when building a stripper such as the Redfish Spring Run you have both an internal and external stem. These are built at the outset using a plywood form. You laminate a number of one eight inch thick strips of hardwood (about an inch wide) over the form. Once the hull is stripped the bow and stern of the kayak is squared off and the external stems are epoxied on and then shaped on the boat to a nice tapered edge.

I was looking for a web site that illustrates the approach and the only one that came to mind is Bill Price's site where he is building Beth's Silver. There are some pictures of the form with the internal stems on it. I couldn't find any pics with the external stems in rough form.

I seem to recall Nick describes a similar approach in his book for building a Guillemot.

You could try a similar approach. You would start by squaring off the ends of your S&G and shaping them into a smooth arc. Make a cardboard template that mimics that arc. Use the template to make a plywood form. Make external stems as described above. Then proceed as if you were building a stripper.

In Nick's book he doesn't use the plywood form, he shapes the stems directly on the boat. My concern about using that approach in your case is that you will probably need to build up thicker stems than he does, and also it is a challenge holding the stems on the bow and stern while expoxing them on the boat.

It would be easier (although more work) to first make a form and then build up a number of laminations over that form. That way the stems already have the shape you want before you try to expoxy them to the boat.

That's what I would do. Good luck.