How to Bond Through Boat Hull Fittings

Galvanic corrosion can afflict every metal part of your boat that's in the water.
Sometimes called salt water corrosion, you prevent it with the zinc anodes on your hull and motor. Not all the metal parts of the boat that are in the water have their own zinc. Unless those parts are electrically bonded to a nearby zinc, the metal part will corrode. If you have metal through-hulls, you can solve the problem with a wrench and some wire.

Things You'll Need

  • Measuring tape
  • 10 AWG gauge stranded copper wire
  • Wire cutters
  • Wire strippers
  • Adjustable wrench
Show More

Instructions

    • 1

      Measure the distance from the through-hull fitting to the zinc anode on the hull of the boat, using a measuring tape. Add at least 12 inches to this measurement.

    • 2

      Cut a piece of 10 AWG stranded copper wire this length with wire cutters. Strip 1 inch of insulation from both ends of the wire with wire strippers.

    • 3

      Loosen the nut -- located inside the boat -- on the mounting stud of the zinc anode on your boat's hull, using an adjustable wrench. Wrap one end of the wire around the stud. Retighten the nut.

    • 4

      Loosen one of the nuts on the inside part of the through hull fitting. Wrap the wire around the nut. Retighten the nut.