I learned something new to me today. After doing a run across the river I turned the board over and had a look at my 46cm Canefire and noticed that it was bent like a banana (guessing about 1cm at the tip- so a fairly straight banana) After sailing in the opposite direction the fin was bent the other way too. How about that?!

Shane,
Photos or it didn't happen

Seriously though, I'm not quite sure I understand - do you mean it was angled over about 1cm off vertical or the tip was bent 1cm. I find the latter fairly improbable but the fin could be loose in the box or box itself could have some movement. G10 definitely flexes under load but from my observations has no delay in it's memory.

[Disclaimer - I have been wrong before though]

Good idea- I'll try to get around to putting some photos up to prove it

The fin had a sideways bend along its entire length consistent with the lateral forces applied while sailing- nothing to do with the box or anything like that. And I'm amazed that there is a significant delay in the memory of the G10- enough for me to still see the bend after I have stopped sailing...

Here you go- a couple of photos of the fin still bent from the last tack in to the shore yesterday!



I guess this could be why Vector fins now uses carbon for their Canefires....

Are you sure it was bent the other way on the other tack?

I can imagine a situation where it's permanently bent... but never seen one with memory before. But then again I've never gotten off on the far side of the river to check.

Interesting!

Yes very interesting, it definitely stays bent indefinitely which ever way I bend it over my knee- like plasticine. Not too impressive for an expensive fin which is supposed to be from a reputable company..

Time to invoke the warranty I think.

I've seen a G10 fin of Slowies with about 3-4 times that much bend as his board lay on the lawn at Peli about 6-8 years ago between sessions on a windy day.

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yoyo said...

I've seen a G10 fin of Slowies with about 3-4 times that much bend as his board lay on the lawn at Peli about 6-8 years ago between sessions on a windy day.

Good to hear- maybe it's not malfunctioning after all. I tested a couple of my techtonics by bending them across my knee and they retain a bit of the bend too- but not as much as the Vector it seems.

I suspect the resin is soft, maybe they got the ratio wrong when mixing it.
I'd invoke the warranty if it's got one.

I've been testing fins for stiffness lately, across my knee, or in a vice, and I haven't noticed any evidence of memory.
I did have a fin a while back bent like that. I tried to straighten it by weighting and heating it. It did straighten a bit, but over time returned to it's original bend.

I remember a few years back a kiwi going for the 1hr mentioned his g10 fin went banana shaped. I havent had any probs myself

yeah I had one that was made from chinese cheese. It was really really bent after one powered up run (34cm fin deflected permanently by 60mm or so at the tip). As decrepit says its probably the resin poorly mixed. Resin gets pretty cheesy when its not been cured properly or has been mixed improperly. Or it could have just been a bad batch of resin. Not sure where they source their "G10" from but if its from china say no more. Probably works fine for electrical distribution boards which is the normal application of thick G10.

That would explain it- uncured resin or something.. My fin hasn't completely failed like yours did Chris but it's certainly malleable.