Make a Pair of Bunk Glides for Your Boat Trailer




About: When I was a boy, I was amazed how my grandfather could make flotsam and jetsam into useful things. I am proud that I have inherited some of his skill.

Trying to launch my 18' boat has always been a strain. It would be easier if my trailer had rollers, which it doesn't - it has carpeted bunks. It's all I can do to push the 1400 pound boat and motor combination, especially when I'm perched on top of the trailer tongue, trying to keep my feet dry.

Then again, I have heard several people talk about the potential corrosion my boat can incur from the aluminum hull sitting on carpet, wet with salt water and wrapped around pressure treated wood. I haven't seen any damage, but the boat is new and I'm not crazy about the idea of it happening.

I looked at several different bunk glide products, but realized I would have around 100 bucks in it by the time I was done. There had to be a better, and cheaper, idea. One I could build instead of buy.

Step 1: PVC Is Slippery

PVC may not be quite as slippery as nylon, but while looking at a piece of 1x4" PVC trim board, it occurred to me that it would still make a good bunk glide: it is easy to work, thick enough to countersink the screw heads, and best of all, would provide little friction when I was either launching or pulling the boat out of the water.

I bought a piece of the trim board and twenty 1 1/2" stainless steel screws at my local building supply yard. That's all I needed, and at $30 dollars, it was considerably cheaper than any commercially made bunk glides I had seen.

The piece of PVC trim I bought was 18' long and the bunks on my trailer are about 7' each, so first I cut it to length. Then I cut a slight bevel on the front end of the pieces and lopped the top corner off the rear ends. I then sanded both cuts, making the rear into a rounded bullnose. I also planed and sanded down both top sides for the length of the boards so there were no sharp corners in contact with the hull of my boat.

The photo shows the trim piece after the cut but before finishing the rounding.

Step 2: Screwing and Countersinking

Next, I marked where I wanted my screw holes. Using a countersink, I drilled and recessed the holes so there is more than 1/4" inch of PVC above the screw heads. I don't know how fast it will wear away - not that fast, I would guess - but I'll be sure to keep an eye on the screw heads every time I launch. I don't want them scratching my hull.

Step 3: Mounting

Using the stainless screws, I mounted the glides to my bunks. I decided to leave the carpet intact for appearance, although it now serves no other purpose. The good thing is it doesn't touch the hull anymore.

Step 4: Finished Product

This is the trailer after the addition of the bunk glides.

I am very pleased with the end result. Before, it was hard to launch the boat and equally hard to recover it. There was so much friction that I was afraid that I was going to pull the bow eye out of the hull.

Now, the boat slides easily onto the glides and I can crank the winch with one hand.

I could have bought a similar thing, but I did this for much less money and very little effort.

Note: After two years, the PVC is holding up well and the screw heads are still out of the way.

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    14 Discussions


    3 years ago on Introduction

    Works great on my 24 ft pontoon, It used to be a two hand cranking job to load my old 24 ft pontoon, now it cranks on with one hand. Even with me standing on the front of the pontoon it was still easy for my son to crank the pontoon on. It was so easy we had to test the limit. Cost me a few more bucks for eight PVC boards plus put in eight carriage bolts per bunk ( counter sunk) . Well see how they hold up but the initial test is great.

    Thanks RangerJ

    1 reply

    3 years ago on Introduction

    +1 on everything "inthebin" said about HDPE Starboard. It is a little less slick/hard than the UHMPE that is used on the bottom of drift boats to make then slide off rocks but as he said, cheap and great for this application, and after this lightbulb moment, what I'm going to use. Starboard is the same stuff cutting boards are made of, plus UV resistance. Thank you InTheBin for all the information about plastic decking and Aluminum-- I did not know that 6061 was an issue in Saltwater. I have bunches of it and was going to use it on my boat project. Also didn't know that about bronze/brass being a disaster in conjunction with aluminum. I can't thank you enough for all this information!


    4 years ago on Introduction

    It's a great idea, but be careful. I'm a manufacturing engineer and work with plastics all the time. Plastic glides are great, I have used them on all my boats, including my 22' Starcraft aluminum boat. PVC is easy to work, cheap, and strong. But it can be brittle, oxidizes badly in the sun, and is very abrasive. Watch for cracks, if it breaks the screws you used will damage your hull. Plastic or composite decking boards often have embedded minerals, which would act like fine sandpaper. Instead of buying pre-made nylon boat glides, I go to the local shops that make Starboard (or equivalent) boat accessories and ask the for waste cuttings. The will usually sell them cheap, since a 3" wide strip will make your bunk slider, but is too narrow for almost anything else. I have found 1/2" thick pieces, 8' long and 4" wide, for under $20. Starboard is basically polyethylene, so it's slick, waterproof, and not brittle. One last note, the most common aluminum is 6061, which will quickly turn to white powder in salt water. But almost all aluminum boats are made from 5000 series, which is impervious, as my 1979 Starcraft can attest to. You don't need to worry about salt water in your bunks if your boat is 5000 series (the Starcraft is 5086). What also kills aluminum boats is copper or brass, it actively eats aluminum. Don't use brass screws or copper based anti-sieze in contact with aluminum, use stainless steel. Replace popped rivets with stainless screws or rivets. Also old screws or nuts laying in the bilge will vibrate when running and quickly wear a hole in the soft aluminum bottom.

    1 reply

    Reply 4 years ago on Introduction

    Thanks. That's a lot of good info.

    The PVC I used for the glides is made for trim on houses. I looked at it today, and it is still looking good; it may contain additives to ensure that it lasts a long time. It is still slick, too, and I can still crank the 18 foot boat'motor up with one hand.

    You are right about the screws, and if I see they are getting close to the hull, I will replace the whole works.

    I have also heard of people using PVC fence sections with good results. I almost did that, but it is much thinner and lacks depth to countersink the screws. I have used composite materials for other things and found them to be full of all kinds of nasty stuff, like metal. It was weird to be cutting a piece of what I thought was plastic and see sparks shooting off the blade.

    I bought a good quality boat, so the aluminum should be ok. Everything is welded, so no rivets or screws in the hull.

    Thanks again. That's what I really like about Instructables: the chance to connect with people who know what they are talking about. I see you just signed up; congratulations, welcome, and I am looking forward to your projects.


    5 years ago

    Looks really good. I bet one could also use composite decking boards as well. They have quite a few colors available and maybe use the "hidden fastener" hardware to not worry about screw heads gouging the hull?

    1 reply

    5 years ago on Introduction

    That looks great and really economical. Your boat is aluminum, do you think it would work just as well on fiberglass?

    1 reply

    Reply 5 years ago on Introduction


    I think it would be worth a try. I don't think it would hurt anything, as the PVC is probably softer than the fiberglass. They sell the nylon glides, which as far as I know can be used on glass boats, so I would think this would be ok, too.

    The thing is to keep an eye on them - you don't want the screws to work loose and gouge up your boat. I'd also keep an eye on the boat. And, if you have antifouling paint on it, it will probably wear that off and make a mess of the glides, too.


    Reply 5 years ago on Introduction

    Thanks. I guess it's the white against the charcoal carpet. I've been very pleased with them; they make the launching and recovery so much easier.