old kayak convert from sit in to sit on

Gday all, This is my first post here and your forum seemed like a good place for sdome advice an idea I have,

ive got an old fibreglass kayak that I bought off ebay, anyway due to my impulsive buy Im left with a kayak that is in need of repair and the cockpit is too small for me.

Ive been thinking as it is in need of repair,

would it be possible to cut the hole larger and make it into a type of sit on enclosed kayak?

My idea was to cut an elongated hole about 110mm long, narrow at the feet end. I would then shape some foam into a seat, sides and feet rest and then fibreglass the lot and make the kayak watertight.

It is about 4.1m long, 650mm wide and about 270mm deep. im not sure what type of kayak it is. Photos of it can be found below,

http://cgi.ebay.com.au/ws/eBayISAPI...ee-All-Categories&_fvi=1&_rdc=1#ht_500wt_1154

Would my idea work?

Any thoughts greatly appreciated and thanks in advance.

 

Could work. Things to consider; SOT's tend to be wider (although yours is fairly wide) as even raising the seat a couple of inches can effect stability. Leave vent holes, or put a hatch in it as the pressure difference between a hot summers day and cold water can be quite something. Also a drain hole in case water does get in, and a bulkhead (or 2) would do no harm.
Good luck, Al.
al@trinitykayaks.com

 

You don't have to raise the seat in order to make it a ride-on. This boat is configured like a sit-on-top, but the seat itself is barely off the bottom of the hull.

No, it's not a kayak, but it inspired me to attempt the same thing you're proposing.

 

as someone who has done 1/2 assed fiberglassing of kayaks....

I would say you would be better keeping this intact as a spare for someone to go kayaking with you.

To get the cockpit strong enough to not crack under your weight and feet banging about means quite a bit of weight.

If you are changing the seat and foot rests their is a good chance you wont get it right the first time and will be left with something that quickly gets uncomfortable.

Your kayak is a 'river runner' designed for quick turns and Eskimo rolls.

It will be hard to keep on track in calm waters and quite tippy, due to nature of hull design under the water.

I'm hoping you weren't planning to take your modded boat in anything but calm waters with land within easy swimming distance.

You might consider simply cutting the cockpit a bit bigger like an Old Town Loon and make a lip out of foam and glass that.

and stuffing empty screw-capped plastic bottles in the ends for emergency flotation but you will still be left with a squirrelly, tippy boat.

I'd just keep your boat as is and use it for a car-roof Thule luggage if nothing else.

 

I have built and paddled many different types of sea kayaks and I think you can do this without any problems if you do it correctly.

first of all I would take the kayak out on the water as it is to see what it is like, and if you like the way it behaves. This way you will have a better idea of what you are starting with. patch any leaks with duck tape or similar, but some seepage is not an issue for just 20-30 min of a test paddle.

Presuming it is acceptable, you can make it a sit-on-top style as long as you do not raise the seat, you need to keep the CG at the same ride height. If that is not what you want, you could build-up the seat height with foam blocks or similar on your test paddle to see how the CG height affects the stablity. Most kayaks, even a wide one like you have, are very sensitive to CG height, so make sure you test it first.

That said, if you do this properly you should actually increase the strength by what you propose. The "hole" in the deck of a conventional kayak is the weak point, and usually most manufacturers will strengthen the hull around the coaming to compensate for the weakness in the design. So make sure it is plenty strong around your sit-on-top opening. And you might consider adding a bulkhead fore and aft of the opening, and either hatches or removable panels (simple screw-in access panels) so you can get to the closed off areas of the hull. Reinforce the areas around where you cut out for the hatches as well.

Also consider this will add a lot of weight, as well as the cost and effort to build and convert your kayak. If you like experimenting than by all means do it, and have a good time. But it would be far easier, and likely not any more cost, just to find a used sit-on-top.

Good luck.