How to Waterproof Your RC Car (DIY Guide & Methods)

There’s a running debate in the RC community that goes back years: can you ever make an RC car truly waterproof, or is “splashproof” as good as it gets?

Some hobbyists say you’ll never seal every gap, and that chasing puddles is asking for fried electronics. Others build their rigs for mud, snow, and shallow water runs, swearing by balloons, silicone, and coatings that let them bash through anything.

The reality is somewhere in the middle. No RC car is immune to water damage, but with the right DIY methods you can protect your electronics, extend your car’s life, and keep driving when the weather turns wet.

If you’re wondering how to make your RC car waterproof, this guide covers safe, tested, and affordable ways to do it and points out where it’s smarter to protect rather than submerge.

Key Takeaways

• RC cars can’t be 100% waterproof - but they can be made reliably splashproof and safe for rain, mud, and snow.
• Electronics are the weak spot: ESCs, receivers, and servos need protection, while brushed motors can run wet but require aftercare.
• DIY methods work: silicone sealant, Plasti Dip, liquid electrical tape, balloons, and grease are proven, affordable options.
• Batteries should never be submerged - LiPos in particular must be shielded and kept dry.
• Testing and maintenance matter: safe step-by-step testing, plus cleaning and drying after runs, are as important as waterproofing itself.

Some drivers enjoy the DIY waterproofing challenge, others prefer rigs that are already sealed and ready. For those, here’s our roundup of the best waterproof RC cars.

Can You Really Waterproof an RC Car?

When people talk about waterproofing RC cars, what they usually mean is making them splashproof.

A car can be protected well enough to handle rain, wet grass, puddles, and even snow, but no setup is completely immune to water.

The goal isn’t to make it submersible - it’s to shield the electronics, minimize damage, and make post-run care quicker and safer.

Motors and Heat Risks

A brushed 540 motor will happily spin in wet conditions, but it pays a price in brush wear. Regular cleaning and re-lubrication are essential if you want it to last.

Brushless motors are more sensitive - water exposure can cause serious issues, which is why many drivers add coatings or guards instead of letting them run bare.

Too much sealing, though, creates its own risk: heat buildup. Always leave some ventilation for motors and ESCs.

Servos, ESCs, and Receivers

Servos aren’t sold as waterproof by default, but they can be protected with simple tricks like balloon wraps or silicone along the case seams.

ESCs and receivers are even more vulnerable, unless specifically rated as waterproof. Many hobbyists place them inside small sealed boxes or use liquid tape to insulate connections.

These DIY steps don’t make them indestructible, but they give you plenty of protection for wet-weather driving.

Brand Claims vs. Reality

Companies like Traxxas and Arrma often advertise waterproof electronics on their monster RC trucks and buggies, and while their sealing is good, it’s not absolute.

Their cars can handle splashes and snow, but saltwater or heavy mud will still push the limits.

Every wet run means a teardown afterward - drying, cleaning, and a bit of grease if you don’t want parts seizing up.

Different Environments, Different Risks

Snow, puddles, mud, and the beach each bring different hazards. Drivers who enjoy tackling rocks, mud, and uneven terrain with RC rock crawlers know just how important waterproofing becomes. Snow seems harmless until it melts inside a chassis.

Freshwater puddles can usually be managed with coatings and grease. Saltwater at the beach, however, is the most destructive - it corrodes connectors and gears rapidly.

Waterproofing extends your car’s range, but every terrain comes with its own maintenance checklist.

Tools and Materials for DIY Waterproofing

Waterproofing an RC car isn’t complicated, but it does require the right supplies. Most of what hobbyists use is inexpensive, widely available, and easy to apply at home.

The trick is knowing which product protects which part of the car. That’s the foundation of how to make your RC car waterproof without overspending.

Sealants and Coatings

• Silicone Sealant: Flexible, durable, and perfect for sealing gaps in servo housings, receiver boxes, and battery compartments. It seals tight and stays flexible, so it won’t crack or peel later.
• Plasti Dip or Conformal Coating: Brush-on or spray-on coatings that form a protective layer over circuit boards, ESCs, and connectors. They insulate electronics from moisture while remaining removable if repairs are needed.
• Liquid Electrical Tape: A quick-drying option for insulating wire joints, exposed solder points, and connectors. Easier to apply precisely than Plasti Dip.

Protective Grease

• Marine Grease: Applied to bearings, gearboxes, and universal joints, this keeps water out of moving parts and reduces the risk of corrosion.
• Petroleum Jelly (budget alternative): Less durable than marine grease, but still useful for protecting connectors and small exposed contacts.

Enclosures and DIY Shields

• Waterproof Receiver Boxes: Some RC models include them, but cheap aftermarket boxes or even a small food container can keep electronics dry.
• Balloons and Heat-Shrink Tubing: Old-school tricks that still work - balloons around servos, or heat-shrink tubing over connectors, create simple but effective barriers.
• Tape (Electrical or Duct): A short-term fix for sealing gaps, though not as reliable as coatings or boxes.

Cleaning and Drying Tools

• Compressed Air or a Small Fan: Essential for drying after a wet run, especially around motors and battery compartments.
• Silica Gel Packs or Rice: Helps pull out lingering moisture if electronics get damp.

Common Waterproofing Products and Their Uses

Tool / Product	Best For	Notes
Silicone Sealant	Sealing gaps in servo housings, boxes	Flexible, durable, doesn’t crack
Plasti Dip / Conformal Coating	ESCs, receivers, connectors	Removable if repairs are needed
Liquid Electrical Tape	Wire joints, exposed solder points	Precise application, quick-dry
Marine Grease	Bearings, gears, drive joints	Long-lasting, corrosion resistant
Petroleum Jelly	Connectors, small contacts	Budget-friendly, short-term use

Having the right gear is only half the equation. The real difference comes from knowing where and how to apply it: which parts need sealing, which can be left alone, and how much protection is necessary.

With the basics in hand, it’s time to move from the toolbox to the car itself and walk through the practical steps of waterproofing.

Step 1: Waterproofing the Electronics

Electronics are the heart of your RC car, and also the first components to fail when exposed to moisture. That’s why mastering electronics protection is the single biggest part of how to make your RC car waterproof.

The Receiver Box

Most cars don’t come with a truly waterproof receiver box. A simple upgrade is to use a small sealed container, even a compact food box with a gasket lid works if you cut clean holes for wires and seal the edges with silicone.

If you’re using the stock receiver housing, run a bead of silicone around the lid and openings to close any gaps. Some hobbyists also slide the receiver into a balloon or plastic bag before tucking it inside for an extra layer of protection.

The ESC (Electronic Speed Controller)

ESCs are especially vulnerable to water damage. If yours isn’t sold as waterproof, you can protect it with one of three methods:

• Conformal coating or Plasti Dip: Paint or spray directly onto the ESC board for a flexible protective layer.
• Liquid electrical tape: Brush it over solder joints, exposed wires, and connectors for a tighter seal.
• DIY enclosure: Place the ESC in a small waterproof box if you want to avoid coatings.

Pro tip: Avoid fully sealing the ESC inside thick coatings with no airflow - overheating is a common mistake. Always allow some ventilation so the ESC can shed heat.

Servos

Standard servos usually have small gaps where water seeps in. A balloon sleeve (cut a hole for the output shaft and seal the neck) is an old-school trick that still works.

Another method is to carefully apply silicone sealant along the casing edges to block leaks.

If you’d rather skip DIY fixes, you can also upgrade to a waterproof-rated servo designed for wet conditions.

Connectors and Wires

Exposed connectors and solder joints are often overlooked. Cover them with heat-shrink tubing before you run, or brush on liquid electrical tape for a water-resistant coating.

Pay extra attention to the battery plug and motor leads - even a light splash there can short out electronics.

A Note on WD-40

Few topics spark as much debate as using WD-40 on RC cars. Some drivers spray it into brushed motors after a wet run because it does a good job of pushing out water and preventing short-term rust.

Others warn against it, especially anywhere near electronics or plastic housings. WD-40 seeps into seams and screw holes, breaking down adhesives and causing casings to loosen over time.

The middle ground is this: WD-40 can be used sparingly on metal motor parts after cleaning, but it should never be applied to ESCs, receivers, servos, or connectors.

For electronics, stick with dedicated products like liquid electrical tape, conformal coating, or silicone spray - they’re designed to insulate, not just displace water.

Step 2: Protecting the Motor and Battery

Electronics aren’t the only parts that need attention when learning how to make your RC car waterproof. Motors and batteries face different challenges: motors are exposed to water and dirt during every run, while batteries must be shielded from even small amounts of moisture.

Brushed vs. Brushless Motors

A brushed motor can keep spinning even when splashed or briefly submerged. Many beginners are surprised to learn you can actually run a brushed motor wet - but the trade-off is faster brush wear.

If you plan to drive through puddles or mud, the safest approach is to rinse the motor with clean water afterward, dry it thoroughly with compressed air, and apply a drop of oil or grease to the bearings.

Brushless setups don’t tolerate water at all and can be ruined quickly. Exposing them to water often leads to corrosion, shorts, or complete failure.

Hobbyists who run brushless setups usually shield the motor with silicone spray or a protective casing to reduce exposure. Fully submerging a brushless motor isn’t recommended, no matter what coatings are used.

Brushed vs. Brushless Motors in Wet Conditions

Motor Type	Water Resistance	Aftercare Needed	Risks
Brushed	Can run wet, even submerged briefly	Rinse, dry, re-lube after runs	Accelerated brush wear
Brushless	Highly sensitive to water	Keep dry, protective spray/casing only	Corrosion, shorts, failure

Batteries and Power Leads

RC batteries (especially LiPos) are not waterproof. Even a splash across an exposed connector can cause a short.

To keep them safe:

• Place batteries inside a sealed or semi-sealed compartment, adding a bead of silicone around the edges if needed.
• Use heat-shrink tubing or liquid electrical tape to protect battery leads and connectors.
• Keep the pack itself dry at all times. If a LiPo gets wet, disconnect it immediately, dry it with a fan, and inspect it for swelling or damage before charging again.

Heat Management

When learning how to waterproof RC cars, it’s easy to focus only on sealing parts. But motors and ESCs still need ventilation.

Too much sealant or casing can trap heat, leading to overheating during long runs. The balance is to shield openings against splashes while leaving enough airflow for cooling.

Maintenance After Wet Runs

Even the best waterproofing won’t last if you skip maintenance.

After every wet session:

• Remove the battery and dry it separately.
• Blow moisture out of the motor with compressed air.
• Reapply grease or oil to bearings and moving parts.
• Let everything dry fully before storage.

Step 3: Sealing the Chassis and Connectors

Even if the main electronics are protected, water often finds its way in through the chassis and wiring. Sealing these weak points not only helps waterproof your RC car but also reduces long-term wear from dirt, mud, and sand.

Chassis Protection

RC car chassis aren’t designed to be watertight. Small openings around the battery tray, suspension arms, and motor mounts let water and grit inside.

The simplest solution is to run a thin bead of silicone sealant along visible gaps, with extra attention around the battery compartment. For quick fixes, strips of electrical tape or duct tape across openings can also help - though they need replacing after each run.

Bearings, Gears, and Moving Parts

Moisture doesn’t just threaten electronics; it also corrodes metal parts. Applying marine grease to bearings, gearboxes, and drive joints forms a protective barrier.

This doesn’t make them waterproof in the strict sense, but it keeps water from sitting on the surface and causing rust.

Many off-road drivers also pack a little grease into wheel hubs before a beach or snow run to keep sand and salt from grinding down the bearings.

Connectors and Wiring

Exposed connectors are one of the most common failure points when running in wet conditions.

Cover battery plugs, motor leads, and ESC connections with heat-shrink tubing for a snug, protective fit.

For irregular shapes, liquid electrical tape is a reliable option because it molds around wires and dries into a flexible, waterproof coating.

DIY Hacks That Still Work

RC hobbyists have been waterproofing cars long before purpose-built products were common.

Some of those old tricks still hold up today:

• The balloon method: Slide a balloon over a receiver or servo and seal the neck with zip ties.
• The sandwich box hack: Place a receiver or ESC in a small food container, drill holes for the wires, and seal the openings with silicone.
• Plastic wrap and tape: Crude, but effective in emergencies when you just need to keep mud off connectors for one session.

Step 4: Testing Your Waterproofed RC Car

Once your RC car is sealed and coated, it’s tempting to head straight for the nearest puddle. But testing should be gradual. Rushing the process risks shorting out electronics before you know what’s holding and what isn’t.

• Start small: Begin with a light mist from a spray bottle or garden hose. This simulates rain and helps you spot any immediate weak points. Check inside the receiver box, around the ESC, and near battery connectors for signs of moisture.

• Controlled puddles: Next, drive the car slowly through a shallow puddle - just enough to cover the tires but not fully submerge the chassis. Pause afterward and open the receiver box or enclosure. If it’s dry, your sealing work is holding. If you see moisture, dry everything, reseal, and test again.

• Snow and wet grass: Snow and damp grass are common test grounds for waterproofed RC cars. Both are safer than deep water because the exposure is lighter. The risk comes when melted snow seeps into the chassis. Always dry the car afterward and store it in a warm place to prevent condensation.

• Deeper water: If your goal is to run through deeper puddles or mud, build up to it gradually. Don’t fully submerge the car - even waterproof-rated models like some Traxxas and Arrma vehicles aren’t designed to act like submarines. Drive through water slowly, then stop and check for leaks or damp connectors.

What to Watch For

• Sudden stuttering or loss of throttle/steering → ESC or receiver may be taking on water.
• Steam or excessive heat → motor or ESC could be overheating due to poor ventilation.
• Moisture on battery leads → disconnect immediately, dry fully, and don’t recharge until safe.

Step 5: Maintenance After Running in Wet Conditions

Every wet run leaves a trail - mud in the chassis, water in tight corners, grease pushed aside from bearings. Waterproofing slows the damage, but it doesn’t stop it. A quick routine after each session is what keeps the car running like it should the next time you pull the trigger.

Cleaning Non-Waterproof RC Cars

If your car is only lightly protected or not waterproofed at all, immediate cleaning is critical after a wet run.

Use compressed air or a soft brush to knock away mud and debris. Disconnect the battery right away, then dry electronics in a warm, ventilated place. Silica gel packs or even a bowl of uncooked rice can help pull out lingering moisture if components got splashed.

Cleaning Waterproof RC Cars

Waterproofing buys you time, but it doesn’t eliminate care. Rinse the chassis with a gentle spray of clean water to wash away dirt and salt.

Dry it thoroughly with compressed air, paying attention to tight spots around the ESC, receiver box, and motor mount. Open up the receiver box after a few wet runs to confirm the seal is still holding - small leaks can build up unnoticed.

Drying Methods that Work

• Compressed air: The fastest way to clear water from servos, connectors, and tight spaces.
• Soft fan or warm airflow: Speeds up evaporation without overheating components.
• Absorbent packs (silica gel): Useful for drying batteries or electronics stored overnight.

Long-Term Durability Tips

• Reapply marine grease to bearings and gear joints every few wet sessions.
  Inspect tape, seals, and balloons regularly - they degrade faster than permanent coatings.
• Keep a log of how your car behaves in wet conditions; if you notice stuttering, weak throttle, or servo lag, it may be time to recoat or reseal.

DIY Waterproofing Solutions

Not every fix requires specialty products. RC drivers have been waterproofing cars for decades using simple household items, and many of those tricks still work today.

While they won’t replace professional coatings or sealed enclosures, they’re budget-friendly and effective enough for casual wet runs.

Cheap and Accessible Methods

• Petroleum jelly: Smeared over connectors or lightly packed into servo openings, it blocks out water and helps prevent corrosion.
• Plastic balloons: Wrapping a servo or receiver in a balloon is one of the oldest DIY waterproofing methods. Seal the balloon neck with a zip tie for a snug fit.
• Duct tape or electrical tape: Quick to apply over gaps or wire joints. It’s not long-lasting but can save a session when you want to run in wet conditions.

Household Liquids and Coatings

• Clear nail polish: Works as a light coating for solder joints or small circuit areas. It insulates against moisture, though it can chip over time.
• Mod Podge (sealed craft glue): Some hobbyists experiment with it as a protective layer, but it’s not fully waterproof when dry - better to stick with products designed for electronics.
• Silicone spray: A flexible spray-on option that creates a water-resistant surface. Effective for connectors, battery compartments, and wire insulation.

Natural or Budget-Friendly Hacks

• Rubber materials: Rubber bands, gloves, or cut-up inner tubes can be repurposed to create quick seals.
• At-home sealers: Simple mixtures like candle wax or beeswax rubbed on connectors offer short-term waterproofing in a pinch.

DIY Waterproofing Hacks: Pros and Cons

DIY Method	Effectiveness	Durability	Cost
Balloons	Good for servos/receivers	Medium (can degrade)	Very low
Petroleum Jelly	Works on connectors	Short-term	Very low
Duct/Electrical Tape	Quick seal for gaps	Low (needs replacing)	Very low
Nail Polish	Good for solder joints	Medium	Low
Silicone Spray	Versatile coating	Medium-High	Low

Where DIY Falls Short

Homemade waterproofing is a great way to protect your RC car on a budget, but it’s not perfect. Tape peels, balloons degrade, and coatings wear off over time.

If you plan on driving in wet conditions often, combining these tricks with longer-lasting solutions like conformal coatings and marine grease will keep your car safer.

Ready for the Wet Runs

Waterproofing doesn’t turn an RC car into a submarine - but it does change the way you use it.

Instead of dodging puddles, you can drive through them. Instead of parking it when snow falls, you can pack bearings with grease and keep going. Instead of worrying about every splash of mud, you can focus on the throttle - which is the real payoff of learning how to make your RC car waterproof.

The work you put in (sealing receivers, coating ESCs, wrapping servos, shielding connectors) pays off in longer sessions and fewer surprises. And while the job isn’t permanent (maintenance always comes back around), it gives your car a wider season and a lot more playtime.

If DIY isn’t your style, you can always look into vehicles that are designed for harsher conditions from the start. Our guide on RC cars for adults highlights models built for bigger power, tougher terrain, and wet-weather fun straight out of the box.

FAQ

1. How can I waterproof my RC car for mud or rain?

The best approach is to seal electronics first - coat the ESC and receiver with Plasti Dip or conformal coating, wrap servos with balloons or silicone, and protect connectors with heat-shrink or liquid electrical tape. Adding grease to bearings and joints helps keep mud and water from grinding down moving parts.

2. What products are best for waterproofing RC electronics?

Hobbyists often use conformal coating, liquid electrical tape, or Plasti Dip for ESCs and receivers. Marine grease works for bearings and gears, while silicone sealant closes gaps in housings or battery compartments. These products are affordable and proven to keep water away from sensitive electronics.

3. Can I drive my RC car through water after waterproofing?

Yes, but only in shallow conditions like puddles, wet grass, or snow. Waterproofing makes an RC car splashproof, not submersible. Even brands that sell waterproof models, like Traxxas or Arrma, still require cleaning and drying after a wet run.

4. What are the risks of waterproofing incorrectly?

Over-sealing electronics can trap heat, leading to overheating. Using the wrong products (like spraying WD-40 on ESCs or receivers) can cause more harm than good. Poor seals around a receiver box or servo may also let water in slowly, creating hidden corrosion.

5. How do I test if an RC car is waterproof?

Start small: mist it with water, then run it through shallow puddles before tackling snow or mud. After each stage, open the receiver box and check for moisture. If it stays dry, you’re ready to move up. If not, dry everything and reseal weak spots before running again.

6. Is silicone spray enough to waterproof my RC car?

Silicone spray can help, but it’s not a complete solution. It works well on connectors, wires, and exposed surfaces, but electronics like ESCs and receivers still need coatings or enclosures to stay safe. Think of it as an extra layer, not the only protection.

7. Which parts of the RC car should be sealed?

Focus on the electronics: ESC, receiver, and servos. Protect connectors and wiring with heat-shrink or coatings. Bearings, gearboxes, and joints also benefit from grease to keep water and grit out. Batteries should always be shielded and kept as dry as possible.