Protecting Against Unseen Oxidation and Corrosion

Protecting Against Unseen Oxidation and Corrosion
Four anodes: Here we see a collection of sacrificial anodes that have been seriously depleted as they did their job protecting other vital engine components.

Salt can have detrimental effects on a boat’s exterior as well as internal engine components. Annual service is therefore the most important preventative maintenance procedure because it allows factory-trained technicians to inspect the outboard every 100 hours.

The internal combustion engine is self-defeating due to normal wear and tear, carbon buildup, and corrosive effects of ethanol. Saltwater can also damage the engine’s cooling water passages and the newer four-stroke engines have sacrificial anodes that can be inspected and replaced during annual service to reduce damage to the cylinder block and heads. Steel corrodes whereas aluminum oxidizes, and thin-walled sections within the exhaust system are especially vulnerable. Leaks in the exhaust system can cause expensive repairs and even powerhead replacement.

We have historically inspected engine anodes every 300 hours and found little oxidation. However, we recently serviced an outboard the owner uses farther south on the Texas coast. The engine had logged 500 hours and the owner requested anode inspection, which we found to be seriously degraded, even though he flushes the engine regularly.

Speaking with the engine manufacturer I learned that higher salinity levels of the Lower Texas Coast causes accelerated degradation of the sacrificial anodes. We now recommend replacement of the anodes anytime significant signs of degradation are discovered. These anodes are there to protect the engine, and with this revision to our service protocol we can ensure that no matter where the angler fishes, the engine will not suffer from internal corrosion and oxidation damage caused by saltwater.

To protect external surfaces of the powerhead we recommend applications of Corrosion-X Red.

Chris Mapp
[email protected]
| Coastal Bend Marine
Port O’Connor, TX | 361-983-4841