Damage inside the cockpit

A couple of months ago I bought a brand new Think Evo 3g in the performance layup (orange stripes).
I had some bad luck as I got thrashed by a wave in my second paddle session on it - harsh enough so that the boat got a huge crack along the seam between the cockpit and the stern. I got it repaired by a professional who told me it was no big deal since the boat was not leaking through it.
Maybe the problem was not just that crack, because after the accident I started to hear a noise inside the cockpit. It's like a loud "click" every now and then. I inspected it after a paddle session and found out that inside the cockpit, a couple of inches in front of the spot where I sit on, it has become a little soft. When I pressure that spot with my fingers I can hear a noise like "broken cookies" as we say here in Brazil... The nouse is louder and more frequent when I paddle upwind.
I thought that such boats had some kind of support structure under the seat. If they really do, in my boat it seems that something happened with that structure - like it was crushed os dislocated somehow.
The repair guy told me to forget about it, because he doesn't believe it will ever need a repair.
Do someone have experience with this?
How are Think surfskis built under the seat, is there some support structure, or are they totally hollow there?

leolinha wrote: A couple of months ago I bought a brand new Think Evo 3g in the performance layup (orange stripes).
I had some bad luck as I got thrashed by a wave in my second paddle session on it - harsh enough so that the boat got a huge crack along the seam between the cockpit and the stern. I got it repaired by a professional who told me it was no big deal since the boat was not leaking through it.
Maybe the problem was not just that crack, because after the accident I started to hear a noise inside the cockpit. It's like a loud "click" every now and then. I inspected it after a paddle session and found out that inside the cockpit, a couple of inches in front of the spot where I sit on, it has become a little soft. When I pressure that spot with my fingers I can hear a noise like "broken cookies" as we say here in Brazil... The nouse is louder and more frequent when I paddle upwind.
I thought that such boats had some kind of support structure under the seat. If they really do, in my boat it seems that something happened with that structure - like it was crushed os dislocated somehow.
The repair guy told me to forget about it, because he doesn't believe it will ever need a repair.
Do someone have experience with this?
How are Think surfskis built under the seat, is there some support structure, or are they totally hollow there?

Hello,

Your Evo Gen3 has a stringer that runs right under the seat area to support your weight and add structural rigidity to the craft. By the sounds of it, the damage sustained in the incident has cracked or dislodged that stringer, as well as the visible damage to the outside of the ski which you've had repaired. Think skis have internal kevlar seams (they're not simply bonded decks and hulls) , and it would take quite an impact to crack one of those, which would tie in with the ski experiencing some large forces which could have cracked or dislodged a stringer.

Kind Regards,


Stewart O'Regan



Think Kayak Australia

Mob:     0404 236 638
Web:     www.thinkkayak.com.au
Skype:  stewieor

Hi Stew, thank you for your answer!
The crack was like half a meter long (2 feet) but it wasn't wide, it was more like a hairline crack. The seam itself didn't split open, it seems that the deck was under such a pressure that it flexed but just the gelcoat/paint cracked.
The damage inside the cockpit doesn't show, everything is looking good, the cockpit walls are very rigid. Just this point on the hump is soft and clicking.
What do you think, do you advise me to take the boat back to the repair shop and get the cockpit repaired? Or let it be and forget about it?
Well I know that it is hard to answer such questions without seeing the boat... And I also think that such a repair would be very invasive, maybe the repair guy will have to cut through the cockpit and open up the ski to reach the stringer. Perhaps this is not worth it... Who knows?
All I know is that I am not comfortable with the idea of paddling a damaged ski. Where I live I am the only surfski paddler so that I paddle alone almost 100% of the time.

What I think has happened is the top of the hump gets the most damage due to being most exposed and a lot of people tend to stand or sit on it. So I think it is the nomex that has been crushed. If the stringer has come adrift under the seat you have problems, unlikely though, it would be very bendy in that area if you put it on trestles and push down on it at the edge of the seat.
My suggestion is to inject epoxy into the soft area and see what that does. It might just be physical impact on the external skin and not structural.

Thanks Ranga!
Yes, maybe the damage was caused by my butt crash landing on it as I jumped over a wave - in this case, nothing to do with the other incident.
Is this stringer made of the same pink foam that can be seen through the front hatch? That foam feels really soft and fragile. I can imagine that being easily crushed under the seat, at least locally.
The stringer is not loose. When the ski is laying on trestles and I turn it upside down, nothing moves. Sometimes I hear a tiny noise from something loose inside, it seems to be a very small piece of plastic. Someone here recently told a story about something loose inside the ski and was told that it is probably a piece of glue.
As far as I know my ski has no nomex core, it is made of fiberglass over a foam core.

Hi Leolinha 
I sent you a pm a few days ago about this. 
I have experienced this on a ski a few years ago. The stringer came loosen underneath the seat, within a small area and the seat started making noises every time I rotated and paddled hard. I solved this by drilling severeal small holes thru the deck along the stringer and injected epoxy with a syringe. The resin filled the holes up and all I had to do after was to sand it down slightly and spray paint it to cover the repair. 
I would guess you have two issues though, one being the loose stringer and second the soft spot/ delam of the actual seat in the same spot.However,  if you are lucky this process could fix both problems. 

Ps. I am not by any means an expert on this area, but this worked for me and my ski. 

Good luck 

M 

Yes the stringer is the pink foam, it is good enough and does not compress very easily and does not take on water. It is surprisingly strong for the weight. As for the sound you are hearing, I am not 100% sure if it is not Nomex.
You need to do the stress test with the ski upright, not upside-down, unless you are paddling it that way!

Mats Walsted: thanks for your post. I didn't get your private message though! I sent private messages twice here, but it seems that nobody gets these messages.
I think that your problem with your ski is similar to mine. I paddled my Evo today and inspected it once more, but for me it's hard to believe that the stringer is damaged. No noises inside, hull is very rigid underneath the seat. Maybe it's just a deck problem.

Ranga: I didn't mean that I did your stress test with the ski upside down. I meant that no matter how I move or place the ski, I don't hear any noises coming from the stringer.
I did your stress test today only. Put the ski on trestles and pushed down as you said. Nothing happens, the ski is not bendy. It really seems to be structurally sound. Maybe I didn't push hard enough... I am always surprised by how hard you repair experts do those kind of tests! I would be afraid to push too hard and mess the ski up even more.

I have heard this small tick sound around the bucket in my performance Evo II. It's a specific spot an inch or so forward of the deepest part of the bucket. The ski is second hand but it was in near-new condition and I have been gentle with it. No particular softness anywhere.
I know that the way Think glues stringers in is not perfect. I have a small area all the way in the bow where the glue looks questionable (actually managed to flow some epoxy in using a long stick and a toothbrush taped to it). So perhaps the stringer under the seat has an area without glue that makes the sound.
Anyway, I am not worried about it.