How to Repair Small Cracks and Scratch in Your Fiberglass Boat
Whether from a muffed landing or a dropped pair of fishing pliers, boat owners are bound to suffer from some scratches, nicks, and gouges in their fiberglass boats. With a little patience and basic supplies, however, the damage can be repaired to look almost invisible.
Start by masking off the area that will remain unaffected and using acetone to clean up the damaged fiberglass surface. Then sand the area to a smooth finish.
Small cracks and scratches are the most common problems on fiberglass boats. They can be caused by almost anything, from branches on the riverbank to grocery carts in parking lots. Luckily, they are usually not serious and can easily be repaired by sanding and buffing. The first step in this process is to clean the area that needs repair with a mild soap and water solution. This will help to ensure that the repair materials bond properly with the fiberglass and allow them to cure. Then, tape off the area that you will be working in to keep it neat and confined. Once the area is clean, start with a low-grit buffing wheel to smooth out any fiberglass erupting from the scratch or crack. Once the area is smooth, you can use gelcoat, epoxy, or resin to fill the scratch. Once the product is applied, sand it down again until it is flush with the rest of the boat. Then, switch to a buffing wheel and buff the surface to bring out the shine and finish of your fiberglass.
If the scratch goes all the way through the gel coat layer, you will need to fill it with fiberglass “chop.” This is a putty-like substance that contains fiberglass strands and can be mixed with epoxy or another bonding agent to create a fiberglass patch. You can find fiberglass “chop” at most marine stores or online.
Once you have the material you need, mix it according to the manufacturer’s instructions and apply it to your scratch or ding. Ensure that it is “mounded” slightly above the boat, and let it set. This usually takes about 1–2 hours, depending on the humidity level.
Large cracks and scratches
Even the most durable fiberglass boats will eventually experience scuffs, scratches, deep cracks, and gouges as they navigate oceans or lakes. While taking your boat to a professional for large mechanical and cosmetic repairs is recommended, you can fix smaller dings yourself with the help of a few tools and materials.
The gel coat that gives fiberglass boats their glossy appearance is made from an epoxy or polyester resin-based thermoset polymer. Gelcoat is applied to molds during the fabrication process and, once cured, forms a hard protective layer that keeps water out of fiberglass and protects the laminates underneath.
Gelcoat can be sanded down and polished to make it as smooth or shiny as new, but the long-term use of abrasive pads can cause the underlying fiberglass to become brittle and develop spider cracks. Once these cracks form, the underlying laminates will begin to deteriorate, and water can start to seep into the fiberglass structure.
Small cracks and scuffs can be repaired using a specialized epoxy fiberglass repair kit, which is available at most marine stores or online. These kits come with all of the necessary ingredients and are easy to use. You will also need a few disposable application brushes and a fiberglass cloth to wrap around the crack.
If you are repairing a deep gouge or scratch that is larger than a toothpick, it is best to mix some epoxy resin and use a brush to apply it to the gouge or scratch. It may take multiple applications to fill and level the void, but it will give you a much better result than gelcoat paste, which only hides the damage and won’t last.
Some people choose to grind a stress crack with a dremel tool and then simply fill the crack, but this will likely return sooner than later and could be a sign of a serious structural issue that should be examined by a professional. If you notice any cracks or dings on your fiberglass boat, it is important to have them fixed right away to prevent water from damaging the fiberglass structure and rusting metal components like the anchor.
Hole in the hull
Few boat owners like to think of their fiberglass hull as having a hole. Nonetheless, such damage is often a fact of life for anyone with a fiberglass boat. The good news is that the most dreadful holes in fiberglass can often be repaired using a little bit of fiberglass fabric, a few cans of resin, and equal parts skill and care. The end result is a repair that is almost indistinguishable from the original.
For example, let’s say a 1/8″-diameter screw hole was made through the deck of a fiberglass-lined vessel with a plywood core. This is considered a low-risk repair because the hole is small in diameter and is in an area that is not structural. However, the hole does allow bilge water to flow through, and this could eventually lead to delamination of the plywood core. The best solution would be to use a wood plug, bond it in, and then laminate over the plug. This will not only be stronger, but it will also provide a seal to prevent the passage of water into the hull.
First, sand the edges of the hole to make it sound like fiberglass with a disc sander or an electric drill with a sanding attachment and medium-grit sandpaper. Next, enlarge the hole slightly. This is to allow you to cut a piece of fiberglass that fits tightly over the hole. It is important that the patch fit snugly so that it will be watertight.
Once you have the correct size patch, you should sand the back side of the patch to roughen it up to facilitate bonding with the resin used for fiberglass boat repair. Once you sand the patch, apply fairing compound to the surface and edges of the patch. This will smooth out the patch and help it blend into the hull’s fiberglass surface.
Once the fairing compound is dry, it’s time to start working on the top of the patch. You will need to make a piece of 10-ounce roving about the thickness of the hull. Cut a few pieces of this and lay them down in the hole, overlapping one on top of the other. When you have a good number of layers of the roving laid in, cut a piece of 7 1/2-ounce fiberglass cloth and lay that on top. When the layers of roving and glass are in place, mix some epoxy resin and fill the patch.
Finding the right location
It’s a good idea to do some research before choosing a fiberglass repair company to work on your boat. The company should have a long track record of doing this type of work as well as offering high-quality customer service. Choosing the right company will save you a lot of trouble and ensure that your boat gets the best care possible.
If you own a fiberglass boat, you know that it can be susceptible to damage from all kinds of things. From a muffed landing to a dropped pair of fishing pliers, any boat can be subject to dings and scratches. However, if you find yourself with a hole in the boat, this is a serious problem that needs to be addressed immediately. A hole in the hull can cause the boat to be unseaworthy and unsafe to sail in.
To fix a hole in your fiberglass boat, you need to first identify the location of the damage. You can do this by using a screwdriver and tapping the affected area of the boat. If you hear a dull sound, this is a sign that there is delamination in the damaged laminate. It’s important to get this repaired as soon as possible to prevent further damage to the rest of your boat.
The next step is to sand down the damaged area and prepare the surface. This is where you need to use a good amount of patience, as it takes a while to sand down the fiberglass and gel coat. Once you’ve done this, it’s time to prime and paint the area.
Finally, once the primer and paint have dried, you can apply a top coat, and you’re done! You’ll be amazed at how much dough you can save by doing this yourself instead of paying astronomical marina fees.
Fiberglass is a relatively easy material to work with, so it’s no surprise that many people choose to do fiberglass boat repairs on their own. With just a little bit of knowledge and the proper tools, you can have your boat looking like new in no time at all!