In my eternal quest for light (& cheap), I chose Gull Select oars, 1-3/4" shaft laminated fir from NZ, that come barenaked. Never wrapped an oar before, but since it costs $30-35, I gave it a go.
The best rope is braided polypropylene or other low-stretch, non-absorbent type (don't use nylon as it sags when wet). 3/16" is about right. I chose black (gangsta wrap) but you could look for something to coordinate with your tubes. For each 1-3/4" shaft I used 30 ft. For a 2" shaft, use about 40 ft. You also need rubber donuts or other compatible stops.
Tools: wrapping jig (below), utility knife, butane lighter for rope ends, needle nose pliers.
Materials (besides rope & oar): duct tape, nylon string, quick-set gel epoxy, rubber donuts, grips & tips.
Here's the wrapping jig I built.
2x2 with 5/8" holes at the ends + 2 oarlocks padded with rags (so your shaft won't get marked up– lots of chances for puns here, which I'm resisting). First, set the oars right on your frame and mark the center of the lock (the duct tape).
The black strap is to keep the shaft snug (otherwise the weight of the blade will tip it up). The shaft should rotate freely. I measured up (toward the grip) 4-1/2" to start the wrap. Most of the wrap should be below the oarlock. The measured piece of rope is stacked in the rigger's bag (otherwise it gets tangled up).
Here's the start. Note that I chiselled a groove for the rope, so there's no bump— not an option for synthetic shafts.
Turning the oar away from your body, so you can really reef on the rope, do about three wraps and then tighten up: push the wraps left— together— and pull hard, taking up all the stretch.
Next one's big, so you can see what's going on.
When you've used about 75% of the rope, tape the wrap down. Then tape a loop of strong, slick cord (white) as above, gulp some beer, remove the center piece of tape, and continue the wrapping process.
Don't pull the last several wraps tight—you'll take up slack later. When you're near the end, pull the tape off and slip the end of the rope through the loop on the small cord.
Pull the end of the rope under
the wraps (see why they have to be loose?) with an inch or two (enough to grab) following the small cord out.
Work the slack out of the loose wraps, while keeping the end straight and snug. (A perfectionist might mark where the end lies under the wraps, then undo the thing and chisel a second groove— I didn't).
Once it feels tight, work your way along the whole wrap to even out the tension, then go back and get the final bite on the bottom part.
Cut the rope. Don't bother to fuse the end— frayed, it blends in better. Then even out the wraps one last time.
Getting the donuts on (some are tighter than others) can be a vicious butt-cramp. Soaking them in warm water helps, and so does spraying the shaft and the wraps (with water, not beer). Here's the result:
The reason you want more rope below the lock is obvious, I hope.
Last step is to run a bead of quick-set gel epoxy around the bottom edge of the rope, so it doesn't peel back when you ram it through the lock. I didn't put any epoxy on the grip end, but I did use a wee copper nail there.
Here's one afternoon's bad-ass work.
The grips were a separate item, as were protectors for the blades (on back order). Total bite (shipping included): $73.82 per oar. Plus about 4 hours of work, two cans of Fat Tire, and one blister.
Guess I should write a book. But free works, too.