Marlin,

I can't claim to have used Dynel, but I've played around with epoxies, fiberglass, additives, etc. for a while.  I am planning on making some paddles using some of the techniques I learned working on composite aircraft and cedar strip canoes.

Here's an adaptation of one of those techniques: Get some thick polyethylene sheet plastic material (4-6 mil), as well as some thin (1/2-1 mil) stuff.  Try to get it from a roll so that there are no folds or creases in it.  Cut an oversized piece of each thickness plastic for your paddle blade.

Use a felt tip marker to mark the thick piece of the plastic the exact shape that you want the final size of the fiberglass to be.  Mark it ~3/8" longer than the blade so that you can make the "tip".   Also make sure to mark it so that you know which side the ink is on (epoxy dissolves felt-tipped pen marks and will discolor your wood).

Flip the inked piece over so that the ink is down on your work surface.  Place an oversized piece of fiberglass cloth on top of the plastic (your blades will be stronger if you run the threads diagonal to the blade edges, or "on the bias").  Pour on some mixed up epoxy, place another blank piece of plastic on top, and then squeegee the "sandwich" to wet out the cloth.  Use enough epoxy that the sandwich is a little wet.  You don't want a "dry" layup because it will also have a rough finish.

Now... use a "pizza cutter" rolling razor knife (Fiskar makes a good one that is widely available) to cut cleanly and neatly through the "sandwich" following the lines that you marked on the plastic.  Carefully peel away the thin piece of plastic, and lay the wet cloth with the thick plastic backing on your paddle right where you want it.  Squeegee or press it into full contact with the wood and eliminate any air bubbles, but don't peel off the thick plastic yet.

This gives a neat (almost glove-less) layup exactly to size, without frayed glass edges.  The thick plastic will keep the cloth sticking out straight past the end of the paddle, particularly if you can tape some cardboard or other backing on top of the plastic to keep it in contact with the blade, and then lay the paddle plastic side down while the epoxy sets up.

When the epoxy is "green" (gelled up and the cloth stiffened but still not fully cured), flip the paddle over and repeat on the opposite face.  Now you have a fully glassed blade with a fiberglass "channel" at the tip for the Dynel, fortified epoxy, etc.  If you stand the paddle on end with the tip up, you can pour or pack the end-treatment into the channel.  My preferred mix is a stiff epoxy/microfiber/phenolic microsphere mix that is both tough without being brittle.  Once it all cures good and hard, you can peel off the plastic layers and have a nice, slick surface.

If you want a really rugged paddle, you could then surface abrade the edges slightly and wrap them with a 2" wide strip of 2 oz cloth laid on the bias... again, use a plastic sandwich to keep the application neat and avoid lifted, displaced strands.  Use very thin plastic for this one, because the thick stuff won't bend around the narrow edge of the paddle.

If you don't want to wrap the blade in glass (or it's already wrapped), you can get the same results using clear packing tape to make the channel at the paddle tip.  Just  abrade the paddle tip well enough for the epoxy to soak in and make a good bond.  I have been known to make a thin mix and paint it onto the wood first.  If the wood resists soaking it up, I'll heat it with a heat gun to open the pores and help wick the thin epoxy into the fibers to get a really good bond.  Then, I put the thick mix on while the first coat is still green.

Have fun!

WS