3 Mind-Blowing Facts About An Underwater Cutting Torch

welder setting up plasma cutter

Welding Buddy Experts

April 10, 2021
underwater cutting torch

It is inevitable for construction to happen in aquatic locations, which is why underwater welding and cutting became of vital importance. If you’re a welder assigned to build a particular marine structure, you would want to ensure that you keep things at a low budget without slowing down on your progress.

Underwater cutting torches are known for their speedy work rate at a relatively more affordable price. Furthermore, they deliver equally promising results like a standard cutting torch. While they are quite similar in terms of their parts and functions, it is still a question to many as to how this incredible tool operates. 

In this article, we will discuss the processes that transpire inside the underwater cutting torch, how it is used, and some fascinating facts that will shed light on the remarkable history of welding equipment.

How Does It Work?

For the welders out there who are already experienced in using a cutting torch kit, you would know that its basic parts encompass a torch tip, two separate tanks, valves, hoses for the oxygen and acetylene, a mixing chamber, and a handle. An underwater torch is similar to a regular cutting torch; it is a piece of useful equipment for a wide array of applications, from rescue operations to repairing damaged metal during accidents and preparing plates that are needed for a specific welding activity.

Several people may be questioning: How can an underwater torch work if the fire that it emits can be put out by water? The Cornell Center for Materials Research (CCMR) explains that flames require a combustible material and an oxidizer, analogous to a lit candle where the combustible substance is the candle wick that slowly evaporates because of the flame’s heat. At the same time, oxygen contained in the atmosphere sustains the flame. These two elements manifest in an underwater cutting torch. The combustible supply and oxidizer are provided by the hoses, leading to the torch since oxygen is unavailable underwater.

The underwater flame exits the torch tip once it is formed by mixing the gas from the oxygen tank and the combustible substance, either hydrogen or acetylene, from its tank to the mixing chamber. Maintaining a steady flame requires having a stable bubble around the working location. This gas needs to be yielded at a high pressure to counter the strong and steady water pressure.

Aside from the gas, you need to be equipped with separate jets that contain compressed air so that a bubble will form out of the torch tip and enclose the flame, protecting it from water. This bubble will then extend from the flame and the adjacent region directed on one’s work location.

Types of Underwater Cutting Torch

Delving into Bevaldia’s explanation of underwater cutting, the method is rather simple. There are two kinds of electrodes being utilized in underwater cutting torches: (1) an oxygen-arc (oxy-arc) cutting tubular steel and (2) an exothermic (ultra-thermic) type. An electrode is defined as a passageway for the electricity stored inside the torch that shall deliver the desired clean and precise cutting result.

According to tube welding expert, the oxygen-arc cutting tubular steel is a kind of rod that consists of a hollow steel tube with a flux coating that provides your torch a waterproof feature. This electrode holder comes with an oxygen passageway, and its preheating procedure is executed by striking an arc between the metal and the hollow area of the electrode. The oxygen level gets depressed the moment you strike the arc, allowing oxygen to flow through the electrode and granting you the ability to cut.

In the process of oxidation, the metallic pieces are blown away. This equipment performs efficiently and is compatible with tasks involving steel.

On the other hand, an exothermic cutting torch utilizes electrodes that are filled with small fuel wires and high volumes of oxygen to continuously burn through metal. You don’t have to use an arc for this tool. Instead, you can immediately shut off the electrical current when the rod has been ignited.

An exothermic torch is often used on other aquatic surfaces such as concrete, rocks, coral, selected steel, and other non-conductive materials. The reason behind this can be explained by a thermo-chemical reaction where heat remains for a longer time since exothermic materials are capable of sustaining them. In comparison to the oxy-arc rod, the exothermic rod is capable of melting cast iron, stainless steel, and non-ferrous metals instead of oxidizing them.

If you are interested in getting your torch, one of the reputable brands you may consider purchasing is a Broco underwater cutting torch. By surfing the net or visiting a welding shop closest to you, you will surely find a Broco underwater cutting torch for sale.

3 Underwater Cutting Torch Trivia You May Not Know About

Now that you have an idea of what underwater cutting torches are, how they work, and the different types available, you may be interested to know pieces of information that make this welding tool praiseworthy. Below are three fast facts that you may find fascinating:

1. Underwater torches developed the US Navy.

In a text published by Bela Ronay and Cyril D. Jensen, the Naval Service practiced underwater metal-cutting techniques for several decades as part of their salvaging and other operations. During this time, two methods of cutting were popularly used, particularly the oxy-hydrogen and arc-oxygen processes. Carbon electrodes were incorporated until the older oxy-acetylene procedure was introduced for non-aquatic welding activities. Manufacturing companies of welding tools eventually adapted this invention and stimulated its development with concerned institutions and experts.

2. There are requirements to be an underwater welder.

According to the Commercial Diving Academy Technical Institute, you need to qualify for the basic minimum requirements to become an underwater welder. This is because it is very demanding to perform duties in shifting work environments (i.e., extensive traveling, long hours, and work ethics). Below are some of the requirements which you are expected to possess or provide:

  • High School Diploma or GED
  • Mechanical Aptitude Certification
  • Ability to Swim
  • Commercial Diving Certification
  • AWS Certified Welding Training

For more information, just visit a diving school nearest to your area.

3. Underwater welding helps protect the environment.

One of the most commendable things about underwater welding is that it advocates for the protection of marine biodiversity. Wayne the Welder writes in his article that underwater welders constantly monitor and repair pipelines that travel from various areas and depths of the ocean. They ensure that offshore oil rigs are secured to prevent leaks and oil spills that will drastically damage the ocean and nature as we know it. This information enlightens us that with a cutting torch set, we are capable of changing the world for the better.

Did you find this article helpful? Share your insights in the comment section. We would love to hear from you!


  1. https://bevaldia.com/underwater-cutting-solutions/
  2. https://www.ccmr.cornell.edu/faqs/how-do-underwater-flares-and-torches-work-when-water-puts-out-fires/
  3. https://www.commercialdivingacademy.com/underwater-welder.cms
  4. https://onlinelibrary.wiley.com/doi/abs/10.1111/j.1559-3584.1945.tb01686.x
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