Underwater Cutting & Welding

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Oxygen arc cutting Steel-Tubular Electrodes 

Oxygen arc cutting Steel-Tubular Electrodes The oxygen arc cutting steel-tubular electrode consists of a steel tube with a waterproofed  flux coating which is applied during the manufacturing process. The electrode is 14 inches long with a 5/16-inch outer diameter and a bore diameter of slightly less than 1/8 inch. The… Read more >>

Steel-Tubular Electrode Cutting Technique : cast iron and non-ferrous metals 

Steel-Tubular Electrode Cutting Technique (cast iron and non-ferrous metals). Cast iron and non-ferrous metals do not oxidize; therefore, underwater cutting essentially becomes a melting process. There is no chemical reaction of the oxygen and the base metal. Therefore, the only benefit realized by the oxygen is the mechanical effect of… Read more >>

Steel-Tubular Electrode Cutting Technique : Thick plate 

Steel-Tubular Electrode Cutting Technique : Thick plate When cutting steel plate that is 1/4-inch thick or greater with Steel-Tubular electrodes, use the drag technique and proceed as follows: Insert the electrode into the collet opening until it bottoms out against the washer. Tighten the collet nut. To start the cut,… Read more >>

Exothermic Electrode Cutting Techniques 

Exothermic Electrode Cutting Techniques The 1/4-inch exothermic cutting electrode may be used to cut steel up to 1/2 inch in thickness. The 1/4 inch electrode leaves a narrow kerf and is preferable for fine cutting. When visibility is poor or when cutting heavier steel, the 3/8-inch electrode is more efficient…. Read more >>

Exothermic Electrodes Oxygen Requirements 

Exothermic Electrodes Oxygen Requirements. Exothermic cutting consumes a large volume of oxygen; therefore, a 3/8-inch inside diameter oxygen hose is required to maintain sufficient volume. The hose size is important because it is the oxygen volume together with heat that does the cutting while the pressure blows the slag away…. Read more >>

Underwater Cutting 

One of the major tasks in underwater cutting and welding of the Salvor is the refloating of stranded vessels and the clearance of navigable harbor areas of wrecks and grounded ships. Most often this requires the use of underwater cutting equipment. This section presents detailed technical information and procedures to… Read more >>

Underwater Welding : Introduction 

Underwater Welding Although underwater welding does not have as many applications in marine salvage operations as underwater cutting, underwater welding is an extremely important and useful process. By substituting welding for mechanical methods of joining, the overall cost and time spent on the job can be reduced considerably. Historically, most… Read more >>

Exothermic Electrodes : Trouble Shooting 

Trouble Shooting Exothermic Electrodes. Oxy-arc cutting, especially exothermic cutting relies on an unobstructed oxygen flow to be most effective. With inadequate oxygen flow, the rod will burn but not produce the desired cutting effect. Since the actual cutting result is derived from the volume of oxygen reaching the target, any… Read more >>

Strength Of Underwater Fillet Welds 

Strength Of Underwater Fillet Welds The strength of a completed weld joint may well become the most important factor in the success of an entire salvage operation. The loading on a member, such as a padeye, involves both static and dynamic forces. Dynamic loading may be a combination of tension,… Read more >>

Underwater Welding : Shipbuilding Materials 

Underwater Welding :  Shipbuilding Materials The underwater welding diver should be familiar with the different types of steel used in shipbuilding in order to select the appropriate welding electrodes. Today shipbuilders have a wide range of steels which are used in the construction of ship’s hulls and superstructures. Quite often,… Read more >>

Underwater Welding – Mechanical Barriers 

Underwater Welding – Mechanical Barriers Cofferdams and Caissons. Cofferdams and caissons are used at the waters edge or in the splash zone and below the water surface. While the structure excludes the surrounding water from the work area, its upper section is open to the atmosphere. This technique is depth-limited… Read more >>

Exothermic Electrodes | Cutting Technique | Concrete, Rock and other Non-Conductive Materials 

Exothermic Cutting Technique (Concrete, Rock and other Non-Conductive Materials). When cutting non-conductive materials, a striker plate attached to the ground cable is necessary to strike an arc. The striker plate is placed next to the material to be cut. Call for SWITCH ON, squeeze the trigger slightly, drag the electrode… Read more >>

Steel-Tubular Electrode Cutting Technique : Thin Plate 

Steel-Tubular Electrode Cutting Technique : Thin plate. When cutting steel plate which is 1/4-inch thick or less with Steel-Tubular electrodes, use the following technique. This technique is slightly different from that used on thick plate. Instead of maintaining the electrode tip in the cut and pressing against the lip of… Read more >>

Oxygen Arc Cutting 

There are two types of electrodes used for oxygen arc cutting: Steel-tubular (manufactured by Arcair) and the exothermic types (Arcair’s Sea-Jet and BROCO’s Ultrathermic). These electrodes provide excellent cutting results and can be used with a constant current DC welding generator set on straight polarity (electrode negative) supplying current to… Read more >>

Underwater Welding Arcs 

Underwater Welding Arcs **Underwater welding arcs **do not behave the same as on the surface and the activity of the gas bubble is particularly important to successful completion of the underwater weld. When the arc is struck, the combustion of the electrode and the detachment of water creates a gas… Read more >>

Underwater Cutting Oxygen Purity : Grounding the Work 

Underwater Cutting Oxygen Purity The oxygen purity for all underwater oxygen cutting should be 99.5 percentor greater. As the oxygen purity is reduced, so is the cutting efficiency. A one percent decrease in oxygen purity will result with a 25 percent reduction in cutting speed. In addition, the quality of… Read more >>

Underwater Welding Overview 

In underwater welding, the installation of large patches, as well as the attachment of suitable pad-eyes presents a more complicated problem to the diver than does underwater cutting. Considerable practice is necessary to achieve a consistently good standard of underwater welding for salvage work. As a result, the diver’s underwater… Read more >>

Underwater Welding – Wet Welding 

Underwater Welding – Wet Welding In underwater welding, the wet welding process used for salvage operations is usually a simple underwater joining technique. The materials required are commercially manufactured shielded metal arc equipment and waterproofed electrodes. Minimal ancillary devices are needed. These include lighting, staging and hand tools. There are… Read more >>

Underwater Welding : Joint Fit-Up 

Underwater Welding : Joint Fit-Up Since most underwater tasks are more cumbersome than similar topside work, the proper positioning of large members or plates underwater for welding is also quite difficult. Positioning and fitting must be done with thoroughness and care to ensure a satisfactory weld. In underwater fillet welding,… Read more >>

Underwater Shielded Metal Arc Welding Electrodes 

Underwater Shielded Metal Arc Welding Electrodes. Commercial manufacturers have made significant progress in the development of waterproofing systems for wet welding electrodes. Details of these systems are proprietary to each manufacturer; however, the results of their cumulative efforts have produced a new generation of wet welding electrodes. Certain electrodes are… Read more >>

Conditions Adverse To Underwater Welding 

Conditions Adverse To Underwater Welding Before welding operations are started, the job should be inspected to determine whether or not the welding can be performed effectively at the work site. Satisfactory underwater welds are more difficult than welds laid down topside. The following factors make underwater welding difficult: a. Diving… Read more >>

Underwater Welding Shielded Metal Arc Welding 

Underwater Welding Shielded Metal Arc Welding There are two basic techniques used today in shielded metal arc wet welding: the self-consuming technique and the manipulative or weave technique. With the self-consuming technique, the electrode is dragged across the work and a significant amount of pressure must be applied by the… Read more >>

Fillet Weld 

A fillet weld is a triangular weld used to join two surfaces that are at approximately right angles to each other. i.e., lap, tee and corner joints are normally welded with a fillet weld. A fillet weld should have a leg length equal to the plate thickness up to 3/8-inch… Read more >>

Exothermic Electrodes 

Exothermic Electrodes The BROCO Ultrathermic electrode consists of seven small rods inside a thin steel tube. One of the seven rods is a special alloy that will burn independently after an arc is struck and oxygen is flowing through the tube. The remaining six rods are made of mild steel…. Read more >>

Piercing Holes in Steel Plate with steel-tubular electrodes 

Piercing Holes in Steel Plate with steel-tubular electrodes. Holes can be easily pierced in steel plate using steel-tubular electrodes. The following technique is recommended: Touch the plate lightly with the electrode at the desired point. Hold the oxygen trigger down and call for SWITCH ON. Hold the electrode stationary for… Read more >>

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