Quick answer

To waterproof a Redcat crawler for wet trails, you need to protect the electronics, seal the servo and ESC, and prepare the chassis for water exposure. Start by confirming which components are already water-resistant, then apply conformal coating or silicone sealant to exposed circuit boards, use dielectric grease on connectors, and always perform a post-run drying routine. The Redcat Ascent-18 International Scout II Brushless is a good example of a ready-to-run platform that can be made wet-trail ready with careful prep.

Know what you're protecting before you seal anything

Not all Redcat electronics are waterproof out of the box. The receiver, ESC, and servo are the three most vulnerable components. Check your manual or product page for IP ratings; if a rating isn't listed, assume the part is not water-resistant and needs treatment. The Ascent-18 International Scout II Brushless includes a 2.4GHz radio, battery, and charger, but the catalog does not specify water resistance for those items, so treat them as unprotected unless you confirm otherwise. Applying waterproofing to a part that's already sealed can trap moisture inside, so verify first.

Seal the ESC and receiver with conformal coating

Conformal coating is a thin polymer film that protects circuit boards from moisture without blocking heat transfer significantly. Remove the ESC and receiver from the chassis, open their cases carefully, and brush a thin layer of silicone-based conformal coating over both sides of the PCB. Avoid coating the FETs' heat sink surfaces and any connector pins. Let it cure fully—usually 24 hours—before reassembling. A common mistake is coating the entire ESC including the heat sink, which can cause overheating. Checkpoint: after curing, inspect for missed spots around solder joints and capacitor legs, which are common corrosion points.

Waterproof the servo with grease and a sealed case

Steering servos are often the first to fail in water because their output shaft seal is minimal. If your servo isn't marketed as waterproof, you can improve its resistance by packing the output shaft area with dielectric grease and sealing the case seams with a thin bead of silicone sealant. Do not fill the entire servo with grease—it can interfere with the motor and potentiometer. For a more reliable solution, consider upgrading to a waterproof servo designed for wet conditions. Checkpoint: after sealing, rotate the servo horn by hand to ensure it moves freely and the seal hasn't created drag.

Protect connectors and battery with dielectric grease

Every electrical connector on your crawler—between the ESC and motor, ESC and battery, and servo and receiver—is a potential entry point for water. Apply a small amount of dielectric grease to the metal contacts before plugging them in. This displaces water and prevents corrosion. For the battery, use a waterproof LiPo sack or a sealed battery box if your chassis has one. Never submerge a battery in water; even waterproof batteries can have vent holes that let moisture in. Checkpoint: after applying grease, plug and unplug each connector once to spread the grease evenly, then wipe away excess.

Prepare the chassis and tires for wet trails

Waterproofing isn't just about electronics. Water can pool in the chassis and rust steel hardware. Drill small drainage holes in the lowest points of the chassis if they aren't already present, and replace any plain steel screws with stainless steel where possible. For tires, check that the foam inserts aren't waterlogged—if they are, dry them out or replace them. The RER33013 spare wheel and tire set includes a gold wheel with center knockoff and two silver wheel hexes; if you're running wet trails often, having a dry spare set ready can save a run. Checkpoint: after drilling, deburr the holes and make sure no plastic shavings remain inside the chassis.

Do a post-run drying routine every time

Even with waterproofing, moisture can linger in crevices and cause corrosion over time. After every wet run, rinse the chassis with fresh water if it was exposed to mud or salt, then shake off excess water and dry with compressed air or a towel. Pay special attention to screw heads, bearings, and the motor. Remove the battery and let it air-dry separately. A common mistake is storing the crawler wet or putting it away without drying—this leads to rusted bearings and corroded connectors. Checkpoint: after drying, spin the wheels and listen for gritty bearings; if you hear noise, dry and re-lubricate them.

Wet-trail waterproofing steps

  1. Step 1: Inspect and document electronics: Identify the ESC, receiver, and servo. Check manuals or product pages for water-resistance ratings. If none are listed, plan to waterproof them. Take photos before disassembly to help reassembly. Checkpoint: If a component is already sealed, do not open it—sealing a sealed unit can trap moisture.
  2. Step 2: Apply conformal coating to exposed circuit boards: Remove ESC and receiver cases, brush a thin layer of silicone conformal coating on both sides of the PCB, avoiding heat sinks and connector pins. Cure for 24 hours. Checkpoint: Inspect solder joints and capacitor legs for full coverage.
  3. Step 3: Seal the servo and grease connectors: Pack the servo output shaft with dielectric grease and seal case seams with silicone. Apply dielectric grease to all electrical connectors before plugging them in. Checkpoint: Ensure the servo horn moves freely and connectors are fully seated after greasing.
  4. Step 4: Prep chassis and tires for water: Drill drainage holes in low chassis points, swap to stainless hardware where possible, and ensure tire foams are dry. Keep a spare wheel and tire set like RER33013 ready. Checkpoint: Deburr holes and verify no shavings remain inside the chassis.
  5. Step 5: Establish a post-run drying routine: After each wet run, rinse off mud, shake out water, dry with compressed air, and remove the battery. Spin wheels to check bearings and re-lubricate if needed. Checkpoint: Never store the crawler wet—dry it completely before putting it away.

Redcat parts that support wet-trail prep

  • Redcat Ascent-18 International Scout II Brushless - 1/18 Scale Brushless Electric Rock Crawler: Redcat Ascent-18 International Scout II Brushless - 1/18 Scale Brushless Electric Rock Crawler - Includes: 2.4Ghz Radio, Battery, Charger, Ready to Run A ready-to-run crawler that can be prepped for wet trails; its included electronics should be checked for water resistance before sealing.
  • RER33013: Redcat Racing RER33013 is a spare wheel and tire set offered as a replacement part for select Redcat Racing vehicles. This set features a gold wheel with a center knockoff and includes two silver wheel hexes. Listed for current vehicles including MONTE CARLO and SixtyFour, and legacy vehicles. Having a spare set of wheels and tires lets you swap out waterlogged foams after a wet run without ending your session.