How to Build a Pontoon Boat

The design of a pontoon boat – also regarded as a party barge, is quite an inexpensive build compared to other boat designs. It comes with a sophisticated form of shallow draft that reduces its risk of submerging. This, indeed, is the reason why a number of big vessels are equipped with pontoon boats for emergency situations. In the United States, pontoon boats are popular for serving as rental boats to ferry people across rivers. Moreover, their user-friendly structure and maneuverability through most water bodies label pontoon boats an ideal fishing-cum-sightseeing vessel.
Before Building the Boat
Building a pontoon boat is not tough, though it is not easy as pie. It, certainly involves work, and an elementary degree of understanding the mechanics of assembling the boat. The basic structure of a home-built pontoon boat is like a catamaran or a trimaran boat, where the platform is used as a dock. All one needs is quality material, a blueprint of the boat, and undoubtedly, hard work.
Three Points to Remember
Design
Sketch out a concrete plan for the boat. There are small-, medium-, and large-sized cruisers that one may build; however, considering that you are a novice, we begin with a small-sized pontoon boat with just the basic, absolutely necessary design.
Location
Prefer a location that is close to the waterfront and where your boat-in-the-making may be moored safely.
Material
While building the boat, ensure you choose the right kind of material. Some may suggest using PVC pipes for pontoons; however, aluminum pontoons are always advisable for use. Aluminum is sturdier; a hydrodynamically sound metal that promises safety and serves you for long.
As far as the material-buying activity is concerned, stores dedicated to boating material ought to have the hardware. To make the task easier, frequent boating departments lined near water bodies. If you are a regular at scanning online stores, punch in the name of the hardware or material that will be required in the search bar, review, and add it to your cart! You may visit their forums, read reviews on products, take a look at their ratings, scour the details of the material, and finally get to the cash counter once you are thoroughly satisfied. For those who think online it is, a word of caution: Document your purchases. See to it that you receive what you order
Material for Building a Pontoon Boat
Frame Hardware
~ 2 Rows of Aluminum Pontoons (type 5052 H32 aluminum; the rows being 12′-0″ each, 36” in diameter)
~ 10 Aluminum Hat Cross-channels (6′-0” cross-channels extending from one pontoon to the other, each measuring 2.5″ thick and 4″ wide)
~ Boat trim (2” x 4” for a 6′ x 12′ cruiser)
~ Stainless Stern and Bow Trim Corner Caps (4½” high and 4¼” wide)
~ For Anodized Aluminum Tube Railings (24” high and 1½” diameter)
~ 4 Railing Corner Caps (3” thick)
~ 4 Aluminum Braces (10” high)
~ 10 Pontoon Rail Risers (⅜” thick)
~ 2 Hinges for the Gate (9” in length and 2” wide)
~ For Plywood Decking
~ 3 sheets of 7-Ply, ¾” Plywood Decking (for a deck that is 6′ x 12′)
~ ¾” plastic slip-proof vinyl carpet
Enhancers
~ 1 Seat (with swivel and an adjustable pedestal)
~ 6 Webbing Attachment Straps (1” thick)
~ A Pair of Sidelights
~ 2 Pontoon Fenders
~ 2 – 4 Deck Cleats
~ Trolling Motor
~ Prefabricated Foldable Deck Ladder (A 4-step ladder would be just fine)
Fastening Material
~ Epoxy resin (2 gallons), screw gun, hammer, Cordless drill with ⅛” drill bit
~ Marine Carpet Glue (2 gallons)
~ Jacks
~ Pontoon Deck Joint Tape (50′-0” long roll, 2″ wide)
~ 3½” Stainless Fence Bolts (A pack of 32)
~ 1½” Stainless Deck Bolts (A pack of 100)
~ U-shaped Trowel (⅛” thick)
~ 80-grit sandpaper
~ 1 Foam Brush (2” wide)
Procedure for Building a Pontoon Boat

Illustrative sketch of a patch of the deck of the pontoon boat
Aluminum Pontoons
Parallel the two rows of aluminum pontoons on a flat surface. The internal distance between the two, when placed, should be 3′. The pontoons must be fabricated with type 5052 H32 aluminum. This aluminum/magnesium alloy displays resilience to corrosion, courtesy of the moisture that the metal comes in contact with.
Aluminum Hat Cross-channels
The two rows of pontoons must then be connected with the aluminum hat cross-channels 18” center to center. The adjacent gap between every cross-channel should be 18”. Cross-channels reinforce the pontoons for enhanced support and reliability.
Plywood Decking
Remember: Your marine-grade plywood has to be sanded and sealed before installation. You are to use a 7-Ply ¾” marine-grade ply. In accordance with its thickness and consistency of layers, seal the plywood. Saw the plywood sheets according to the size you desire for your boat deck, and place it on the cross-channels.
Drill holes through the plywood and cross-channels for 1½” stainless deck bolts, every 12” across the deck. Don’t fasten the bolts yet. Now, sand the plywood surface and its edges with 80-grit sandpaper. Dust the plywood post sanding. Using a 2” wide foam brush, seal one side and the edges of the marine-grade plywood with epoxy. Let it dry completely to switch over to the other side of the ply.
Repeat this process 5 to 7 times to save your deck from premature deterioration and warping. Needless to mention, this process would consume a considerable amount of time. Once the sealing process is complete, run a strip of joint tape on each cross-channel.
Install the plywood decking over the joint tape to secure it to the cross-channels. Fasten the deck to the cross-channels with 1½” stainless deck bolts. Fill the peripheries of the fasteners (bolts) with epoxy resin, wherever necessary.
Now, apply a ¾” plastic slip-proof vinyl carpet with marine carpet glue on the plywood. This, sure, would do a good turn to your deck as this would prevent slippage. You must consult a fabricator before carpeting, to check whether the carpet should be laid before, or after the aluminum tube railings are installed.
To camouflage the raw edges of the ply, carpet, and the cross-channels, a boat trim is applied to refine the look of the deck. Attach the trim to all four sides of the boat. Use trims that are inherently equipped with bumpers and grab handles.
Consult a fabricator to ready the aluminum railings for your boat. Ideally, the components mentioned in this section should be attached to the tube railing. However, the fabricator may have a different take on the said issue and may suggest another feasible way to construct the railing and boosting its reliability. Consider his inputs, as well.
Anodized Aluminum Tube Railings
The fabricator will measure your deck, and accordingly construct the anodized railing for the boat. An anodized railing promises strength and longevity, thereby appearing well-groomed in the bargain. With regard to the positioning of the railing, a 2′-0” distance from the rear and front end of the boat, respectively, should be maintained. Thus, your railing will span 8′-0” of the total 12′-0” of the plywood decking.
Rail Risers
To span the life of the fence railing, as well as the vinyl-boosted ply, rail risers are used. The risers are U-shaped with circular edges. They are positioned in a way that the circular edges, seat the base of the rail, and the U-shaped depression encircles the 3½” stainless fence bolt. Preferably, 5 rail risers across the length and 2 across the width of the pontoon deck are installed.
Aluminum Braces
Your boat’s rail is braced with aluminum braces to provide the much-required support to your rails. It nullifies the probability of rattling. The brace is then drilled and fastened with bolts onto the railing and through the deck.
Railing Corner Caps
Railing corner caps are used to strengthen the dimensions of the railing. The radius cap is drilled through and bolted down to the deck. In the meantime, until the railing is ready to be installed, you may work toward assembling the rest of the hardware and enhancers.
Webbing Attachment Straps
Use three webbing attachment straps on both the pontoons to provide your cruiser with an enhanced hold. A 1” wide strap must embrace the pontoons through their circumferential surface extending through the cross-channels on to the deck. Fasten the strap with epoxy resin, followed by drilling 1½” stainless deck bolts for a sustainable and solid grip.
Deck Cleats
They provide deck support and facilitate an easy way to slip a tie-down through two holes at the base. For all those keen fishermen and women, cleats come in handy. Just slip the fishing line through the holes at the base of the cleat, with a bobber attached to fetch a catch!
Attach deck cleats on all four sides of the deck with the help of stainless pontoon deck bolts. You may leave out the stern (rear) corners of the boat, and attach the cleats at the corners of the bow (front section) of the deck only.
Sidelights
To increase the quality of visibility for navigation during the dark hours, install sidelights at the front corners of the deck. However, do not place the pair at the edge. Space the sidelight 1′-0″ away from the deck corner. Sidelights are a must as they are proven aids to navigation.
Trolling Motor
Install the trolling motor; it would adhere to the outboard setup of the pontoon boat. The trolling motor is installed at the stern (rear) of the boat. Just use the hand-held remote controller to start the motor, and maneuver the boat.
Mount a seat amidships (in/toward the center) of the boat. To redefine comfort on board, choose a chair with armrests and an adjustable backrest. A swivel and an adjustable pedestal ought to be a part of the seating package in order to cruise in comfort.
Pontoon Fender
Knot the hanger string of the pontoon fender to the topmost rail. Position the fender in a way that its string length extends through the deck to the pontoon rows. Fenders are an important inclusion to the boat design, as they keep the aluminum railings from damage when docking. They serve as cushions that brave the docking impact while mooring the pontoon boat.
Foldable Deck Ladder
Hinge a foldable deck ladder to the hat cross-channels with the help of 1½” stainless deck bolts. You needn’t worry about the storage of the ladder. When not in use, it may be pushed backwards to the frame of the pontoon.
Important!
This small-sized cruiser capacitates for 3 to 4 individuals. Burdening the boat with more than the number mentioned may hamper the buoyancy of the boat. The illustration shows only a patch of the deck being covered with ¾” plastic slip-proof vinyl carpet; however, the deck is to be carpeted completely. This approach is used purely for illustrative purposes.
Make sure you adhere to all the safety regulations. Stock an essential pack of gear, such as life jackets, throwback rubber rings, ropes, whistle, and a bell aboard. A light-duty pontoon trailer would tow the boat into the water. However, practice is an absolute must, when you are keen to perfect your skill of plowing your pontoon boat through the waters with considerable ease. Prefer having a mate accompany you to help draft the pontoon boat. Have someone guide your movements. To wrap it up, you may be a bravado at heart, but when it comes to casting the pontoon boat, assistance, indeed, is insisted!

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