How to Build a Transom Hatch for a Bass Boat

Boats without transoms create a larger risk of loss.

The transom, the flat back panel of a boat, prevents water from entering the hull of the boat. Transoms also hold inboard motors and major wiring components. A hatch can be installed in a transom so access can be gained when maintenance needs to be performed.

Things You'll Need

• Safety glasses
• Work overalls
• Measuring tape
• Permanent marker
• Masking tape
• Circular saw
• Carbide-tipped saw blade
• 1-inch plywood
• Bucket
• Stir stick
• Water
• Epoxy resin
• Epoxy hardener
• Epoxy brush
• Fiberglass cloth
• Scissors
• Duct tape
• Plastic roller
• Sandpaper
• Drill
• Carbide drill bit
• Screwdriver
• 2-inch machine screws - 16
• 2-inch hinge - 2
• Hasp
• Waterproof foam tape

Instructions

1. Put on your safety glasses and work overalls.

2. Locate the area on the transom where you want the hatch to be located. Determine the thickness of the fiberglass. Draw an outline of the hatch on the transom using the straight edge of the measuring tape or a ruler.

3. Examine the transom to make sure there are no wires or support beams in your proposed location. If these components are present, adjust the position and size of the hatch.

4. Line the inside and outside of the marked area with masking tape. This will prevent the fiberglass from cracking during the cutting process.

5. Place a carbide-tipped saw blade in a circular saw. Adjust the saw blade so that it cuts slightly deeper than the thickness of the fiberglass. Cut out the marked area. Sand the edges with sandpaper until smooth. Discard the piece you just removed.

6. Measure the length and width of the hatch. Add 1 inch to both measurements. Measure, mark and cut a corresponding piece of 1-inch plywood.

7. Mix the epoxy resin and epoxy hardener according to the manufacturer's specifications. Place the resin in a bucket.

8. Coat the piece of plywood with a thin coat of resin using a paint brush or paint roller.

9. Measure, mark and cut multiple strips of fiberglass cloth that are 2 inches longer than the width of the plywood piece.

10. Lay strips of fiberglass over the width of the board. Fold the edges down flush against the sides of the board. Overlap the edges of the strips by 1/2 inch. Coat the strips with a coat of resin until the strips are saturated.

11. Run a plastic roller over the entire surface of the board. Smooth out any wrinkles or air bubbles. Allow the resin to dry. Sand the resin until smooth.

12. Apply three more coats of resin to the surface. Allow each layer to dry and sand until smooth.

13. Flip the board over and repeat Steps 8 through 12 to cover the board completely in fiberglass.

14. Run a strip of waterproof foam tape around the exterior of one side of the hatch. Position the hatch above the hole in the transom.

15. Position a hinge at the top and bottom of the left side of the hatch. Position a hasp at the middle point on the right side of the hatch. Mark the mounting holes on the fiberglass. Place all the materials to the side.

16. Insert a carbide tip in the drill. Drill through the mounting hole markings on the transom and transom hatch.

17. Line the bottom of each hinge and hasp with waterproof foam tape. Replace all of the parts. Secure the pieces together using screws.

Tips & Warnings

• The transom hatch can be painted to match the transom.

References

• Transom Fix: Dan's I/O Boat Transom Repair Adventures
• Yacht Survey: How to Keep Your Boat From Sinking
• Waterproofing the Transom Wood and Laying the First Piece of Fiberglass