This is one of the most common questions asked among boaters. There are many options out there, everything from traditional zinc anodes to prop speed reducers to stainless steel driveshafts. It can be overwhelming trying to find which option is best for you.
When choosing equipment for corrosion protection on your boat’s drive, there are several things you need to take into consideration:
Location and Installation – Where is your drive, and how is it installed? This will determine which options are available to you.
What Type of Water Do You Typically Boat In? – Salt vs. Fresh, Cold vs. Warm, etc.? This will help determine the appropriate metals for your specific application.
How Fast Do You Typically Go? – Cruising speed, racing speeds, etc.? This will help determine the appropriate equipment for your specific application.
Budget – How much money do you want to allocate for corrosion protection? This will help determine which options are available to you.
What Type of Anti-fouling Paint Do You Use? – Different types of paint require different types of protection. This will determine the compatibility and effectiveness of your chosen option.
Zinc Electrolytic Anodes
Zinc anodes are best used when you are constantly surrounded by water, such as when you’re traveling by your boat in saltwater or freshwater with high levels of chlorides or sulfates. They work great on many types of ballast tanks.
Prop Speed Reducers/Silencers
A prop speed reducer (also called a “silencer”) is installed at the end of your driveshaft and slows down the speed of your propeller. It does this through a mechanical process in which the energy in forwarding motion is turned into heat.
A prop speed reducer is perfect for boats that spend time in saltwater but do not necessarily need anodes if they are using anti-fouling paint that is not compatible with stainless steel.
Steel Anodes
Steel is best used when you are constantly surrounded by water, such as when traveling by your boat in saltwater or freshwater with high levels of chlorides or sulfates. While steel anodes are not necessarily required for boats only used in freshwater, they can still provide excellent corrosion protection to your drive if desired.
Zinc/Aluminum Anodes
Zinc and aluminum are the most common types of sacrificial anodes used when boats spend time in saltwater. They are also effective when used in freshwater or chlorides if you’re using anti-fouling paint incompatible with stainless steel.
Silver Anodes
Silver anodes produce silver oxide that provides cathodic protection to the underwater metals in your boat. Silver anodes are only effective if you’re using aluminum propellers and spend time in salt water with high levels of chlorides or sulfates.
Aluminum Boot Stripe for Painted Surfaces
Aluminum boot stripes work by providing a “sacrificial” surface that corrodes instead of the metals below the boot stripe. The corrosion then produces a black oxide that camouflages the boat’s metal parts and reduces the need for future painting.
Boot stripes work effectively in both saltwater and freshwater. While they are not required when your boat spends time in saltwater, they can provide excellent corrosion protection to aluminum propellers if installed properly.
