Some (usually high-end) fly rod blanks seem to become considerably more susceptable to breakage when they are used in sub-freezing weather. Does cold cause graphite to become more brittle? It's common practice, at least for me, to dip the rod tip in running water to remove ice build up in the guides. Could the graphite/matrix absorb water and freeze, making the blank more brittle? I can't see how water in any quantity could get inside the blank tube.
Has anyone else noticed that graphite rods become more vulnerable to breakage in sub-freezing weather?

No, in fact, graphite is quite "happy" at very cold temperatures. If not, it wouldn't be a very good material to use on aircraft, which operate at sub-freezing temperatures on a constant basis.

The idea that carbon fiber becomes brittle at cold temperatures is just another myth.

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I have shattered two rods in freezing temps ... both times I didn't do a thing I don't normally do in respect to a hookset. After the second time, I started to believe that modern graphite rods MIGHT become more "brittle" (for lack of a better term) and more susceptible to breakage. However, those temps are so rare here in Tampa that I don't really have enough experience to be sure. Maybe some of our Alaska and Wisconsin builders will know for sure

Tom, what about the resins used? Are THEY less happy in sub-freezing temps?

Phil,
Carbon fiber actually maintains most of its properties at low temperatures as Tom points out. However, if you dip your rod into the water to melt ice from the guides or for whatever reason and there is a large difference between the temperature of the water and the temperature of the air the result will be a large temperature gradient over a small area of the rod and high stresses in that area as a result. These high stresses plus any additional stress that you add by deflecting the rod may well result in breakage.

Having been born and raised in Wisconsin, and living in Alaska for the past 23 years, I can assure you that sub-temps have nothing to do with rod breakage. Tom hit the ball outta the park....Temp has nothing to do with rod breakage...

I fish and bend my float rods HARD in 10 degree F temps with no failures what-so-ever. If your breaking rods at below O, it is pure irony.

And, there wouldn't be parts on the F-117 stealth if it were suseptibale to cold temps...

Cold plays no part. I know lots of guys will tell you it does, but they would be incorrect.

I've fished in -15° temps for Lake Trout thru the ice using braided line with rod made from an IMX tip section from a 2 power Spin Jig. It was cold enough that you couldn't drop a jig 100' without the line freezing in the hole. You had to constantly break ice by stepping in the hole.

And that's nothing compared to what aircraft go thru.



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Better to have and not need than to need and not have.

The fact is, fishermen break rods and few believe themselves to be the culprit. So anything, be it a supposed defect or extremely cold temperatures, will get the blame when the worst happens.

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I know that extremely high temps can be bad for graphite, but how about temps in a car? Let's say 80 degrees outside? Maybe around 100 degrees inside the car?

Cheng,

I doubt that 100 degress will harm a rod for short periods of time. I've actually fished in temps like that and had no issues, but I'm just one guy that's done it a few times so my results are hardly conclusive. I would think that any time a rod is left in heat and it is deflected, then the rod could take a set over a long period of time.

jeremy

The opposite side of the coin is that extreme heat will break down the resin which binds the fibers into the matrix. But 100 degrees F isn't going to do it. You'd have to exceed 200F before that'll happen.

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The graphite fibers in a blank are bound by a polymer, I believe, and many polymers are known to be sensitive to temperature. The "jet fighter" analogy seems to be a red herring, unless the graphite/polymer matrix used in fish poles is identical to that used on supersonic aircraft? Emory's speculation about temperature gradient seems plausable, much more so than an IMX fighter jet.

I just read a report of the degredation of finish on SCV rods. My (anecdotal) experience confirms this fact, regardless of how successfully this finish has been in other applications. My own experience combined with several similar anecdotal accounts from experienced fly anglers will not allow me to dismiss as "imaginary" any correlation between fly rod blank failure and sub freezing temperatures.

Most graphite prepegs used in fishing rod construction these days utilize a thermoplastic resin that isn't much affected by the type temperatures we'd be talking about here. Within the realm of temperatures most of us would ever experience during a real world fishing experience, it's really not an issue. A rod left in a hot attic or car trunk on a very hot day would be more at risk than one fished on a very cold day. But even then, modern graphite rods are pretty good about withstanding the temperature ranges the makers' expect the rods to be used in.

I can't argue about the St. Croix surface coatings. Great blanks but not very durable finishes. I believe they're working on tougher stuff now.

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I think that fisherman tend to get clumsy in cold weather. I know I do. That leads to more broken rods.