Redoing Your Ski Boat's Engine Cover: A Step-By-Step Guide

Redoing the engine cover of a ski boat is a complex process that requires a high level of skill and patience. It involves repairing or replacing the upholstery, which is different from upholstering a car seat or couch. One must first remove the existing fabric and take pictures of the old upholstery from multiple angles for reference. It is important to not cut the skin off, as it may result in staples being left behind. Each piece should be replaced one at a time, and new vinyl upholstery or fabric can be ordered from a company or made oneself. Common tools for installation include seam removers, slip film, a screwdriver, a staple remover, stapler, stainless steel staples, and spray adhesive. Additionally, it is crucial to check the foam and ensure it is still usable, replacing it with new marine-grade foam if necessary. This process requires sewing and stapling, and it is recommended to wait to trim any extra fabric until the installation is nearly complete.

Measure the opening above the engine

Measuring the opening above the engine of your ski boat is a crucial step in redoing the engine cover. Here is a detailed, step-by-step guide on how to do it accurately:

Firstly, it is important to understand the different types of measurements you will be taking. In this case, you will be measuring the width and length of the opening above the engine. These measurements will be used to create a flush or raised engine cover.

Now, gather the necessary tools: a tape measure, a straight edge (for added accuracy), a notebook and pen to record your measurements, and an extra pair of hands to assist you.

With your tools ready, follow these steps:

• Measure the Width: Stand inside the boat and extend the tape measure from left to right at the widest point of the opening above the engine. Ensure the tape measure is straight and level for an accurate reading. Record this measurement.
• Measure the Length: For the length measurement, start at the front of the opening, right where it begins, and extend your tape measure to the back of the opening. Again, ensure the tape measure is straight and level. Record this measurement.
• Deduct for Fiberglass (Flush Cover): If you plan to create a flush engine cover, you will need to deduct 5/8 inch from both the width and length measurements to allow for the fiberglass. These corrected measurements will be used to cut the plywood mold for the fiberglass.
• Add Clearance for a Raised Cover: If you opt for a raised engine cover, you will need to add 1 inch to both the width and length measurements. This addition will allow the bottom edges of the cover to rest on the deck.

By following these steps and taking precise measurements, you will have the dimensions needed to create a well-fitted engine cover for your ski boat. Remember, accurate measurements are essential for a successful project, so take your time and double-check your work.

Cut and prepare plywood

Cutting plywood can be a challenging task, especially if you don't have the right tools. Here are some detailed instructions on how to cut and prepare plywood for redoing an engine cover on a ski boat:

Tools and Materials:

• Plywood: Ensure you have the required size and thickness of plywood for your project. For a ski boat engine cover, you will likely need marine-grade plywood, which is designed to withstand the elements.
• Cutting Tools: You can use a variety of tools to cut plywood, including a circular saw, table saw, jigsaw, or handsaw. Choose the tool that best suits your skill level and the complexity of your cuts.
• Safety Gear: Wear protective gear, such as eye protection, ear protection, and gloves, when cutting plywood. Cutting plywood produces a lot of dust, so consider working in a well-ventilated area or outdoors.
• Guide Track: To ensure straight cuts, it is recommended to use a guide track or a straight edge clamped to the plywood. You can purchase a guide track or create your own using a circular saw and some clamps.
• Measuring Tools: Have a measuring tape, straight edge, and a pencil or marker for marking your cutting lines.
• Sandpaper: Medium-grit sandpaper can be used to smooth the edges of your plywood after cutting.

Cutting and Preparing Plywood:

• Measure Twice, Cut Once: Before making any cuts, carefully measure and mark your cutting lines. Double-check your measurements to ensure accuracy. Remember that the blade width will affect the final size of your plywood piece, so account for the "kerf," which is the width of the blade.
• Choose the Right Blade: Select a sharp blade with a high tooth count to achieve smooth cuts and minimise splintering. For a circular saw, look for a carbide-tipped blade labelled for plywood or "finished cuts."
• Set Up Your Work Area: Prepare a stable and well-supported work area to cut your plywood. You can use sawhorses with long 2x4s or a piece of rigid foam insulation as a cutting surface. Ensure your work area is clean and free of obstructions.
• Cut with the Good Side Down: When using a circular saw, place the plywood with the "good side" facing down. This will help prevent chipping on the finished surface.
• Use a Guide: Attach a straight edge or a guide track to your plywood using clamps. This will help you make straight cuts and minimise errors. Adjust your guide to account for the width of the saw's base plate or shoe.
• Make Your Cuts: Line up your saw with the guide and ensure the blade is aligned with your cut mark. Start the saw before bringing it in contact with the plywood. Cut along the guide, maintaining a steady and consistent speed. Always follow the safety instructions for your power tools.
• Finish the Edges: After cutting, use sandpaper to smooth any rough edges and surfaces. You can also apply painter's tape along the cut line before cutting to help prevent splintering.

Remember to take your time, work safely, and follow the specific instructions provided by the manufacturer of your power tools. With careful measurements and precise cuts, you'll be well on your way to creating a new engine cover for your ski boat!

Apply resin and fiberglass

To apply resin and fibreglass to your ski boat engine cover, you will need a fibreglass kit, a belt sander with medium-grit sandpaper, and a dust mask and safety glasses for protection.

First, measure the width and length of the opening above the engine. Deduct 5/8 inch from each measurement for the fibreglass. Cut a piece of 1/2-inch plywood to these corrected measurements—this will be your fibreglass mould. Use a circular saw or table saw to cut the plywood.

Now, refer to the instructions for your fibreglass kit. Apply three layers of reinforced fibreglass to the surface and sides of the plywood mould. Leave the fibreglass to harden completely, then remove the plywood mould. Sand the rough edges and surface of the fibreglass cover using a belt sander with medium-grit sandpaper. Remember to wear a dust mask and safety glasses during this step.

If you are using epoxy resin, you will need to use some type of glass to prevent the resin from flaking or cracking off. Epoxy resin will hold without glass, but it will crumble over time if the engine cover flexes.

Attach stainless steel butt hinges

To attach stainless steel butt hinges to your ski boat's engine cover, you will need the following materials:

• A pair of stainless steel butt hinges
• A cordless drill with a screw tip attachment
• Stainless steel bolts with flat washers and nuts
• Safety glasses and a dust mask (for protection)

First, measure and cut your engine cover from 3/4-inch marine-grade plywood. You can make a flush or raised cover, depending on your preference. For a flush cover, measure the width and length of the opening above the engine and deduct 5/8 of an inch each way for the fiberglass. For a raised cover, add 1 inch each way to the measurements to allow the bottom edges to rest on the deck.

Once you have your cut-out, it's time to attach the hinges. Position a pair of stainless steel butt hinges along one edge of the cover, ensuring the hinge pins are aligned at the outside edge. It is important to place each hinge 2 inches from the respective end of the cover.

Next, using your drill, create pilot holes at each of the pre-drilled holes in the hinge butts. The size of your pilot holes will depend on the size of the pre-drilled holes in the hinges, so ensure they match.

Now, insert the stainless steel bolts into the pre-drilled holes in the hinge butts and through the pilot holes in the cover. Secure each bolt with a flat washer and nut on the underside of the cover. Tighten these securely with a socket and ratchet.

Finally, finish your engine cover with non-slip deck surfacing for a flush cover, or auto primer and paint for a raised cover.

Your ski boat now has an attached stainless steel butt hinge engine cover!

Install new vinyl upholstery

To install new vinyl upholstery, you will need to first remove the existing boat fabric. Take pictures of the old upholstery from multiple angles for reference. Then, remove the staples, being careful not to damage the foam if you plan on reusing it. Mark or number the fabric with chalk to create a sewing guide for the new pieces.

Next, remove the stitching from the old fabric with a seam ripper or a single-edge razor blade. You will use the old vinyl as a pattern for the new upholstery. Inspect the existing foam and board to determine if they can be reused. Over time, foam loses mass and shrinks, so ensure that any old foam is not collapsed or damaged. If the foam is sagging or water-damaged, it will need to be replaced.

For the marine plywood, check for any signs of peeling or warping. If the laminate has come off or is warped, it should be replaced to prevent water damage to the new upholstery. The new marine plywood should match the existing plywood, and you can use the old material as a template for the new one.

Now, you can lay out your new boat upholstery vinyl with the marked pattern pieces. Try several layouts to make the most efficient use of the new marine vinyl before tracing and cutting out the patterns. After you have cut out the patterns, you can start sewing. Use an industrial sewing machine to handle the heavy boat upholstery vinyl, and very heavy industrial-grade bonded polyester thread to hold the pieces together.

Once your boat seat cover is sewn, lay it over the foam and plywood base. Secure the material in the correct position using a staple gun, starting with the corners to tighten any slack. Then, continue stapling with a staple every 1" across each side. Trim any excess vinyl to within 1/4" of the staples.

Finally, use cushion underlining to cover the exposed underside wood and trimmed vinyl edge. Staple the cushion underlining with staples every 1", getting as close to the staples as possible but no less than 1/8". Finish off the underside with matching Hidem welt trim, placing your staples between the two vinyl flaps on the Hidem.

Frequently asked questions