Rowing Grumman aluminum canoe

Advice
#10

@Guideboatguy,

May I buy you a virtual beer? Please message me your email, if you would accept it. Or I can make a donation somewhere on your behalf.

Thank you for being so helpful.

When you said significant inboard oar overlap is ok, does that mean my left hand should hold end of right oar and my right hand should hold end of left oar? That would solve the problem and make the rig very simple, I think. Here is how.

I took some careful measurements and did some dry runs (mimicking rowing actions in my canoe).

I found:

  1. I can sit close to floor height, right behind the stern (last) thwart and row the canoe backwards from there. When wife is sitting backwards on bow seat, the bow thwart actually does not interfere much (we did try it on the canoe).

  2. I can likely install oarlocks, on gunwale, right in the middle between center thwart and stern (last) thwart. There is still enough space, in front of my stretched hands holding virtual oars, and behind me for a child/a small adult to sit, even when I rock back and forth.

So we likely won’t need to remove thwarts.

  1. without knowing it, I lost 10 lbs and wife gained some weight. So we are at, in lbs, 32, 55, 114 and 123.

So for trim, maybe (please correct me) we can do this:

10 lbs (or less) of food/gears at bow before bow seat;

114 lb wife steering w/ single blade paddle /sitting at bow backwards;

55 lb kid sitting in front of wife and behind center thwart;

123 lb me sitting close to floor height behind stern thwart and row oars/arms between center and stern thwart;

32 lb kid sitting on stern seat, backwards or forwards (he is tiny at 4yo, so he can fit either way).

Does that trim plan sound good? That way, we don’t need oar locks on outriggers?

If so, we just need to screw oar locks onto gunwale.

To lock oar blade angle, will this kind of oar lock design work:
https://www.academy.com/shop/pdp/ProductDisplay?productId=4152524&campID=606107900&groupID=31502000358&device=m&productID=110081657&gclid=Cj0KCQjwrszdBRDWARIsAEEYhre7EekxcaP6VHbVQJiFhX0rsPBgayMC1PupgW-tDmU-Pfe3QumVJYkaArWWEALw_wcB

Or do I need that Oar Right like this one:
http://www.paddlesandoars.com/ACCESSORIES/OAR-RIGHTS/

Please feel free to refer specific products for our purchase.

Thank you again!

#11

As for the trim of the boat, the main thing is that you are thinking about it. The exact placement of the kids and gear is something you will figure out, and it need not be perfect. Trim is a problem for many people who just don’t think about it at all, but that won’t be an issue for you. Be as fussy as you want about trim, or just moderately fussy, and things will work out okay.

Your plan for rowing from the stern (with the boat going backward) sounds okay. You’ll probably find that whatever height off the floor you can provide will help. Most people find the outstretched leg position with no back support to be awkward, and the lower the seat, the harder that will be. For what it’s worth, in my dedicated rowboats, the center seat (which use when rowing solo) is roughly 4 or 5 inches above the bottom of the hull, and that works fine for me.

I also think mounting oarlocks on the gunwales is the way to go. You can always change things later if you think an outrigger setup would be better or that becomes necessary due to raising your seat height.

That first link you provided looks like a good method to use for a fixed oar position in the oarlocks. Another traditional method uses a pin that goes right through the shaft of a wooden oar. Many oars come pre-made that way. The second link uses a method that is more elaborate and designed for use with oarlocks that would otherwise allow feathering on the recovery stroke. A purist would say you should feather, but I don’t think most people need to be that elaborate (I use pinned oars, that is, no feathering).

As far as overlapping the handles, if I understood you correctly, no, you don’t want to reverse your hands (right hand to left oar, etc.). Doing so would eliminate crossover at the center of your stroke but create extreme crossover when pulling back and reaching forward. With a little practice, crossing your hands ends up being as automatic as walking. I typically alternate which way I cross over on each suddessive stroke, though often, if the wind creates the need to row more strongly on one side, I cross my hands in the same manner for every stroke. Check out these videos. For the upwind clips, one hand or the other, or both, might go higher than normal to make sure the blade is deep enough to be below wave troughs. In calm-water rowing, my hands tend to be lower which creates more crossover, and the hands just brush past each other on the crossover. You’ll see that in some of these clips:

https://www.flickr.com/photos/11908573@N00/albums/72157626731449520/with/5728460843/

Just for perspective, that boat is 15 feet long, 38 inches wide, and has the same 12-inch depth at center as your Grumman, even though the scale here is rather distorted by the wide-angle lens.

#12

One more thing. You will need some kind of a foot brace. You can start out with something really simple like a board secured with a rope at each end to the seat or a thwart that is just behind you, or has rigid support extending at an angle upward to a thwart toward the rear (ahead of you, as seated). Then build something a little more sophisticated once you know what you need. You can buy a special bar for this purpose (normally used as a foot brace when seated and paddling) from Wenonah, probably from Rutabaga Paddle Sports (or other paddle sports stores), and quite likely from Eds Canoe.

#13

@Guideboatguy,

Thank you very much. Very helpful!

Your foot brace ideas are great. I thought about the board over rope idea before, but forgot about it. I will try boards fixed angularly over thwart in front of my feet.

Now we have almost everything figured out! I enjoy this learning experience.

Just need to make an extension aluminum rod to (reversibly) turn my modular aluminum kayak paddles into longer oars then. Will try Home Depot’s aluminum rods first. Or I will just buy a new pair.

#14

Bummer.

My DIY aluminum extension tube idea (for converting my kayak paddles into oars) may not work. Unless I find a seller other than Home Depot.

Those aluminum tubes at Home Depot are too heavy to be used on canoe oars and their diameters are far off (I only found 1" and 1.25", but I need 30mm or 1.181"). They also won’t custom cut their 10’ tubes for me. Hand cutting their heavy duty tubes to 4’ is possible with my hack saw, though I still need lighter tube with the correct inner diameter.

Is there another good seller for aluminum tubes? I am going to check my local ACE and Harbor Freight. Just want to save some space by converting my kayak paddle to oars.

One off-the-shelf alternative is a pair of 7.5’ oars with oarpins installed for $113 shipped:

https://www.sailboatstogo.com/catalog/PARTS/5033

Seller told me those oars come with clamp-on oarpins/oarlocks, so their blades are set at the correct fixed angle for rowing. All I need to buy then is oarlock sockets.

Is there an alternative oar/oarpin combo that I should consider?

Thank you very much!

#15

There is a special place in purgatory for people that ‘row’ canoes. You can probably get out but you will have to portage that thing for at least half of an eternity. :wink:

#16

My extension tube idea probably won’t work, as my machinist friend told me metric (30mm) aluminum tubes are not easy to find in US.

I can irreversibly modify my two extra kayak paddles into oars, by cutting off blades and smooth put the ends. They are 8’ long, perfectly symmetrical and seem strong (with 30mm shaft diameter). They split in the middle and the two parts snap into each other with spring-loaded pins.

If purchasing dedicated oars is a much better idea, please kindly recommend oars, oarlocks and sockets.

Here is 4 that I found:

  1. 7.5’ regular duty (edit: 1.125" shaft diameter) oars with oarpins for $113 shipped to me (for a pair):

https://www.sailboatstogo.com/catalog/PARTS/5033

  1. 7’ “heavy duty” 1.25" shaft oars without oarpins for $94 shipped (for a pair):

https://www.sailboatstogo.com/catalog/product/5276

  1. Caviness aluminum 8’ aluminum with 1-3/8" shaft for $74 each without shipping:
    https://www.jamestowndistributors.com/mobileportal/show_product.do?pid=52042

  2. 8’ spruce for $160 a pair:
    https://www.clcboats.com/shop/products/boat-gear/rowing-gear-accessories/flat-blade-spruce-oars.html

Academy has clamp-on oarlocks for $10 a pair, which has so-so quality (I saw them today).

To get oarlock sockets (for $20 each), I may have to go to my local West Marine, if no better alternative is available:

https://www.westmarine.com/buy/west-marine--stainless-steel-edge-socket-oarlock-1-2-outside-diameter-shank--6820377?recordNum=7

Or this:
https://www.jamestowndistributors.com/mobileportal/show_product.do?pid=2287

I wonder which mount should I buy, for my use. Angled, side mount or top mount.
https://www.clcboats.com/shop/products/boat-gear/rowing-gear-accessories/bronze-oarlock-sockets.html

Advice is highly appreciated.

#17

You can get better oars than those, but even basic nice ones will cost more. I just looked at Sawyer Paddles and Oars, and saw a decent wooden oar with a traditional flat blade that looked pretty good, but for almost twice the price.

http://www.paddlesandoars.com/Oars/SAWYER-UTILITY-OAR/

If used with a clamp-on oarlock, there’s no need for the rope wrap and rubber stop options. I would probably prefer something like this to those take-apart aluminum kinds, but it all depends on what you can afford.

#18

^ Thank you very much!

What about oarlock sockets? I saw at least 3 types: angled, side mount or top mount.

https://www.clcboats.com/shop/products/boat-gear/rowing-gear-accessories/bronze-oarlock-sockets.html

These two seem to get good online reviews:

https://www.jamestowndistributors.com/mobileportal/show_product.do?pid=2287

https://www.westmarine.com/buy/west-marine--stainless-steel-edge-socket-oarlock-1-2-outside-diameter-shank--6820377?recordNum=7

#19

I have not looked at the gunwales of a Grumman in several years, but I think you can get by with either the angled or the side mount sockets. I believe there is a slight protrusion of the top face of the gunwale toward the outside, but if my memory is correct, it’s not enough to interfere significantly with placing an angle socket mount along that edge. I think that a side-mount socket will need to be mounted just below that protrusion, which may prevent the oar pin from settling all the way to the bottom of the socket, depending on how wide the horizontal bearing area at the top of the oarlock pin happens to be. You will want to look at the gunwales yourself and decide which mounting style for the sockets is better.

You will not be able to use the top-mount style, that is for sure. That is for a wide, flat-topped gunwale surface. The top plate of your gunwales is not very wide.

Those West Marine oarlocks will be quiet in operation, with the nylon insert, but I fear that that insert might wear out rapidly. Either of the other brands look to be durable. My oarlock sockets are brass, and on one boat the oarlock pins are brass and on the other they are stainless steel. Both are very quiet in operation, but they must be kept clean (I even clean and grease them before every trip, but most people would not take the trouble to use grease.

#20

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#21

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#22

I put my finger to approximately where I am putting the oarlock sockets.

You can see the outside and inside photos.

Yes, there is a gunwale protrusion towards outside, maybe about half the thickness of my index finger.

The gunwale protrusion towards inside is deep enough for my entire index finger.

#23

Flat surface width at that gunwale location is 26 mm.

#24

Gunwale protrusion towards outside is about 5mm and about 21-22mm towards inside.

#25

Okay, so that protrusion will be in the way. With a side-mount socket, it will almost certainly interfere with the oarlock pin dropping down fully into place, and for an angle mount, it will prevent a flush fit of the side portion (vertical surface) of the mount. I think if you got a strip of aluminum or brass of the proper thickness, and placed that along the side of the gunwale below that protrusion, you could use either type of oarlock socket mentioned above, though surely the angle-mount socket would be better. The strip of metal would need to have a thickness that is pretty close to matching the amount of protrusion of the top plate of the gunwale. I’ve seen strips of aluminum of various thicknesses available at most good hardware stores. The width of the strip could be anything that’s as wide or wider than the “height” of the horizontal mounting surface of the oarlock socket. Drill that spacer plate so your mounting bolts go through both the gunwale and that plate. This will beef-up the location of the oarlocks, besides just making the oarlock sockets fit the boat better.

#26

I am going with either Sawyer Utility or Smoker Utility. Talked to Aaron at Sawyer over the phone and he recommended those two.

#27

Thank you again, @Guideboatguy.

I have never seen oarlock sockets in person, so I would do exactly what you recommended (even though at this stage I don’t fully understand everything).

#28

I read your advice several times, looked at socket photos and measured again. Now I under 95% of it. It does sound like angled Mount would be better. I will google angled mount photos and look at them more. It is easy yo return to West Marine, so no worries, even if I need to go there a few more times.

#29

@Guideboatguy

Is the one-piece 8’ Small Stealth a lot better than Sawyer Utility 7.5’?

http://www.paddlesandoars.com/Oars/SAWYER-SST-OAR/

Cost difference is only $40 between the two pairs.

Aaron say the Small Stealth should be slightly lighter and tougher, though it may not matter for my casual use.