Underwater Welding Process and Gear Guide

Underwater Welding Process and Gear Guide

The process of underwater welding defies logic. Can you imagine electricity flowing through water and leaving the welder unscathed? As you may guess, there is a lot to this. Below are some things to think about;

Underwater welding functions in a similar way to topside welding, even though the environment is different. Underwater welders take the risk, but not as much as you are thinking. The process of underwater welding is misunderstood, leaving rumors and explanations that are open-ended and are not true. Before understanding how this type of welding functions, it is crucial to get basics regarding surface welding.

When you think about underwater welding, what gets to your mind? Maybe it is the underwater welding suit, surrounded by firing electricity and water at the metal gap that requires repair. The welder is either performing hyperbaric or wet welding. Each of the processes of welding is slightly different, both of these procedures borrow principles from surface welding but employ them differently.

Underwater Wet Welding Process

The sites have water surroundings. However, this does not mean that they have direct exposure to water in the whole process. It creates gaseous bubbles that keep the site shielded temporarily. The shield comes from the flux when melting on the electrode. It is made up of seventy percent of hydrogen. As the flux continues to melt, it will cover the weld site and protect it from water in the process of cooling. Nevertheless, even with protection, water has effects on the weld.

Since the electric arc creates immense heat amounts, it sprays thousands of bubbles while welding. More than the annoyance, the bubbles may blind the welder and make it hard to see the site of the weld.

Hyperbaric welding process

Also called dry welding, hyperbaric welding offers a weld site that gets insulated from the water. The insulation gets accomplished through a barrier full of gas. The procedure is similar to topside welding with several exceptions. This process takes place under extreme pressure, and it is approximately 0.7% pounds per inch or more. Pressure has to increase to keep constant the air volume and set the ratio to the surrounding amount.

This welding process is carried out in a pressurized underwater habitat. The habitat might fit around the site of the weld or even expand up to one room’s size. This procedure can be costly. Larger habitats are expensive, and they cost more money for purchasing and upkeep. Additionally, maintenance while being used will rack up the bill because it is supplying constant electricity and gas to the welder.

Finding tools for your underwater welding project can be a task that is daunting. There is so much that need to be put into consideration. They include;

  • Function
  • Purpose
  • Quality

Welder-divers require the right items to accurately, safely and efficiently do their job. This guide will help you navigate through the process of selecting underwater welding equipment.

Underwater Welding Equipment

Every welding job is quite different. Their tools and soot have to be versatile and can take a great abuse. Because many underwater welders weld the topside, it is crucial to understand the way their tools work differently in marine environs.

To weld the underwater properly, the commercial diver requires five major tools;

  • Power supply
  • Stinger
  • Electrodes
  • Diving suit
  • Accessories
  • Diving helmet

Diving helmet

under water welding helmet

These are ears and eyes for hyperbaric welding tasks. The welder needs a helmet that is reliable for the job. From the surface, the hood of the helmet protects the face and eyes of the welder during the job. Helmets save this role, in addition to allowing for breathing for the diver.

Many use the same helmet they would go during regular commercial diving with one addition. The welding screen attached to the mask front is for protecting the eyes.  Some welding screens flip down or up like a hood and the come in different shades.

Types of diving helmets

Underwater welders use these helmets according to the project.

Open Circuit

This helmet employs the non-return gas valve, side weights, anti-fogging lens, new characteristics, and inner cushion. It is a very popular and standard helmet for divers doing it on commercial bases. Since it utilizes the non-return valve, the air you expel goes to water.


This type of helmet follows similar principles like the open circuit but recycles the exhaled gas of the diver and gets it back to the system at the same pressure.

Free-Flow Helmet

Outfitted with simplistic designs, the helmet is characterized by large transparent visors for greater visibility. Due to its simplicity, the diver takes it apart and puts it together with the help of a wrench and screwdriver. It is employed for shallow water and hazardous materials.

Wet welding only utilizes surface supplied air; therefore, it is worth to mention that the utilized equipment in SSA is specialized and is only used by professionals. SSA is vital for underwater welders because it enables communication with the surface team operating the welding machine.

Accessories of underwater welding

Added to the helmet, welders require necessary attachments and accessories on their job. They include;

Diving Knife

Just the way the whip is crucial to Indiana Jones so is the knife to the welder diver. It is an essential tool for many situations, whether they want to cut in the project material, free themselves from entanglement, or wedge opens a door. The diving knife does this job.

Umbilical cord

This is the place where the gas gets pumped to and from the surface to the welder.


This is crucial to keep the diver buoyant and in one area while doing her or his work.

Compressor and gas panel

A team that is qualified monitors the gauges of gas and maintains a steady supply of air that is coming to the underlying diver. Divers monitor them directly. Many of them employ low-pressure gas because of low maintenance and an unlimited supply of air.

Bailout Gas

Utilized for emergencies, this gas gets carried by divers as a secondary source of gas supply in case the SSA equipment fails. It appears in the form of minor scuba tanks.

Knife Switch

The knife switch is not similar to the diving knife. It is utilized while using underwater electric equipment when welding. Constructed like a simple lever, it controls electricity floor from the topside to provide power to your tools.

Diving Suit

under water welding suits

The diving suit is a flexible armor for your task. What is the main difference between a scuba diver’s suit and underwater welder’s suit? It depends on the activities you do. Many commercial divers employ the drysuit because it offers more protection and superior control of climate as compared to the wetsuit.

Drysuits are shell, rubber, or neoprene, depending on your diving environment. Nevertheless, as an additional external protection layer, several underwater welders put on coveralls on top of suits.

In case molten metal comes in direct contact with the suit, it can burn through. Coverall is vital for this task. To protect hands, the welder puts on rubber, thick linemen gloves on top of several latex pairs.

To keep water from getting to gloves, they can snap a rubber band on the wrist section.


A respirator is crucial and is often overlooked as equipment for welding. Hot metals can release gasses that are toxic to the air, zinc and magnesium fumes in particular. The fumes can result in Parkinson’s-like symptoms, asthma, lung cancer, and hearing loss. Individuals always skip respirators as they cannot find a fitting model under the welding mask. Put additional work in looking for low-profile, small respirators that fit the mask.

Improper use of respirators is dangerous. Respirators do not work minus proper air supply or filters. Make sure that the respirators you purchase matches with material types you are working with. Always make sure that the respirator is fitting and seals or else it will not protect you.

Hands, chest, and arms

Your hands, chest, and arms are the closest to the fire line for the molten slag and sparks. There is no need for satisfying dexterity while picking the safety gear. Depending on the job, you will either require the welding apron or full welding jacket with different welding sleeves. Gloves are necessary for all types of welding.

Waterproof Electrodes

The electrode is a very crucial part of the underwater welder tools because it provides material for welding. There are many materials and sizes to select from, beginning with the small 1/8 inch welding rods which work on mild steel to a larger 5/32 stainless steel rod.

The main difference between the underwater welding and topside is the coating; marine electrodes need to be extremely resistant to water. Some divers coat their electrodes, but many of them last for more hours.

They work perfectly well for depths that go up to thirty-three feet. Below that level, the pressure will cause added porosity that can damage the integrity of the structure.

Water Resistant Coating

It would be better if it can hold up for long in the hostile marine environment.

High Strength Yield

Materials of better quality inside the electrode provide high-density weld that can last for long. Typical diameters are 5/32 and 1/8 inches.

Underwater Stinger

When it comes to the marine stinger, less is more. They hold electrodes and are primarily manufactured from lightweight plastic reduce possibilities of fatigue and cramps.

Underwater welders that train with particular stingers always prefer using the same type while at work even there is a newer model in the market. You need to stick with the thing you know as a consensus. This is due to the feeling that other sections of the job are not predictable.

Nonetheless, updated equipment assists the dive to be safer, have an efficient operation, and help reduce overall costs. This equipment makes these tool types, especially the underwater torches, to be cutting edge. An underwater stinger of high quality has the following physiognomies.


Saltwater is a great conductor of electricity and welder divers require all the necessary protection from this. In case the stinger has good insulation, it will keep welder divers from feeling the current even at two hundred amps.

Lightweight and ergonomic

The bigger the project of welding the more the underwater welder requires a stinger she/he can hold for a long period.

Angled Correctly

The stinger requires the perfect notch and hole where the underwater welder can put in the electrodes. It allows for optimal use in various positions of welding and distinguishability.

Underwater Welding Machine

Current and amperage matters when it comes to the welding machine. Counter to many topside processes of welding, controlling marine welding equipment works well in partnership with the control team and the divers below the boat. Immediately before the diver starts welding, she or he will communicate through the radio towards the control team.

This provides a signal to turn underwater welding machines to the right amperage. The required power is dependent on the electrode size. Since the majority of the weld is done on top, a few companies formulate welding machines that are specifically made for underwater welding. Some need additional steps for it to change to an output mode that is safe in underwater use, like taking out the coil from the internal of the machine.

These are the qualities you need to look for in the power source of underwater welding.

Stable and consistent power

The right machine does not have fluctuation in amps without the knob being changed, even with long cables of power; it has to maintain the best, continuous flow.

Duty Cycle

Duty cycle represents time in which the underwater welder can operate the equipment of underwater welding at maximum power or amperage. In case the machine is operating at 275 amps for a sixty percent duty cycle, it means you can weld the full full-throttle for sixty minutes out of ten minutes. Other machines can work at a higher level, but the power requirements depend on the electrode type being used.

DC not AC

In water, all equipment of welding needs to get powered through direct current and not alternating current. Since direct current flows in one direction, it is the best alternative to alternating current when being used underwater. The divers utilize negative or straight polarity that offers a long life for the holder of the electrode.

How to use the welding equipment rightly

Welding may produce hazardous gases to your health during the process of welding. Therefore, the welders need to avoid breathing these gasses and fumes and keep the head from the fume. Additionally, you need to wear clothes that are resistant to flames, such as a shirt and denim pants made from a woven material or a special welding jacket. Additionally, you need to remember not to put on sports shoes because they can smoke, resulting in the burning sensation.

The instructions of the manufacturer come with all welding equipment. They contain crucial safety info and informational procedures which maximize the potential of the machine; therefore, users have to read and understand and follow those safety practices carefully.

When the welder is working, the circuit of work is hot to the extent that it can produce electricity. Therefore, it is crucial to avoid hot parts with wet clothing and bare skin since the electric shock can result in sudden death. The other things are to maintain the holder of the electrode, welding machine, welding cable, and work clamp in a safe condition. While working above the floor level, people have to employ safety of the welding equipment like using the best equipment for protection in the event they unexpectedly fall. Always remember to replace insulation that is damaged.

Welding gets applied in very many fields in the industry. Nonetheless, it will result in dangers and injuries if the users or welders do not know how to select the right safety equipment and methods of avoiding unexpected accidents. The welder has to be aware of utilizing the safety of the welding equipment.

Armed & Ready

The tools above come at a cost that is sizable, but many of those welders get employed by a firm that has this equipment.

In case you do not have this luxury, it becomes possible to base the expenses of your tools from your income and invest where possible. Expenses that are tax deductible will help you succeed as an underwater subcontractor. Besides the electrode and stinger, the tools of the underwater welder are used for these purposes besides welding underwater. It is still important to know the characteristics of the equipment to ensure that you remain informed and using the best for underwater welding jobs.

Click Here to Leave a Comment Below 2 comments
Bob P.

Pretty good equipment/gear list, but a respirator isn’t of much use in underwater welding, given that you’re already using a surface supplied helmet.


    Noted and Thanks for your valuable Comment.


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