Debunking Your Trailer

Over the last several months, I have had my 16-foot Duffield off its trailer for various projects. It seems the boat spends more time on the stand in my garage than in the water. If you are lucky enough to get your boat in the water more frequently, you should inspect and service your trailer’s bunks routinely. Bunks take a lot of abuse from launching, retrieving (especially motoring onto the trailer) and road vibration. There are only three areas to check: bunks, padding and hardware.

The most difficult part of servicing bunks is getting the boat off the trailer. You can let a boatyard put the boat on a rack or a stand, or get a guest slip at a marina. For my boat, I use a stand with crisscrossed 2-inch-by-4-inch boards to support the bow and a PWC stand to support the stern. You can read about it in “Separation Anxiety” (Boating World Magazine, February 2014).

Eye Eye, Captain
Make a visual note of the configuration of your bunks. Even better, take a picture. Trust me, a picture is worth 1,000 words. Forgetting your bunk configuration will lead to at least that many four-letter words. Next, carefully inspect the entire length of the padding on each bunk, and then remove it to inspect the wood. If the carpet is glued in place, save yourself time and aggravation by replacing the bunks and the carpet. Check each bunk for rot and any type of distortion (e.g., splitting, twisting, warping). Also, check all of the bunks’ hardware for corrosion and damage. I plan to replace all of the hardware this winter when I strip, sandblast and paint the trailer.

My trailer has two 11-foot bunks made with 2x4s. The wood was covered with green indoor/outdoor carpet that was worn, especially on the back third of the bunks (picture 1). Since I could not find the staples in the carpet mess, I cut the carpet with a box cutter and pulled it back until I could find the staples (picture 2). Then I used the pointed end of a paint scraper to pry them out (picture 3). The wood looked OK, but I decided to replace both.

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Decisions, Decisions, Decisions
For padding, you want a material that dries quickly and withstands ultraviolet radiation. Carpet with short fibers (bunk specific, marine grade or indoor/outdoor) is the most commonly used padding. You can use glue, nails, screws or staples to secure the padding. Use a high-quality marine-grade or an indoor/outdoor glue. Use stainless steel or galvanized metal for any other fasteners.

When considering wood for the bunks, do some in-store and online research to determine the best locally available lumber and whether to use treated or untreated lumber. The general online consensus favors pressure-treated fir or southern yellow pine, but also consider local lumber (such as cypress, generally available in the south) that is naturally water resistant and doesn’t have chemicals like pressure-treated wood. In addition to the traditional wood-and-carpet bunks, you can search online to find many alternatives, including Trex, high-density polyethylene and inserts applied over carpet. I decided to do the traditional installation with two 2x4x12 pieces of pressure-treated brown hem fir ($8 each) and a 12-foot-by-6-foot remnant of indoor/outdoor carpet ($20). The carpet is secured with staples, so I can easily replace it or inspect the wood.

Removing a bunk is just a matter of removing all of the screws or bolts that secure it. Note the size and location of each screw, and use the old bunk as a template for the new one. Cut the new one to size and mark the location of the fasteners. Apply a coat of water sealant to any cut areas. Once you have the new bunks ready, you can attach the carpet to them. Mount the carpet with the seams facing downward. If you are using glue, do not apply it too thick, or it will bleed through the carpet. Metal fasteners should be installed on the downward side of the bunks. Once the wood is covered with padding, mount the new bunks using new screws or bolts.

For my bunks, I cut the wood down to 11 feet with a 45-degree angle cut at the back end, for obstruction-free loading. I applied a few coats of leftover water sealant to each bunk. While they were drying, I measured and cut two 13-inch panels of carpet (pictures 4 and 5), which is enough to wrap the 2x4x12s with some overlap (2 inches on two sides plus 4 inches on two sides plus 1-inch overlap equals 13 inches). You can trim the overlap as desired. I secured the carpet with staples and then mounted the new bunks.

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Replacing the padding or, worst-case scenario, replacing the bunks and repadding them is a quick and inexpensive job, and it will go a long way in keeping your boat safely on its trailer and, literally, off the road.

One thought on “Debunking Your Trailer

  1. Never use modern pressure treated lumber on trailer bunks to be used for Aluminum boats. There occurs an electro/chemical reaction to certain chemicals used in the preservation process that will react to the hull and produce accelerated corrosion.


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