Marine welding guide covering hull construction, aluminum boat building, offshore structural welding, and classification society requirements. Processes, materials, and corrosion considerations for shipyard work.
Marine welding builds everything from 16-foot aluminum fishing boats to 1,000-foot container ships. The common factor is that every weld will spend its service life in one of the most corrosive environments on earth. Saltwater attacks welds at the heat-affected zone, in crevices, and anywhere the protective coating breaks down.
Steel hull construction uses FCAW as the workhorse process. Shipyards pre-fabricate hull panels and sub-assemblies in the shop using flat-position SAW for long plate seams. These sections are then lifted into position and joined with FCAW in all positions. Hull plate thickness ranges from 3/8 inch on smaller vessels to 1 inch or more on cargo ships and naval vessels.
Classification societies (ABS, DNV, Lloyd’s) set the rules for weld quality, NDT requirements, and welder qualification. Every structural weld on a classed vessel must meet the applicable society’s standards, and inspectors from the society witness critical work.
Aluminum marine construction uses 5086 and 5083 alloys for hull plating and 6061-T6 for structural extrusions. MIG with pulse transfer produces good results on marine aluminum. Filler metal is typically ER5356 for corrosion resistance or ER5183 for higher strength. Cleanliness is critical since aluminum is sensitive to hydrogen porosity from surface contamination.
Offshore platforms, jacket structures, and subsea equipment demand welding to API, NORSOK, or ISO standards. The combination of fatigue loading, corrosion, and difficult access makes offshore welding some of the most demanding work in the trade.
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Marine welding classification requirements from ABS, DNV, and Lloyd's Register. Covers welder qualification, material grades, in-service repair rules, and how classification societies govern vessel …
How to weld aluminum boat hulls. Covers 5083-H116/H321 marine plate, 5356 filler metal, MIG vs TIG, distortion sequence, back-step technique, and AWS D1.6 requirements.
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