How to Build a Deck in a Bass Boatby Matt Marsh
If you have your eye on a fancy new bass boat, but can't afford much more than a simple older one, don't fret. One of the most useful features of a bass boat-its high casting deck, with all that storage space underneath- can be added to a cheaper, simpler open boat. You could, of course, just cut a piece of plywood and tack it in. But a solid, well-built and water-resistant deck is well worth the extra effort, adding to the boat's value when it comes time to sell.
Sketch a rough plan for the new deck. Will it be completely flat or will the bow sections be higher up? Will you include storage lockers along the hull sides or in the bilge? What type of fittings do you want to install for chairs, rod holders, live well access, and so on? All of these details should be addressed before buying materials, so that you don't spend more money or time than necessary. If your boat is small and tipsy, the high fore decks seen on larger bass boats might be unsafe. Stick to layouts and deck heights that are reasonable for the size of your boat.
Buy enough half-inch or three-quarter-inch plywood for all the parts of the new deck, and enough epoxy resin and fiberglass cloth to coat both sides of all the deck parts. Marine-grade plywood is best, but in some areas, MDO or AB/AC exterior plywood is good enough. The "boil test" is the proof: if a scrap of the plywood starts to peel apart after an hour or so in boiling water, the glue isn't good enough for use on a boat. You'll also need some one-by-two or two-by-two lumber for stiffeners, edges and corners. If you're going to install commercially built hatches in the deck to get to the storage space underneath, buy the hatch frames and covers now. If you're making your own hatches, buy hinges and latches for them.
Make templates out of cardboard or scrap wood to fit the shape of the section of boat on which your deck will go. Templates may look messy, but they save a lot of work when you're tracing the complex curves of a boat's bow on sheets of plywood. Start with a large piece of cardboard or several tacked-together pieces of thin plywood. Gradually cut or adjust the template until it fits the desired spot. When you're happy with your templates, move them to the plywood sheets and trace themd.
Cut out the deck shapes from the plywood using a circular saw. Cut them a little bit oversize at first--it is easy to trim them down if they don't fit. Test fit each piece in the boat, and trim it a bit at a time until it fits properly. Decks in a bass boat should never be perfectly level: they should slope slightly aft so that water drains into the cockpit instead of pooling on the deck. Bass boats tend to trim stern-down when at rest in the water, so consider both the on-trailer position and the in-water position of your boat when deciding how much to slope the deck.
Coat one side of each plywood sheet with a thin layer of mixed epoxy, and let it soak in for a few minutes. Apply a bit more epoxy, then a layer of fiberglass cloth. Work out any air bubbles from under the cloth, and add a bit more epoxy if necessary to fully wet out any remaining dry spots. Let this cure for a day or so, then flip the plywood sheets and repeat for the other side. Pay particular attention to sealing the edges of the sheet with epoxy. Plywood-edge grain can suck up a lot of water and must be well sealed to prevent rot.
Measure and mark the positions of any seat bases, hatches and other fittings on the deck. Mark the inner hull sides of the boat at the positions where you will attach the cleats that the deck will rest on. In most small boats, two-by-two wooden cleats should suffice, but you might also choose to use aluminum or steel L angles in metal boats.
Cut holes in the plywood deck with a jigsaw for the seat bases, hatches and other fittings. Seal the cut edges with two or three coats of epoxy. Glue two-by-two stiffeners to the underside of the deck with epoxy to reinforce it under heavily loaded areas, such as seat bases or hatch edges. Paint the top of the deck with non-skid paint, or cover it with a non-skid tread material. Carpet is popular in new bass boats, but tends to grow mold and mildew when wet; it is best avoided in favor of waterproof materials.
Affix cleats of two-by-two lumber to the inner hull sides or the stringer tops so that the deck will have something to rest on. Epoxy works well for securing cleats to a fibreglass hull. Mount your seat, rod and hatch fittings to the deck, bedding them with a sealant such as 3M 4200 to keep water out. If you're building your own hatches instead of using commercially made ones, glue a lip of plywood or lumber to the underside of the deck and use the cut-out piece of deck as the hatch cover.
Fit the deck in place, and glue it to the mounting cleats with epoxy. There's often no need to seal the joint between the deck and the hull side; a bit of air flow will help keep the bilge under the deck from growing too much mold and mildew. Boats flex as they travel, and you should only make a fully rigid joint between the deck and the hull sides if you intend for the deck to take some of the hull's structural loads.
- Some practice is needed to do a good job with epoxy and glass. Make a few test pieces out of scrap wood to get the hang of it before you try glassing entire deck panels.
- Epoxy can cause allergic reactions in some people. Wear appropriate protective gear, coveralls and rubber or latex gloves, and a respirator rated for volatile organics.
Items you will need
- Plywood (half-inch to three-quarter-inch, marine grade)
- Epoxy resin and hardener
- Fiberglass cloth
- Deck fittings (seat bases, hatches, etc.)
- Cardboard or scrap plywood
- Circular saw
- Mixing and spreading tools
- "Buehler's Backyard Boatbuilding", George Buehler, 1991
- speed on the water image by Pix by Marti from Fotolia.com