Although it is a well-known fact that electricity and water do not go hand in hand, you can weld something that is wet. In fact, you might have heard of the term “underwater welding” in which the welding is carried out at high pressures underwater. However, you should note that this process is entirely different from the standard welding process.
For your convenience, I have first laid down a detailed description of underwater welding and then talked about the standard welding process.
Hyperbaric welding can be done either in wet conditions in the water itself (underwater welding) or dry conditions in a positive pressure enclosure (hyperbaric welding).
During wet underwater welding, the diver and the electrode are directly exposed to the water and other elements. Typically, 300-400 amperes of direct current is used to power the electrode, and the divers practice diverse forms of arc welding. This process usually involves waterproof electrodes.
To explain further, the different forms of welding may include shielded metal arc welding, flux-cored arc welding, and friction welding. However, there are a lot of occupational hazards involved with underwater welding, some of which are the galvanic breakdown of dental amalgam, and long-term musculoskeletal and cognitive effects of underwater welding.
Occupational Hazards of Welding
Galvanic breakdown of dental amalgam involves fillings in the tooth that erode a little when welding underwater. Also, musculoskeletal and cognitive effects happen as a result of intense water pressure. While there are no preventive measures for these exact hazards, it’s important to dive safely and stay hydrated.
There are many factors when it comes to the cause of the galvanic breakdown of dental amalgam In fact, galvanic shock can occur when underwater welding, and that is because of magnetic field effects. The magnetic field is caused by welding underwater, and it’s important to proceed with caution when welding underwater.
If an underwater welder has a metallic taste in his or her mouth, it’s possible that the galvanic breakdown of dental amalgam is happening. This is because the metals in the welder’s filings are reacting to a current.
Now, I will talk about a few musculoskeletal and cognitive effects that happen because of various reasons.
Musculoskeletal effects can happen as a result of intense water pressure, as well as, the act of welding underwater and the strength it takes. Also, working in tight spaces can cause some of these effects. For example, joint pain and muscle stiffness can occur in tight spaces. All of these factors can have lasting effects on the body, and here is what they include:
- Joint pain
- Muscle stiffness
- Back pain
- Neck pain
- Impaired hearing
Cognitive effects when welding underwater can occur as a result of inhaling toxins throughout the welding process These fumes include metal fumes, the flux fumes, carbon monoxide, and nitrogen oxide. A few other fumes can be aluminum and manganese. It’s important to be aware of the fumes around you when you are welding underwater.
Another factor to consider is the cognitive effects that diving, in general, can have on the body. Some of these effects can be short-term such as vertigo, which is when you feel as if you are moving when you are actually still. This can cause confusion, and it can happen when you don’t equalize the pressure from your ears.
Cognitive effects include:
- Loss of concentration
Safety During Wet Underwater Welding
- The diving equipment usually consists of a proper diving suit, full face mask, surface supply umbilical cord, a compressor for filling the tank and the air tank on the surface with a properly regulated manometer.
- The welding equipment has a safety switch which eases the flow of current or cuts it according to the requirement of the diver.
- Hydraulically and pneumatically driven tools are used underwater. Electricity is avoided for obvious reasons.
- During underwater welding, special cables with proper insulation have to be used so that the current does not break through to the water or the platform where the welding is being done.
- Typically, a proper communication system is established between the diver and the others on the surface so that the welding can be done correctly.
The Possibility of Application of Welding Processes In a Wet Environment
When you have water in a welding environment, it intensifies unfavorable factors which might lead to cold cracking of welded steel joints.
The process of wet welding is usually characterized by the direct contact of the diver-welder, electrode and base material.
MMA (111), SAW (121), MIG/MAG (131/135), FCAW (136/138), FCAW-S (114), friction welding (42), explosion welding (441), and stud arc welding (78) are possible in wet welding. However, plasma arc welding (15) and laser welding (521) are not possible. In dry welding, each welding procedure except the explosion welding (441) is possible. In local chamber method welding, SAW (121), Friction welding (42) and explosion welding (441) cannot be applied.
The Quality of Underwater Welding
To complete the process efficiently, wet underwater welding requires considerable expertise on the part of the welder. The entire process also involves a high risk of fabrication hydrogen cracking. Therefore, you must be an experienced welder diver to undertake underwater welding projects.
The quality of underwater welding largely depends on the welding consumables and the electrodes that are being used. The flat position of the electrodes generally yields a satisfactory result. But the vertical position of the electrodes generates a poor outcome.
Usually, the Ferritic weld deposits generally show moderate ductility and affect the toughness, and the Ni-base deposits offer adequate mechanical properties.
In the case of nuclear applications, stainless steel repairs have been carried out underwater with the use of stainless steel metal arc electrodes. However, the welding of Ferritic steel with stainless steel is typically unsuccessful due to fusion boundary cracking, and solidification cracking.
Water curtain welding and flux-cored wire welding without a glass shield are the semi-automatic underwater processes. Water curtain welding usually produces high-integrity welds.
Underwater, there is a change in chemical composition of the weld because of the rapid rate of cooling, water salinity, arc stability, and depth. The salinity of the water may provide different welding results. If the diameter of the electrode is small, you can improve the arc stability with increasing water depth and current density.
The Underwater Depth Factor
The underwater weld depth factor impacts the chemical balance in the weld pool because of the increase in oxidation and porosity. With the rise in water pressure, the chemical activity of the oxygen and hydrogen is also increased in the liquid of weld pool.
Also, the increased oxygen levels may lead to a decrease in the hardening capacity of the weld metal and lead to the occurrence of small structures of coarse grains consisting of ferrite grain boundaries. As a result, it may lead to poor mechanical properties.
If there is a high amount of hydrogen in the weld pool, it shall lead to an increase in the porosity of the welding.
Welding In the Rain and Other Inclement Weather Conditions
You might have heard other welders describing how they were welding while being stuck in ditches with the rain and mud surrounding them, and lightning striking the grounds in rapid flashes. It might have made you wonder if you can weld something that is wet? Is it even legal to weld in the rain?
Although many companies ensure that their welders do not work in inclement weather, there are no legal obligations regarding welding in wet weather. Therefore, it is not illegal. However, since electricity and water do not go hand in hand, you must consider a few things while dealing with moisture.
- Focus on staying dry: You must be cautious while dealing with moisture. Rain is not the only dangerous thing that you will come across while welding; even your sweat can be a hazard.
Your welding gear has been specially built to nullify the effects of electricity. But in case your equipment becomes wet, it shall no longer be able to protect you.
Gloves play a significant role in protecting your body from electrocution. In case they accidentally fall in a puddle, you pick them up and wear them, and then touch your arc or the electrode, you are inevitably going to be electrocuted.
More Safety Tips
Your boots should also be dry while you are welding. The welding boots are made with rubber to ensure insulation from the ground. But if they get wet, they shall not be able to perform their function. Moreover, if you accidentally step in a puddle while welding, you might get electrocuted.
- All kinds of moisture are your enemy while welding: It is one of the most important things which you should consider. Even areas with high humidity can be hazardous for you because they may cause dampness in your safety gear.
You should also be careful about your body moisture level. If you sweat a lot, then in a hot environment, your gloves can get dampened.
- It is not a good idea to weld in the rain: Welding in the rain can be dangerous for your well-being as well as equipment. If water gets into your gear, it can get damaged entirely. You should remember that amperage burns but voltage kills.
Additionally, you should watch out for your shield gas because the wind accompanying the thunderstorm may blow it away, thus adversely affecting the stability of your welding arc, and compromising the quality of the weld.
In case you are in the middle of a welding project while the rain hits, it is better to forsake it immediately. Ensure that you turn off all the equipment, and then carry the machine far away from the storm. If you cannot find a suitable place to shelter the machine, cover it with a tarp. Also, do not resume your work until the storm is completely gone and you are sure that your equipment is dry.
How To Weld In Wet Conditions
If you are arc welding, then you require a live electrical circuit. Of course, you use a hand-held machine due to which you are prone to electric shocks and burns especially during wet conditions. Since water can damage the insulation on the welding cables, clamps, plugs or electrode holder, you should use proper safety equipment.
Here are some things which you should follow if you need to weld in damp conditions:
- Put an insulating mat or a dry platform so that you are not in direct contact with the wet surface.
- You can use a rubber floor mat or a wooden pallet to stay away from the wet surface.
- Ensure that the mat is large enough to offer you protection when you need to bend down or kneel to complete your work.
- Pick baggy overalls which cover your entire body. Do not roll up your sleeves or remove your gloves while you are welding. Also, do not remove your helmet while welding.
- Check the electric cables thoroughly before welding. Ensure that they are not damaged because working with damaged wires may result in electrocution.
- Use an electrode holder which is wholly insulated so that there is no chance of accidental contact with such components which may have an electric charge.
- While welding in wet conditions, ensure that there is someone along with you so that he can help you out in case of emergency.
- Ensure that the maximum open circuit voltage should be less than 80 volts.
Thus, you can weld things that are wet. However, there are a lot of risks involved in doing so. If you are welding underwater, you should have appropriate safety gear and equipment so that you can stay safe.
However, in case you are in the middle of a welding project, and it starts raining, you should immediately stop your welding work because you may get electrocuted. You should avoid welding in wet conditions because it is not considered to be safe.