Important note: The following modification was only done on my own boat and at my own risk!
I first like to give a few + and - points about the take apart concept.
+ great for small storage spaces
+ easier to ship (think air travel)
- will make the kayak heavier
- will create some flex in the hull
- not cheap
- possibility of water leak (danger of sinking if the leak is sufficient)
For myself the biggest factor to go this way, was the storage issue. I had to be able to bring my boat through several turns into our storage room in our apartment building.
I made this modification 3 times to identical kayaks. The first one was trail and error... it worked but had a minor issue with water leaking into the cockpit, not much but enough to drive me nuts. I like to use gear that will perform 100% and not just 95%. Overall, it wasn't dangerous but drove me nuts.
When selecting the kayak, make sure you have plan on how to reattach the rudder/ or skeg cables! I also found it difficult to make this modification to a kayak with a day hatch, as you will not have enough room in the day hatch to laminate!
I selected the Impex/ Formula Diamante, a boat that not only fits me perfect it also was really easy to work on.
The following pictures will only reflect my design and materials I had available back then. I'm sure someone else could make it more elegant, lighter and/or stronger.
Let's move on to the pictures:
Please don't get confused by the different color of the boats. As I only took pictures of the first two modifications.
The first boat was a total write off ( windfall damage) I bought this boat for
$50 and didn't have much to loose
In this picture you can clearly see the over lapping laminated parts. The bottom part was permanently attached to the rear of the boat, to avoid water leaking into the rear hatch.
The first step will be to find the best location for the new joint. I used the location of the rear bulkhead. It was important to keep one half in the original shape of the hull. After marking the cutline with some masking tape I used a Fein Multimaster to start cutting. After that I applied resin to the already prepared 1/4" thick new bulkhead and set the front half of the boat (with the old bulkhead still attached) standing upright on it and waited for the resin to cure.
Then I was trimming the old bulkhead out and fully laminated the new one in. I again used the Multimaster to trimm down the new add on and made the bulkhead for the rear half fit to the front half. That way I could match the hull shape. The new bulkhead was put in place the same way as the front one (sorry wrong picture, but the same idea), except this time I had to match the outlines with pushing the rear half into place with some tape and clamps.
Again, laminating everything into place with some strand mat and resin.
To join both halves together, I use stainless steel screws and hinges.
I also laminated a strip of glass around the outside, finished with gel coat
The next pictures will show you in more detail on how everything is hold together. Just to clarify, the hinges are glued into place on the back part of the boat with sikka flex. If I ever get a water leak from those hinges, it will only happen in the cockpit as this is the part where the screws are removable.
Screws along the inside are also holding the halves together
Latches are there for extra strength, just in case the lamination would come apart....
Here you can see how I solved the skeg cable "issue"
I'm paddling with this construction for almost 3 years and never felt unsafe or had any issues with too much flex or delamination.
Please feel free to ask questions as I'm sure I forgot to explain some points in the process. Again, if you are planing to do the same to your boat, your are on your own, I'm not responsible for your modification. Being in a kayak can be dangerous especially if you made some major modifications like this one! Play save and stay within your limits!