British Columbia's aquaculture industry depends on reliable marine infrastructure — float systems, walkways, pen frames, feed systems, and equipment platforms that must survive years of saltwater exposure, tidal forces, and heavy loading. Getting the fabrication right from the start saves enormous costs in maintenance and replacement down the road.
Choosing the Right Aluminum Alloy
Not all aluminum is equal in marine environments. For aquaculture fabrication, we primarily use two alloys. 5086 aluminum is excellent for hulls, floats, and structural members that will be in constant contact with saltwater. It has superior corrosion resistance and welds well. 6061-T6 aluminum is stronger and ideal for structural framing, handrails, and equipment mounts. It machines well and takes anodizing for additional protection.
Welding Considerations
Marine aluminum welding requires TIG (GTAW) welding with pure argon shielding gas. The material must be scrupulously clean — any contamination in the weld will become a corrosion initiation site. We use 5356 filler wire for most marine joints, which provides excellent corrosion resistance and good strength.
Design for Marine Environments
Designing for aquaculture means accounting for dynamic loads from waves and tidal current, personnel and equipment loading, biofouling growth adding weight over time, maintenance access — everything needs to be reachable, and corrosion-resistant fasteners (stainless steel or monel). Avoid mixing dissimilar metals where possible. Galvanic corrosion — where two different metals in contact with saltwater create an electrical cell — is the number one killer of marine metal structures.
Corrosion Prevention
Even with marine-grade aluminum, proper finishing extends service life. Options include anodizing for additional oxide layer protection, barrier coatings for below-waterline surfaces, sacrificial zinc anodes for galvanic protection, and regular freshwater rinsing of accessible surfaces.
Float System Design
Float systems for aquaculture need sealed air chambers for buoyancy, non-skid decking for personnel safety, structural redundancy so a single failure does not sink the system, modular connections for easy reconfiguration, and properly sized scantlings for the expected loading.
At T & C Fabrication, we have built float systems, pen infrastructure, and marine equipment platforms for aquaculture operations across the Discovery Islands and Vancouver Island. Call Ted at 250-202-1643 or contact us to discuss your marine fabrication needs.
