How to Enclose a Pontoon

Enclosing a Styrofoam pontoon is a necessary step in producing a pontoon that will resist leaks and water-logging. Aluminum pontoons do not need to be enclosed or sealed. They are drained and welded, or filled with sprayed foam, and do not need an enclosure. Styrofoam pontoons, on the other hand, are highly susceptible to leaking and becoming corrupt and water-logged. A double-sealed wrap of marine-grade vinyl lasts for years and prevents leakage and minor damage, as well.

Things You'll Need

  • Marine-grade vinyl sheeting
  • Heavy shears
  • Vinyl-to-vinyl epoxy
  • 840-degree heat strip
  • Sawhorses
  • Straightedge
  • Permanent marker
  • 1 ½-inch pine wood lath
  • Paint brush
  • 1/16-by-1/2-inch steel strapping
  • Steel strapping tension tool
  • 2-by-4 common lumber
  • Tin snips
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Instructions

    • 1

      Perform a test-seal operation before beginning the actual pontoon enclosure. Cut a 12-inch test piece of marine-grade vinyl sheeting. Apply a liberal amount of vinyl-to-vinyl epoxy along a 1-inch strip on one edge. Fold back the opposite edge, double it in on itself and press it down on the glued strip. Lubricate the action surface of a heat strip with vegetable oil and place it down on the folded edge. Start at 300 degrees for one minute and allow the weld to cool for one hour. Test the weld by trying to pull the welded fold-over piece away from the glued edge. It should not separate. Adjust the temperature and time until an optimum weld results without melting the fabric.

    • 2

      Mount the pontoon on a work surface or pair of sawhorses.

    • 3

      Measure and cut a single strip of marine-grade vinyl sheeting longer than the pontoon and sufficiently wide so as to enclose its circumference by 120 percent. This provides sufficient wrap-around for the vinyl material.

    • 4

      Position the vinyl material laterally under the pontoon so that the end of the wrapped strip of vinyl is on top of the pontoon. This is the surface that will be touching the underside of the boat. Use a straightedge to mark the line where the surfaces will be bonded.

    • 5

      Lay a piece of 1 1/2-inch wood lath on the edge of the vinyl that is to be folded. Apply a thin coat of rubber cement to the upper surface of the lath. Pull the vinyl fabric back over the lath with a 1-inch strip of fabric hanging over and past the lath. Apply a liberal amount of vinyl-to-vinyl epoxy to the strip of vinyl fabric that is covering the lath. Starting at one end, work along the edge of the vinyl material, folding the edge back onto the epoxy glued surface that is over the lath. Apply a liberal amount of vinyl-to-vinyl epoxy to the third surface -- the bare upper surface of the folded sandwich.

    • 6

      Use a paint brush to spread a liberal amount of vinyl-to-vinyl epoxy in a 6-inch wide band that is 3 inches above and below the bonding line previously drawn.

    • 7

      Pull 1/16-by-1/2-inch steel strapping bands under the pontoon. They should be positioned every foot along the length of the pontoon.

    • 8

      Pull the glued lath over the pontoon and stick it near the lower end of the 6-inch-wide strip of applied epoxy. Work along the length of the lath until it is parallel with the long axis of the pontoon.

    • 9

      Use a steel strapping tension tool to pull the vinyl material tight and hold it there through the epoxy/heat-seal operation. Lay a 2-by-4 atop the lath and place heavy weights (concrete blocks or stacks of bricks) on top of the 2-by-4 and allow it to seal for one hour.

    • 10

      Cut the steel strapping with tin snips and pull off the lath (it was temporarily glued with rubber cement for easy removal). Use the heat strip in overlapping iterations to heat-seal the glued surface. Do a corner fold and cut the ends of the vinyl material. Wrap end pieces cut to fit the pontoon end and epoxy and heat weld them as before.