sculling oar project

[curtisv]

I've been saying for years that I wanted to build a sculling oar.

I sold my outboard years ago and have sailed engineless since.  Just sails and anchor.  No wind situations are rare here, but I have slept aboard waiting for wind to improve.  What has prompted me to do something was the crowding of the ramp I used to use, and the protection from wind and long trip out at the best alternative ramp.  Ryder's Cove in Chatham has become a zoo.  Nasty tourists in their motorboats.  The River Road ramp in Orleans is steep enough and deep enough, but the river is narrow and high banks and houses in places block most of the wind.  Last season, I towed my CP23 from the ramp with my kayak when wind didn't cooperate on launch day, and made it back all but a few hundred yards under sail on retrieval day.

So now I'm sufficiently motivated to build a sculling oar.

First step was to sketch out some plans.



The oar has to exit at the transom below the stern pulpit rail, but above the tiller and rudder assembly if it is to be centered.  I want the rowing position to be forward in the cockpit and the oar about 4 feet above the seats, chest high when standing.  The oar then has to bend to meet the waterline, else end up as long as the boat herself.  As is, as built, the oar is about 15 feet.  The diagram above was the basis for the bending jig.

I decided to build a prototype first and then build the final oar such that it can be broken down into three or four pieces and stored in a cockpit locker.

The prototype is made of cheap knotty spruce, intended for furring strips.  It came in 16' lengths, 3-1/2" wide.  The lumber yard had only three and practically gave them away.  I found one other 2-1/2 " wide piece and that was going to have to be good enough.  The pieces were cupped so I ran them through the surfacer a few times and got most of the cup out.  The blades are getting dull so I'll need to get them sharpened before the next attempt.  The sides were also chewed up, so a few rip cuts on the table saw were needed.  This gave me four pieces wide enough but some would be needed for the blade.  Two pieces had to be cut into two shorter to get rid of nasty knots.

The glue layup was in three steps.  Since the prototype is throwaway (after one season or less testing), I didn't scarf the joints.  I used a few butt joints, but managed to avoid a joint near the bend.  The first glue up was just two layers.  At about 5/8" width after surfacing, a lot of clamp force was needed for the bend.  I used marine epoxy, so allowed 48 hours to dry like a rock.  Second glue up added a layer and some blade pieces.  Third glue up added the rest of the blade and another layer.  The third glue up should have been done as two steps, but again taking short cuts.

Next came shaping.  I started with the blade end as that is most interesting.  Most of the blade shaping was done with a block plane, with some help from a Sureform style rasp.  So far I shaped the blade and a little under 1/2 of the oar shaft.  Shaping the shaft is mostly done with the rasp and is going quickly, with the result being nicely roundish, but certainly not round.

I took some pics along the way, but still on my camera.  I'll post pics later with an update on progress.

Curtis

[bob lamb]

Way to go, Curtis!
 "The biggest problem with sailboats is their motors" (anon quote). I'm with you on this oar.  I've been researching the idea w/o much success for a long time.  Now, someone who has it figured out is doing it.  I'll be following you with great anticipation. (And probably copying you)

Sea ya
Bob

[GretchenG]

Interesting, I've been wondering if anyone had tried sculling a CP!  When I was planning to build a flat-bottomed plywood boat I thought I'd try a yuloh with it, but I wasn't sure how a yuloh would work with a keel.  I'll look forward to hearing how it works for you.  There's lots of info on the web, actually, but you have to search for "yuloh" to avoid results about rowing a scull.

[curtisv]

Way to go, Curtis!
 "The biggest problem with sailboats is their motors" (anon quote). I'm with you on this oar.  I've been researching the idea w/o much success for a long time.  Now, someone who has it figured out is doing it.  I'll be following you with great anticipation. (And probably copying you)

Sea ya
Bob

Bob,

Don't copy the plan yet.  This is a prototype and its purpose is to figure out if the oar works as planned, or if the plan needs minor adjustments.  The jig was built to the plan with 8.5x2.5 and 4.5x4.5 parts to it.  The oar is slightly shorter since at least at the blade end it can't go all the way to the corner of the jig.  After clamps were released, the oar sprung out about 3" which is not bad, give the length.

The rough shaping is done.  I have one more day (today) of rough sanding.  Then I'll need to fine sand and apply some sort of finish to protect the wood.  I may just slap on some epoxy and let the prototype be ugly.  If I varnish it would set me back a week in dry times between coats.  (Ideas, suggestions on that?)

I may know early next week whether its fine as is, or whether it is too deep (rowing at knee level) or not deep enough (rowing at head level to keep the blade in the water).  I'll let you know how it goes.

Photos are still on the camera.  Right now its time for me to go make more sawdust (get back to my rough sanding).

Curtis

[Bob23]

Anyone ever see or use this:
http://www.duckworksbbs.com/ProductDetails.asp?ProductCode=GC%2DSM
Bob23

[curtisv]

Todays activities included a lot of sanding.  Mostly with 36 grit, then some with 60.  That was a success.  I won't bother fine sanding.  That was followed by making a mess.  Not a success.  There were two gaps in the blade and I wanted to fill them at least partially by wedging some very thin stock left over from some rip cuts and putting some excess glue in to further fill the gaps.  The epoxy was a lot thinner than I expected and leaked out leaving a bunch of runs.  Hence the mess.  So tomorrow I'll have some scraping or work with the rasp more sanding to get rid of the runs.

Photos uploaded soon.  Typing on a tablet at the moment.

Curtis

[curtisv]

Some photos.

The blade end after the final glue up, clamps off:



Out of the clamps before shaping sitting on a pair of 4x4 on the bench (not part of the blade - would be might thick), in front of a CP23 for scale:



During rough shaping.  I was shaping the handle end (you may notice it is squarish) and the cinder block is used to counterweight when I press hard on the sureform.  This is first pass of rough shaping.



Blade end close ups, top side, then bottom side:




I have some other photos, but these do a fairly good job of illustrating where I'm going with this project.

Turns out that I didn't take any photos today so I only have photos so far up to the more or less final pass of shaping and the start of sanding when only a first pass sanding on the blade was done.

Curtis

[nies]

With the org. rudder(al. blade) you could scull to some degree on my CP16 , but with the Ida rudder there is no purchase power side ways, of course the Ida rudder is power steering.............just a few thoughts.....................nies

[curtisv]

Yesterday's mishap.

That was followed by making a mess.  Not a success.  There were two gaps in the blade and I wanted to fill them at least partially by wedging some very thin stock left over from some rip cuts and putting some excess glue in to further fill the gaps.  The epoxy was a lot thinner than I expected and leaked out leaving a bunch of runs.  Hence the mess.  So tomorrow I'll have some scraping or work with the rasp more sanding to get rid of the runs.

Has been fixed.  I could only put in an hour or two today.  The fill pieces were a big improvement.  The epoxy runs weren't so bad and are mostly sanded off at this point.

A little sanding left to do.  Not sure what finish to apply.  I'd like something that won't delay further with multiple long dry times, but I do want it to look nice for the rest of this season.  (Ideas anyone?)

Curtis

[curtisv]

With the org. rudder(al. blade) you could scull to some degree on my CP16 , but with the Ida rudder there is no purchase power side ways, of course the Ida rudder is power steering.............just a few thoughts.....................nies

Nies,

Hadn't thought of that.  So if this oar doesn't work well all I have to do is put the old aluminum blade back on?  Sounds simple enough   

Curtis

[brackish]

A little sanding left to do.  Not sure what finish to apply.  I'd like something that won't delay further with multiple long dry times, but I do want it to look nice for the rest of this season.  (Ideas anyone?)

The two part polyurethanes (Bristol, Perfection Plus, others I'm sure,) can be used in almost a wet on wet manner, with recoats occurring from one to three hours.  I put five coats of Bristol on my wooden parts on a single summer day, then sanded the fifth coat lightly to get rid of imperfections after a 24 hour cure, then one final coat.  I think Perfection Plus has a three hour recoat, with a light sand between.  Expensive, but can be done much more quickly than marine varnish.  I'm not knocked out with Bristols longevity, but I've heard Perfection is more durable.

I think with any of the coatings, you will have to let your epoxy coat cure a few days to eliminate the possibility of blush.

[curtisv]

Brackish,

I didn't epoxy coat the oar.  The only epoxy that is supposed to be there at this point is at the glue joints.  The last epoxy was applied Saturday, so tomorrow should be fine anyway.  Thanks for the warning.

I may head to the local West Marine and see if they have Bristol or Perfection Plus.  Sounds like it is worth a try.  Otherwise I'll varnish.

Curtis

[curtisv]

More photos.

Here is the worst part of the epoxy mess after shaping the pieces wedged in place and sanding lightly (to the extent that 36 sandpaper sands lightly).  The picture was taken yesterday.  I sanded all the epoxy off by now.



I took a photo of the sanded oar next to my CP23 for scale comparison.  The oar is about 14 feet long.



Tomorrow I should decide what to finish the oar with.

On the other hand -- there is Bob23's notion that "the longer the planning and procrastination step, the better the outcome" so maybe I shouldn't rush to a decision.

I suppose if I'm going to varnish or use Bristol or Perfection Plus, then I'm going to have to use finer sandpaper than the 60 I stopped at.  Oh well -- more sanding to be done.

For a prototype I'm spending way to much time on this.

Curtis

[Bob23]

   This is an interesting project. Where to you plan to carry the oar aboard Remote Access? How about finishing with Armada or Cetol? It will definitely need periodic touch up and either of those is easily touched up.
   Can't wait to see how this works.
Bob23

[curtisv]

   This is an interesting project. Where to you plan to carry the oar aboard Remote Access? How about finishing with Armada or Cetol? It will definitely need periodic touch up and either of those is easily touched up.
   Can't wait to see how this works.
Bob23

Bob,

Funny you should mention Cetol.  I just got finished sanding almost the last of the Cetol off my exterior teak (did the handrails this year).  See http://cpyoa.geekworkshosting.com/forum/index.php?topic=6719.0.  I have a half can of original (very orange) Cetol, and 1/2 can of (somewhat less orange) Cetol Light.  I really don't want to continue to use Cetol.  It goes on easy, unlike varnish, but is not all that durable and requires all the work of scraping that varnish does.  If I wanted all that work, I'd varnish.  Maybe I will varnish my exterior teak someday, but for now its bare wood and teak oil.  Needless to say, the bare wood idea doesn't get along with spruce.

I went to West Marine and discussed what I was doing, including that it was a spruce prototype.  One of the guys there knew someone that made oars (for his own use).  I also know someone who has supervised construction and finishing of a lot of oars for a youth rowing competition (kids make their own rather large boats and row them as teams - sort of like a Viking inspired one design)  All seem to favor using epoxy with the 207 hardenner, the clear stuff.  Easy to apply, very durable, and looks good on well sanded spruce  So tomorrow I sand with finer sandpaper (than 36), and then epoxy.  That will happen after I help a neighbor restep his mast (had fitting issues and had to take it down on the water), so maybe tomorrow afternoon, maybe Thursday.  This will get done ... eventually.

The other question was about storing the oar.  Maybe you don't think it will fit in the cockpit lockers?  The photos sure make it look that way.  Perhaps that would be a bit tight.

The prototype is one piece.  The final version (when/if I get around to that), will be 3-4 pieces.  I can't put a joint on a bend, so probably four.  The final version when broken into four pieces should fit quite nicely in the cockpit locker.

That only leaves the problem of how to store the 14' one piece prototype.  I figure I'll invert it, bring it forward almost to the blade, and tie the handle to the backstay.  I think that will work as long as it doesn't interfere with the boom and mainsail.  There is a fair amount of room, so it just might work.  Otherwise, the side deck lashed to the stancions.

Curtis