PVC Kayak Trailer Bunks - the right and wrong ways

In 2010, I bought a Hobie Pro Anger 14. Because of the boat's heft and tendency for standard cradles or bunks to deform the hull, I cooked up the idea of using lengthwise PVC to conform to and yet support, the hull. The idea took off after I published the original video of the concept in early 2012, but many overlooked the part about mounting the PVC so that it could indeed flex and conform to the boat hull. Hopefully this subsequent video will clear up the confusion and clearly indicate the purpose of using PVC for kayak bunks. The original video can be found here: • Pro Angler Tandem Trai...
*Using PVC sections mounted cross-ways on the trailer is NOT the same concept and will NOT perform the same task.

[@coachrobm]

I've been using 3" PVC pipe for 10 yrs. with no problems on my original Hobie Mirage and now current PA 14. As Tom Kirkman mentioned, the important thing is for the PVC to be able to flex and conform to the kayak hull. I have two 8 ft. sections of 3" PVC pipe (Sch 40) on my current trailer 10-11" apart, and they're bolted at the very ends ONLY. This gives the PVC pipe enough flex in the middle section of the kayak to conform to the hull. It's been working well. Hull is as good as new.

[@joesmo5143]

Very good info. 😋

[@darranjacobsen4366]

That was much more helpful than the video

[@irenejenna7004]

Building my first kayak trailer. Plan to use this method! Have cheap pelican kayaks now, intend on building my trailer to easily modify to a Nucanoe when we upgrade. I am thankful I found this video before building! I am mostly handy, but I am very confused on how to bolt the pvc to the superstrut leaving it loose, but the bolt being secure. Please help this gal get it right so I can protect my investment!

[@NobodyOwesYouAnythin]

Awesome!!! I’ve been looking for the perfect design for My 12’ Ascend T12 kayak. Makes perfect sense and won’t break the bank either. Thank you very much. Subbed.

[@TalkFishTVHawaiianDan]

Very well engineered, mahalo Tom!

[@stevenbargar3537]

For those of you who seemed to have missed the point. He is 100% correct regarding the flexibility and play that is necessary to optimize the support and reduce the risk of hull damage. Many have mimicked the setup and failed to take these fine points into consideration thus, resulting in damage to their kayak.

[@troywehr4029]

Could you make a follow up with how you mounted the pipe?

[@elvisrickey4625]

Hi Tom, First of all, excellent video. I have done what you suggested and it works great. I don't know if you are still answering questions, but I have positioned the PVC pipes for my Kayak. They are free moving using rubber as you suggested, however they really bow when the Kayak is on the trailer. Almost to the point that when I am driving it looks like the Kayak is bouncing and might snap the pipes (over 100lb Kayak). If I tighten the hold down straps it creates even more of a bow. So what I did was, put the Kayak on the pipes to let them find their natural position. I then put support under the center to help support and stabilize them. The support doesn't appear to have changed the natural fitting of the pipe to the Kayak and everything appears more solid. When the Kayak is not on the pipes they raise up off the center support. I would very much appreciate your thoughts on this. Thank you.

[@TomKirkman1]

I think you did the right thing. Once the pipes are conforming to the hull, support under that isn't going to hurt anything. The hull remains supported in that hull shaped "cradle" and all should be well.

[@elvisrickey4625]

@@TomKirkman1 👍Thank you.

[@johntrask7818]

I have a new PA14...can you suggest distance between two mounting points? Thank you Sir!

[@roywwilson]

Hi Tom, I just got back into kayaking and watched a lot of your videos when converting my old trailer. I ran across some PVC pressure test plugs and thought these would allow the pipes to move as you demonstrate but without holes in the pipes and bolts. Could I send you some pics and get some feedback?

[@patrickocampo2749]

Great video! I love the idea of the Rubber Spacer. Silly question, where can I find a spacer like that and is it just a square flat spacer or do you recommend anything in particular?

[@TomKirkman1]

What I used is something like rubber from a tire sidewall. Can't remember when I got it.

[@frzncstrd7647]

Thanks for clarifying the true purpose. I have seen a ton of rigid designs and oversized pipe. Im going to try 2” schedule 80. I am interested in seeing what kind of life I get out of it and how it holds up on bumpy dirt roads. Thanks

[@joesmo5143]

I hope it works for you, I may try the same thing. 😋

[@MrDgill25]

It’s been 3 @frzncstrd7647 and 2 years for you @joesmo5143 how is it going for you guys? Thanks

[@frzncstrd7647]

@@MrDgill25 no issues with the pipe. An occasional check to make sure things are snug on the fittings.

[@NasTimeAdventures]

Great video. I was thinking about using timber given the distance between my two fixing points. Do you feel 6ft is too much space between fixing points when using plastic? That is all I have and I'm worried the plastic will deteriorate and crack over time.

[@TomKirkman1]

Will your timber flex and conform to the shape of the hull? If not, you'll damage the hull. That's the point of the PVC - it flexes and conforms to the same curvature as the hull.

[@bobbybass1944]

Hey Tom , This is a great idea . My only question is, how do you secure the pipe ?? My trailer is similar to yours .

[@martins.7175]

Thank you for sharing knowledge

[@KeepBodyAndSoulTogether]

Very smart idea

[@AhnkoCheeOutdoors]

Aloha from Hawai'i Tom. Do you have any thoughts on using black ABS pipe versus PVC pipe? I know ABS is more Impact resistant than PVC though PVC can handle more PSI. My kayak is a Solo Skiff which weighs in at close to 200 pounds with gear onboard. Do you have any recommendations as to what diameter pipe I should use at least a minimum size. Mahalo nui for the informative video.

[@TomKirkman1]

You want to use whichever is the most flexible - the idea is to have the pipe conform to the hull shape. If the pipe is too large or too stiff, it won't do that and you can damage your hull.

[@andrewn.2990]

Supposing I use 3" PVC for my 12' Kayak, ( I may use 4") what is the maximum distance for the bottom crossbars to be so the pipes don't collapse and break from the weight of the kayak?? While I trust your method of allowing the pipes to flex, I see so many videos where the pipes are supported underneath the entire length?? Andy-New Kayaker

[@michaelholder2294]

Great idea have you made a more detailed video?

[@LesgoBrandon7]

​ @TomKirkman1 Hi Tom. I definitely want to do my kayak trailer like yours and I understand your ideas and reasoning. Exactly how to attach the pvc to the trailer is what has me confused and not know exactly what I should buy to attach it. Do you just have just one hole in each end of the pvc or two? Do you have rounded wash inside? Do you just use one locknut on each screw? Any advice would be helpful on the best way to attach the pvc, I'm afraid I'll screw it up and the pvc will crack or break, thanks.

[@TomKirkman1]

I need to take a photo because it's hard to explain yet easy to do. You can bore a hole all the way through so you can get a socket in there to the bottom hole, or struggle with a wrench (I did) in through each end.

[@jimlongest3469]

Great video. This explains more than anyone else on why and how to use the PVC pipe. What did you use for the rubber spacer?

[@TomKirkman1]

Various things will work. In this video I used rubber cut from anti-fatigue mats. Old tire sidewalls can work. Lots of things out there for this purpose. You get the height with just a tad bit of cushioning.

[@jimlongest3469]

@@TomKirkman1 Thank you.

[@nojaysimpson]

I used an vehicles rubber floor mat. Just cut into squares with a groove for the screw.

[@robertreynolds6043]

I am using anti vibration pads sold for washer/dryer.

[@yakzen4120]

What bout the seat drain? I cut a section out to fit.

[@jeffcarter5244]

@TomKirkman1, do you have any video or specific description of how you attached the pipe to the crossbeams? Purchasing a 2020 loadrite kayak trailer tomorrow and want to add pvc to make launching easier.

[@TomKirkman1]

Just a bolt and nut from the crossbar up and into the bottom of the PVC. But you need to use a locknut and don't tighten it all the way down onto the pipe. The pipe has to be free to move a it both side to side and to allow flexing without having a sheer point at the attachment location.

[@jeffcarter5244]

@@TomKirkman1 thanks

[@ashlouka]

@@TomKirkman1 do you bolt though both sides of the PVC pipe or just “inside” the pipe? Otherwise you would have a sharp piece of nut or bolt sticking out the top of the pvc wouldn’t you?

[@TomKirkman1]

@@ashlouka Just inside the bottom. Note in the video that you do not see any bolt heads protruding from the top of the pipe.

[@MrMikedeguzman]

I have 2 Sit on Top kayaks. They are double kayaks weighing 75 pounds and are 13 feet long. What size (in diameter) PVC should I use and what length? I have two 2x4 wooden cross bars that are bolted into the frame of the trailer.

[@TomKirkman1]

Can't really advise you on that - depends on your specific boats but I'd guess no more than 2 inch diameter. Length is something you'll have to gauge as you work on trailer. The important thing is that the PVC flex to conform to the hull, rather than the hull having to conform to fit the PVC. Affix the pipes at the ends so the mid section can flex to fit the hull.

[@rcppop3090]

What type of bolts did you use to mount the pvc to the trailer? Carriage style bolts, or does it not really matter?

[@TomKirkman1]

Doesn't really matter. But you need to be able to get a wrench or ratchet into the pipe to hold one end of the bolt while you tighten the lock nut on the opposite end. If using a trailex type trailer like this one, then the lock nut is in the trailer channel and only one wrench is needed. I typically leave them just a little lose to further allow the PVC to "move" and conform to the boat hull.

[@rmdodson312]

What size pvc did you use? I have a 2019 outback and I’m hearing a lot of 3” instead of 2” which seems too big and wouldn’t fit as well. Also what did you use for connecting pvc to trailer? Screws? I’ll be securing unistrut to a wood box, and pvc to the unistrut.

[@TomKirkman1]

As the video points out, the entire purpose of using PVC is to have something that flexes and conforms to the hull. 3-inch PVC is stiffer and may not allow that to happen. Use whatever size will flex and conform to your hull.

[@darranjacobsen4366]

Great ideas and statements. But, I came here to find out HOW? Not just telling me what I need to do

[@TomKirkman1]

Telling you what you need to do is "how." I don't know what more I could add.

[@louieleos1218]

Dumb question but how the heck do you make sure the holes are in the same spot in the front and back of the pvc

[@r0bd]

As long as your end cuts are square, I would snap a line on it. If not, you might be able to get away with using some markings/printing on the pipe as reference.

[@charlieedwards6345]

What size diameter pvc pipe would u recommend for a 100 lbs fishing kayak?

[@TomKirkman1]

No more than 2 inch. It must flex to match the hull shape.

[@orbelin.]

I have a Passport 10.5 weights about 65 lbs unrigged not sure if i should go with the 2 or the 3 inch.

[@TomKirkman1]

Go small as you can - the idea is for the PVC to bend and conform to the hull. Too large and the hull will be required to bend and conform to the pipe.

[@orbelin.]

@@TomKirkman1 got it, thank you for the quick reply! 👍

[@MovingToMnPro]

I've heated and bent mine to fit the hull.

[@drobinson9068]

Thanks for the video Tom. I remember your initial video and you’re right, you were the first. Question, Hobie has recently stated that the PA should not be stored or transported on parallel PVC rails. They claim possible damage to the scuppers. What are your thoughts on this?

[@TomKirkman1]

I haven't seen any damage to the scuppers nor do I really see how they would be damaged by using the PVC in this fashion. The weight is spread out over a large area, not concentrated on just the scuppers. Now if you don't support the PVC rails in the manner I've shown here and your hull is only touching the rails at a few points, then yes, hull damage could certainly result. That was my point in having the rails bend and flex to properly conform to the hull. However, Hobie supplies the boat warranties, not me! So you'd have to consider that when storing or transporting your boats.

[@SuperBardley]

I have a Revo-16 and a TI, and there is a similar warning for those as well, however, my read of the warning is worded in such a way as to advise against storing the vessels on the plug-in carts, which do pass directly thru the scuppers AND utilize a crossbar at the same locus. In this case, the problem is concentrated loading over the knife-edge of the crossbar. Mathematically, the PVC bunks are clearly the best practical storage solution -- no I will not go into the mechanics of that, but Tom's comment RE the continuous distribution of the loads are exactly correct. There is a better solution, that is more problematic IMO, and that is to wet store it or put it on an enormous pillow. LOL

[@GarryNichols]

No he wasn't, I've seen pvc since the 80s.

[@drobinson9068]

@@TomKirkman1 actually the weight is distributed only along the PVC. In theory the kayak could sag in areas not supported by the PVC.

[@Paulkrowe]

@@SuperBardley 0

[@John-of5sh]

I see this was posted 3+ years ago so maybe I won't get an answer. ANYWAY, don't you lose the flex when you tie the yaks down?

[@TomKirkman1]

No, the pipes flex the instant you set the boat on them.Tying the boat down doesn't affect that. Once the pipes conform to the hull you're good. I would advise in any case not to overdo the tie down tension for other reasons - a lot of people go way overboard when tying their boats on their racks. As long as the boat can't slide forward or backward, you're fine.

[@John-of5sh]

@@TomKirkman1 Thanks for the rapid reply !!! Definitely on my “To Do” list! Thanks again Sir for sharing your time and ideas!

[@jerrykrobby]

For more "flex" use SDR 35 sewer pipe instead of schedule 40 pvc pipe. SDR 35 is a thinner wall pipe and has a good amount of flex alone whereas schedule 40 pipe is more rigid.

[@TomKirkman1]

Could be a good tip, particularly when shorter boats and shorter pipe sections are used. Thanks.

[@HELIARCMASTER]

I have a question how do you figure it was you. How long ago did you do this? I built my first trailer using PVC over 25bn years ago. And I would not claim that. This is funny!

[@TomKirkman1]

It comes down to having proof, which I have. Prior to my original use, to prevent hull hogging on plastic kayaks, not a single person had published any similar set-up. Claiming it is one thing, proving it is another. I have youtube videos from almost 10 years ago showing it, and articles with Hobie from before that detailing it. Where can I find your video or article predating mine that feature the lengthwise tubing, not cross-ways tubing that does not serve the same purpose. Please watch the video - it's about more than just using PVC - it's about HOW to use it.

[@HELIARCMASTER]

@@TomKirkman1 25 years there was no publishing. I have proof but I am not claiming what you are saying bro. Have at it since it means so much to you. I fabricated my first trailer 38 years ago. What were u doing then?

[@TomKirkman1]

@@HELIARCMASTER Developing many of the kayaks and kayak fishing accessories that are in broad use today.

[@martins.7175]

It’s funny that this is what you took from the video…..not the knowledge he chose to share.

[@tazmac4559]

What size and what skedule is the pipe?

[@TomKirkman1]

2" #40 seems to work well.

[@tazmac4559]

TomKirkman1 thankyou so much as im setting up my trailer now

[@TheSacramentoInsider]

what trailer is that?

[@TomKirkman1]

Trailex aluminum.

[@LesgoBrandon7]

@TomKirkman1 Hi Tom. What are the foam looking things the rubber mats are on? Thanks.

[@MrJuzzmagic]

please tell the diameter of the pvc tube

[@doctorkayak]

If you want to get him to respond all you have to do is tell him he's wrong. Then he gets all excited! LOL

[@keithkelley3037]

tom..i just received a new windrider 16 trimaran that is a rotomolded boat weighing about 250 lbs....and the pvc idea seems perfect.....the hull includes a keel running 1/3 the length of the hull so I'll need to suspend the pvc high enough to allow the keel to raise over the trailer frame; but, the pipe sure sounds perfect...thank you very much

[@TomKirkman1]

I'm not sure that this system is at all good for the WR16, you'll just have to work at it and see how things turn out.

[@rickss69]

3" pvc is too rigid...use 2" to allow enough flex to conform to the hull.

[@realsafoxmulder]

I've used Hobie bunks since day one and my Hobie Pro Angler 17T's deck is warped as F. These $300 bunks only offer two small contact points, plus they end up cracking into pieces. Shame on Hobie ..

[@sfevildick]

PVC bunks are cool….. But I wanna pet that dog.