Replacing Boat Bow Rails: A Step-By-Step Guide

Boat owners may want to replace the rails on the bow of their boat for several reasons, including enhancing safety, improving aesthetics, or repairing damage. Bow rails can be customised to any height and length and fabricated from stainless steel or aluminium. Replacing bow rails typically involves removing the old rails, cleaning the surface, filling old screw holes, marking screw locations, bending the new rails to fit the boat's contours, drilling holes, and securing the rails with screws and sealants. The process can be complex, requiring specialised tools and careful techniques to avoid damaging the boat.

How to replace rails on the bow of a boat

Removing the old bow rail

Protect Your Boat's Surface: Before you begin, it's important to cover any parts of the boat that may be damaged during the removal process. Use cardboard, plywood, or any other suitable material to shield the deck and hull near the bow rail. This will prevent scratches or other damage during the removal process.

Gather the Necessary Tools: Make sure you have all the tools you need before starting. This may include screwdrivers, wrenches, a hacksaw, a drill, and personal protective equipment like gloves and eye protection. Having everything within reach will make the process smoother.

Remove End Caps and Fittings: Start by removing the end caps of the bow rail. Depending on their condition, you may be able to unscrew or pry them off. If they are heavily corroded, you might need to cut them off with a hacksaw or use a blow torch to loosen them, but be extremely careful not to damage the boat's surface. Once the end caps are off, move on to removing the fittings that secure the rail to the boat.

Drill Out Rivets or Remove Screws: If your bow rail is attached with rivets, you will need to drill them out. Use a drill bit that is slightly larger than the rivet shaft to make the process easier. If the rail is attached with screws, use the appropriate screwdriver or wrench to remove them. Work carefully to avoid damaging the boat's surface.

Carefully Remove the Rail: With the end caps and fittings removed, you can now take out the bow rail. Gently pull and bend the rail away from the boat, working your way along the entire length. If the rail is stiff and difficult to remove, you may need to use a gentle hammer to tap it loose in small sections, being mindful not to damage the boat's hull or deck.

Clean and Prepare the Surface: Once the old bow rail is removed, clean the surface thoroughly. Scrape off any remaining sealant, residue, or corrosion. You may need to use a solvent to remove stubborn residue. Fill in the old screw holes with an epoxy filler to prepare the surface for the new rail installation.

Remember to take your time during the removal process and be cautious to avoid damaging your boat's surface. It's always a good idea to have a helper to assist you, especially when managing the length of the bow rail or holding tools.

Measuring the boat for the new rail

Measuring your boat for a new rail is an important step in the process of replacing your boat's rails. Here are some detailed instructions to ensure accurate measurements:

First, understand that due to the curves of your boat, you will need more rail than just double the length of your boat. A good rule of thumb is to add the boat's length to its beam (width) and then double that sum. This will ensure you have enough rail to complete the job.

Next, mark the location for the new rail. Use masking tape to tape off the area above and below where the new rail will be installed. This will create a neater job when applying sealant. Mark the locations for the fastener holes every 6 inches (15 cm) around the entire boat. These marks will guide you when drilling holes for the new rail.

Now, measure the length of the rail needed. Start at the middle of the transom (the vertical section at the back of the boat) or at a transom corner. Measure forward along the boat's centerline to the bow (the front tip of the boat). This measurement will give you the length of the rail required.

If your boat has a curved bow, you will need to account for this in your measurements. Measure the distance from the centerline to the outermost point of the curve on one side. Double this distance to get the additional length needed for the curve. Add this to the previous measurement to get the total length of the rail required.

For accurate measurements, it is recommended to work with a partner. They can help hold the tape measure and ensure the measurements are taken along the correct lines.

Finally, when ordering the new rail, be sure to account for any waste that may occur during installation. It is better to have a little extra than to run out midway through the project.

By following these steps, you will have accurate measurements for your new boat rail, ensuring a proper fit and a successful installation.

Preparing the new rail

Before you start, you will need to gather the right tools and supplies. These include a rub rail kit, a heat gun, a scraper, masking tape, rags or paper towels, a caulking gun, an adhesive sealant, screws to suit your boat, and a screwdriver.

The first step in preparing the new rail is to measure your boat accurately. Due to the curves involved, you will need more rail than just double the length of your boat. A good rule of thumb is to add your boat's length to its beam and then double that sum to ensure you have enough rail to complete the job.

Once you have measured and ordered the correct amount of rub rail, you can begin preparing it for installation. Start by uncoiling the rail and folding it back on itself to find the centre point. Mark this point with a piece of masking tape, ensuring that the lip of the rub rail is at the bottom.

Next, cut the rail into manageable sections. You will need two sections of equal length that extend from the centre of the bow to the transom on either side of the boat. It is important to cut the rail slightly longer than needed, as you can always trim the excess later.

Now, you will need to create a smooth, gradual curve along the length of each section. This can be done by marking the rail every inch and making slight bends at each mark, gradually working your way towards the desired curve. This technique will help distribute the bend evenly and minimise the risk of creasing the metal.

Finally, before you can install the new rail, you will need to drill holes for the fasteners. Place the centre point of the first section against the centre of the bow and mark the locations of the fastener holes with a pencil. Then, using a power drill and a 1/8-inch bit, drill through the pre-drilled holes in the rub rail to create mounting holes in the deck cap. Repeat this process for the second section, ensuring that the lip of the rail remains at the bottom throughout.

Attaching the new rail

Planning:

Before starting the installation, it is crucial to gather all the required tools and materials. These include a power drill, drill bits, a power driver with a Phillips bit, acetone, a scraper, epoxy filler, marine silicone sealant, rags or paper towels, a caulking gun, and screws that suit the material of your new rail (such as stainless steel or aluminum) or vinyl. Additionally, ensure you have a helper to assist you during the process.

Measuring and Preparing:

To ensure you have enough rail material, measure your boat's length and beam, then double the sum. This will give you the minimum amount of rail required to complete the job. Prepare the surface by removing the old rail, cleaning away any residue, and filling in the old screw holes with epoxy filler. Mark the locations for the new screw holes with pencil marks above the gunwale to avoid drilling into them later.

Taping and Positioning:

Apply masking tape above and below the new rail location to create a neat finish when applying the sealant. Ask your helper to hold the new rail in place while you mark the fastener holes every 6 inches around the boat. Starting at the middle of the transom or a transom corner, unroll a few feet of the coiled rail and create a natural location for the end caps.

Drilling and Securing:

Drill holes through the rail and the boat, countersinking the holes through the rail. Apply a marine-grade sealant to the back of the rail and the fastener threads, then install the fasteners to secure the rail. Continue this process around the boat, using a heat gun to soften the rail material at corners or the bow to help it take the bend. Overlap the ends of the rail by one-eighth of an inch if you need to join two coils together.

Trimming and Capping:

When you reach the starting point again, pull the splices together and install a screw one inch in on both sides of the joint. Trim any excess rail material at the transom, ensuring it is clean and mated with the transom angle. Install the end caps provided with your kit or purchase suitable ones separately.

Sealing:

Finally, use a gloved finger to smooth out any excess sealant that has been squeezed out above and below the new rail. Remove the masking tape by pulling it up and away from the edges. Ensure you clean your finger frequently to avoid spreading sealant onto unwanted areas.

Sealing the new rail

Prepare the Surface:

Before you begin sealing, make sure the surface is clean and dry. Remove any residue or debris from the old rail using a scraper or sandpaper. Fill in the old screw holes with an epoxy filler to create a smooth surface.

Tape the Area:

Use masking tape to tape off the area above and below the new rail. This will create a neat seal and protect the surrounding areas from any excess sealant. Mark the locations for the new screw holes with a pencil, ensuring they are above or below the rail and not in the previous screw holes.

Apply Sealant:

With your finger, apply a bead of marine-grade sealant along the length of the new rail, both above and below it. Make sure the sealant is evenly distributed and fills any gaps between the rail and the boat's surface.

Install the Rail:

Drill pilot holes through the pre-drilled holes in the new rail, creating mounting holes in the boat's surface. Use a power drill with an appropriate drill bit for this step.

Secure the Rail:

Screw in the new rail using stainless-steel screws. Before driving each screw into place, dab the threads with marine sealant to ensure a watertight seal. Work your way around the boat, securing the rail in place.

Smooth the Sealant:

Once the rail is securely in place, use your gloved finger to smooth out any excess sealant that has squeezed out. Clean your finger frequently to avoid spreading the sealant onto unwanted areas.

Remove the Tape:

Carefully pull up the masking tape, starting from one end and moving slowly and evenly. This will leave a neat edge to the sealant and ensure that the rail is securely bonded to the boat.

Allow for Curing:

Give the sealant adequate time to cure and harden. Follow the instructions on your chosen sealant for the recommended curing time. Do not use the boat or expose it to water during this period.

By following these steps, you will effectively seal the new rail, protecting it from water ingress and ensuring a long-lasting and aesthetically pleasing finish.

Frequently asked questions