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How To Refurbish An Old Boat Trailer

If your trailer is past its prime, it may be time for refurbishment. You may be able to do most of the work yourself and save money in the process.

Old trailer bars closeup

The finished result replete with new bunks, lights, wheels, and fenders.

If you're like many BoatUS Members, you like DIY projects, especially those where the rewards are satisfying to look at — not to mention the savings. Boat trailers are excellent candidates for DIY refurbishment, made all the more attractive after you recover from the sticker shock of a comparable new model.

Assessing Your Trailer

Is your trailer a candidate for refurbishing? Not if the frame is nearly rusted out, for sure. But if, after looking at it closely, the frame is still solid, then you have "good bones" from which to start. Just about everything else (springs and axle, hubs, fenders, wheels and tires, bunk supports and bunks, wiring, rollers, winch, jack and coupler, and safety chains) can be effectively replaced as my wife Laura and I discovered when we looked over our vintage 1978 trailer that carried an aluminum skiff.

Tip

If structural repairs or changes are required that you don't have the skill, confidence, or time to complete yourself, consult an expert.

Be especially careful in your inspection if your trailer's seen saltwater in its lifetime or if you've used acidic hull cleaners. Trailers subjected to these elements typically have significant rust-through and the frame can be very weak. If in doubt, bring it to a trailer shop to have an expert give it the once-over. It's worth the hassle and expense because it just might save you from a catastrophic failure while towing, or at the very least, save you from wasting money and time on a basket case.

For this article, we refurbished a generic galvanized skiff trailer. The old winch was rusty, the frame was showing some minor signs of surface corrosion, the wooden bunks were rotting, and the lights didn't work consistently. A new single axle trailer was priced at just over $1,200, so I knew that a little time and effort would translate to significant savings.

Tech Support

Difficulty: Moderate

Materials:

  • Light and wiring kit: $60
  • Winch and strap: $75
  • Tongue jack: $30
  • Bunks and carpet: $100
  • Safety chains and hooks: $25
  • Hardware, glue, staples: $100
  • Cold galvanize paint: $10

Cost: Will vary, depending trailer size and its condition, the running gear was already in decent shape, so my total was about $400.

Note: This job will differ with each trailer and its good and bad parts. Some of the tools you may need, depending on the trailer, include angle grinder, impact wrench, anti-seize penetrating oil, wrenches, Dremel tool, electric drill and assorted bits, screwdrivers, crowbar, bottle jack or other type of jack, electric and hand wire brush, hack saw, volt/ohm/meter, and a good staple gun.

Getting Started

"How do you get the boat off?" is a common question, and it can be as easy or as complicated as you make it. The size, weight, and type of boat will have a bearing on how easy — or difficult — it is to remove it from the trailer. In my case, the boat was small and lightweight so I was able to pick a good spot in our yard, tilt the boat nose-high, and secure the boat while I pulled the trailer out from under it. If you don';t want the boat sitting on the ground, block it up carefully so that it’s supported at the transom corners and along the keel.

On a previous occasion with a larger and heavier boat, I built a temporary cradle from treated pine to hold the boat while I rerigged the boat and rebuilt the trailer.

Stripping The Trailer

With the trailer free of the boat, strip all components from it and make a list of what you'll replace. With today's smartphones, it's easy to make a digital photo record of everything you remove, so putting it back together won’t be a puzzle. In addition to taking photos, take measurements of where things like the axle, winch, bunks, or rollers, and any spare tire may go.

For this project, I wanted to get the trailer back to just the frame and start from there. I removed the old rotten wooden bunks, the very rusty winch, the lights, and safety chains. I also removed the axle, springs, and wheel/tire assemblies so that I could properly inspect them for wear and corrosion. The added benefit was that with these components removed, the bare trailer frame was much lighter and easier to handle. I was able to singlehandedly flip the trailer to check the underside, something that would have been impossible with the wheels, springs, and axle in place.

Time For Paint

Much of the galvanized coating was in good condition, and the main structural members, I was pleased to note, were all in sound condition. A thorough wire brushing to remove surface rust and scale was pretty easy, though messy and time-consuming. I followed this with a good acetone wipe to clean the surface and prepare it for me to spray cold galvanize paint on all the exposed areas. Some components, especially around the bunk mounts and light brackets, were pretty corroded and required cutting off with an angle grinder.

Putting It All Back Together

Reassembly of the trailer was straightforward and quick. I measured for the new bunks using the old ones as templates. Then I cut them from treated pine 2-by-6 boards and covered them with new carpet, which I glued with contact cement and stapled with stainless steel staples on the underside. To reattach bunks and other components, I used Grade 5 galvanized steel bolts and washers and Nylock locking nuts to eliminate rusting and rattling loose. With the new bunks and winch in place, I wired the trailer with new LED lights and wiring kit, taking care to use grommets and other insulating material where the wiring insulation might chafe. After reinstalling the fiberglass fenders with new stainless bolts, we were ready to winch the boat back onto its trailer. That’s the easy part — just back up to the boat, detach the trailer from the vehicle, hook up the winch strap and carefully winch the trailer under the boat. With a couple of helpers to ensure it goes steadily, the process is much easier than it sounds.

1. Many lighting kits come with these squeeze Scotch-Lok type of wiring connectors that don't stand up to regular dunking. Use waterproof crimp connections instead:

Lighting kit closeup


2. The old trailer was in a sorry state. One of the first jobs was removing the old trailer bunks:

Removing old trailer bunks


3. The dirtiest part of the job was removing the old rust prior to refinishing:

Removing rust

4. To protect the light wiring from chafe and keep everything neat, I used these clips, which require no drilling or alterations to the trailer:

Protecting wiring with clip

5. In addition to the bunks themselves I replaced the severely corroded support brackets:

Corroded bracket

6. I attached waterproof carpet to the bunks using contact cement and stainless steel staples:

Attaching waterproff carpet to bunks

Hit The Road

Before hitting the road, double check all your work, make sure all bolts are tight, and bunks or rollers are well secured. If there is any possible issue, have a professional shop check it. Your trailer will probably be seeing highway duty, so it must be in good condition. In some states you may need to have your trailer inspected, so check with your local Department of Motor Vehicles for regulations in your area. Often smaller trailers without brakes have less stringent requirements than larger twin- and triple-axle trailers capable of carrying heavy boats, but it always pays to check.

John Tiger

John Tiger is a freelance boating writer and frequent contributor to many magazines.