How to Fix Holes on RC Car Body

Clean the area around the hole. Use rubbing alcohol and a cotton swab to clean away any dirt or debris from the area around the hole. This will help the epoxy bond better.
Sand the area around the hole. Use sandpaper to lightly sand the area around the hole. This will help create a rough surface for the epoxy to adhere to.
Mix the epoxy. Follow the manufacturer’s instructions for mixing the epoxy. Be sure to measure the epoxy accurately, as using too much or too little can affect the strength of the bond.
Apply the epoxy to the hole. Use a mixing stick to apply the epoxy to the hole. Be sure to fill the hole completely and smooth the surface of the epoxy.
Allow the epoxy to cure. Allow the epoxy to cure for the amount of time specified by the manufacturer. This can take anywhere from a few hours to a day, depending on the type of epoxy you are using.
Sand the repaired area. Once the epoxy has cured, use sandpaper to sand the repaired area until it is smooth and flush with the rest of the body.
Paint the repaired area (optional). If you want to make the repaired area less noticeable, you can paint it with the same color as the rest of the body.

If the hole is large, you may need to use a backing material, such as a piece of plastic or metal, to support the epoxy.
If the hole is in a location that is subject to a lot of stress, such as the front or rear bumper, you may want to use a stronger epoxy, such as a two-part epoxy.
Be sure to allow the epoxy to cure completely before sanding or painting the repaired area.