Preventing kayak warpage while towing

Last September I bought a plastic Necky Chatham 16. I transport it with a trailer, and secure it by strapping the kayak down to two pieces of PVC pipe covered with foam that are about 5ft long. (These pipes are secured to the trailer, and they run lengthwise along the kayak, so basically the kayak is cradled on either side by a PVC pipe.



Unfortunately, I realized after a few trips that I had warped the kayak by transporting it this way. I didn’t think I had strapped it down excessively tightly, but being such a long plastic kayak, it seems somewhat prone to getting bent.



I managed to massage the warpage out of the hull by applying hot water and pressure to the right places in order to get the warp out of the bottom of the hull.



But obviously, I don’t want this to happen again. The solution I came up with is that I’m going to heat up the PVC pipes and bend them upwards at either end to better match the shape of the hull. This way, instead of strapping a U shaped hull down to straight pieces of PVC pipe, I’ll be strapping a U shaped hull down to similarly shaped pieces of pipe. This should allow me to securely strap down the kayak while avoiding putting the kind of force on it that bent it before.



Does this sound like a good plan? I’m just making sure I didn’t overlook anything in the physics of all this. In fact, I figure that even if the pieces of PVC are bent a little more severely upwards than the shape of the hull, I should be ok, because the points of pressure where the straps are are at the ends of the pipes. So, even if the pipes are bent a little more severely than the shape of the hull, strapping it down to them should not put a force on the hull that would bend it, as it does when you try to strap the hull down to the straight pieces of pipe as I did before.

Or
Transport them upside down with crossways bars just like a roof rack resting on aft deck and front edge of coaming with or without foam blocks. The hull is shaped for water not racks whereas the deck is more rigid.

Decks often stronger
Same as above - carry them upside down.

Or Hang Them On Thick Nylon Straps
Of at least 1/4 inch thick, which will somewhat wrap around, but not deform the hull.

Or
http://www.nrs.com/product/1445/nrs-15-hd-tie-down-straps

Still have issues
Transporting upside down is not possible due to the amount of rocker the kayak has. The front tip of the kayak would hit the tongue of the trailer if it was laid upside down on the trailer.



The wider straps also would not help as it’s not deforming the kayak right where the straps are, it actually bent the kayak so there was a dent in the bottom of the hull, nowhere near where the straps were.



Thanks for the suggestions though.



There is no way to attach a photo to this forum, is there?

Much Too Thin and Narrow
For daily use and transport. Those straps are used to secure and not to hang. The thick nylons are easier to slip in and slide a kayak through, since they’re about 4 inches wide and a semi loop is already formed. Only problem is the kayaks will swing back n forth or sideways on the straps when the trailer is moving.



No worries, I use those thin narrow straps to tie down my kayaks on trailers with padded rigid horizontal bars. Maybe if the rigid lateral tubes were spaced wider, cot like, and kayaks hull resting on the thick wide straps, they can be additionally secured down with your thin straps above the deck? That’s how I’d do it.

photo posting
Post your photo on a free photo sharing site like Yahoo Flickr and then paste the link to the shots or an album of them into your post on here.



Yes, it would be helpful to be able to visualize how you are currently hauling to offer constructive suggestions.

Here are photos
Here is how I am towing it now. What’s odd is that the lengths of pipe are so short in comparison to the kayak that I wouldn’t think the straps would be far enough apart to bend the kayak. The dent in the bottom of the hull was made a little in front of the seat, basically right where the Necky logo is.



I’m also wondering if having so much of the kayak hanging off of either end was partially the cause. Maybe the hull was subjected to too much flex when going over bumps.



I’m thinking I may put on longer pieces of pipe, but also bend either end to match the contour of the hull. That way the hull is better supported, and again, it won’t be a U shaped hull being strapped down to straight pieces of PVC pipe.



http://i198.photobucket.com/albums/aa300/a938475/kayak/_MG_6324_zpsrtyyelmy.jpg



http://i198.photobucket.com/albums/aa300/a938475/kayak/_MG_6323_zpstacahi9h.jpg



http://i198.photobucket.com/albums/aa300/a938475/kayak/_MG_6322_zpsr2vpls0z.jpg

Webbing
I’d go order some polyester webbing from strapworks.com and attach 2 “slings” to the verticals on your trailer; maybe I’d reinforce them a little first.



With the kayak suspended from the webbing I’d then strap it down with the orange cam straps that you have so it won’t move.



The webbing provides support not just in one place but all around the outside of the hull.

J-cradles
Mount them to the traer and carry the boat properly.



I think part of the problem is all the weight is carried on the two faces of the hull but not any on the stronger keel.



I carry 17’ foot boats on a DIY rack and the only two points of contact are two 2 1/2" PVC pipes perpendicular to the boat. Carried hull down or up on one side, held in place with three 1" ratcheting cam straps (OH NO!!!) and don’t have any problems. Total contact area less than 12 square inches, probably way less.



If you built a little box on the trailer you could carry the boat deck down. You could also put some crossbars on top of the box and rock it in style. Throw your gear in the box.



If the bend in your PVC isn’t identical on each pipe you’ll have issues, you’ll have to make sure the pipe doesn’t roll to one side, and you’ll have to make sure he bends don’t change while the trailer is stored.

Foam blocks
That support method almost guarantees a deformed hull.



You’d be a lot better off with foam blocks crosswise at the front and back edges of the trailer. Spend some time carving the foam to exactly match the hull profile to reduce stress.



The foam blocks can be glued to plywood panels (or planks) that are then screwed to the trailer deck. That makes them removable - I wouldn’t glue foam directly to the trailer deck. Straps could go through hardware (e.g. D-rings) bolted to the panels/planks.

I’m going to use foam blocks
I like the foam block idea. I think I’m going to use foam blocks at each end of the trailer, and then run the strap around the whole frame of the trailer like this.



http://i198.photobucket.com/albums/aa300/a938475/kayak/_MG_6325_zps9ddvl3xu.jpg



Also, I know it wasn’t clear before, but those PVC pipes are bolted down to the floor of the trailer. So if I did bend them, I would not have to worry about them rolling back and forth. They are secured in place.

If you use foam blocks…
…the boat will oilcan wherever they are placed…because the hull profile is very flat through the middle 2/3…also the plastic is cheap recycled, and very prone to warp. I owned one of these briefly and had to resort to J-cradles.

Skegy

– Last Updated: Apr-18-16 9:11 AM EST –

There are only two ways to haul this kayak on this trailer. First of all this trailer is way short, and j cradles will work because the weight is concentrated on the sides of the hull, not the bottom. The other way is to bolt or screw two 2x4s to the trailer (spaced appropriately) and on each end of the two boards bolt or screw a cross section that will be directly under each bulkhead. That is where you would tie your kayak (bottom down) without warping it. You can glue or tie contoured foam blocks to the 2x4s. Also for the extent ions you could have some steel tube welded instead of using wood.

I Second This!
But would lengthen the wooden side rails and narrow the spacing between them before attaching the webbing and suspending the kayak.

On edge
I haul all of my boats on the trailer on edge. First, you should consider elevating the rack the boat is carried on, so that it is closer to eye level with following drivers. Have uprights mounted wide enough to allow the boat between them on edge, but leave enough room for plenty of padding. Try to arrange cross bars as close to bulkhead locations in the boat as possible.



I have four cross bars that are spaced about 30" apart so that they support the center of the boat and not the ends. On edge, the boat is the most rigid and should resist deforming best. I cover all the supports with wrappings of carpet underlayment foam and then wrap layers of plush carpet over that. The wraps are held in place with strong duct tap.



My trailer is stored outdoors year round and this stuff lasts for years out in the weather. You can get all the underlayment and carpet for free from almost any flooring (carpet) dealer just for hauling it away. They always have lots of leftovers from install jobs.

Ditto j racks

– Last Updated: Apr-18-16 11:01 AM EST –

It's just not worth going to all that effort to put it in the rain catching position when it's so much stiffer on edge. I had a Chatham 16 for many years and have seen a Chatham 17 in the rental fleet. They put just enough plastic to meet weight numbers but given the design it's a flexy hull with flat spots forward of the seat a common occurrence. There's too much weight cantilevered over the middle section for it to not warp a bit. I've seen Chatham 17 stored and transported upside down that developed an extra inch or two of rocker over a summer. It's a good kayak.
If you really want to transport it deck up put a block of foam on the trailer tongue so the front half of the kayak is supported. Right where the Chatham name is located.

Straps should not flare out to the edge of the trailer but as close to the hull as possible in the above pics.

Ps, double check rear bulkhead waterproofness. I've see a few detach as the method and amount of sealant isn't adequate to the task.

"Eye level with the following drivers"
Yes, yes, yes. Drivers are often so distracted that you need to make the kayak as obvious as possible. Tie a neon cloth strip to the tail end of the kayak, too.

Flag it
If the boat sticks out behind the trailer more than a couple of feet, legally you probably have to have a flag on it–depending on your state’s law. I always flag my boats. If you travel across state lines (interstate), you are required to have a 2’X 2’ red flag.