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Fiberglass Boat Repair

Owning a fiberglass boat occasionally means enduring dings, scratches, and even holes. Thankfully, these are not the end of your vessel: fiberglass is remarkably repairable!¬†Fiberglass Boat Repair¬†involves washing, sanding, and dewaxing. Before beginning a fiberglass repair, preparing the damaged area is important. It’s also necessary to ensure the adhesion of the repair patch to the undamaged laminate.

Boat ServicesFiberglass repair kits have everything you need to make quick and lasting repairs. These kits include the epoxy and fiberglass materials needed to fix cracks and holes, gelcoat blisters, and delaminated cored panels. They also include tools and illustrated instructions for making these small repairs to fiberglass boats. These kits are available in a wide variety of sizes, including those that are easy to transport and store aboard your boat.

Before you can make a fiberglass repair, it is important to prepare the surface. It is necessary to clean the area around a crack or scratch with sandpaper to rough it up so that the resin will adhere properly. Once the sanding is done, you can lay down a piece of fiberglass cloth over the crack or scratch. This will help to strengthen the patch and prevent further deterioration of the fiberglass. The next step is to mix together the resin and hardener. Once you have mixed the product according to application guidelines, you can apply it to the damaged fiberglass.

If you are repairing a fiberglass hull, it is a good idea to use polyester or vinyl ester resin. This type of fiberglass resin can withstand chemicals and high temperatures, allowing it to hold up in harsh environments. It is also water-impermeable, preventing mildew and rotting. These types of resin are ideal for repairing fiberglass boats, as they will not absorb excessive moisture and allow it to damage the structure.

Using the right fiberglass for a repair is just as important. You can find a wide range of fiberglass boat repair products online, but it is best to choose the type that is appropriate for your specific needs. Typically, this will depend on how large the repair project is and what type of surface it is. For example, for a larger project, it is a good idea to use biaxial with a 3/4 oz. Matt sewed on the back of it. This type of fiberglass cloth is strong, resists peeling, and will form well around corners.

Using the wrong materials for a fiberglass repair can lead to frustration and a poor finished product. It is recommended that you do not use automotive bond’s or any other type of filler paste for fiberglass repairs. These products can crack and are not designed to last in a marine environment.

A hole in a fiberglass boat is usually an indicator of delamination, but it can also indicate impact damage or a failure of the hull. Whatever the cause, repairing it involves a similar procedure. Begin by ensuring that the area around the hole is completely dry. Then, enlarge the hole as needed to expose firm fiberglass. This will help ensure a good bond for the patch.

Then prepare a patch to match the contour of the hole in the interior. Cut a piece of light cardboard to be at least 2 inches larger than the inside of the hole all the way around. Cover it smoothly with plastic wrap, and tape in place. Then set it into the inside of the hull, making sure that it matches the hole’s contour exactly.

Once the patch is in place, sand it smooth. This step is critical, as a poorly sanded surface will weaken the patch. Use a disc sander or an electric drill with a sanding attachment and medium-grit sanding disk, making sure that you don’t overspend and remove the cardboard backing.

If the hole is in a high-stress area, back it with fiberglass fabric. This step is not required for low-stress areas, but it’s an important safeguard against delamination of the patch.

Lastly, apply a gel coat to the area to match the color of the surrounding hull. A gel coat is an excellent sealant for holes, but it’s not a replacement for a proper fiberglass repair.

The best way to prevent a future leak is to repair the hole properly using the proper fiberglass techniques. If a fiberglass repair is done poorly, water will leak through it, potentially damaging the entire structure and perhaps even sinking the boat. The following two examples illustrate typical repairs to machined holes and impact damage in fiberglass boats.

The first step to fixing any fiberglass damage is identifying the area. This can be done by sounding the hull with a hard mallet and marking any areas where the solid glass doesn’t resonate, as well as the surrounding fiberglass. This is a good indicator that there may be delamination present, which must be corrected before proceeding with any other repairs.

The next step is to grind away any old fiberglass and epoxy that is bonded to the damaged section of the hull or stringer using a belt sander. This is a messy job, but it must be done to prevent rotted wood from infiltrating the repaired area.

It is important to keep in mind that any fiberglass work you do must be resealed with a quality polyurethane sealant. This is what gives fiberglass its sheen and is the only way to prevent water from seeping through the damaged section. If it is not properly sealed, the new fiberglass will eventually delaminate from the boat and ruin its appearance.

This is a common problem in older boats, especially those that have been afloat for many years and have had several layers of fiberglass added to their surface. It is recommended that you use a marine-grade polyurethane to ensure the best results.

For any section of the hull that is cut out for repair, you need to prepare the area for bonding. This can be done by grinding the contact surfaces of the new fiberglass and the existing hull to remove any damaged areas or sanding down to the fiberglass mat. After grinding, a scarf angle should be ground into the fiberglass. This is an angle that is calculated from the thickness of the original fiberglass to be approximately 12:1. The purpose of this is to create a surface for the new fiberglass to bond to so that the structural integrity of the boat will not be compromised.

It is also important to remember that any core sections of the boat that are damaged must be replaced. If they are not, the structure will eventually weaken, and the boat will start to warp or collapse. Many fiberglass repairpersons will fill these areas with foam or wood and sand them down to make them look acceptable, but this is not the correct method of making a successful repair.

Scratches in gel coat may seem insignificant at first, but if left unattended, they can create gouges. Unlike dings and surface scratches, gouges require more serious attention as they threaten the structure of your boat.

Light scratches can usually be smoothed with rubbing compound and buffing. The first step in the process is to assess the damage. If the scratch is in the gel coat layer and does not extend into the fiberglass core, it may only need wet sanding and then polishing to restore its sheen. If the damage is more serious and exposes the core, you will need to fill it.

To do this, you’ll need a gel coat repair kit, including a gel coat paste that provides both fillers and finish in a single application, a plastic spreader, and a release film. Mix the gel coat with pigments until you match the color of your boat, and apply it to the damaged area. Then sand and polish as directed to smooth the patch and blend it with the surrounding fiberglass, just like you would with the rest of your boat’s gelcoat.

You can also use a superior product called durable to repair scratches in fiberglass boats. This product is stronger, easier to work with than gel coat, and it comes in a variety of colors to match your boat’s color scheme. Unlike gel coat, durable can be cured underwater, so it’s an ideal choice for boats that are routinely in the water or that spend most of their time at marinas. It’s used on the decks of 11 nuclear aircraft carriers and numerous warships and naval vessels.

Whether you’re working with gel coat or durable, the first thing to do is remove any wax or grease from the area with acetone. Then sand the damaged area with 80-grit sandpaper, moving to 150-grit paper and then 240-grit. Wipe the area clean and dry before proceeding.

If you’re repairing a hole from the inside, you’ll need to scar the area around it to create an angle for the new fiberglass to attach to. For example, if you’re patching a 1″ hole, you’ll need to grind or sand away an angle of 12:1. After grinding, wash the area thoroughly with a dewaxing solvent and a rag to remove any residue that might interfere with the bond between the new and old fiberglass.