Sloppy Rod

[Paul Arden]

It’s possible to make a fantastic 3WT for fishing streams which involve 5-25’ casts for example. But then when you carry 90’ of line, two line weights heavy, it explodes. Of course it’s possible to make the same rod able to carry 90’ and maybe even make 130’ casts without destruction, but only by compromising up-close performance.

Back tomorrow. Just met my wife for the first time in a week!

Cheers, Paul

[Lasse Karlsson]

And they said they can identify the type of break that produces - what it looks like.

Magnus,
Do you know what the difference in the nature of the area around the break looks like for a compression failure (what Tim calls a "good" break) and one caused by ovalization? That should put a lot of this discussion on ovalization to rest.
Gordy

Hi Gordy

Have you read Kirkmans article on rodbreaks?

Cheers
Lasse

[George C]

Have you read Kirkmans article on rodbreaks?

Here's a link for those unfamiliar with the above mentioned article.
https://northforkcomposites.com/wp-cont ... rticle.pdf

[Lasse Karlsson]

Thanks George

Cheers
Lasse

[Torsten]

Hi James,

So you've taken a random rod and decided that because you can bend it by hand my results are somehow invalid, hmm indeed!

I've not written that your results are invalid, rather I'm wondering how to interpret them. The deflection at break seemed to me subjectively quite small (of course I could be completely wrong). My concern would be the small surface contact area and thus high stress at the test points - here is a simulation (maybe interesting for Daniel, he has access to Abaqus?)


More examples/measurements would be quite nice especially glass rod sections.

Thanks,
Torsten

[Torsten]

Hi Paul,

I broke a 4wt Snowbee this way (many years ago) while trying to carry 90ft.+ of a DT - broke also shortly above the handle.

Perhaps you could take a few pictures of the broken blank the next time you break one.

Incidentally Magnus, I think that the modulus of the 3WT you brought down is very important. I have since broken another 3WT trying to carry a long 5WT line (not 10WT!). It popped just above the handle. Fault of the rod?

Cheers, Paul

Thanks,
Torsten.

[John Waters]

I remember those old ICSF glass rods Torsten. I started with a Winston cane fly distance rod, then progressed (?) to glass rods for fly distance. We use a maximum 38 gram line now but then it was a maximum 42 grams, fast sinking lead lines for the single handed fly distance. Very dense lines and difficult to manage in the air, the glass rods we used were cut down surf rods, very tippy action. I had a laugh at Morsie's comment about some blokes who learnt to cast at a casting pool running for cover when they have to use heavy gear in Australian salt water fishing conditions, hahaha, Love to know who, but I'll have more to say about that later. We used to cast the 42 gram line for fly accuracy also and the rods were terrible compared to today's graphite, purpose built, casting rods. I have used the modern glass rods but prefer graphite for fishing and casting, purely a subjective judgment on my part.

John

[Paul Arden]

Sure I’ll take photos next time Torsten. Above the handle they are clean breaks straight across. With this split the rod just comes into two during the casting stroke.

Different to higher up the rod where the breaks often (not always) appears “crushed”, ie split either side (these are the ones where I suspect ovalising). I usually get a second cast out of this form of split, in fact the first indication is the feeling that something went wrong during the stroke.

These are not ferrule breaks which are far more common and how most of my casting rods ultimately die. What I find interesting about that is that it’s always the same ferrule that pops on a given model. For the TCR5&6 it is the first female ferrule above the handle. For the HT6 it is the middle ferrule.

Cheers, Paul

[gordonjudd]

Have you read Kirkmans article on rodbreaks?

Lasse,
I was not aware of the Kirkman article describing different types of rod failures and how to spot them, and thank George for giving the URL needed to download it.

Unfortunately after reading it I am still at a loss as to how you would look at a break from a breakage test like the one Echo does on their rods and be able to tell if it broke due to an ovalization failure or a compressive strain failure.

echo_rod_break.jpg (33.29 KiB) Viewed 1992 times

In the case of graphite rod blanks, when the load limit is reached and exceeded, the fibers on the bottom of the rod, which are in compression, will blow inward. At that point you no longer have a tube and a catastrophic failure is the result.

All in all that sounds like an ovalization failure to me rather than a strain failure. I thought the big limit in graphite was its strain failure rate of around 2% as compared to the 5-6% strain limit for graphite. It seems like ovalization failures could be eliminated by increasing the rod's hoop strength.

So Mangnus, what do your experts say about which mode comes first (ovalization or strain) and how do you tell the difference by looking at the break?

Gordy

[Magnus]

Gordy

Why is this becoming an interrogation?

Magnus