Replacing Boat Hatch Struts: A Step-By-Step Guide For Beginners

Gas struts are an essential component of many boats, providing support for hinged hatches and freeing up your hands by keeping the hatch lid from slamming shut. Over time, these gas struts, also known as gas shocks or gas springs, may need to be replaced. This process involves a few simple steps, from weighing the boat hatch and determining the mounting points to calculating the required strut force and installing the new strut. While it may seem daunting, replacing the gas struts on your boat hatch can be a straightforward task with the right tools and guidance.

Measure the hatch's weight

Before you start replacing the spring struts on your boat hatch, it's important to measure the weight of the hatch accurately. This is a crucial step because the weight of the hatch will determine the type and size of the spring struts you need. Here's a step-by-step guide to measuring the weight of your boat hatch:

• Remove the hatch: Start by unscrewing the hatch from its hinges. This step will give you access to the entire hatch and make it easier to handle during the weighing process.
• Choose an appropriate scale: Select a scale that can accurately measure the weight of the hatch. You can use a bathroom scale or a digital scale designed for weighing fish. Place the scale at a convenient height that allows you to place the hatch on it comfortably.
• Weigh the hatch: Place the hatch on the scale and record the weight measurement. Make sure the hatch is stable and not wobbling on the scale. Take the weight measurement in pounds, as this unit will be used in the subsequent calculations. In the example provided by Boating Magazine, the hatch weighed 20 pounds.
• Reattach the hatch: Once you have the weight measurement, you can reattach the hatch to its hinges. Ensure that the hatch is securely fastened before proceeding to the next steps.
• Consider the angle and mounting position: Keep in mind that the angle and mounting position of the spring struts will also impact the required force. The force exerted by the struts depends on factors such as the distance between the hinge and the strut mounting point, as well as the length of the strut.
• Calculate the required force: To determine the force required for the spring struts, you can use the formula: Force Required = weight x length ÷ distance between the mounting point of the gas strut and the hinge. This calculation takes into account the weight of the hatch, the length of the strut, and the positioning of the strut in relation to the hinge.
• Factor in a safety margin: Although you now have a calculated force value, it's recommended to add an additional 10% to 20% lift force to ensure that you have ample lifting power. This safety margin helps compensate for any variations in conditions or unexpected factors.
• Consider the application: Keep in mind the intended application of the spring struts. If you're installing them on a lightweight electronics box door, a lower force rating may be sufficient. However, for a thick, heavy fiberglass hatch, you'll need a higher force rating, such as 90 pounds.
• Select the appropriate strut length: Spring struts come in various lengths, and you'll need to choose one that matches your hatch. Measure the height of the hatch and refer to the general rule that the correct strut length is typically around 55% of the hatch's height. However, be sure to take actual measurements rather than relying solely on this rule of thumb.
• Check temperature operating ranges: If you're installing spring struts in an engine room or near exhaust components, pay close attention to the temperature operating ranges specified by the manufacturer. Ensure that the struts you select are designed to operate within the expected temperature range of your boat's engine room.

By carefully following these steps, you can accurately measure the weight of your boat hatch and gather all the necessary information to select the appropriate spring struts for replacement. Remember to consider factors such as the angle, mounting position, force rating, and length of the struts to ensure a successful installation.

Calculate the required strut force

To calculate the required strut force for a boat hatch, you can use the following formula:

Required strut force = Weight of the hatch lid (pounds) x Distance from the hinge to the centre line of the hatch / Distance from the hinge to the strut mounting point on the hatch

This formula takes into account the weight of the hatch lid and the distances from the hinge to both the centre line and the strut mounting point. By calculating the required strut force, you can ensure that the gas strut can support the hatch when open and allow it to close easily without slamming.

For example, let's say you have a boat hatch with a lid that weighs 20 pounds. You want to support the hatch when it is open at a certain angle, and the distance from the hinge to the centre line of the hatch is 24 inches. The distance from the hinge to the strut mounting point on the hatch is 16 inches. Plugging these values into the formula, we get:

Required strut force = 20 pounds x 24 inches / 16 inches = 30 pounds

So, a strut with 30 pounds of force is required for this particular boat hatch.

It's important to note that the placement of the gas strut can affect its effectiveness. Generally, the best place to mount the strut is halfway between the hinge and the centre of the hatch. The length of the strut should be approximately 55% of the height of the hatch. Additionally, the strut should be clear of any potential interference as it is designed to handle only vertical forces, not side forces.

When selecting a gas strut, it's crucial to consider the weight and length requirements, as well as the operating temperature range, especially if it will be mounted in an engine room. Gas struts are available in different materials, such as stainless steel or nitride-coated steel, with varying levels of durability in saltwater environments.

Choose the right brackets

When choosing the right brackets for your boat hatch, there are several factors you need to consider to ensure a successful installation. Here are some detailed guidelines to help you through the process:

Type of Brackets:

Select brackets that are specifically designed for gas struts or spring applications. These brackets should be able to accommodate the gas strut's ball stud or socket mechanism. Angled and flat brackets are commonly available, and you should choose the type that best suits your boat hatch's configuration.

Material and Durability:

Opt for brackets made from high-quality materials, such as stainless steel. This is especially important if your boat is exposed to saltwater environments, as stainless steel offers superior durability and corrosion resistance. Ensure that the brackets can withstand the weight of the hatch and the forces exerted by the gas struts.

Size and Fit:

Measure the mounting points on your boat hatch and select brackets that fit those dimensions perfectly. Ensure that the brackets have the appropriate number and placement of mounting holes. The brackets should also provide sufficient clearance for the gas struts to operate without interference from other components.

Installation Method:

Consider the installation process and choose brackets that come with the necessary mounting hardware, such as bolts or self-tapping screws. If you have limited access to the mounting area from behind, select brackets that can be attached using screws. If through-bolting is possible, make sure to use stainless-steel fasteners for a secure installation.

Manufacturer Recommendations:

Refer to the gas strut manufacturer's guidelines or recommendations for bracket selection. For example, if you're using Taylor Made Products gas struts, they offer a range of compatible brackets that are designed to work with their struts. Using brackets from the same manufacturer can ensure better compatibility and ease of installation.

Safety Considerations:

Always prioritise safety when working with boat hatches and gas struts. Ensure that the brackets you choose are rated to handle the weight and forces involved. Follow the manufacturer's instructions for proper installation and maintenance to prevent accidents or equipment failure.

By carefully considering these factors, you can choose the right brackets for your boat hatch spring strut replacement project, ensuring a secure and functional installation. Remember to refer to installation guides and seek professional advice if needed to complete the job safely and effectively.

Measure for the gas strut

To measure for the gas strut, you need to follow these steps:

Step 1: Weigh the Boat Hatch

Firstly, you need to establish the weight of the hatch. Unscrew the hatch from its hinges and use a scale to weigh it. You can use a bathroom scale or a digital scale designed for weighing fish. Once you have the weight, reattach the hatch to the hinges.

Step 2: Determine the Upper Mounting Point

Open the hatch to the desired angle and mark a point for the gas spring's upper bracket mounting. This should be located on the underside of the lid, around a third to halfway from the hinge to the opposite side of the hatch.

Step 3: Mark the Lower Mounting Point

The lower mounting point is usually just below the upper mounting point. It doesn't need to be perfectly vertical, but ensure there is enough room for a mounting bracket or ball stud.

Step 4: Measure for the Gas Strut

With the lid open, measure from the upper mounting point to the lower mounting point. This will give you the required extended length of the strut. For the compressed length, measure from the lower mounting point to the rim of the compartment, and then from the upper mounting point to the lower edge of the lid, both at the same angle. Add these two measurements together.

Step 5: Calculate the Required Strut Force

Use the following formula to determine the force required:

> Weight of Lid (pounds) x Distance from Hinge to Hatch Centre Line (inches)

> ——————————————————

> Distance (inches) from Hinge to Strut Mounting Point on the Hatch

This calculation will help you choose a strut that matches the required dimensions and force.

Step 6: Choose the Right Brackets

Select the appropriate brackets for your gas strut. Angled and flat brackets are available to accommodate different installation configurations. Ensure you have the correct hardware for installation.

Additional Considerations

When measuring for a gas strut, you may also want to consider the following:

• The function of the gas strut: whether it needs to open unaided, assist, or hold open.
• The speed and frequency of movement.
• The dimensions and weight of the hatch.
• The position of the hatch and its centre of gravity.
• Environmental conditions such as temperature and humidity.

Mark the upper and lower mounting points

To replace the spring struts on a boat hatch, you'll need to first identify the upper and lower mounting points. This will involve measuring and marking the correct spots for installation. Here's a detailed guide on marking the upper and lower mounting points:

Determine the Upper Mounting Point:

Open the hatch to the desired angle at which you want it to be supported. The upper mounting point will be located on the underside of the lid. Using a measuring tape, measure a point that is approximately one-third to halfway from the hinge to the opposite side of the hatch. For example, if your hatch measures 24 inches from the hinge to the opposite side, you would mark a point 8 to 12 inches from the hinge. This location is crucial for the proper functioning of the gas strut. Make sure to mark this point clearly with a pencil or marker.

Consider the Strut Angle:

When determining the upper mounting point, it's important to keep in mind the desired angle of the gas strut. The strut should be installed at a slight angle, not perfectly vertical. This will ensure that the strut provides the necessary support and range of motion for the hatch. Adjust your marked point accordingly to achieve the desired angle.

Mark the Upper Mounting Point:

Once you've identified and measured the correct location, clearly mark the upper mounting point. You can use a pencil, marker, or even a small piece of tape to indicate the exact spot where the upper bracket of the gas strut will be attached. Make sure the mark is visible and easy to reference when installing the bracket.

Identify the Lower Mounting Point:

The lower mounting point will typically be located just below the upper mounting point. It's important to ensure that the lower mounting point has sufficient space for the mounting bracket or ball stud. Check for any potential obstructions or interference that might hinder the installation or operation of the gas strut.

Mark the Lower Mounting Point:

After confirming the suitable location for the lower mounting point, clearly mark this spot as well. Again, use a marking method that is easy to see and reference during the installation process. With both the upper and lower mounting points marked, you can now proceed to the next steps of measuring for the gas strut length and calculating the required strut force.

Remember to take your time during this process and double-check your measurements and markings. Accurate marking of the upper and lower mounting points is crucial for the proper installation and functioning of your new spring struts on your boat hatch.

Frequently asked questions