Stud Welding in the Shipbuilding Industry

Stud Welding in the Shipbuilding Industry

Ships and vessels in the marine industry can have millions of fasteners, pins, and other stud types. So, stud welding is a highly applied process in the shipbuilding industry. 

Shipbuilders and maintenance crews can use our stud welder rentals to quickly and efficiently place fasteners when working on the ship frames, walls, bulkheads, and other vessel parts.

Introduction to Stud Welding in Shipbuilding

Shipbuilding relies on stud welding to connect different materials in various configurations. But, it’s the stud welding that’s crucial for applications where riveting is not an option. Stud welding allows making a weld that’s stronger than the stud itself without the need to drill the base metal or use overlapping pieces.

Importance of Reliable and Efficient Joining Methods

There is little room for error when building a multi-billion dollar vessel that must endure harsh seas and unpredictable weather anomalies, like rogue waves and hurricanes. So, joining steel and other materials with exceptional weld strength is paramount. There is no substitute for picture-perfect welds in the marine industry because lives and extremely expensive equipment rely on them.

The marine industry has a long turnover time. Ships, submarines, and other vessels are not built in a day; they often take years to produce. Welds not only need to be perfect but they must be placed efficiently to reduce the unnecessary time of vessel production.

While shipbuilding requires many different welding processes, the efficiency and weld quality of stud welding are hard to beat. Fusing fasteners, pins, bars, tabs, hooks, and other stud stypes can be done quickly and with absolute precision.

Advantages of Stud Welding in Shipbuilding Applications

• Unlike riveting, stud welding removes the need to overlap metal pieces, which significantly reduces the vessel’s weight
• Allows fast and precise stud welding
• Supports welding dissimilar metals and alloys
• Creates lightweight bonds without excess filler metal
• Corrosion-resistant materials are unlikely to lose these properties due to stud welding
• Extremely fast arc time reduces HAZ 
• No need to access the other side of the weld
• Can weld many different types of studs
• Simple to automate
• Produces strong, reliable welds
  

Key Applications of Stud Welding in Shipbuilding

The marine industry uses stud welding for a vast number of applications. Fasteners, pins, headed pins, and other studs are necessary for decking, insulation, fittings attachment, man-hole rings, and hundreds of other applications. But, some applications rely on stud welding more than others, like hull construction, decking systems, and on-board piping. 

Hull Construction and Repair

Constructing a functional and fully equipped ship’s hull is a complex task that requires a multi-disciplinary approach, from metallurgical analysis and steel alloy selection to the mechanical aspects of welding and metal shaping. Stud welding plays an important role in ship hull construction and repair because it allows fusing bolts, fasteners, insulation and electrical installation hooks, and other crucial studs directly to the hull parts.  

Stud welding is often used to make water-tight ship hull plate connections, making this welding process indispensable for ship hull construction.

Decking and Flooring Systems

Laying wooden decks and other floor systems over the steel decking substrate on ships became dramatically easier after the invention of the stud welding process. Fasteners are stud welded to the steel deck quickly, making the floor installation a breeze. Once fasteners are in place, insulation is laid in the floor space, and the wooden decking is secured using the welded fasteners. 

Piping and Pipe Support Systems

Studs provide support for piping systems running throughout the vessel. Pipes carrying the essential infrastructure for the ship are often suspended from the steel ceiling structure using welded pipe hanger studs. 

Stud Welding Techniques for Shipbuilding

The two most commonly applied stud welding methods in shipbuilding are the drawn arc and capacitor discharge stud welding processes. Both are universally used across many industries, but their application in shipyard welding is vital for cost and time savings.

Drawn Arc Stud Welding

Drawn arc stud welding works better for thicker base metals and larger studs. It works by drawing an arc, hence the name, from the tip of the stud to the base metal, melting and fusing them in the process.

The stud is loaded into a stud gun, placed firmly against the workpiece, shrouded by a protective ceramic shield called “ferrule,” and welded in place. The ceramic shield protects the weld and contains the arc heat and the molten metal during the fusion process.

Once the trigger is pressed, the gun lifts the stud slightly and draws an arc between the stud and the surface. Almost instantaneously, the stud gun releases the spring, which plunges the stud into the molten pool in front of it and fuses it to the base metal. The whole process is measured in milliseconds, making it highly efficient for shipbuilding. It’s particularly useful for joining thick studs for decking and hull construction.

Capacitor Discharge Stud Welding

Capacitor discharge stud welding uses a pre-charged capacitor to quickly discharge a high amount of electricity to expedite the welding process and reduce the time under heat. The high-powered capacitor stores an immense amount of energy and unleashes it all at once, which minimizes heat buildup, leading to reduced HAZ and warping of thinner base metals.

Studs used with this stud welding variant typically have a small guiding pin at the tip for precise placement. Other than that, the process is much the same as the drawn arc stud welding. The stud gun fires the electrical current and pushes the stud into a molten metal pool to form a seamless and clean joint.

Thanks to its immense speed, chances of warping and discoloration are minimal. So, capacitor discharge stud welding is typically used to join studs to thin metal sheets.

Stud Welding Equipment and Consumables

Stud welding equipment includes a stud welder, stud welding gun, and consumables like ferrules and studs. But you may also need a power generator for a stud welder when working in the shipyard or on the ship. 

The Tru-Weld TW6900 stud welder is a perfect example of a heavy-duty machine capable of drawn arc stud welding heavy studs needed in the marine industry. Its duty cycle allows welding several 1-1/4-inch thick studs per minute or unlimited studs with a thickness in the range of 1/4 – 5/8-inch. But, it’s equally important to weld lighter studs needed for insulation attachment and supporting pipe systems on a vessel, and welders like the Proweld CD-312 and Proweld ARC-1850 are perfect for the job. 

Benefits of Stud Welding in Shipbuilding

Stud welding was developed for the shipbuilding industry in 1930 by the New York Navy Yard to attach wood to steel. But it quickly found use in many parts of the shipbuilding process thanks to its numerous benefits. It still remains one of the most essential processes in the marine industry for efficiency and cost reduction.

Strength and Durability of Stud Welds

Stud welds are often stronger than the studs themselves if welded correctly. Welding a stud to a surface using other arc processes like MIG or TIG wouldn’t always result in a full stud-to-surface fusion. Thick studs can only be welded with a circumferential fillet weld using other arc welding processes. On the other hand, stud welding fuses the entire surface of the stud’s tip to the base metal, which provides a superior bond.

Speed and Efficiency in Shipbuilding Processes

The shipbuilding industry is always looking for ways to reduce the vessel’s time to completion. Manufacturing a ship is a notoriously slow process regardless if the vessel is a commercial cruiser, an industrial freighter, or a ship for military use. All stakeholders in the marine industry want their vessels made safely but quickly, and stud welding is one of the processes that helps do just that.

Stud welding doesn’t require drilling or accessing the welded surface from the other side, making it a significantly faster and safer joining method than riveting. Stud welding can also be automated to additionally improve welding speed and accuracy. But, manual stud welding is already a rapid process that doesn’t require automation to reap the speed benefits.

Enhanced Corrosion Resistance

Since stud welding is completed in a manner of milliseconds, stainless steel base metals are unlikely to lose corrosion resistance due to high heat. In addition, a completely flush with the surface stud doesn’t leave any crevices for corrosion to seep in. Likewise, applying a protective coating over the stud easily covers the minimal stud weld profile and protects the whole configuration from corrosion. 

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Future Trends and Innovations in Stud Welding for Shipbuilding

Stud welding is a developing field. Many industries rely on stud welding for the efficient production of fabricated metal products. So, welding institutes and businesses continually innovate for improved stud welding speed and safety. 

Automation and Robotics in Stud Welding

Automation can improve the speed and precision of stud welding and reduce safety risks by removing the operator from the welding area. While many studs need to be manually welded “on-site” during vessel production, parts produced in a shop environment can benefit from automated stud welding.

Welding automation will play a major role in the future of the industry. Today, almost all businesses in the metalworking industries are struggling with skilled labor shortages and increased production needs. So, many innovative automated welding systems are at the forefront of the industry, trying to improve efficiency and production.

Environmental Sustainability in Shipbuilding Processes

Industries of every stripe are working hard to reduce their impact on the environment and implement sustainable practices. The shipbuilding industry uses a lot of energy and resources to produce vessels for different sectors and needs. But, making a ship is a long-term investment for the owner and the society, as we all need a developed marine industry for the world to function as we know it. 

Shipyards are starting to use innovative design solutions to cut the energy needed to manufacture vessels and achieve zero-waste, zero-emission ships. Applying specialized hull designs and surface finishes can reduce vessel resistance and cut fuel consumption. In addition, hybrid propulsion technologies can significantly reduce ship’s emissions. 

The stud welding process helps achieve sustainability goals by reducing the needed resources to join studs to the metal sheet. Compared to MIG and TIG, where you must lay the filler metal wire and use a shielding gas, the stud welding process saves on the filler material and the gas. But, it also cuts transportation costs and used fuel. Delivering the shielding gas bottles for gas-shielded arc processes wastes energy and contributes to the built-in carbon of the ship. 

While this seems like an insignificant comparison, remember that a large navy or cruising ship contains millions of studs. Welding each stud manually using a MIG, TIG, flux-cored, or MMA welding process would require significant labor, transport, filler metal, and shielding gas (depending on the used process). 

Finally, the stud welding process produces welds that will last a very long time, justifying the resources used to make them. 

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Conclusion

The shipbuilding industry is continuously evolving as it aims to produce safer and sustainable ships faster and more efficiently. Ever since the New York Navy Yard introduced stud welding to the marine industry, this welding process has become indispensable for achieving high shipbuilding efficiency. 

Our fleet of stud welder rentals can help shipbuilders and maintenance contractors weld studs quickly, accurately, and with exceptional weld quality. Red-D-Arc provides made-in-the-USA Proweld and Tru-Weld stud welders, offering high-end features and factory presets for maximum efficiency, ease of use, and weld strength.