Effect of cold on thermoplastic

Was reading the thread in the discussion forum on Gel Coat Stress Fractures: http://www.paddling.net/message/showThread.html?fid=chat&tid=1031715

It’s a lengthy discussion, so thought I’d start a new topic. The guys at Boreal told me that because they’re way up north in Quebec, they build their boats for those conditions.

They said they don’t build kayaks in thermoplastic because extreme cold makes it brittle.

Any thoughts?

That’s as good a reason as any, but
I would imagine that poly boats are in danger mainly from handling errors (being dropped while loading) in very subzero temperatures. People are not going to actually paddle them for long in subzero air, and of course the water is usually not super-cooled.

I’ve run trips where the morning air temperature was 13 degrees F, and the poly boats that were along on the trips were showing normal durability.

Maybe someone (Flatpick?) has some actual data on cold weather brittleness.

we do
alot of our strength and impact testing at 30 below zero. If it works in the cold it’ll work in the warm.

I’ll get some results BUT we have found that thermo and roto both are less strong in sub zero BUT plenty strong enough.


second hand information but…

– Last Updated: Dec-24-08 4:32 PM EST –

Russell Farrow, of Sweetwater Kayaks and a member of the 2nd IR Vacation to Hell, wasn't very impressed with thermoform plastic. When the Vacation to Hell was first put together the crew was going to use thermoform kayaks. Russell did a few tests that involved freezing a kayak and then hitting it and dropping it. The results did not impress him. Apparently the thermoform was very prone to shattering when frozen. They decided against using the thermform kayaks because, in Russell's words 'you aren't sending us on a dead man's mission'.

but those weren’t OUR thermo-formed kayaks!!!



And Duralite was more durable?
Those things shattered at room temperature.

I’ve cracked a few poly and Royalex boats moving them when it was 20 below, enough that I hang up my paddle on those days. I think it’s a weak excuse to not build in a certain material.

I think he meant Gen2
I dont like Duralite neither. I saw a duralite Tsunami 145 at JAX, and I pressed my thumb into the kayak bow’s side under the gunwhale, and it compressed with little effort. Yet, On my Gen2 Pamlico 140, I cant even push the plastic inwards at all, and I’ve tried pushing my thumb in on the same place- the side of the bow. I’d take Gen2 over duralite any day. I store my kayak right side up laying on its hull, but it is still symetrical and seems there are no major deformations. Gen2 is an excellent material.

OK, but here’s the thing. In whitewater
the poly kayaks are way more durable than the composite kayaks at ANY temperature at which people actually paddle.

I don’t much like poly, and I have mostly composite boats, but I would not be stupid enough to use a composite boat on a rocky creek on a subzero morning, if I had a poly boat as an alternative.

In SE whitewater circles, I am just not hearing of poly kayaks shattering or cracking in subzero weather. So I don’t know what those Sweetwater tests mean. One guess is that poly sea kayaks may be made a little more brittle than poly whitewater kayaks, because the extra stiffness impresses the customer. Flatpick and company are an exception.

we’re talking about Thermo-formed boats here NOT roto.

I think the boats the SW was going to use were Deltas. And on a trip like the Vacation from HELL, I’d be NOT wanting to use a Delta, Eddyline, Hurricane, or Airelite or ANY thermo formed boat.

Heck you can freeze a f/g boat into and ice flow and wait till spring to thaw it out w/o issue. We used to live on a sailboat that occasionally froze into the river, one time it was a foot thick. NO problemo.



Wait a minute…
isnt thermoplastic that type of plastic that resembles composite- with a multi color layout- different hull and deck colors?? Because all this time I was thinking of Rotomolds, which seem to hold up fine in extreme cold. I was watching Euromaxx, and they showed prijon rotos paddling up in the arctic in extreme cold, and the kayaks did just fine. Just look at Jon Turk.

Prijon- BLOW
the german Prijon boats are blow molded…a completely different animal.

do your research Pammy!


Rotomold and glass
I have Rotomold and Fibre Glass boats on my trailed. I use them all year around in Newfoundland Canada, _ 15 is normal but the air by the sea or an unfrozen lake will be a little warmer.

We batter these things coming and going from the pool in winter.

I had a bulk head broken due to an external impact but the hull was unaffected.

My Old Town Discovery is a different beast but it fares well also, She is 21 years old.

I don’t think I would worry about Cross link, Rotomold or Fibre Glass boats.

You may be talking about something a little different.

The water can’t be much less than 27F…
…or it would be frizzed.

PS. Seems to me that the boat…

…can’t be much colder than the water–except during transportation. But if it’s going to be THAT cold,

like in the low teens F, are you really going to be


Paddling in the teens
apparently they do in Northern Quebec…

Thanks for the input. To clarify, I was asking about ABS plastic, not polyethylene. Big diff.