A Bimini Boat How-To Guide For Beginners

Bimini tops are a great way to protect yourself and your passengers from the sun and rain while out on the water. They are inexpensive, easy to install, and can be tucked away when not in use. Before installing a Bimini top, you need to select a suitable one. This involves taking measurements of your boat, including the length, width, and height of the windshield. You should also consider the size of your boat and the amount of shade you want. Once you have your measurements, you can shop for a Bimini top that fits your needs. When it comes to installation, the process is relatively simple and similar across models and designs. It involves preparing the Bimini top, marking the mounting points, drilling holes, and securing the Bimini top in place.

Choosing the right size bimini top

Measure the Width:

First, determine the width of your boat at its widest point, typically the beam width. This measurement will guide the selection of your Bimini top's width. It is recommended to add a few extra inches to ensure adequate coverage. Standard sizes are available, so choose the closest option.

Determine the Length:

Consider the length of your boat to decide on the necessary coverage. A longer Bimini top will cast a larger shadow, but manoeuvrability may be impacted. Opt for a length that strikes a balance between shade and practicality.

Calculate Mounting Height:

The mounting height is the vertical distance from the mounting point to the top of the gunwale. Ensure that this measurement allows for sufficient headroom, enabling comfortable movement within the boat.

Select Fabric Width:

The fabric width of the Bimini top should align with your intended activities. If you plan to host multiple passengers or engage in fishing, for example, a wider fabric will provide more comprehensive coverage.

Consider Frame Height:

The frame height is the distance from the mounting point to the top of the Bimini frame. Ensure this height allows for comfortable movement and adequate clearance beneath the top.

Adjustability:

Look for Bimini tops with adjustable features, such as telescoping support poles and collapsible frames. This adjustability allows for a custom fit and adaptability to varying weather conditions.

Coverage Area:

Decide on the area of your boat that you want the Bimini top to shade and cover. Bimini tops come in various lengths, typically ranging from 5' to 9', with 6' being the most common length.

Mounting Points:

Find the midpoint of your desired coverage area to determine the main mounting points. This will help ensure that your Bimini top is centred and securely attached.

Height Preference:

Consider whether you want to stand or sit under the Bimini top. Measure the desired height from the mounting points to the overhead position of the Bimini top. Remember that opting for a taller height will provide less shade.

Boat Type:

The type of boat you own may dictate the number of bows (steel frames) required. Typically, runabouts use three bows, while pontoons and larger fishing boats require four.

By carefully considering these factors and measurements, you can choose the right size Bimini top to enhance your boating experience.

Preparing the bimini top for installation

Firstly, lay out the bimini top on a flat surface to get a sense of its size and how it will fit on your boat. This step is crucial to ensure that the bimini top provides sufficient coverage for your boat. Most average-sized boats will require a three-bow bimini top, but this may vary depending on the size and shape of your boat.

Next, assemble the bimini top frame by connecting all its sections. This step may vary depending on the model of your bimini top. Some tops may require tools and screws to assemble, while others may be designed like a tent with tubes that slip together easily. Refer to your bimini top's manual for specific instructions.

Once the frame is assembled, slip the canvas onto it. This will give you a clear idea of the size and coverage of your bimini top. Now, you can start measuring the distances between the mounts and comparing them to the specifications of your boat's rails. It is essential to ensure that all the mounts are parallel on both sides to avoid an off-centre or askew installation.

Mark the locations for the mounts carefully. Consider the coverage you desire and ensure that the bimini top does not obstruct anything when collapsed. Once you are satisfied with the measurements and markings, you can begin drilling holes for the mounts. Remember that you only need to puncture the first topmost side of the rails when drilling.

After drilling the holes, you can install the mounts. Some people prefer using heavy-duty stainless steel rivets and a heavy-duty riveting tool for a sturdier base. If you use screws or bolts made of a different material than your railings, consider coating the connection spots to prevent corrosion and rust over time.

With the mounts in place, you can now attach the bimini top frame. This step may require an extra set of hands as it can be tricky to manage the canvas and frame simultaneously. Remember that the frame will not be very stable at this point, so you must install the rigid supports to hold it in place securely.

The rigid supports are crucial for ensuring the bimini top can withstand strong winds. These supports are usually installed vertically at a slight angle at the back of the frame to bear the weight of the top. Additionally, the bimini top should come with straps that hold it down and prevent it from folding unexpectedly.

By following these steps, you will have successfully prepared your bimini top for installation, ensuring a secure and functional addition to your boat.

Installing rigid supports

Once you've assembled your bimini top and connected all the sections of the frame, you can move on to installing rigid supports. These rigid supports will bear the weight of the bimini top and keep the frame steady in strong winds.

The rigid supports are installed at the back of the frame, slightly angled to support the weight of the top. The bimini top should also come with straps that hold the top down, preventing it from folding in a breeze. These straps are flexible, so you don't need to be too precise with your measurements when installing them.

To install the rigid supports, you'll need to drill holes and screw in mounts for the supports. Mark the spots for the mounts carefully to ensure they are parallel on both sides. Drilling holes that puncture the first topmost side of your rails should be sufficient. You can use heavy-duty stainless steel rivets and a heavy-duty riveting tool for a sturdier base.

Since the rivets or screws will likely be a different material from your railings, these connection spots may be more susceptible to corrosion over time. Applying a coat of marine-grade silicone sealant or butyl tape before moving on to the next step can help prevent this.

With the mounts in place, you can attach the rigid supports and test the stability of your bimini top. Remember to follow safety guidelines and enlist help if needed, as this process can be tricky.

Drilling holes for mounts

Marking the Mounting Points:

Before you start drilling, you need to identify the desired location for your bimini on the boat. Pick up the assembled bimini top and place it in the desired mounting location. Extend the top to its fully open position and mark the locations where the largest bow will be anchored to the boat. These marks will guide where you place the mounting brackets. Ensure that the mounting points are the same distance from either the bow or the stern for even weight distribution.

Selecting the Right Tools:

Different bimini top models may require different tools and equipment. It is important to refer to the manual provided with your bimini top to ensure you have the correct tools for a safe and efficient installation. You will typically need a marker or pencil to make temporary marks, and a heavy-duty riveting tool if you plan to use rivets for a stronger hold.

Drilling the Holes:

When you have marked the locations for the mounting brackets, it's time to drill the holes. Using a drill bit that is slightly smaller than the screws you will be using, carefully drill the holes needed to secure the brackets to your boat. Take your time and be cautious to avoid any wires or components that may be damaged by the drill bit.

Securing the Brackets:

After drilling the holes, it's now time to attach the mounting brackets. Place the brackets in the marked locations and secure them firmly to your boat using the provided screws. Make sure to tighten the screws adequately to ensure a strong and stable connection. Repeat this process for the other side of the boat, ensuring symmetry and stability.

Finishing Touches:

With the brackets securely in place, you can now attach the main bow of the bimini top to the brackets. Position the forward-attaching eyes and drill the necessary holes to secure them in place. The forward strap eyes should be mounted at a minimum of a 45-degree angle as they will bear the most strain when the boat is in motion. Finally, adjust the straps so that your bimini top is riding near a horizontal position.

Remember, these are general instructions, and your specific bimini top model may have unique requirements. Always refer to the installation manual provided with your bimini top for detailed instructions specific to your product.

Securing the bimini top with screws/rivets

Bimini tops usually come with all the screws, bolts, fasteners, and hardware required to mount them in place. However, they won't come with any tools, so you'll need to gather the following:

• Marker, pencil or anything to make a temporary mark
• Heavy-duty riveting tool
• Drill with a 9/64" bit
• Phillips-head and flat-head screwdrivers

Some bimini tops require screws to assemble the frame, while others are designed like a tent, allowing you to slip the tubes together without the need for screws or fasteners.

When securing the bimini top to the boat, you will need to drill pilot holes for the deck hinges. After drilling, secure the deck hinges with the provided screws.

• Lay out the bimini top canvas with the bottom side up.
• Identify the hook-shaped bow side frame parts and the center bow frame part.
• Assemble the side and center bow parts by aligning the pre-drilled holes.
• Use ½” no. 8 screws to connect the bow parts securely.
• Repeat this process for the short bow, again aligning the pre-drilled holes and securing them with screws.
• Pass the assembled long bow assembly through the sleeve in the back of the top.
• Pass the short bow through the sleeve in the front of the top.
• Pass the looped end of each hold-down strap over each end of the long and short bows.
• Use a no. 8, 1/2" screw to fasten the strap to the bow frame at each pre-drilled hole.
• Connect the short frame ends to the jaw slides on each side of the long bow frame. Ensure the jaw slides are tight enough to hold securely while still allowing the short bows to pivot.
• Place the assembled, folded-up bimini top onto the boat, with the bows and sleeves down.
• Fit the eye ends of the main bow support into the deck hinges and secure each connection with the provided thumb bolts.
• If using rivets instead of screws, use a heavy-duty riveting tool to secure the hinges.
• Measure and mark the position of the eye straps on the gunwale of the boat, ensuring they are exactly opposite each other on both sides.
• Drill pilot holes for the eye straps using a drill with a 9/64" bit.
• Secure the eye straps with the provided screws.
• Attach the snap hook to the eye straps and adjust the hold-down straps.

Note: If you are using a stainless steel frame, you will need to use rivets instead of screws. A hand riveting tool and necessary rivets should be included with your bimini top. Always wear safety goggles when operating a riveting tool.

Frequently asked questions