: Can anyone tell me where I can get plans for a 14 to 16 foot fibreglass
: kayak?

You need either a mold or a plug that you can either fill with fiberglass or wrap glass fabric around, respectively. A plug is easier to make if you are just making one boat.

Use any plans for a strip built kayak of that length. You can use 1/8th inch thick pine or cedar strips for this, instead of the usual 1/4 inch strips.
Don't worry about the quality of the wood or fancy joints.

Build the hull from these thinner strips, fill all gaps with wood filler, sand and fair,and then seal this, wax it, and apply a mold release agent. You now have a "plug" or a male mold around which you can build up layers of glass cloth and mat. If you build a hull thickness of 1/8th inch of fiberglass your outside lines and shape will be exactly that of the strip-built design. Apply a few more coats of resin to fill in the pattern from the weave of the glass cloth, sand smooth, and pull the hull off the plug.

Alternately, you can make a solid plastic plug from the 4x8 sheets of foam building insulation which you can get at lumberyards or home building stores like Lowes or Home Depot. Get some construction cement, like Liquid Nails (r) (check that it will work with your foam and not dissolve it) and glue together as many pieces as you need. If your kayak design has measurements for "lofting", as you might find in books like "Kayakcraft, by Ted Moores, you can lay out the lines on each slab of insulation and cut a rough outline of each piece with an inexpensive hotwire cutter ( check your local art supply or craft stores). Then laminate these layers together to give you a solid plug. Now just go after the thing with a belt sander, surfoam plane, rasp, or simply a block of wood with some coarse sandpaper tacked on, and knock down all the edges, smoothing the hull shape into something rounder and sleek. Seal this, wax it and coat it with a mold release.

Now make the deck the same way. Join deck and hull in the same manner as you would do with a strip built kayak, sand the seams.

If you used polyester resin you can paint it now, or leave it s is. If you used the more expensive epoxy resin then varnish or paint the boat -- inside and out -- to protect against UV.

Considering the added weight, materials and time involved, if you are only making one or two boats going with straight fiberglass is a waste. It is faster and cheaper to make a woodstrip kayak which is covered on each side with fiberglass. You have the integrity of a seamless, waterproof, fiberglass surface, bonded to each side of a strong, lightweight, flexible core. You use less glass cloth and less resin, which means less money. You get a unique boat that looks far more valuable than a plastic boat.

hope this helps

PGJ