Noticed water oozing from what looks like a pin hole or maybe small crack in the tail of my dyno. See pic. I'm assuming it got in the way it is coming out? No idea really how long it's been happening. Doesn't seem to be heaps in there. I've just got it standing on the tail for the moment. I'm on hols and want to use the board if possible. Any ideas? Is this a really bad sign or something not that serious?

Not good and needs to be fixed. A day in the sun, tail down, will help of course then a smear of solar epoxy will keep you sailing - not an urgent fix

Ok, thanks. I'll do all that. Long term what needs to be done? Pro repair?

Hard to see, a sand back and a smear of goop possibly could be enough if its just pinholes, but if there is a crack its def worth proper repair as it might be glassing on bottom and tail

musorianin, how often do you check your vent ? (Is this a Cobra factory board ?)

Gortex vent. I give it a wash with fresh water regularly , but don't touch it otherwise. It says "don't touch". Not a fan of gortex vents, but that's what the board comes with...

Vulnerable spot, tip of tail.
Whatever fix, you gotta drain for a couple days, then seal before using.

How much weight difference?
In the sun it may ooze elsewhere. Otherwise, sand and fiberglass or at least ding stick or solarez.

Look at mast track, strap insert, fin box, etc.

stand on tail over night with a paper towel under and see how much comes out, lot of pin holes, I returned a Goya Bolt that lots of pin holes, replacement board was perfect.

Pretty sure the water has gone now. Doesn't seem to be any real weight gain (by feel... Don't have scales) going keep it draining a bit longer and then do the solar rez and see how it goes.

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musorianin said..
Gortex vent. I give it a wash with fresh water regularly , but don't touch it otherwise. It says "don't touch". Not a fan of gortex vents, but that's what the board comes with...

I hope you don't take it out to wash it! That would totally stuff it, it would no longer breath.
In fact with water already inside the board, the goretex should be replaced with a normal vent. It doesn't take much dampness on the inside of the goretex to stop it breathing out. When you get the tail leak fixed, get the vent changed at the same time.

The worst thing for Gortex is salt water. Gortex valves will brake down in 15-24 months. Replace day one with a standard rubber o-ring valve.

No, I just spray the board down every now and then after use. I haven't touched it ever. I might change it however at some point.

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musorianin said..
Gortex vent. I give it a wash with fresh water regularly , but don't touch it otherwise. It says "don't touch". Not a fan of gortex vents, but that's what the board comes with...

In addition to other suggests, I recommend removing this Gortex plug and dip a tissue wick in the vent hole and see if it's wet. If it is, then the vent hole could be faulty (eg cracked hole, or uneven land).

Its a bit odd having a leak like that and not much sign of an impact. Maybe another case of them sanding too much material off before painting, I think Basher had a tail split n a Dyno because of that. Or maybe to keep weight down they have skimped on reinforcement in that area. No point in having a lightweight board if it leaks. I wonder how much of the tail's rail is wafer thin.
A friend has just had the nose of his Cobra built foil board repaired after a catapult. The repairer told him there was no carbon at one point, they had sanded it all off.

I had a 2009 Mistral slalom board and chucked it (with rig attached) off the harbour wall in Poole Harbour as I wasnt near one of the access steps. I caught the uphaul on my harness hook and the tail slammed against the concrete. It just chipped the paint off, no damage to the carbon at all. It was one of the lightest boards I've had but was solid.

Although I'm not sure this tail leak is vent screw related, as the topic has come up, I replaced the goretex on my Severne with one of these

www.supercheapauto.com.au/p/aeroflow-metric-port-plug-m12-x-1.5/SPO3820905.html

M12 x 1.5mm not a standard plug.

On my Severne Alien I also noticed that even without the vent, there was no air escaping from the heated board. Stuck a screwdriver down about 10cm, almost the depth of the board, to pierce whatever seal was preventing, and it started hissing. The whole vent system was useless in stock form.

Raises the question, would a $3000 board be covered by warranty for a faulty goretex vent?

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obenebo said..
Although I'm not sure this tail leak is vent screw related, as the topic has come up, I replaced the goretex on my Severne with one of these

The tail leak could be a precursor to total delamination caused by water entering the board via the vent hole. In my experience, faulty vent holes have a fairly high defect rate with Cobra boards. I've reworked a lot of vent holes in these boards (four of my boards - 2 x brand new, 2 x 2nd hand from dealers), and 2 x friends boards). A cracked vent thread or a land that is uneven can cause half a cup of water to enter board during a given session in my experience.

A vent I bought, a cheap copy of the chinook one, had a tooling edge in the middle of the sealing face.
Agreed that let in about a cup of water before I realised, and replaced it.

Update. Think the issue with weak tail mentioned above is evident. Very modest sanding prior to intended filling with solarez revealed this . Tbh, I did go a bit harder once it started revealing itself in all its glory. I'm leaving it for now.


Seems to be paper thin back there and a cavity. I suspect factory defect. This board has had zero abuse, just normal use and few modest jumps here and there since I bought it new. Taking it to a repairer tomorrow. Re the vent and moisture. I think the good news is that the board is still light. Can't feel any soft spots. Boxes seem solid. Moisture is all gone from the tail and it's been standing there over two days. However, I'll change the plug over anyways. Luckily I also have a stash of old sh***y boards down here I can use. Thanks for the feedback all, and have a great new year.

I don't think the underpaid workers that made the board give a sh,t.

fill it with solarez - preferable the fiber reinforced one - and go sailing.
When you have time, fair it and spray - its not structural

Thanks Mark. That's the kind of advice I like on a windy day.

Suncure Fiberfill, yellow and green packet (?) in my video

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musorianin said..
Update. Think the issue with weak tail mentioned above is evident. Very modest sanding prior to intended filling with solarez revealed this . Tbh, I did go a bit harder once it started revealing itself in all its glory. I'm leaving it for now.


Seems to be paper thin back there and a cavity. I suspect factory defect. This board has had zero abuse, just normal use and few modest jumps here and there since I bought it new. Taking it to a repairer tomorrow. Re the vent and moisture. I think the good news is that the board is still light. Can't feel any soft spots. Boxes seem solid. Moisture is all gone from the tail and it's been standing there over two days. However, I'll change the plug over anyways. Luckily I also have a stash of old sh***y boards down here I can use. Thanks for the feedback all, and have a great new year.

Ironically, its next to the 'QC Passed' sticker. Hope you get it fixed ok.
A friend's Dyno split on the nose after dropping the mast on it during a gybe, it wasnt even a catapult, he fell of the back and the rig went forward. Haven't seen him since he took it in for repair. The repairer is one of the best in the business.
Do thin squarer noses and tails contribute to the chances of this happening?

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PhilUK said.. >>>>
Do thin squarer noses and tails contribute to the chances of this happening?

I believe so, a rounded nose/tail can deflect the mast, a square nose/tail won't

My wider nosed boards suffer more mast damage than narrower ones, but that could also be the result of inherent stability a narrow board will not only deflect the mast, but roll with the blow. A wider board is harder to roll, so takes more of the force.

Filled it. It looks rough AF but seems solid, board did 50 odd kms today so I'll have a look tomorrow and see what's what. Hopefully it sees me out for the hols and then I'll either do a bit of tidying up or take it to someone who knows what they're doing. Thanks all for the advice.

don't get it hot ,or transport in a plane hold ,until you change that bung.

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obenebo said..
Although I'm not sure this tail leak is vent screw related, as the topic has come up, I replaced the goretex on my Severne with one of these

www.supercheapauto.com.au/p/aeroflow-metric-port-plug-m12-x-1.5/SPO3820905.html

M12 x 1.5mm not a standard plug.

On my Severne Alien I also noticed that even without the vent, there was no air escaping from the heated board. Stuck a screwdriver down about 10cm, almost the depth of the board, to pierce whatever seal was preventing, and it started hissing. The whole vent system was useless in stock form.

Raises the question, would a $3000 board be covered by warranty for a faulty goretex vent?

Thanks for that. I was looking for one of those and couldn't find one. There are plenty of fine and coarse threads around but not 1.5mm.

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decrepit said..
don't get it hot ,or transport in a plane hold ,until you change that bung.

Noted. Thanks

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PhilUK said..
Ironically, its next to the 'QC Passed' sticker.

That didn't escape my attention!


Thanks all. Happy sailing.