Active boaters put a lot of miles on their boat trailers - especially during the summer months. A good trailer means safe travels, so it's important to make sure that your trailer, and all of its parts, are durable. The bunks (sometimes called "runners") on your trailer help to properly support the boat and distribute its weight evenly. They're usually carpeted, so over time, the carpet becomes soggy and ragged, which accelerates the rotting of the wooden bunks. In this article, easy-glide vinyl bunk covers called Bunkaps (www.bunkaps.com), supplied by Harley Corp., are installed. 

Step 1
The first step involves inspecting the condition of your existing bunks. Remove the carpet and look for any signs of rot. It's best to start this project with fresh, new bunks. If you invest in new wooden bunks, make sure they're pressure treated. Bunk carpet collects sand that can scratch the hull of your boat, and it also promotes mildew growth, which can accelerate wood rot. Once you remove your existing bunks, use them as a pattern for cutting new ones. Using a measuring tape, measure for the precise location of the bunks on the trailer for optimal use. Try to replace the brackets in the same relative position as they were before. Angle the bunks to conform to your boat's hull and then tighten firmly. Alignment and tightening are critical, so take the time to be precise. Loose bunks won't provide any protection, and if you don't align them properly, your boat will never rest squarely on your trailer. For extra-long life, you may want to consider replacing the old galvanized bunk hardware with stainless-steel nuts and bolts. 

Step 2
Standard lengths for this particular product are 5, 6 or 8 feet. In order to get them to fit properly, you'll most likely have to cut them to size. In this case, the bunks were between 5 and 6 feet long. Using a circular saw (with a fine blade for a smooth edge), cut the vinyl to the right length. You may want to take a small piece of very fine sand paper and smooth the cut end to remove the rough edges. Leave about three quarters of an inch over-hang on each end. This allows for the water to run off away from the wood and prevents the boat from striking the wooden bunk ends when you're floating it onto the trailer. Slip the Bunkaps over each of the bunks tightly. Measure and mark the side screw locations, but don't insert the screws just yet. You'll need about seven screws, placed about 10 inches apart, evenly spaced on each side of the bunk. The number of screws will change depending on the length of your bunks. Once the holes are marked, you're ready to proceed to step three.

Step 3
You can drill the screws directly into the bunks without marking them first, although it's not recommended. At this point, it's best not to cut corners, because most likely you'll end up, at best, with ill-fitting bunks or, at worst, permanently damaged bunks that will force you to start the project over. To prevent the sides of the Bunkaps from wrinkling, take the extra step of pre-drilling the holes using a 1/8-inch drill bit. Once the holes are drilled, then it's time to insert the screws. If you're using a power screwdriver or drill, be extremely careful to limit the output torque. Over-tightening could damage the Bunkaps side panels beyond repair. Use a hand-type screwdriver for final tightening to prevent any breakage. If you should happen to damage a side panel, try using  a stainless-steel flat washer just beneath the screw's head for immediate repair. Remember, additional stainless-steel screws can be added for more strength, if needed. Space added screws evenly and at major stress points, like at the center of the bunk and around the sides.

Step 4
Once you've installed the Bunkaps on your trailer, you may need to re-adjust the bunks to conform to your boat's hull. This may be difficult to do if the boat isn't on the trailer. It's a good idea to put the boat back on the trailer and see if the bunks are sitting flush on the bottom of the hull. If not, don't try to adjust them with the boat on the trailer. Remove the boat and adjust the bunks so that they sit flush between the hull's ribs for best results. One quick suggestion here - if you purposely don't completely tighten the swivel head on the brackets that hold the bunks to the trailer, they'll automatically adjust from the weight of the boat the first time you put it on the trailer after the installation. At this point, you can tighten the brackets (with the boat on the trailer) for a permanent angle and position of the bunks. One final tip from the manufacturer: If your Bunkaps develop a powdery-dry surface or a sticky high frictional surface, then simply apply a liberal amount of baby oil (or similar product) to the surface, and this should help lower the friction.