Newbie Question

Two months ago I purchased two kayaks. My wife and I are RVers and the kayaks are intended to live on the roof of my van while traveling and towing my travel trailer. My wife got a Perception Sundance 9.5 and I got a Wilderness Pamlico 120. I have Yakima racks with foam blocks. Since the kayaks are to live on the roof for months at a time I have them strapped upside down on v shaped foam blocks. This works very well for the Perception, however, I have experienced a problem with the 12ft Pamlico. After five weeks on the roof in South Texas, mid to upper 80’s and lots of sunshine, the area of the hull in front of the seat began sagging. This area is about three feet long. In other words, when sighting down the keel from front to back, with the boat upside down, there is about a three or four inch sag in the keel line. The boat still performs OK, but it sure looks ugly and really bothers me.

Has anyone experienced anything similar to this and does anyone have any advice or a solution to this problem.

Fill it up with hot water
It should resume its shape then.

Or you can cut a sheet of minicell or

– Last Updated: May-27-09 4:42 PM EST –

Ethafoam so that, shoved between the hull and the bottom, it pushes the bottom back where it was. Some days in the sun should help the plastic remember where it should be.

You can re-insert the foam whenever you strap the boat on the car. Best is to strap the boat on bottom up, as you say you have done. The straps should not have distorted the hull, but evidently they did. Also good would be to carry both kayaks on edge. That might require upright posts for your crossbars, but it can be done without.

Generally the bottom of these plastic boats is the LEAST able to withstand distorting pressure from sitting on racks. If your boats have internal bulkheads, strapping them on over these internal supports will prevent distortion.

Rethink things a bit …
When temps get up into the 100s this summer the plastic boats on the roof are going to warp no matter what. Can you put them inside your van and leave the trailer behind?

Do you really have to burn gas to drag a house with you? How do your actions affect others? How many parking spaces do you take up when you park? How many people have to wait behind you on narrow roads? Simplify and life will be better.

It’s called "oil canning"
which is a deformation of the hull. sometimes you can leave it upside down in the sun to regain the original shape. The Pamlico doesn’t have a front bulkhead, so you’ve got to be careful when tying down. The suggestions above are all good. Search oil canning on this site, as the topic has been covered, and I’m sure you’ll find lots of other helpful info. To avoid this, I store my boats in the garage out of the sun, and I try to hang them suspended from the bulkhead areas. The manufacturer might also provide the points fore and aft of the seat that are strongest and will stand up to beind tied down for long periods of time. Good luck.

sounds like it’s from melting
hot Texas sun + plastic + hot car roof

maybe get a fiberglass boat?

Thank you for the replies.
I have to agree with “bowrudder” as to the cause of the sagging. I sure do love the hot Texas sun, for some things. The sagging bottom is from a combination of the heat and the weight of the bottom itself. I do not believe the dent, oil canning is a result of the tie down straps as the denting is between the straps and not at them.

I plan to correct the problem, either with the hot water suggestion or by letting it sit out in the sun, right side up and see if it will return to shape. Once the shape has corrected, I am thinking about reinforcing the long stretch of keel line with a length of aluminum tubing. I would secure the tubing at one end by inserting it under the seat and perhaps securing it with some spray foam. The front end of the tubing would be secured with a foam bulkhead wedged between the deck and keel. I believe this would help prevent the sagging in the future, and would not add much weight. Comments?

I have also ordered some J cradles for my rack, which I hope will help.

As for rethinking, I do that frequently. Unfortunately whenever I do that I end up with more toys, not less… let’s see, with the added room on the van provided by the j racks, I could probably fit something else up there :-).

Waar ah’ comes fro’…
wez call it “Rack Rot”!


I wouldn’t

– Last Updated: May-28-09 12:09 PM EST –

I wouldn't do that aluminum tube idea for a lot of reasons. One being that it's going to get pretty darn hot, and may contribute to even more melting that may not be as easily repairable. Regular insulation spray foam is no good for the water either.

If you really want to do something more preventative, I would shove some foam blocks of some sort into the boat to retain it's shape while it is being transported. When you put into the water, you could even chuck the foam into the hatch for some extra floatation. (If you used closed cell foam, like minicell or ethafoam/pool noodles)

The J-cradles will probably do the trick, no need to get too drastic until you've tried that.

re-think it???
Sounds to me like they’re doing good like it is. and kayaking…Heck they will probably paddle more places than most of us could ever hope to get to.

Is that the female equivalent of
crotch rot?

J-cradles worked for me…
When I first bought my Tsunami125 I was transporting via foam blocks on cross bars and noticed in the heat of the summer that I had some oil canning. Bought Thule Hullaport Pro (fold down style) and have had no trouble since.

this would require some extra effort but
Here’s a couple suggestions:

  1. You could build wooden boxes on top to shade them from the sun. Build the boxes square and put an air foil in front of each and this will save gas over your current configuration, even if the boxes are much larger than your kayaks.

  2. You could hang your kayaks on the sides of the RV, instead of the top. Pick the most likely side and always park with shade in mind, and this could cut the sun exposure by 75-90%. You could also easily rig 100% shade when not driving this way. Not sure how tall your RV is, but you can slant the kayaks to the extent they are longer than it is tall. You would need to build mounting points and choose them carefully to prevent deformation when they do get hot.

  3. (This option would be most strenuous of all, but potentially mst rewarding.) You could make it a rule to always be in the water kayaking when the sun is shining and it is over 80degrees. This leaves you nights to travel between locations, and early mornings to snatch a few hours sleep, and rainy days and winter to rest up.

Lookin’ a bit better
I set the kayak up on a couple of saw horses in the garage, supporting it on the high spots and weighting the sagging areas from the inside. I then set up an electric heater underneath and warmed the bottom with the heater and a heat gun to about 135 degrees. It seemed to do the trick. It looks much better now, although not perfect yet. Now the question remains, will it retain this shape or return to the saggy shape? I am hoping that the new J cradles will keep the sag from returning. Time will tell.

In the mean time,I’m going paddling this afternoon.

One other thing
I happened to have a four inch pool noodle, in the exact shade of blue, by the way to match my kayak. I cut two lengths and braced them vertically between the deck and the bottom at my tie down points. Although the sagging was not in the area of the tie downs I think this will prevent any future denting in those areas.

What I Did
After straightening the bottom I went paddling. Upon return, the sag had returned. Back to square one. I took a 4’ piece of 1 1/2" PVC schedule 40 pipe and slid it under the seat, where it fit perfectly in the keel groove. Nice and snug. It will not slide further back as the seat back hinge prevents this. The front of the pipe is wedged in place by a piece of 4" dia. pool noodle vertically wedged between the bottom and the deck. After paddling several times this stiffener seems to be doing the trick. The keel line remains relatively straight. This fix did not add much weight and can be removed at any time. Although not ecstatic with this kayak, I think it will serve me well as long as I remain a casual paddler.

I don’t think new posters come here for sermons.

How do you know the RV isn’t their primary residence? People should consider what they say before trying to impose their morals on others.

g2d had a good suggestion above

I agree
That is essentially what I have done (wedging with foam). One issue with the Pamlico is that it has a large cockpit, and the sagging area of the bottom is in the cockpit area not allowing for wedging at the worst part of the sag, hence the pipe, to span the sag area.

I think the perception eclipse poly has the same sort of support.