How to Build an Aluminum Pontoon

The integrity of an aluminum pontoon is crucial to the safety and operation of any boat. If pontoons leak, they will send a boat to the bottom. For this reason, pontoons are sectioned into series of bulkheads. Bulkheads prevent an entire pontoon from filling with water if it develops a hole. For the most part, pontoons are a commercial business. It's almost impossible for an individual to fabricate round nose cones and cylinders to build a pontoon. But if you order parts for one, you can build your own pontoon the size you want with a MIG welder.

Things You'll Need

  • 4 prefabricated 5052 x .080 capped-off sections of aluminum pipe, 36-inch diameter, 24-inches in length
  • 2 prefabricated 5052 x .080 aluminum nose cones, 36-inch diameter
  • 3 clamps, 120-inches
  • Rubber mallet
  • MIG wire feed welder
  • Hand grinder
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Instructions

    • 1

      Assemble all four sections of aluminum pipe sections flat on the ground in any order.

    • 2

      Place three clamps down the length of the sections. Roll the sections slightly to get the clamps spaced evenly down the length of the pipe.

    • 3

      Tap the joints of all the sections with a rubber mallet so that they all fit together flush and evenly. If there is a gap over 1/8 inch between the sections after clamping, remove the clamps and use a hand-held grinder to remove any bumps or high places in the welds, then place them back together in the clamps. Repeat as necessary until all four sections fit together snugly.

    • 4

      Weld the sections together with an MIG welder. As you weld around the circumference of the pontoon, roll the pipe slightly to get access to the bottom of the pipe. Don't remove the clamps until you have welded all the way around each section. Remove the clamps and finish by welding the places under the clamps that you couldn't reach before.

    • 5

      Place the nose cones on the pipe. Lay them flat on their sides. You won't be able to clamp them on because of their shape. Just fit the cones on the pipe as tight as possible. Weld a single spot of weld in one place on top to secure the cones to the pipe. Roll the pontoon over very gently and weld another spot opposite the first one. Do this to both cones.

    • 6

      Weld around the circumference of the cones to secure them to the pipe to finish.