Corrosion Protection - Everything you need to know

So before we put our outboards to the test in the real world, they endure test after test in our state-of-the-art testing center. All so you can take to the water with confidence every time, no matter what. Because when you're on the water, reliability is more than just a word. It's peace of mind.

Click here to download the Corrosion Brochure.

Mercury's aluminum alloys are the most durable and corrosion-resistant on the market.

Not all alloys are made equal. Aluminum alloys with less copper content are superior in resisting corrosion. Copper, a weaker metal, reacts with water and aluminum and sacrifices itself to protect the stronger aluminum metal. The more copper in an aluminum alloy, the more likely it will corrode.

Mercury Marine is the industry leader in producing its own aluminum alloys with very low copper content. No competitor alloy even comes close. Mercury's aluminum alloys contain less than .20 percent copper, while the competition uses alloys with 10 to 20 times more copper content.

The Mercury aluminum alloy lineup:

  • XK360 Less than .20 percent copper content

    XK360, a Mercury exclusive, is the most corrosive-resistant alloy in the market. Mercury uses this alloy on die cast components such as engine blocks, cylinder heads, gear cases, drive shaft housings and sterndrive units.

  • A356 Less than .15 percent copper content

    Mercury uses its A356 alloy on lost foam casting components such as blocks, heads and clamp and swivel brackets. Mercury's unique Lost Foam casting plant is one of two manufacturing sites in the world that used this technology.

  • MercAlloy Less than .20 percent copper content

    MercAlloy, while costly, provides superior impact protection. Mercury uses MercAlloy on large outboard drive shaft housings and most of its aluminum propellers.

Low copper alloys are just the beginning

Mercury's industry-leading corrosion protection includes much more than its exclusive low copper alloys. Mercury's new paint system, exclusive salt shield and use of more stainless steel sets Mercury further apart from the competition.

  • The new MercFusion Paint System

    Mercury provides additional protection with its new MercFusion Paint System. Mercury coats its low copper alloys with an irridite - a chemical film - that provides an excellent corrosion barrier and superior foundation for the rest of the paint process. The alloy is then primed with an electro-deposition primer that creates uniform coverage to seal out the outside environment. The powder paint top coat, which contains plasticizers for superior flexibility and long-term adhesion, is thermo-cured resulting in a much harder, thicker and tougher finish than conventional paint.

  • Salt Shield

    Mercury's exclusive salt shield flushes into the powerhead and water passages to provide excellent resistance to saltwater exposure and heat.

  • More stainless steel components

    Stainless steel components offer maximum protection from corrosion. Mercury's prop, shift and drive shafts, trim and tilt rams, tilt tubes, steering swivel tubes, lower yokes and water pump housings are all built with stainless steel. Mercury's outboards contain at least twice the amount of stainless steel than the competition.

  • Hardcoat anodizing

    Mercury's superchargers, charge-air coolers and trim cylinders are hard anodized to increase corrosion resistance, wear resistance and provide better adhesion for paint.

  • Sacrificial Anodes

    Mercury strategically places sacrificial anodes on the transom brackets and lower units that are designed to sacrifice themselves and protect the aluminum alloy.

  • Continuity Devices

    Mercury's stainless steel braided bonding straps complete the continuity circuit to ensure grounding for corrosion endurance