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How to Protect Your Boat from Saltwater

There is no better feeling than sailing into the ocean to explore the vastness of mother earth. The ocean is home to so many activities. You can go fishing, engage in water sports, visit shoreline towns and discover tons of hidden gems. All these luxuries can be enjoyed only when you own a boat. As fun as owning a boat may sound, the biggest threat most boat owners face is saltwater corrosion.

Though inevitable, here are measures that you can take to protect your boat from saltwater corrosion and ensure it serves you for longer.


How to Prevent Saltwater Corrosion on Boat Exterior

I can’t emphasize enough how important cleaning your boat is when it comes to protecting it from saltwater. Most boat owners whenever they come from a trip, the first thing on their mind is to head home to either relax or share with friends about the great time they had.

What most people forget is that failure to remove traces of saltwater after a trip into the ocean accelerates the corrosion process.

And because of this reason, you should embrace the habit of always cleaning your boat thoroughly whenever you land from a trip. By doing so, you remove saltwater traces that may build up on the boat and initiate the corrosion process.

So, how do you wash a boat? It may look like a simple thing to do but very few people know how to properly clean a boat. Similar to cleaning cars, if you want to give your boat a thorough wash, first you must gather essential supplies.

This includes wash mitts, brushes that can reach those hard-to-reach areas, and most importantly, you will need a paint-safe and environmentally friendly boat shampoo. These shouldn’t be hard to find. And, it’s also important to get some buffing balls and wax which will keep your boat looking shiny and protected from UV damage.

Having gathered the above supplies, you are now ready to wash your boat and protect it from saltwater and the damages it may cause.


1. Rinse the boat with freshwater

The first thing you need to do is rinse the boat with fresh water. This will remove surface dirt as well as saltwater. This eases the cleaning process.


2. Wash the boat with soap

Next, get a bucket and add soap and water. Stir until it forms enough lather. Regarding the soap, you have a better chance of protecting your boat from saltwater by using a specialized boat shampoo than regular soaps. Therefore, ensure that you look for soap made to clean boats. Keep off household cleaning detergents.

Some of these are too harsh and end up eating off the clear coat of your boat paint and this allows saltwater easy entry into the metal of the boat.

Using the wash mitts and soft brushes, start by washing from the top going down. This ensures you don’t spread dirt to already cleaned areas. Depending on the size of the boat, you can divide it into sections whereby you wash and rinse. Or, you can wash the entire boat and rinse it afterward.


3. Rinse the soap

Using a garden hose, rinse the soap off the boat. Let the water run down so that it doesn’t bead on the boat’s surface.


4. Use a microfiber cloth to dry the boat

Inspect if the boat is clean and perform touch-ups on areas that may have been left behind. Finally, grab a microfiber cloth or highly absorbent towel and dry it. Use a clean microfiber cloth and turn it severally to avoid streaking. Once the boat is dry, you can look for flaws or scratches and correct them using rubbing compound or wax.


How to Prevent Saltwater Corrosion on Boat Engine

1. Flush your engine

Another essential way on how you can protect your boat from saltwater is by flushing the engine with fresh water every time the boat comes off the ocean. The engine is the heart of your boat and saltwater leaves deposits within the engine’s compartments.

If not flushed, these deposits can cause the engine to malfunction and the repairs can be very costly, plus it can be risky should the engine stop during a trip.

Before we look at how you can flush your engine, it is worth mentioning that this process doesn’t only apply to boats that have been on saltwater. Should you use your boat on muddy freshwater, the engine also has to be flushed.

There are a couple of ways on how you can flush the engine with fresh water. Please go through your manual and look at the recommendations provided by your manufacturer.

Adhering to your manual is crucial as it ensures you won’t do something that may damage the water pump impeller during the process. Anyway, these are the different ways on how you can flush a boat’s engine with freshwater:


a. Use the built-in flush connection

Flushing the engine shouldn’t be a problem because most boats built in the last decade come with a built-in flush connection. This is located mostly under the cowl or on the motor facing the boat. It should feature either a threaded fitting or snap fitting adapter that allows you to connect the motor to the garden hose.

In some boats, you don’t have to start the motor when using the built-in flush connection. Confirm that in your manual. The benefit of this method is that you can use it to flush an engine of a boat that is kept at a dock. All you have to do is tilt it away from the water.


b. Use flush muffs

The other option is to use flush muffs which are rubber cups held together by a clamp and are fitted over the cooling water intake ports on the engine. You attach a garden hose to one of the rubber cups to initiate the flushing process.

When using flush muffs, the engine should be started but should idle at neutral. The propeller shouldn’t be allowed to turn with fresh water flowing through it. This should go on for about ten minutes. You will see water flowing out. Once that duration is done, turn the motor off and then the water supply.

Your engine will be free from saltwater deposits.


c. Use flushing bags

These are bags made out of vinyl or canvas and are filled with water. To use flushing bags, the outboard motor is tilted into the bag when the boat is on its trailer and the motor is started. These bags contain an opening where a garden hose can be fitted.

The role of the latter is to ensure the water level is maintained at a certain height. With all the above factors in check, you can proceed to flush saltwater and its deposits from the engine.

Flushing is a great way of protecting the engine of the boat from saltwater damage. However, it’s a process that has to be done carefully because there are effects of going about it wrongly. For instance, freshwater should be completely drained from the engine once you are done flushing.

Secondly, an outboard motor should never be started without water. This can damage the engine. Out of the above methods, we recommend the use of a built-in flush connection, as long as it is allowed by your boat’s manufacturer. And never attempt flushing your engine without going through the manual.


2. Grease moving parts

Greasing moving parts in your boat doesn’t just ensure they function properly, but it also prevents saltwater corrosion and rust on metallic parts. If your car needs that much lubrication and is driven on land, imagine the amount of lubrication needed to run a vessel on saltwater? Be it bow rollers, linkages, hinges, latches, and any other metal surfaces, ensure that you grab some marine grease and apply it to all moving parts.

With boats, you should be very generous with the grease as the coatings prevent the metal parts from making direct contact with the saltwater which may kick start the rusting process. It is advisable that every time before heading for a trip, you should inspect if the moving parts are well lubricated.


How to Prevent Saltwater Corrosion in the Future

1. Wax regularly and choose salt-friendly paint

If we are talking about a new boat, you can’t switch to salt-friendly paint right away. But here is what you can do. Wash and marine wax your boat as regularly as possible. Waxing creates a protective layer over your boat and this keeps the saltwater from corroding the paint.

It is also important to fix scratches on the boat paint as soon as possible because these act as entry points for saltwater and in the long run, it could end up causing rust.

For owners whose boats have been around for a while and are in need of a new paint job, here is your opportunity to switch to a salt-friendly paint. Unlike ordinary paint, saltwater paint has a stronger bond that prevents saltwater from making contact with the hull.

As a result, there will be minimal corrosion on the metal of the boat caused by saltwater. It’s worth mentioning that is no type of paint that is strong enough to battle the effects of saltwater. Even if you apply salt-friendly paint, follow the above tips if you want to protect your boat from corrosion.


2. Inspect your boat frequently

For all boats that are driven on saltwater, corrosion is inevitable. This is why you need to always be on high alert. Whenever you see your boat, be on the lookout for minor blemishes, scratches, bubbling paint, blisters, corroded parts, or rust spots. These tiny blemishes grow into bigger problems if not remedied in due time.

As you inspect your boat, should you see any scratches or blemishes, plan on how you are going to fix them as soon as possible. Saltwater is very dangerous especially if it makes direct contact with naked metal. It’s also important to come up with effective solutions to fixing these blemishes.

Because if you leave even a single rust spot unattended to, after a couple of months, it may grow into a bigger rust patch that is difficult and expensive to fix.


3. Keep outboard tilted up when storing your boat at a marina

Most boat owners nowadays are doing a commendable job at keeping their outboards tilted from the water when storing their boats at a marina. By keeping the outboard from the water, you are practically keeping the saltwater away from it.

This can be more useful especially if you have just flushed the engine with fresh water. Other than protecting it from saltwater, tilting the outboard up prevents it from banging against other objects found in the water that can damage it.


4. Opt for an engine and fuel additive treatment

Fuel additives play a great role in removing gunk buildup along the fuel system and engine compartments. Next time you are getting supplies for your boat, look for a fuel treatment that will remove saltwater deposits in your engine’s cooling system.

A good example of a fuel additive you can use in your boat is the Techron Marine Protection Plus. This works wonders even when you sail in the harshest marine waters. The other benefit of fuel additives is that they also increase gas mileage.


5. Take care of sacrificial anodes (zincs) on boat

Sacrificial anodes also known as Zincs are tabs made from Zinc, magnesium, or aluminum. Their role is to be eaten away through galvanic corrosion so that they can protect the metallic components of the boat. This is why they are referred to as sacrificial anodes.

By knowing where these sacrificial anodes are located on your boat, you can always replace them when they wear away so as to ensure the metallic parts of your car are fully protected. You can locate the Zincs from your manual. In most boats, the zincs are found in the lower unit of the engine and inside it.


Is it Possible to Protect Aluminum Boats from Saltwater?

If you know a thing or two about metals, then you are aware that aluminum is the weakling in the electrochemical playing ground. It can be easily corroded by other metals and that’s why aluminum boats require special care when you used on saltwater.

Other than this particular disadvantage, there are many advantages of aluminum boats. They are affordable, lightweight, easy to repair, and require minimal maintenance. But, if you are going to use it on saltwater, you need to be very keen on protecting it from corrosion.

On its own, aluminum corrodes slowly when submerged in saltwater. However, this process speeds up when there are other metals present such as copper. Aluminum forms aluminum oxide when exposed to oxygen and this creates a film that protects the metal from corrosion. This is why most military boats are made of bare aluminum.

As you can see from above, aluminum performs exceptionally well in saltwater. The problem arises when other metals are introduced. Anyway, if you have an aluminum boat and you are worried about saltwater corrosion, the best solution is to attach several Zinc sacrificial anodes to save aluminum.

Above, we have already explained how Zinc anodes sacrifice themselves for the sake of Aluminum. There is no precise number of anodes that are recommended to be used on a boat. You will have to figure that out using a reference electrode and multimeter. Or hire a professional. It also pays off if you can get aluminum-compatible paint.


Is it Possible to Protect Fiberglass Boats from Saltwater?

Fiberglass boats are quite strong and can last for at least 5 decades if taken properly care of. Unfortunately, salt from seawater eventually moves through the fiberglass and gets deposited in porous areas. What this does is put more pressure on the fiberglass and this can damage it.


How Often Should You Wash Your Boat?

Regarding the frequency of how often you should wash a boat, it is advisable that you do so after every trip made to saltwater. A boat’s wax can last two to three months. You should take note of that. Every once a year, you can have your boat detailed by a professional as this ensures it retains its showroom finish for the longest time possible.


How Do I Remove Rust from a Boat?

If you have just spotted some rust, you should remove it right away. A rust remover can help you with that. A good rust remover should be effective on many surfaces including fiberglass, deck fittings, and canvas. Some good examples include Magica and StarBrite. G

alvanised corrosion often looks like blisters forming on the paint, especially below the waterline.


Can I Upgrade a Freshwater Boat to a Saltwater Boat?

Yes, you can, but you will need to be very cautious about how you go about the transition. The first thing you need to do is apply a layer of anti-fouling and salt-friendly paint to the hull. This will help with protecting the boat from saltwater corrosion. You should also consider adding sacrificial anodes.


Do Saltwater Boats have a Shorter Life Expectancy than Freshwater Boats?

There is no doubt that most freshwater boats outlive saltwater boats because of the harsh conditions the latter are exposed to. Be as it may, a smart owner who uses the above preventative measures can keep his/her boat running for years without worrying corrosion.