Very good questions, and thanks for taking the time to look into it.
Every kayak has areas most prone to breakage, or wearing out. Under the seat at the point of the most impact and wear for a creeker, on the ends of the boat for a playboat in shallow water, and around any outfitting attachment points where there is stress.
Jk has eliminated several major breakage areas that exist in all other boats. The hull at the Seat bolts is the most common breakage areas for other brands, but a JK boat doesn’t put those bolts through the hull, but instead in the drop down tabs inside the boat. The way it is attached allows for flexing but not breaking there. We have never had a broken boat due to the seat attachment. The thigh braces is another major breaking area for many boats. We elected to design ours into the boat, eliminating yet another potential breakage point, and all holes that will leak there. This is two areas that are zero stress in owning a Jackson Kayak. No breakage for seat bolts area or thigh brace bolts area.
As for the ends of the boat. They tend to break from wear. Hit bottom in the same area, each time taking material off that area until it is paper thin, and then it breaks. I doubt this has ever happened to someone from Ontario with deep water. We are in Reno, NV where it is shallow and the rocks abrasive (cement). This is the most abusive playpark I have ever seen on boats. 90% of the people paddle All-Stars here because the length of time you can abuse you boat here before you wear through (you WILL eventually wear through) is longer than linear boats by a huge margin. The design helps too, of course.
Breakage in the cockpit rim kiss-offs- where the Back-band pulls on the rim causing stress. The backband is a high stress area of any boat. The tighter you make the backband the more stress. If you sit WAY forward in the boat, causing the backband to go almost straight across the boat with little curvature, that is the highest mechanical advantage situation on the boat, putting the most stress on it, especially if you are really playing the boat hard, like Team JK does. Team JK has broken more boats in this area than the entire general population. People who break them, on team JK are: Devon Barker, Nick Troutman, Stephen Wright, and Clay Wright, primarily. Why? Because those paddlers tend to really sit far forwards in the boat with a really tight backband and then go crazy in their boats! They are the ultimate test paddlers for our kiss off strength, molding, etc.. We have taken several steps to make that area less prone to breakage, and have had only about a dozen breaks there in the Star series out of about 7,000 boats that are out there in the market. We have had about 20 broken ones from Team JK, and most from the paddlers I just mentioned.
In 2008 we moved the backband holes forwards to get the attachment points such that no matter how forwards you go in the boat, you still don’t have the backband going straight across, lowering the stress on it by a lot. (50% or less stress for the paddlers who put their seats all of the way forward). I have never heard of anyone, ever, breaking that area who wasn’t sitting all of the way forward.
As for what to do if you “pull a kiss of through”. This is a non-structural break, that is right under the cockpit rim at your hip. A small piece of tape there to make sure no water gets in the crack and the boat is fully functional. I have seen aqua seal and other sealants used on either the inside or outside and work fine too.
Breakage anywhere in the hull. A boat that is undercooked is most likely to break in the hull. We have about 20,000 boats on the water in the market-place and only get a handful of broken boats to warranty every month. My recent article should have answered the questions on what and why they broke. There is no such thing as a kayak that never will break, and ultimately I would put my money in a cross-linked boat every time.
What if you do break a cross-linked boat? Jackson Kayak does the best job we can to warranty boats and take care of the customer. I think you can put that question to the general public for feedback. No point in me telling you that, since I am the biased manufacturer that will say anything to make a sale. J Well, at least that is a reasonable assumption. Below is the best technique for taking a boat that has broken, and keeping it in good working condition for a long time to come, thanks to Ben Stookesberry, and Clay Wright.
Bitchathane gets the nod hands down, but I’ve had some good luck w/ duct tape as well.
My strategy is to
1.clean the inside surface 4” around the crack with alcohol to remove oils and release agents,
2. sand it lightly with sand paper (or just rough it up with a rock or key) to add side-to-side grip to the bond,
3. heat with hairdryer or heat gun till very warm
4a. Apply bitchathane..
For Duct tape – follow 1,2,3 then:
4b. apply very thin coat of wedgewood contact cement to the roughed, heated, cleaned area. Let dry, and apply a second very thin coat.
5. Apply one crack-size piece of duct tape, then lay longer overlapping strips of duct tape across it in a wider pattern.
6. Re-heat with heat gun / hair dryer as you press it all down hard.
7. For big cracks, follow the same procedure on the outside of the boat as well, but make sure to place the strips of duct tape like shingles to the rain .. from the stern to the bow so that the first rock hit can’t get under every layer.
As for our warranty policy for second hand users, etc.. Our written warranty states that it is for the original owner only. We stand behind that, but have been known to warranty boats that are not in the hands of the original owner any more. This falls in the cases where our boat was clearly not made correctly. Boats that we decide were not molded right, etc. we take responsibility and warranty no matter who owns it. This is not in the written warranty, but again, you can check with the general public on that one.
I am putting this in my blog as general feedback for anyone interested. I hope you don’t mind!
Thanks for the intelligent, well thought out questions.
Sincerely, and see you on the water in your awesome, built to last Star!
325 Iris Drive
Sparta, TN 38583
From: Louis Dionne [mailto:firstname.lastname@example.org]
Sent: Monday, May 04, 2009 8:04 AM
Subject: Cracking and cross-link plastics
I was just reading your article on the JK Story you wrote a few days ago and, if you do not mind have a couple of questions for you.
I’m an older paddler (turning 48 soon – not that old you would say, right?) who started a couple of years ago and making progress in my skills.
I’m 6’2″ and about 175lb. I do a lot of competitive volleyball and so am in quite decent shape.
I haven’t changed weight much over the last 30 years.
I read with great interest that article – as I do most of your articles; they are all the product of a caring and intelligent person.
Early in my very limited paddling “career”, I bought 2 kayaks; a Dagger GT 8.1 and Centrifuge. Both previously owned.
The wave right now at Champlain bridge is great and not too steep; I am having lots of fun carving with the Centrifuge
and learning to spin and do carving blunts. Going out more often this spring, I am making good progress.
Overall, not being water oriented, understanding water dynamics and paddling/surfing has been is a great learning experience.
I plan to buy another kayak this season and this time will be making a longer selection process as I know more about all of this and I will be expecting more. But to keep cost down, will likely aim for a used boat again.
Your kayaks are popular in the Ottawa area and rightly so.
I sat in a Super Star last year and was surprised as to how roomy it was and how comfy; felt like a lazy boy after sitting in my cramped Centrifuge even though I made modifications to provide me with more space (legs, legs, legs).
You don’t hear people complaining about their JK.
So, I plan to borrow/rent an All Star and a Super Star in the coming weeks and see how I like either on the wave.
Now, I hear about people puncturing their kayaks against rocks – and then welding them back together… with varying level of success. But apparently, this is not possible with cross-link plastics.
It seems like I hear more about JK kayaks tearing then being punctured…
Tearing close to the cockpit rim, actually.
(The most recent exemple of that being just last week)
I know that my sampling is definitively not representative, but I am still concerned that I might be buying a 2nd hand Star and have the plastic rip and not be able to leverage much of my “investment”.
(Easy, buy a new one under full warranty….yeah, tell that to the wife…I’ve got to explore the 2nd hand option and sell one in the stable… 😎
Here are the questions…
– How is JK handing repairs and warranty regarding kayaks where the owner is not the original one?
– Is the warranty honored for subsequent owners?
– Is there a date stamp on each hull? Or how do you know what year a JK hull was molded?
– How can I identify a potentially undercooked hull?
– Can a rip be repaired in a JK made out of cross link plastic?
– If so how?
– What is the inherent cause of a rip near the cockpit rim? (curing? design? abuse? flaw vs limitation)
Your answers will be much appreciated.
They will help me select my next acquisition.
All the best to you and your growing family.