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No Alternative

An article by John Rodden

We often get asked about welding with propylene and other LPG based gases that are hotter than propane which are marketed as an 'alternative' to acetylene. Here we explain why there is really no alternative to acetylene!

The most important factors in fusion (gas) welding are;

A neutral flame
The ability to lay down the heat at a minimum temperature of 3106°C (5622°F) with the lowest input of oxygen. The higher the oxygen ratio, the more porosity will be introduced, leading to brittle welds

The ONLY readily available gas that meets these requirements is acetylene.

Cheaper LPG substitutes i.e. propane and polypropylene can be used for 'Bronze Welding' or 'Brazing' in perfect conditions but DO NOT provide the neutral flame or temperature required for 'Fusion Welding' as the chart below illustrates;

Gases Acetylene Propane Propylene Methane
Working Flame 3106°C 2810°C 2872°C 2770°C
Fuel/Oxy Ratio 1 : 1.1 1 : 3.75 1 : 3.1 1 : 1.6
Flame Type Neutral Oxidising Oxidising Oxidising
Max Flame 3160°C 2828°C 2896°C 2786°C
Fuel/Oxy Ratio 1 : 1.5 1 : 4.3 1 : 3.7 1 : 1.8

Take a look at Acetylene in our Product Range

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