How to Replace Boat Trailer Bunks

Boats, like aircraft, rely on the little things just to survive. A little misplaced rivet, a tiny leaking grommet in the fuel system, even a strip of carpet on the trailer can make the difference between playing Kate Winslet on the Titanic's bow, and playing Leonardo DiCaprio in the Atlantic. The carpeting on your trailer's bunks may seem like kind of a trivial thing, but replacing it periodically is crucial for warding off damage to the underside of the boat. And, for something that requires only a couple of hours every few years, there's no reason not to do it as need be.

Things You'll Need

  • Empty boat trailer
  • Tape measure
  • 2-by-4 or 2-by-6 treated lumber
  • Circular saw
  • Outdoors carpet
  • Utility knife
  • Marine-grade spray adhesive glue
  • Staple gun
  • Socket set
  • Electric drill
  • Drill bit diameter of bolts or lag screws used to secure bunk
  • Bolts or lag screws
  • Remove the boat from the trailer; the easiest way is to simply put the boat in the water and tie it to a dock while you perform the procedure. Measure the size of the bunks that need replacing -- generally, trailer bunks are constructed from pressure-treated 2-by-4 or 2-by-6’s. Measure the length and transfer that measurement to the correct sized board.

  • Cut the board to the proper length using the circular saw. Lay the lumber on a flat surface so you can perform the carpet layout on the board. Lay the outdoors carpet under the board and wrap the board tightly with the carpet. Leave approximately 3 inches of overhang on the ends of the board, so you can wrap the ends.

  • Cut the carpet to the correct width and recheck the fit where the ends of the carpet will match each other end to end. The matching seam should be on the elevated side of the board, not the top or bottom. You'll find it easier to stretch the carpet downward than upward.

  • Refit the carpet over the board, do not cut the overlapping ends for the boards at this time. Remove the carpet from the board and lay the carpet flat, upside down, on a solid surface, and spray both the underside of the carpet and the boards surface with marine glue.

  • Fit the carpet to the board once the glue is cured to a tacky feel. Follow the glue manufacture's instructions as some glues may have to be applied differently. Staple the carpet to the board along the mating seams, and allow the glue to fully cure. This may take approximately one to two hours, depending on the glue.

  • Remove the old bunks from the trailer while the glue cures, and measure the holes for either the bolts or lag screws that hold the bunk to the trailer. Transfer this measurement to the new bunks. Drill the bolt holes in the new bunks using the electric drill and the correct sized drill bit.

  • Cut and fit the end pieces of the overlapping carpet with the end of the boards. You can cut an easy one-sided flap and glue the carpet to the end of the board. Use the staple gun and attach along the seams of the carpet with a few staples. Attach the new bunks to the trailer with the new hardware.