For RC car enthusiasts who love taking their vehicles off-road, through puddles, across muddy trails, or even into shallow water, waterproofing is a must. Without it, sensitive electronic components like the ESC (Electronic Speed Controller), servos, and receiver can be permanently damaged. Here’s how to waterproof an RC car.
Why Waterproofing an RC Car Is Important?
RC cars often face a wide range of elements—dust, dirt, water, and mud. Even a few drops of water can seep into the electronics and fry components instantly. While some manufacturers provide “water-resistant” parts, those aren’t always reliable when submerged or splashed repeatedly.
Waterproofing gives hobbyists peace of mind and extends the life of their RC cars. Whether splashing through creeks or mud bogging in the rain, a waterproof rig keeps the fun going.
What You’ll Need
Before starting the waterproofing process, make sure the following supplies are ready:
- Plasti Dip (a flexible, removable rubber coating)
- Clean cloth or old sock (used for motor protection)
- Super glue (to secure the cloth)
- Screwdrivers (for removing components)
- Optional: epoxy, conformal coating, or heat-shrink tubing
Plasti Dip is a preferred method for many due to its ease of use and ability to allow heat dissipation, unlike thicker epoxy coatings.
How to Waterproof an RC Car?
Step 1: Disassemble the Key Components
The process begins by carefully removing the parts that need protection. In the B14 project, we have disassembled the following:
- The motor and transmission
- The front servo
- The ESC/receiver combo (AX-7S)
Removing the servo involves taking out the horn and unscrewing the front mount. The ESC/receiver unit was also taken out of its plastic case to make waterproofing more effective and reduce heat retention later on.
Each component was prepared for coating by gently exposing its internal circuit boards.
Step 2: Waterproofing the Electronics with Plasti Dip
Once the circuit boards were accessible, we used Plasti Dip to coat both sides and the seams of the servos and ESC. A small screwdriver was dipped into the solution and dabbed gently onto the exposed surfaces.
Key Tips:
- Avoid coating the servo or light leads, as this could cause poor connections.
- Allow the first layer to fully dry before applying a second if needed.
- Make sure no spots are left uncoated, as water can enter through even small gaps.
After finishing the coating, all parts were left to dry thoroughly. It’s essential to avoid reassembling or powering on the system until the coating is cured.
Step 3: Protecting the Motor from Debris
Unlike electronic boards, motors can tolerate water, but not debris. If small particles get inside, they can damage brushes or cause the motor to short out.
To avoid this, a piece of clean cloth (like an old sock) was used to wrap around the motor. This helps cover all the ventilation holes found around the motor housing.
Motor Wrapping Process:
- Cut a small square of cloth.
- Gently wrap it around the motor, being careful not to stretch too tightly (which can enlarge the holes).
- Overlap the edges and apply a line of super glue to seal the fabric.
- Trim any excess material.
- Fold the fabric over the front hole and glue it down.
This method allows the motor to breathe and get wet safely, but keeps out harmful debris.
Step 4: Reassembling the RC Car
Once all components were waterproofed and dried, everything was reinstalled into the RC car.
- The ESC/receiver combo was installed without its plastic case to help with heat dissipation.
- Servo leads were routed under the cover, and the power switch was left toward the back.
- The battery connector was pulled through the original access port, and wires were organized cleanly.
Step 5: Field Test – Trails, Mud, and Water
With the waterproofing complete, we took the B14 out for a real-world test. The truck handled the terrain well, with impressive torque in second gear and smooth throttle response.
Then it was time for the mud and water test.
The RC truck was driven through shallow water. At first, everything worked perfectly, even when the ESC/receiver unit was submerged. But after a while, the throttle cut out, though steering still worked. This suggested that either a low-voltage cutoff or a temporary short had occurred.
Lessons Learned
After taking the vehicle home and examining the electronics, a few issues were discovered:
- Some spots of the Plasti Dip had dried unevenly, creating small gaps.
- The unused light port may have been exposed, causing a short when submerged.
These issues were fixed by reapplying Plasti Dip to vulnerable spots and sealing the light port completely. We have learned that it’s crucial to double-check waterproofing once the coating dries, as small cracks or air gaps can form.
Waterproofing an RC car isn’t complicated, but it does require patience and attention to detail. Using Plasti Dip to seal servos, ESCs, and receivers, and wrapping motors with cloth helps protect vital components from water and debris.
On the next run, the builder plans to do a range test and push the system further. But even with minor hiccups, the waterproofing held up surprisingly well.
Pro Tip:
Always test your waterproofed car in controlled shallow water before taking on rivers or deep puddles. And don’t forget to check your batteries—low-voltage cutoffs can mimic water-related failures.
Conclusion
Waterproofing an RC car is a worthwhile project that opens the door to more exciting terrain and challenges. With simple tools, a bit of Plasti Dip, and a methodical approach, anyone can take their RC vehicle off the dry track and into the wild.
Whether climbing muddy trails, splashing through puddles, or testing torque in wet conditions, a waterproofed RC car adds a whole new layer of fun. And if something goes wrong, you’ll know exactly where to troubleshoot next time.
