How to Repair RV Fiberglass Exterior Damage

RV Expeditioners may collect a share of sales or other compensation from the links on this page. This comes at no additional cost to you, and all the prices and availability are accurate at the time of publishing.

Repairing RV fiberglass exterior damage can be a complicated task.

You need to make sure that you have the right tools, items, and guidance so that you can safely and properly repair any exterior fiberglass damage to your RV.

First, you are going to need to make sure you have all of the necessary items you need to repair your RV. More importantly, you need the right safety equipment to make sure that you don’t harm yourself while you are working on this RV repair.

List of Necessary Items and Tools

  1. Eye Protection

First and foremost, you need to make sure that you protect your eyes. Anytime that you are working with fiberglass, paint, or sanding, you need to make sure that you are covering your eyes. Getting any flecks of paint or small pieces of metal near or on your face can irritate or cause damage to your eyes.

Make sure that you have a safe pair of goggles or eye protection that you use when you are repairing RV fiberglass exterior damage. 

  1. Breathing Mask

Exposing your face and your eyes to chemicals used on your vehicle can be harmful. Exposing your mouth to any of the chemicals on your RV can be harmful as well. Small flecks or pieces of paint, metal, and fiberglass can easily fall onto or stick to your face when you are fixing the exterior damage to your RV.

If fiberglass is inhaled, it can cause serious health issues. Inhaling the fiberglass from your vehicle can cause coughing, bleeding, and even respiratory problems. Make sure that you have a protective breathing mask that protects you from swallowing or inhaling any harmful fiberglass.

  1. Gloves

Gloves are another necessary safety precaution that you should be taking when you are repairing the exterior fiberglass damage to your RV. Getting uncoated fiberglass on your skin can cause irritation as well. Since you are going to be working with your hands primarily to fix the fiberglass damage, make sure that you have a pair of work gloves or safety gloves you can use to protect your hands while working. Since you are going to be drilling into fiberglass, your gloves, eye protection, and the mask will protect your skin and face while performing this repair.

  1. Drill

You are going to need a drill to make sure that you can repair the fiberglass effectively. With that, you are going to need some smaller drill bits to get the job done properly. We recommend using a corded drill so that you don’t have to be concerned about having enough battery life or power to get the job done.

Damaged exterior fiberglass can often mean there is damage to the insulation behind the fiberglass. This can require using a drill and foam insulation to make sure you complete the repair, without leaving your paneling open to damage in the future.

  1. Sandpaper of Various Grits

To successfully make the repair, you need to make sure that you have multiple different grits of sandpaper. Repairing exterior fiberglass damage on your RV requires that you sand or cut dry foam insulation so that it can sit flush with the rest of the insulation behind your fiberglass. Having a variety of grits of sandpaper will help you make sure that you have sandpaper that is hard or smooth enough to sand down the insulation.

  1. Auto Body Filler (Bondo)

You are going to need an auto body filler or Bondo to complete the repair. Bondo putty is a lightweight, polyester-based epoxy filler that has been used for years to help make wood and fiberglass repairs to RVs, boats, and other vehicles.

  1. Fiberglass Repair Kit

Fiberglass repair kits come with just about everything you need to complete the repair on your vehicle. Fiberglass repair kits typically come with:

  • Fiberglass resin.
  • Liquid hardener.
  • A plastic spreader.
  • Fiberglass cloth.
  • A mixing stick.
  • Mixing tray.

You can mix then repair materials together into a quick-hardening solution that makes for quick and simple exterior fiberglass repairs.

  1. Foam Insulation

You can purchase foam insulation in most automotive repair stores, and you can even buy it online as well. Foam insulation expands within the repair to provide insulation for the damaged piece of your vehicle. It expands and dries quickly to hold the repaired pieces together, after the repair. 

Step by Step Guide

Now that you guys have all of your materials, tools, and safety gear together, it is time to get started with your repair.

  1. Inspect and identify the problem

The first step in starting the process of repairing a fiberglass exterior is to inspect the problem. Before you start with anything, you want to make sure that you confirm where the exterior fiberglass damage is, so you know how much damage has been done. Taking a quick look at the outside damage can give you a better idea of how much insulation, filler, and even paint you are going to need to complete your repair.

  1. Suit up

Since fiberglass can irritate your eyes, skin, mouth, nose, and respiratory system, this is where all for our safety gear and equipment are going to come into play.

You should be able to get the majority of your safety equipment from your local hardware or homecare store. You can order them online as well. Make sure that you put your gloves, mouth cover, and protective eyewear on as well before you start making repairs to the outside of your vehicle.

  1. Prepare the surface

After you put on all of your safety equipment, the first step you need to take is making sure that you prepare the surface that you’re going to be treating. We recommend wiping down the surface lightly to make sure that you clean off any dust or debris from the area. This will give you a cleaner surface to work on.

  1. Cutaway the excess fiberglass

Next, you need to be sure that you cut away and remove the damaged fiberglass. You can use a sharp knife to carefully cut away and remove the damaged fiberglass or pieces of fiberglass from your vehicle.

  1. Repair the insulation

If you happen to have a deep hole in your fiberglass, you may have to repair the insulation behind the siding of the vehicle. This is where the expanding foam insulation comes into play. You can use the expanding foam insulation to fill in the gap that is left in the insulation. Make sure that you give it some time to dry. After the foam has dried, you can sand down or cut the dry foam insulation so that it is flush with the rest of the insulation on your vehicle.

  1. Apply auto body filler

Next, you will want to use the materials in your auto body filler or Bondo kit to mix your filler material. Make sure that you follow the instructions on the package to mix it together, and then apply it to the hole. Make sure that you give the filler time to dry as well. Then, you can use your sandpaper to sand down the filler so that it is flush to your vehicle.

  1. Fiberglass repair

Afterward, you will want to apply your fiberglass over the filler. Also, give it time for your fiberglass to dry securely on before you sand it flush with the rest of your fiberglass as well.

  1. Match and apply paint

After all the work is done and everything has dried, you are going to want to apply a fresh coat of touch-up paint. You can jump online or get in touch with your RV manufacturer to make sure that you get the correct color for your vehicle.

Tips and Warnings 

Before you get started with your fiberglass repair,  you should be sure that you get the high-quality safety gear you need for the job. Your gloves, breathing mask, and protective eyewear will keep you safe while you are fixing the exterior fiberglass damage on your RV. Since those tiny fiberglass fibers can embed themselves into your skin or lungs, you want to take every precaution you can to protect yourself.

What is the cost of repairing fiberglass on an RV?

Unless you need major tools for repair, self-repair of fiberglass on campers can cost up to $90. The cost of such fiberglass repairs will be determined by the damage present if you visit a shop that does fiberglass repairs. A small crack or hole can be repaired for around $500.


It may seem that repairing exterior RV fiberglass by yourself could be a lot of work. As long as you follow the directions in this article, you are going to have no issues with making the repair yourself.

One of the most gratifying parts of repairing this fiberglass damage is knowing that you accomplished it yourself. Moreso, that you are going to be able to save a massive amount of money on hiring an RV mechanic. After you do a couple of small fiberglass repair jobs on your RV, you are going to be surprised how capable you are in making fiberglass repairs on your other vehicles as well.

5/5 - (2 votes)

Sharing is caring!

1 thought on “How to Repair RV Fiberglass Exterior Damage”

Leave a Comment