Thermoformed kayaks in cold water

I paddle an Eddyline Fathom in Lake Pend Oreille 55 miles south of the Canadian border all year. The lake stays ice free with occasional ice glaze in the bays. (Lake Pend Oreille is 1150 feet deep, 110 miles of shoreline and the largest lake in Idaho. Really an inland sea.) I have never realized a difference in the ABS/Acrylic hull or deck during cold weather. I firmly believe Eddyline kayaks and their proprietary plastic (carbonlite 2000) are superior to all the other brands of thermoformed kayaks I have paddled or sold. I was a kayak/paddle sport retailer for 10 years.
The quality of the plastic and manufacturing makes a big difference in thermoformed kayaks.


I don’t think the quality of ABS plastic is a matter of belief. I think it’s a matter of manufacturer’s published specifications and testing, and there are none. What specific information do you have about Eddyline’s plastic—composition, thickness, etc.? How do those specs compare to say, Delta’s plastic? For something to be “superior to all the other brands” you need to know the specs, test them, compare them. We simply don’t have this data. I think it exists, but consumers don’t have access to it. I don’t think dealers do either.

Anecdotally, you could say something like, “I put kayaks by Eddyline, Hurricane, and Delta (or whoever) side by side and compared the stiffness subjectively by pressing on the bottoms.” That might be a valid comparison, but unscientific. I don’t think Eddyline would win that test. It would be a tie with Delta.

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You won’t feel any difference between warm and cold water paddling, until you hit a rock and it cracks.

If we simply don’t have this data, what’s behind your statement: “I don’t think Eddyline would win that test. It would be a tie with Delta”?
We have two different opinions here and both are 100% valid. Neither is supported by rigorous research, but that’s OK. Informed opinions can be useful too.

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I put my Eddyline and my Delta side by side, bottom up, and pressed on the bottoms to compare them. They were about the same in stiffness/flexibility and “perceived” thickness (there is no way to know the actual thickness). If you test an Eddyline in this way you will be surprised at how thin it feels, and that could make you pause before paddling in cold water where there are obstacles above or under the surface or in moving cold water.

I’ve seen them all come in for repairs. Very un-scientifically I’d say less Hurricanes in for repair than Delta or Eddyline, but the sample size is way too low here. What gets me is that most of the repairs needed on these boats were significant enough to make the boat unseaworthy (cracks/holes in hull or deck usually) which is actually a pretty rare type of damage to see in a rotomolded or composite kayak (again, my experience only).

This doesn’t surprise me. I paddle only thermoformed and like the material, but I’m mindful of its limitations and I treat it well and choose when and where I paddle carefully.

How much difference can water being 50° vs 34° make?

Less difference than 34° vs 30°. :grin:

I would be much more confident at 50 than at 34. Subjective impression. But usually by the time the water gets to 34, the air is much too cold to paddle so it’s not an issue.

I’ve been out in weather 34/34 I’m sure others have also.

ABS is used in many car parts also.

In a thermoformed kayak?

My friend was in it.

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And this is what happens to plastic bumpers in the winter:

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Wikipedia actually has an informative article on ABS plastic. Quotes:

“The proportions [of materials] can vary from 15% to 35% acrylonitrile, 5% to 30% butadiene and 40% to 60% styrene.” So yes, kayak companies could order different makeups.

" The acrylonitrile contributes chemical resistance, fatigue resistance, hardness, and rigidity, while increasing the heat deflection temperature. The styrene gives the plastic a shiny, impervious surface, as well as hardness, rigidity, and improved processing ease. The polybutadiene, a rubbery substance, provides toughness and ductility at low temperatures, at the cost of heat resistance and rigidity." All of those characteristics are directly related to kayaks. This also shows why ABS can’t be simultaneously tough and rigid.

“For the majority of applications, ABS can be used between −20 and 80 °C (−4 and 176 °F), as its mechanical properties vary with temperature.”

“A variety of modifications can be made to improve impact resistance, toughness, and heat resistance.” This points again to manufacturers’ choices.

“The impact resistance can be amplified by increasing the proportions of polybutadiene in relation to styrene and also acrylonitrile, although this causes changes in other properties. Impact resistance does not fall off rapidly at lower temperatures.” That’s good to know but it conflicts with the above observations about cracked car bumpers in Ottawa. Hmm . . .

“Thus, by changing the proportions of its components, ABS can be prepared in different grades. Two major categories could be ABS for extrusion and ABS for injection molding, then high and medium impact resistance.” And I bet the cost varies by grade.

“Molding at a high temperature improves the gloss and heat resistance of the product whereas the highest impact resistance and strength are obtained by molding at low temperature.”

“The aging characteristics of the polymers are largely influenced by the polybutadiene content, and it is normal to include antioxidants in the composition. Other factors include exposure to ultraviolet radiation, which additives are also available to protect against.” Both very important for kayaks, especially given some claims about very long life for thermoformed kayaks.

“ABS is also damaged by sunlight; this caused one of the most widespread and expensive automobile recalls in US history due to the degradation of the seatbelt release buttons.”

Yellowing in ABS plastic occurs when it is exposed to UV light or excessive heat.” That explains why the cockpit turns yellow near the seat. I was told by a kayak company that the yellowing is a sign of advanced age and increasing brittleness.

Bottom line: the specific makeup of ABS is important to its safety properties.

A further inquiry for those who are interested would be how the addition of polycarbonate to ABS affects it properties.

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The % of the US population living in places where the temp regularly drops below 0 deg F (-18 C) is small, so many manufacturers are unwilling to spend the extra $ on R & D and/or better materials to make their products work in an environment that most customers will never experience. Hence, those of who do live in cold climates know that lots of stuff fails in winter, either mechanically or physically.


When it’s icy people slide a little bit, they tap a bumper, they crack and you have to change it," he said.

I don’t think 0 degrees F air temperatire is the zone of concern here. Assuming we paddle for pleasure, the zone of concern would be air and water temperatures in the 30s, like 35 to 40, so late November, early December in the northern states and then again in March and April. I have cracked a thermoformed kayak in those conditions. It was due to human error, but I believe the cold also contributed.

As for geography, there are an awful lot of paddlers in the northern US and in Canada, and there are thermoform kayak manufacturers in both countries. After all, the kayak was a northern invention.

In any case, here’s my personal anecdotal evidence: I’ve paddled 5 brands of thermoformed kayaks in the Northeast in every month except February for the last 20 years. Result: one crack in late November that let water into the cockpit. That’s one crack too many, so I’m very cautious now paddling November through March. I paddled last week, air temperature 37 degrees, water temperature unknown, but there was a fair amount of ice on the lake.

I don’t hit rocks in cold or warm water.

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while paddling eddyline and Delta kayaks side by side at a trade show demo day for dealers, I was amazed how flimsy and cheap Delta felt compared to Eddyline kayaks. Sorry Canadians. This was before Eddyline started manufacturing in Mexico and Arkansas.