Andrew Pace
Fibreglass boats are known for their durability and low maintenance, but they are not immune to problems. Structural damage to the stringers is a common issue, and it's important to know how to make a replacement that will last. Stringers are an integral part of a boat's hull and provide structural support. They can be made of solid wood, plywood, fibreglass, or a combination of wood and fibreglass. This article will provide a step-by-step guide to fibreglassing a boat stringer, covering everything from preparing the surfaces to applying the fibreglass and making sure your boat is safe and supported once again.
Explore related products
What You'll Learn
Identifying damage
Inspect for Visible Damage:
Look for any visible signs of damage on the stringers. This can include cracks, splits, bulges, or other types of visible damage. While small hairline cracks in the fiberglass may not be a major concern, significant cracking that runs deep into the stringer should be addressed. Splits or breaks in wooden stringers are particularly serious, as they can indicate severe rot or structural compromise.
Check for Soft Spots:
Feel the stringers for any soft, spongy, or squishy areas. This is often a sign of moisture damage or rot, especially in wooden stringers. Water intrusion can cause the wood to become weak and spongy, compromising the structural integrity of the stringer.
Listen for Unusual Noises:
Pay attention to any unusual noises coming from the stringers while the boat is underway. A damaged stringer may produce unusual sounds, such as creaking or groaning, indicating potential structural issues.
Tap Testing:
Use a mallet or a hard object to tap on the stringer surface. A damaged stringer will often sound flatter or hollow when tapped, indicating a loss of structural integrity.
Brown Spots and Water Weeping:
Keep an eye out for brown spots on the stringers, as this is a sign of water weeping from the inside out. Water intrusion can lead to rot and structural damage over time.
Drilling Inspection (for wooden stringers):
If your stringers are encased in fiberglass, drill a small hole through the fiberglass into the wood core. Inspect the wood shavings—if they are wet or rotten, it's a clear indication of water damage, and the stringers will need attention.
Flexing or Sagging Hull:
Check for any deformation or sagging in the hull, as this can be a symptom of damaged stringers. A boat's hull can flex or deform when stringers are weakened, resulting in a loss of overall support and stability.
Remember, it is crucial to monitor your boat's stringers regularly and address any damage promptly. While you can replace or repair individual stringers, it is often recommended to replace the entire set to ensure consistent strength and avoid future issues.
Winterizing Your Boat: Filling Engine Block with Antifreeze
You may want to see also
Explore related products
Removing the stringer
First, you need to identify the damage. Look out for any bulges or cracks on the surface or in the tabbing. Tap the stringer surface with a hard object to listen for a change in sound. A damaged stringer will often sound flatter or hollow, or there may be no sound at all. If you are unsure, you can drill a small hole through the fibreglass into the wood core and check for wet or rotten wood shavings. If the wood is not damaged, simply reseal the holes to prevent water from entering the stringer.
Once you have identified the damage, you need to remove the old stringer. Start by removing any nuts and bolts, then use a grinder to cut the tabbing at the core/hull joint, being careful not to cut into the hull laminate. You may need to cut access holes in the hull liner or cabin sole to reach the affected area. If the wood has turned to rot, you may be able to simply rip out the stringer or bang it out. Otherwise, you will need to shave it down along the hull and grind away the remnants.
After removing the old stringer, you need to prepare the surfaces for the new stringer. Grind and sand the inside of the hull to create a clean surface for the new stringer to bond with. Make sure to remove all glass from the old stringer and sand until you have a "new" surface free of contamination and obstructions. Measure the thickness of the fibreglass skin so that you can duplicate it with the new stringer.
Boat Docking: Common Mishaps and How to Avoid Them
You may want to see also
Explore related products
Preparing the surfaces
Firstly, it is essential to identify the areas requiring repair or replacement. This includes inspecting the boat stringers for any signs of damage, such as impact, rotting, age-related wear, or water penetration. Common indicators of a rotten stringer include brown spots, soft spots in the deck, delaminating fibreglass, and a bilge that stays filled with water. Tap the stringer surface with a hard object, and listen for a change in sound; a damaged stringer will often sound flatter or hollow. Once you've identified the damaged areas, be sure to mark them clearly.
The next step is to remove the damaged stringer and core carefully. Use a grinder to cut the tabbing at the core/hull joint, ensuring you do not cut into the hull laminate. This step may vary depending on the construction of your boat. If your boat has a fuel tank, wiring, or cable runs, take extra precautions to avoid accidental damage. It is recommended to delicately drill a hole and measure its thickness with a probe before setting the saw blade to the appropriate depth.
After removing the damaged stringer, it's time to prepare the bonding surfaces. This involves sanding the surfaces with 50-grit sandpaper to create a clean and smooth surface for adhesion. Be sure to abrade not only the bonding surfaces of the hull but also the new core material. Brush away any dust or loose material to ensure a contamination-free surface.
Before proceeding, it is crucial to measure the thickness of the fibreglass skin accurately. This information will be essential for duplicating the thickness when applying the new fibreglass layer. Additionally, if your stringers are wood encapsulated in fibreglass, ensure you have the exact wood dimensions as originally used.
Finally, it is important to note that preparing the surfaces is just one aspect of the overall fibreglassing process. For a comprehensive understanding of the entire procedure, be sure to refer to other resources and seek guidance from experienced professionals.
Understanding Safe Distances for Operating Speed Boats
You may want to see also
Explore related products
![Boatlife Git Rot Kit - 4oz [1063]](https://m.media-amazon.com/images/I/51Csyv2VbOL._AC_UL320_.jpg)
Repairing the stringer
Once the damage has been identified, it is time to remove the old stringer. This usually involves dealing with the fibreglass shell that surrounded the wood, which may need to be ripped or banged out. The next step is to grind and sand the inside of the hull to create a clean surface for the new stringer. All surfaces should be clean, dry and sanded.
If you are replacing the entire stringer, it is important to use the original wood type and dimensions. The new stringer should be cut to fit the size and shape of the core and dry-fitted and trimmed for a good fit. The bonding surfaces should be abraded with 50-grit sandpaper.
A resin/hardener mix should then be used to wet out all contact surfaces of the hull and core. Apply a liberal amount of thickened epoxy to one side of the contact area, and push the stringer into position with firm hand pressure. Shape any squeezed-out epoxy into a fillet, and apply additional epoxy if necessary for a smooth finish. Finally, clean up any excess epoxy before it cures, and replace the fibreglass skin.
The First Historic Boat Race: Oxford vs. Cambridge
You may want to see also
Explore related products
Finishing
Now that you have successfully replaced the stringer, all that’s left to do is finish the job. Firstly, ensure that the fibreglass skin is replaced, so that your deck is fully supported once again. If you are using fibreglass and resin, cut the fibreglass cloth to size, allowing for tabbing. You may need 4-5 layers of fibreglass, depending on the thickness of the repair. Once the fibreglass is cut, mix the resin according to the instructions on the package. You can use a paintbrush or roller to apply the resin to the fibreglass, and then apply the fibreglass to the repair area.
After the fibreglass has dried, use a sander to level the surface, removing any bumps or lumps. Wipe away the dust and debris with a clean rag. If you are dealing with a wooden stringer, it is important to seal the wood with varnish or epoxy. This is especially important for wooden boats, as it will protect the wood from water damage. If your boat has inboard engines, it is important to ensure that the stringer is solid, as the engines will be mounted on the stringers.
If you are unsure about your repair, you can always consult an expert or watch video tutorials online. Remember, it is always better to fix a problem sooner rather than later, as issues with boat stringers can compromise the integrity of your boat's hull.
Repairing Dry Rot on Your Boat: A Step-by-Step Guide
You may want to see also
Frequently asked questions
Stringers are part of a boat's structure, providing extra strength and support. They are usually made of wood or a combination of wood and fibreglass.
Look out for any bulges or cracks on the surface or in the tabbing. Tap the stringer surface with a hard object and listen for a change in sound. Typically, a damaged stringer will sound flatter or hollow.
You will need a grinder, a small saw blade, a sander, a paintbrush or roller, and a flashlight and mirror to inspect the damage.
First, identify and mark the damaged area. Cut away, grind, and sand the damaged area. Measure and cut the fibreglass cloth to size, then mix and apply the resin. Finally, apply the fibreglass to the area and allow it to dry.
