propane for load-bearing projects like steel beams.

4. Propane tends to produce more slag. 

Another downside of using propane for welding is that it tends to produce more slag. Slag is the byproduct after you're done welding, and it can create problems when trying to achieve a smooth, even weld.

Propane welding can also be somewhat unpredictable, making it difficult to control the heat and resulting in inconsistency between welds. For these reasons, it's generally best to avoid using propane for welding projects.

5. Propane can produce harmful fumes.

The oxygen-to-gas ratio must be within a specific range for propane to burn effectively. 

When the gas does not meet this ratio, it results in incomplete combustion, which generates excessive carbon monoxide. And if there is no adequate ventilation in the area, this can be quite hazardous to you.

If you work in a closed garage or workshop, prolonged exposure to carbon monoxide can lead to carbon monoxide poisoning. It can be deadly if left untreated, as the poisonous gas takes the place of oxygen in the circulation.

6. Propane can get expensive.

To generate the highest possible flame temperature, it is important to understand the oxygen requirements of different fuel gasses.

Acetylene has a relatively low requirement, at 1.2 to 1. This means that for every volume of acetylene used, only 1.2 volume of oxygen is required. On the other hand, propane has a higher requirement of 4.3 to 1. This means that for every volume of propane used, 4.3 volume of oxygen is required.

Propane is a cheaper fuel than acetylene, making it a more economical choice for welding projects—on the surface. However, a propane welding torch kit uses more oxygen than an oxy-acetylene torch kit, so the overall cost of using a propane kit can be higher.

7. Propane is dangerous to store and use.

Propane is a highly combustible gas, which makes it dangerous to store and use. So if a propane tank is exposed to heat or flame, it can explode, causing serious injury or even death.

It's also heavier than air, so it will sink and accumulate in explosive concentrations. For these reasons, propane is not ideal for welding. There are other gasses less volatile and easier to store and use safely.

propane welding - a welder using a torch

Best Applications of Propane Torches

Despite the many drawbacks of using a propane welding machine, there are still some applications where it may be a great choice.


Brazing is a type of welding that uses a filler metal to join two pieces of metal together. The filler metal has a low melting point, so it can be melted and fused without melting the base metals.


Soldering is another type of welding that uses a filler metal like brazing. The only difference is that soldering happens at temperatures below 840°F (450°C), while brazing is above that temperature.

Soldering is typically used to join smaller pieces of metal together, such as electronic components.

Cutting Metal

Propane torches can be used to cut metal like oxy-acetylene torches. When using a propane torch for cutting, hold it slightly higher to use the outer flame cone to preheat the metal faster. This is because most of the heat is accumulated there.

Use an Oxy-Acetylene Torch Kit Instead for Welding

Propane is not the best choice for welding due to its many drawbacks. While propane torches have their uses, they're not the best for welding projects. However, there are still some applications where it may be a great choice, such as brazing, soldering, and cutting metal.

If you're looking for a safe and better tool for welding, an oxy-acetylene torch kit is a better option. Browse our product reviews to find the best torch kit for your next welding project!

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