Marine welding on the British Columbia coast presents challenges that land-based fabrication simply does not. Saltwater, tidal conditions, humidity, and the constant threat of corrosion require specialized knowledge, materials, and techniques. At T & C Fabrication, we have built and repaired marine structures across the Discovery Islands and Vancouver Island for years, and these are the key challenges we navigate on every marine project.
Galvanic Corrosion: The Invisible Enemy
When two different metals are in contact in saltwater, they form a galvanic cell — essentially a battery. The less noble metal (the anode) corrodes at an accelerated rate, sometimes failing in months rather than years. This is why you cannot simply bolt a stainless steel fitting to an aluminum frame in saltwater. Every fastener, bracket, and connection point in a marine structure must be evaluated for galvanic compatibility. We use isolation bushings, proper alloy selection, and sacrificial anodes to manage galvanic corrosion.
Material Purity and Cleanliness
Marine aluminum welding demands exceptional cleanliness. Any contamination in the weld — iron particles from grinding, oil from handling, moisture from improper storage — becomes a corrosion initiation site in saltwater. We use dedicated stainless steel brushes for aluminum (never carbon steel), clean all joint surfaces with acetone before welding, store aluminum material off the ground and covered, and use only clean, dry filler wire.
On-Site Marine Welding Conditions
Working on docks, floats, and marine structures means dealing with wind that disrupts shielding gas coverage, humidity that can cause porosity in welds, tidal conditions that limit access windows, and confined spaces and awkward positions. Our mobile welding service carries windscreens, extended gas nozzles, and the patience needed to produce quality welds in less-than-ideal conditions. Rushing a marine weld to beat the tide is never worth the risk of a defective joint.
Corrosion Prevention After Welding
The heat-affected zone around a weld is more susceptible to corrosion than the base metal. Post-weld treatment is critical in marine environments. For aluminum, this may include passivation treatments, barrier coatings, or additional cathodic protection in the weld zone. For steel marine structures, hot-dip galvanizing or marine-grade epoxy coating systems are essential.
T & C Fabrication specializes in marine and aquaculture fabrication for the BC coast. Call Ted at 250-202-1643 to discuss your marine welding project.
