Tuesday, July 1, 2014

Building Oars and Oarlocks

Having decided on Tulip Poplar for my oars, I drove down to Hearne hardwoods and found a straight plank 12' long x 2" thick.  I had them joint one edge.  I cut the two looms to 1 3/4" square and then used my jointer to make them eight sided.
Make the loops eight sided 
I marked off 10" by 1 1/8" diameter handles and then cut them out.
Cut out the handles

Make the handles eight sided
 I used a rasp, plane, chisel and sand paper to get everything mostly round.  As with most of my projects, I was able to justify the purchase of a new tool.  In this case it was a saw rasp from duckworks.
Round with a rasp and sand paper
I should have cut out the curved flats where the blades meet the looms before I rounded the looms - it would have been so much easier.  Ah well.  Then I glued on the blades.  I didn't have any marine plywood handy so I used AC Fir.  I put a fillet of thickened epoxy and embedded five or ten strands of linear fiberglass into the fillet.
Glue the blades
I tapered the loom with a drawknife and gave everything a coat of epoxy.  Then I put on three coats of spar varnish on the looms and a few coats of white rust-oleum enamel on the blades.
Taper the looms

Coat with epoxy, then varnish
10' 3" - that is a long oar
I made buttons (or stops) out of 1/4" nylon braid.  I tied a turks head as tight as I could get it but it was still loose enough to slide when subjected to a lot of force.  I varnished them in place - hopefully it will be good enough to keep them in place.
Turks Head Buttons
 After a trial row I found the oars needed counter weights.  I chose 1 3/4" propeller shaft zincs, each weighing 2.5 lbs each.  I think they are just right.
Couterweights
The cockpit coaming is about four or five inches inboard of where the oarlocks are normally mounted on a Core Sound 20 so I created outriggers out of ash and cherry.  The geometry isn't ideal - I have to sit on four or more inches of foam cushions to be comfortable.  

Outriggers for oar locks

Outriggers mounted on the coaming

Stowed under the coaming
Oars at the ready