Repairing Inflatable Boat Transoms: A Step-By-Step Guide

Repairing the transom on an inflatable boat is a manageable task for the DIY-inclined. The transom, which is often made of plywood or aluminium, can be used to mount trolling motors, strap down gear, or hold on to while speeding through the water. Over time, the transom may break, rot, rust, or come unglued from the boat. In most cases, you will need to remove and replace the transom. This involves softening the glue with heat or a solvent, cleaning the seams, applying PVC glue, and securing the new transom with ratchet straps. For a strong bond, it is crucial to ensure that all surfaces are clean, dry, and free of moisture and debris before gluing. Additionally, using the correct type of glue for your boat material, such as PVC or Hypalon, is essential for a successful repair.

Removing the transom

Before removing the transom, ensure your boat is completely dry. You don't want to attempt this repair right after taking your boat out of the water.

To remove the transom, you will need to apply low levels of heat over the seams where it is mounted to the boat. Typically, the transom will be glued in place, so the purpose of the heat is to soften the glue enough to separate the transom. Be careful not to use heat that is too intense, as this may damage the PVC seams and the inflatable boat chambers. An alternative to heat is to use a methyl-ethyl solvent to soften the glue.

Once the glue is softened, gently pry or wiggle the transom back and forth to loosen and separate it from the seams. If the transom is severely damaged and breaks during removal, you may need to continue applying heat or solvent to loosen the remaining glued sections. Be careful not to damage the PVC seams during this process.

After removing the transom, clean the old glue and any dust or debris from the seams. You can use a solvent to remove stubborn glue residue and a cloth or vacuum to wipe away debris. Ensure that the seams are completely clean and dry before proceeding with the next steps.

If your transom is made of wood, such as marine plywood, and has rotted, you will need to create a new transom. To do this, glue together sheets of marine-grade plywood to achieve the required thickness. For example, you can glue three sheets of 9mm marine ply to create a transom with a thickness of 27mm. Ensure that the glue you use is suitable for bonding wood, such as epoxy resin.

If your inflatable boat is made of PVC, you will need to prime the new wooden transom with a single-part Hypalon adhesive before final fixing with a PVC two-part adhesive. This is because PVC adhesive does not stick to wood, but Hypalon adhesive will. Allow the Hypalon adhesive to dry completely before applying the PVC adhesive.

For boats made of Hypalon, ensure you use the correct two-part Hypalon adhesive for all gluing processes.

Cleaning the seams

Before gluing the seams of your inflatable boat's transom, it is important to clean them thoroughly to ensure a strong bond. Here are the steps you should follow:

• Remove Old Glue: Use a power tool, such as a heat gun or a solvent, to remove any old glue or adhesive residue from the seams and transom. Be careful not to damage the PVC seams during this process.
• Clean the Surfaces: Once the old glue is removed, clean the seams and transom surfaces with a solvent such as MEK (methyl ethyl ketone) or acetone. This step is crucial to preparing the surfaces for the new adhesive.
• Dry the Surfaces: Ensure that both the seams and the transom are completely dry before attempting to glue them together. It is recommended to work in a low-humidity environment to avoid moisture affecting the adhesion.
• Prepare the Transom: If your transom is made of wood, such as marine plywood, you may need to prime it with a suitable adhesive. For example, if you are using PVC adhesive, prime the wood with a thin layer of Hypalon adhesive first, as PVC adhesive does not stick to wood.
• Masking (Optional): To ensure a neat finish, you may want to mask off the repair area to avoid excess glue creating an unsightly mess.

By following these steps, you will effectively clean the seams of your inflatable boat's transom, creating a strong and lasting bond when you glue the new transom in place.

Applying glue to the seams

When applying glue to the seams of your inflatable boat, it is important to follow the correct procedure to ensure a strong and long-lasting bond. Here is a step-by-step guide to help you through the process:

Prepare the Surfaces

Before you begin gluing, it is crucial to ensure that the surfaces are clean and free of any dirt, salt, moisture, or foreign objects. Use a stiff brush and a 50/50 acetone/MEK (methyl ethyl ketone) solvent mix to scrub the area. You can also use MEK to wipe down the surfaces, as it softens the surface and aids bonding. If there is any old glue residue, remove it by sanding the area gently. Be careful not to sand too deeply, as the new glue may not adhere well to the mesh reinforcement within the PVC fabric.

Choose the Right Glue

The type of glue you use will depend on the material of your boat, which is usually either Hypalon or PVC. Hypalon is a more rubber-based material that dulls and can become chalky over time. It often has a rubbery smell. On the other hand, PVC retains a sheen and is more "plasticky." It is important to use the correct two-part glue for the material of your boat.

Apply the Glue

The glue application process typically involves two coats. First, mix the two parts of the glue according to the manufacturer's instructions. Then, apply a thin, even layer of glue to both surfaces that will be joined. Allow the glue to dry for up to an hour, or until it is dry to the touch. Apply a second thin coat of glue to both surfaces, which will activate the first coat. Wait for about 5 minutes, and then bring the surfaces together.

Join the Surfaces

Joining the glued surfaces is a critical step that needs to be done correctly. Mark all the components and plan the process during a dry run without glue. Ensure that the surfaces are oriented correctly and do not touch prematurely. Once you are ready, firmly press the surfaces together, removing any air bubbles with a roller or a smooth tool. Any excess glue can be wiped off, and the joint should be left to dry according to the manufacturer's instructions.

Additional Tips

• Work in a clean, dry environment with good ventilation.
• Perform a "stand-up in the middle and jump about" test, as suggested by Jake Frith, to check the strength of your repair.
• If you are regluing a transom, ensure the boat is completely dry before starting.
• When removing old glue, you can use a methyl-ethyl solvent or low levels of heat. Be cautious not to damage the PVC seams or chambers.
• For gluing wood to PVC, you can prime the wood with a single-part Hypalon adhesive, as PVC adhesive does not stick to wood.

Setting the new transom

Step 1: Prepare the Transom and Boat Surfaces

Before gluing the new transom, it is crucial to ensure that both the transom and the boat surfaces are clean and dry. Use a solvent or a power tool to remove any old glue, dust, or debris from the transom and the boat seams. This step is essential to ensure a strong bond between the transom and the boat.

Step 2: Prime the Transom

If your transom is made of wood, you will need to prime it with a suitable adhesive. For example, if your boat is made of PVC, you will need to use a single-part Hypalon Adhesive to prime the wood so that the PVC adhesive will stick to it. Allow the primer to dry completely before proceeding to the next step.

Step 3: Apply PVC Adhesive

Once the primer is dry, apply a thin layer of PVC adhesive to both the transom and the boat seams. Make sure to follow the manufacturer's instructions for the best results. Allow the adhesive to dry for about an hour or the recommended time by the manufacturer.

Step 4: Activate the Adhesive

After the first coat of adhesive has dried, apply a second thin coat to both surfaces. This second coat will activate the first coat and prepare the surfaces for bonding. Wait about five minutes for the adhesive to become tacky.

Step 5: Join the Transom and Boat Seams

Bring the transom and boat seams together, pressing firmly to remove any air bubbles. Use clamps or ratchet straps to secure the transom in place and ensure a strong bond. Make sure to follow the glue manufacturer's instructions for curing time.

Step 6: Finalize the Repair

Once the glue has cured, remove any excess adhesive and clean up the area. Inflate the chambers and use ratchet straps to press the sides firmly against the transom if needed. Allow the glue to dry completely before using the boat.

Remember to work in a well-ventilated area and follow all safety precautions when working with adhesives and solvents. With these steps, you can successfully set a new transom on your inflatable boat, ensuring a strong and durable bond.

Allowing the glue to dry

It is important to follow the manufacturer's instructions for the specific glue you are using, as the drying and curing times can vary. In general, it is recommended to allow the glue to dry in a clean, dry environment, as dirt, salt, moisture, or other foreign substances can affect the strength of the adhesive bond.

During the drying process, it is crucial to ensure that the repaired area is not disturbed or touched, as the glue is not repositionable. Any necessary clamping or strapping should be done carefully to ensure the transom is secured in place until the glue has fully cured.

Additionally, it is worth noting that the boat should not be used until the glue has completely dried and cured. This may take several hours or even days, depending on the adhesive used. It is essential to follow the manufacturer's instructions and recommendations to ensure the repair is successful and the transom is securely attached to the boat.

Frequently asked questions