Washing a Boat Like a Car? 7 Key Differences [Waxes, Soaps, Etc.]

At first thought, you may think (like I initially did) that there really isn’t much difference in washing a car vs a boat. I mean, you just need to get them both clean, so what’s the big deal? After doing more research, it occurred to me that there is quite a large difference in how and why you wash a boat or car, and so I wanted to take the time to share these differences with you.

In this post, I’ll explain how washing a car is different than a boat, and offer a few recommended products you may need.

1. Environmental concerns

Out of all the reasons to choose marine-specific products, environmental concerns are one of the biggest. Especially when washing a boat hull in the water (or even on a lift) it’s imperative to use a biodegradable boat soap.

A popular product in the boating community is a product is made by StarBrite and is a biodegradable soap that you can use to clean the outside and inside of your boat when actually washing your boat in the water itself.

Serious penalties can be levied if contamination occurs to an ecosystem or freshwater source, so it’s something to be mindful of. If you do use a non-biodegradable soap when your boat is on a trailer, it’s not as big of a deal, but still something to keep in mind.

2. Gel coats and oxidation on a boat

Unless you have a custom paint job on your boat, chances are it came manufactured with a gel coat. Gel coats are a type of resin that simply protects fiberglass on a boat, and can be pigmented like paint (to give a boat it’s color). Gelcoats are pretty strong and resistant in general, but are porous and can begin to oxidize over time.

Polishing your boat’s gelcoat

These coatings will eventually begin to look duller and need to be polished to restore the same richness of color your boat came with. The process of polishing a gelcoat is similar to cars in a sense because essentially you are using a compound to remove something (like a scratch on a car or in this case a slightly eroded layer of gel coat which results in a chalky or dull appearance).

When removed with a compound and polish, you reveal a more clear and bright (but thinner) layer of gelcoat on your boat.

This is totally normal, but in theory, you never want to have to polish a gelcoat too much over time, since you are essentially making this protective layer thinner with each pass. But enough about gelcoats…the key is to keep them protected with a wax or sealant.

When it comes to compounds, glazes, and waxes, they all do different things. If you’re a little fuzzy on these differences, check out Compound vs Clay, Polish & Glaze! 7 Products to Understand.

2. Hull strippers, compounds, and the importance of boat wax

Whenever attempting to restore the appearance of a dirty boat, several products need to be used that you likely don’t have in your car wash bucket. Restoring a faded, dirty boat usually requires three steps as follows:

1. Apply a hull stripper that will remove wax, stains, and everything else
2. Apply a cutting agent with a buffer/polisher (like a marine compound/polish to remove oxidation and restore luster) once the hull is clean
3. Apply a good marine grade wax. to protect your restored gelcoat.

While you don’t need to wax your boat by hand every time you clean it, I would recommend a good wash and wax product like OrPine. This stuff is great for adding an extra layer of wax to protect your gelcoat every time you wash.

Removing discoloration requires more products than cars

• Hull strippers/cleaners are one of those products you will need to pick up specifically for boats, because the slime, algae, and salt that can stain your hull can’t really be removed by soap alone.
• A dirty boat (especially the hull) is much more apparent than a dirty car, because of the brownish ring (or discoloration in general) that leaving a boat in the water for an extended period of time can do.
• Compounds and polishes to restore a faded gelcoat are also quite different than a compound you might use to remove a scratch on your car because typically they are designed to polish fiberglass.
• However, if your boat has been painted, automotive-grade products are okay to use.

3. Boats require marine-grade products

Unlike cars and most other vehicles, most of the time you are going to be dealing with a fiberglass gelcoat like I’ve mentioned, which can require different types of products depending on what you are looking to do. Below are a few of my recommendations specifically for boats.

Removing Wax and Cleaning Stains

• Removing wax from fiberglass boats: Star Brite Sea Safe Hull Cleaner on Amazon
• Removing water lines from fiberglass boats: Mr Clean Magic Eraser (Try it!)
• Brightening Aluminum boats: Star Brite Aluminum Boat Cleaner on Amazon

Soaps for Maintenence Washing

• Biodegradable boat soap: Star Brite Boat Wash Soap on Amazon
• For washing and waxing (my favorite): OrPine Wash and Wax on Amazon

Polishing and Protecting the Exterior

• Compounding and polishing a gelcoat: 3M Marine Compound and Finishing Material 
• Creating a glossy shine before waxing: 3M Marine Glaze on Amazon
• Waxing: TotalBoat Premium Marine Paste Wax on Amazon
• Applying these products: DEWALT Variable Speed Buffer & Polisher w/ Pads on Amazon

Marine Wax vs. Car Wax

If you compare the price of marine wax products compared to automotive waxes, they’re likely more expensive due to the resiliency of marine wax. Some boat owners have compared automotive-grade wax to marine wax in experiments, and the automotive-grade wax tends to dissolve or break down very quickly in water as opposed to marine wax.

Keeping a barrier of protection (which is the purpose of wax) on your boat at all times is important because it makes it easier to repel algae, slime, barnacles, and everything else that can make a boat appear murky. This also leads to you having to wash it less often to remove this discoloration.

This video does a good job of explaining the importance of creating this wax barrier

Performing a Maintenance Wash

Like washing mud off of a car, washing the salt or general dirt off of a boat is important. Be sure to use a soap that will not strip wax off of your boat unless you plan to wax over it again. A simple rinse with non-stripping soap/wax like OrPine will do the trick.

Over time the base layer of wax you apply by hand (after a hull cleaner is used) will eventually need to be reapplied, which is why you shouldn’t use a hull cleaner unless there is obvious discoloration that can’t be removed by a simple maintenance wash alone.

3. Opt for a pressure washer or high-pressure nozzle

Depending on the size of your boat, and since most boats have a lot more surface areas to wash than your car, investing in a good pressure washer isn’t a bad idea.

If you have a boat with a deeper full (over 6 feet tall), you may want to consider a gas pressure washer capable of reaching a taller boat. Honda makes a pretty affordable line of pressure washers like the GC190 on Amazon that I really like for this use case.

Due to the fact that a boat is always in constant contact with water, having a little extra pressure and a higher GPM (gallons per minute) is ideal for knocking off stubborn salt and washing larger boats quicker.

However, a lightweight electric pressure washer may be all that you need. I recently did some research and handpicked 5 of the best budget electric pressure washers out there under $300 that you may want to check out.

If you have a smaller boat and don’t want to go the pressure washer route, having a high-pressure nozzle that’s adjustable may be all you need for quick rinses.

4. Applying Wax By Hand Can Be Time Consuming

Applying wax to a boat is obviously pretty time consuming, especially if you’re doing this by hand (which I wouldn’t recommend for most people). For reaching under the hull and in tight spaces, you can find a quality orbital polisher like the DEWALT model I listed above for less than $200.

Since oxidation on boats can be more difficult to buff out than cars, a dual-action polisher may not produce the results you desire.

DA polishers are great for cars because they have an automatic shut off feature when too much pressure is applied, but a rotary tool with a polishing pad (when used properly) is more effective for boats. Just ensure you know what you’re doing.

6. Use Brushes on the inside and when necessary

I normally don’t recommend using brushes on cars because of how soft the clear coat is (easily scratched), but with boats they’re typically okay when clean. An extra soft nylon brush is a good choice, because you don’t have to worry about scratching paint/decals if dirt gets trapped in a mitt with a shorter pile.

Since boats usually take more work than cars do, using a foam cannon can be a good way to apply soap instead of dipping a brush in a bucket for suds.

With that said, mitts do have their place as long as you keep them clean. Based on my experience, mitts can do a better job of cleaning hard to reach areas, so it’s probably a good idea to try both options depending on how large your boat is.

7. Vinyl cleaner on the interior

As opposed to a car, most boats use some sort of vinyl or plastic upholstery for the seats, which is where a good vinyl cleaner comes into play. 3M and Meguiar’s both make a pretty good vinyl cleaner you can pick up designed specifically for boats.

You want to avoid bleach, because based on my experience can dry out vinyl, and even lead to disintegration. My dad once tried a bleach mixture on his vinyl boat seats, and it began to dissolve the vinyl and stitching after about a season of use.

Conclusion

Overall, a boat’s gel coat is a pretty durable surface that still needs attention, much like a car’s clear coat. It’s definitely more difficult to clean a boat than a car, but now that you know a few products you can use, it should be a lot easier.

If you’re not seeing results after washing and waxing your boat with traditional car care products, it may be time to use a few of these marine-grade products to restore your boat to an optimal condition.

Cleaning your boat is critical to prevent rust (especially around saltwater) and should really be washed every time you take it out of the water. While you may be able to wait a couple of days when out of freshwater, rinsing your boat of salt a minimum is essential for boat owners.

As a disclaimer, just be sure to always use a product recommended for your boat based on the surface you’re cleaning. Happy boating!