Aluminum or galvanized steel for a boat launching trolley?

STEEL :

Advantages

• Very strong et rigid  high mechanical resistance, ideal for parts that must withstand heavy loads.
• Cheaper that aluminium (in general)
• Less sensitive to fatigue  it retains its properties longer under repeated load/unload cycles.
• Easy to weld and work with  useful for repairs or custom fabrication

Disadvantages

• Heavy weight  heavier than aluminium, which can make the boat heavier and reduce performance.
• Corrosion  very sensitive to seawater
• Less aesthetic over time

ALUMINIUM :

Advantages

• Lightweight  reduces onboard weight, improves speed and maneuverability
• Corrosion – resistant  requires less maintenance than steel
• Good strenght to weight ratio  used for masts, booms, travellers

Disadvantages

• Less rigid than steel  may deform under high stress
• More expensive to purchase
• Galvanic corrosion  if in contact with other metals, risk of accelerated corrosion in the presence of salt water
• Fatigue  aluminium fatigues faster than steel and can crack over time under repeated stress

Stainless steel is often preferred for fasteners, chainplates, and critical structural components  strenght + corrosion resistance

Aluminium is deal for everything that must be lightweight (masts, booms, travellers, blocks, winches)

DINGHY TROLLEYS

Galvanized steel – Pros

• Stainless steel screws and wheel axle  corrosion resistance
• Strong and sturdy (ideal for heavy loads or intensive use)
• Generally more durable over time for « all-terrain » or collective use (clubs, marinas…)

Aluminium – Pros

• Lightweight and easy to disassemble, solid aluminium centerboard axle
• Easier to handle alone (move, disassemble, store)
• Less prone to rust (no need, for galvanizing like steel)
• Well suited for individuals or those who need to transport/assemble the trolley quickly

In summary :

Galvanized steel = strenght and durability

Aluminium = lightness and maneuverability

Corrosion of galvanized steel vs aluminium

Galvanized steel is a type of steel coated with zinc to protect it from rust and corrosion. The zinc layer act as sacrificial anode, corroding first to protect the underlying steel. As a result, galvanized steel is highly corrosion-resistant, making it ideal for outdoor use.

Similarly, aluminium is highly corrosion-resistant due to the formation of a thin but dense aluminium oxide layer on its surface. This aluminium oxide layer acts as a barrier to protect the underlying metal from further corrosion. Additionnaly, this oxide layer is self-repairing : if the surface is scratched or damaged, the aluminium oxide layer quickly reforms and prevents corrosion from occurring.