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Thread: Adding Counterbalancing Weights to Oars

  1. #1
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    Default Adding Counterbalancing Weights to Oars

    I had a chance to try out some different types of oars at the CWB Homebuilt Boats weekend a month ago and was really taken with the improved action and feel of a pair of oars that had internal lead weights added to the inboard ends to counterbalance the blades better. In fact, I was so impressed that I was inspired to add some weights to Rowan's oars after that trial. Here's how i did it for those of you who might want to try out something like this for yourselves:

    The first trick was deciding where and how much weight to add. You still want to oars to be slightly blade heavy, so you don't want to overdo it. You also don't want to increase your reciprocating mass more than necessary or weaken the oar. All of this implies putting a smaller amount of lead as far inboard from the oarlock fulcrum as possible to get the maximum leverage from your weight, so I put the lead inside the oar handles themselves. I decided that I could afford to bore a 3/4 hole down the inside which would still leave me enough wood around it at the thinnest part. A lead slug 3/4 slug 3 inches long is about 1.32 cubic inches which comes out to about 8.6 ounces per oar.

    First trick is clamping your oar straight and level at a convenient height for working. The ol' hydraulic workbench came in handy as usual, with a few jigs and wedges of wood to hold her steady while I marked the centerpoint of the oar handle.



    Next, I used a long shank drill bit to make a pilot hole for the auger bit. A long drill bit is useful for sighting the trueness of your hole as you have a longer baseline to sight on. I had a helper sight from the side while I sighted from the top to get this hole dead straight down the center of the handle. A bit of masking tape wrapped around the bit serves as a depth stop.



    Next, I sharpened up an auger bit with a file and got out the trusty brace drill for boring this end-grain hole. An advantage to using a nice, slow hand tool like this rater than a power drill is that you are less likely to screw up all at once. With a brace and bit, you have to be determined and persistent to screw up completely



    I then turned a couple of chunks of lead on the metal lathe into 3/4" cylinders to fit the bores. Lead is super easy to machine, but lead dust isn't very good for you so you need to take reasonable precautions. If you didn't have a metal lathe, you could just saw up square chunks on the bandsaw, or use lead shot and just fill up all the cracks with epoxy I suppose.



    I then glued the lead into the hole with epoxy with a 3/16" thick wooden plug to hide the metal.


  2. #2
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    Default Re: Adding Counterbalancing Weights to Oars

    For those without a lathe, you can also pour lead into a piece of 1/2" copper tubing. Preheat the tubing to make sure it is dry or you may be producing a steam fired canon. Pour the lead in very slowly, heated trapped air can expel the lead almost as well. You can fill the pipe with lead scraps and heat the pipe with a torch. Wear a full face sheild.

    How did you determine how much weight to add?

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    Default Re: Adding Counterbalancing Weights to Oars

    I figured out the balance point of the existing oars compared to the wear marks in the leathers where I like to row and then added weight to the handle to bring that balance point much closer to the fulcrum point-- they now seem to balance about 12 inches outboard of there which should be enough to just overcome the buoyancy of the oar blades and leave 'em pretty neutral. It has been a combination of empirical experimentation and wild-ass guessing.

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    Default Re: Adding Counterbalancing Weights to Oars

    Quote Originally Posted by James McMullen View Post
    It has been a combination of empirical experimentation and wild-ass guessing.
    Isn't that pretty much a description of life? Nicely put. New acronym too: EEAWAG

    I just may have to try this (the weight, the EEAWAG I've been doing right along)

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    Default Re: Adding Counterbalancing Weights to Oars

    Quote Originally Posted by James McMullen View Post
    I had a chance to try out some different types of oars at the CWB Homebuilt Boats weekend a month ago and was really taken with the improved action and feel of a pair of oars that had internal lead weights added to the inboard ends to counterbalance the blades better. In fact, I was so impressed that I was inspired to add some weights to Rowan's oars after that trial. Here's how i did it for those of you who might want to try out something like this for yourselves:

    The first trick was deciding where and how much weight to add. You still want to oars to be slightly blade heavy, so you don't want to overdo it. You also don't want to increase your reciprocating mass more than necessary or weaken the oar. All of this implies putting a smaller amount of lead as far inboard from the oarlock fulcrum as possible to get the maximum leverage from your weight, so I put the lead inside the oar handles themselves. I decided that I could afford to bore a 3/4 hole down the inside which would still leave me enough wood around it at the thinnest part. A lead slug 3/4 slug 3 inches long is about 1.32 cubic inches which comes out to about 8.6 ounces per oar.

    First trick is clamping your oar straight and level at a convenient height for working. The ol' hydraulic workbench came in handy as usual, with a few jigs and wedges of wood to hold her steady while I marked the centerpoint of the oar handle.



    Next, I used a long shank drill bit to make a pilot hole for the auger bit. A long drill bit is useful for sighting the trueness of your hole as you have a longer baseline to sight on. I had a helper sight from the side while I sighted from the top to get this hole dead straight down the center of the handle. A bit of masking tape wrapped around the bit serves as a depth stop.



    Next, I sharpened up an auger bit with a file and got out the trusty brace drill for boring this end-grain hole. An advantage to using a nice, slow hand tool like this rater than a power drill is that you are less likely to screw up all at once. With a brace and bit, you have to be determined and persistent to screw up completely



    I then turned a couple of chunks of lead on the metal lathe into 3/4" cylinders to fit the bores. Lead is super easy to machine, but lead dust isn't very good for you so you need to take reasonable precautions. If you didn't have a metal lathe, you could just saw up square chunks on the bandsaw, or use lead shot and just fill up all the cracks with epoxy I suppose.



    I then glued the lead into the hole with epoxy with a 3/16" thick wooden plug to hide the metal.

    Do not use epoxy with lead shot.
    The lead shot will float in the epoxy and not make a dense filling.
    It also does not glue all the BB's together. Been there.
    Instead, fill it with lead shot and glue in a wood plug.
    I love the smell of fresh cut plywood in the morning.

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    Default Re: Adding Counterbalancing Weights to Oars

    I use a pair of Barkley Sound 8' spoons. I drilled only 1/2" diameter but went in quite a long ways. I have a spool of 1/2" lead 'wire' from Non Ferrous Metals on Harbor Island in Seattle. Snipped off a couple of lengths, slipped them into the oars, and plugged the ends.

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    Default Re: Adding Counterbalancing Weights to Oars

    Quote Originally Posted by donald branscom View Post
    Do not use epoxy with lead shot.
    The lead shot will float in the epoxy and not make a dense filling.
    It also does not glue all the BB's together. Been there.
    Instead, fill it with lead shot and glue in a wood plug.
    What about a mix of lead shot and bedding compound, chased with a glued in wood plug? If I heard a rattle in there I'd go insane.
    Quote Originally Posted by James McMullen View Post
    Yeadon is right, of course.

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    Default Re: Adding Counterbalancing Weights to Oars

    Donald, what size of shot have you tried that with - I've been considering that technique for other circumstances.
    Brute force and ignorance, all in one bulky and unappealing package

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    Default Re: Adding Counterbalancing Weights to Oars

    Quote Originally Posted by donald branscom View Post
    Do not use epoxy with lead shot.
    The lead shot will float in the epoxy and not make a dense filling.
    It also does not glue all the BB's together. Been there.
    Instead, fill it with lead shot and glue in a wood plug.
    Huh? The specific gravity of lead is 11.35 and that of epoxy about 1.2 .
    Explain, please.

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    Default Re: Adding Counterbalancing Weights to Oars

    I'm perplexed by that too. I've used lead shot held together with epoxy to ballast sailing models and it worked just fine. What I did was pour the lead shot in first to get the weight distribution balanced just so, and then ladled thin epoxy over it. It worked just fine for me.

    Were you mixing up lead shot and epoxy stew? Thick resin and tiny little shot? Work too much air into it? With thin, warm resin poured in over the top I can't imagine you'd have any problem with a completely captured oar counterweight made of shot.

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    Default Re: Adding Counterbalancing Weights to Oars

    Yea James, I've done the same, epoxy/ lead shot for model keels. Worked swell! (see thru too)

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    Default Re: Adding Counterbalancing Weights to Oars

    That's what I did with my 12mR model with a winged keel. I used System3 epoxy, because it was thinner than WEST. I did a little at a time, both because I wanted to make sure the epoxy got everywhere and because I know it is exothermic (although the lead would make a good heat sink, wouldn't it?). My concern was that the winged keel was plastic, which would have made it difficult to cast directly. Oh, by the way, I was following the kit manufacturer's directions. I believe it was #9 shot. In any case, worked well. As an added side benefit, I have enough left over to cast a couple of ducks...

    For the oars, I probably wouldn't have turned an ingot, I would have cast one directly. But hot lead or lead dust... choose your poison. You pays your money and you takes your chances.

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    Default Re: Adding Counterbalancing Weights to Oars

    I had a chunk of lead, a bandsaw, and a lathe standing by. For me it was vastly quicker to just turn 'em than to melt a buncha lead. My slugs came out accurate to the nearest thousandth too. . . . .something I've not had all that much luck with when casting

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    Default Re: Adding Counterbalancing Weights to Oars

    I was using lead shot for a model boat when I found out that the shot WILL float in the epoxy.
    Also I found out the epoxy does not saturate the lead shot.
    I love the smell of fresh cut plywood in the morning.

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    Default Re: Adding Counterbalancing Weights to Oars

    Notes to myself:
    Mix the shot and epoxy together. Don't rely on epoxy draining through a mass of shot.
    use slow hardener

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    Default Re: Adding Counterbalancing Weights to Oars

    Well... have you tried them out yet?

    I don't know what kind of models you all are building, but on our T37 we use standard boat zincs. a bit lighter than lead, but easy to obtain and work with. They can even be had in a hydrodynamicaly friendly teardrop shape.
    There's the plan, then there's what actually happens.

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    Default Re: Adding Counterbalancing Weights to Oars

    I'll try them out on Thursday. . . unless there's any wind.

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    Default Re: Adding Counterbalancing Weights to Oars

    Quote Originally Posted by James McMullen View Post
    I had a chunk of lead, a bandsaw, and a lathe standing by. For me it was vastly quicker to just turn 'em than to melt a buncha lead. My slugs came out accurate to the nearest thousandth too. . . . .something I've not had all that much luck with when casting
    Who needs to do any casting? Turning it on the lathe is fine if you have a lathe handy, but it would have been a more direct solution (particularly if you didn't have a metal lathe) to simply drill out the handles as described, melt a batch of lead in a cast iron skillet on the kitchen stove and pour it directly into the holes in the handles. We used to do this with the business end of baseball bats when we were kids, then stick a bung in the end and finish it off so's nobody'd notice. We didn't need steroids to send it over the outfield fence!

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    Default Re: Adding Counterbalancing Weights to Oars

    Yeah, but what kind of ladder do you recommend climbing up with a saucepan full of hot, molten lead to pour into the ends of oars which are like 10' off the ground when vertical?

    I still think my way was better. Less burney.

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    Default Re: Adding Counterbalancing Weights to Oars

    Quote Originally Posted by James McMullen View Post
    Yeah, but what kind of ladder do you recommend climbing up with a saucepan full of hot, molten lead to pour into the ends of oars which are like 10' off the ground when vertical?

    I still think my way was better. Less burney.
    Cut a hole in the kitchen floor (chain saw is quick) & let the end of the oar rest on the basement floor. Has the added advantage that any spills land in the basement.

    Hey - just trying to help!

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    Default Re: Adding Counterbalancing Weights to Oars

    Less burney: hahahaha.

    Dad played pro ball, so corked bats were a no-no; we took a wiffle ball bat, cut open the end, stuffed a two-by-two in, taped it shut, and hammered the tennis balls we found behind the racket club. Tennis balls are wicked for change-ups; lots of scuff.

    Around here, you could just put a pot of lead on the roof during the afternoon and be ready to pour in a few hours

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    Default Re: Adding Counterbalancing Weights to Oars

    Quote Originally Posted by James McMullen View Post
    Yeah, but what kind of ladder do you recommend climbing up with a saucepan full of hot, molten lead to pour into the ends of oars which are like 10' off the ground when vertical?

    I still think my way was better. Less burney.
    Dude, you just have no sense of adventure.

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    Default Re: Adding Counterbalancing Weights to Oars

    Actually, I was thinking that if you simply drilled holes in a 2*4 with the same bit you used in the oar, they couldn't help but be the right size. If they shrank "just enough", you'd get the tolerance you need.
    Heute ist so ein schöne Tag...

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    Default Re: Adding Counterbalancing Weights to Oars

    I've been meaning to jump in for days. Thanks for this thread, James. Counterbalancing oars is absolutely key to good oars and enjoyable rowing.

    At WB School I had my students use little bits of scrap lead flashing that we cut up and literally mashed into holes bored into the handles just like James shows. The best bits for this are augers or spade bits. Here is a shot of one student busy cutting up the bits. The lead compresses into the hole and the hole is plugged with a bung, so no epoxy is needed. But it is important to re-check the balance on the bench for each oar before gluing in the plug!



    In my shop, we'll pour lead into thin-walled copper tubing. The nice thing with this is that you can use the density of lead and do a volume calc.

    I'll post more...
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    Default Re: Adding Counterbalancing Weights to Oars

    I'd be concerned about the diameter of the hole bore compared to the outside diameter of the tapered grip. If the remaining wood ends up being quite thin, mightn't the grip snap off when stressed (e.g. dropped on the hard, or lashed down for travel)? If a lead billet was a tight fit, it would stiffen things up somewhat. Loose pieces of lead would add no structural strength unless they were epoxied.

    Not sure it's an issue for flatwater rowing, except for the longevity of the oar. But I use the same wood oars for my skiff and my whitewater play-cat, and have jammed one in the boulders a few times. Ouch!

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    Default Re: Adding Counterbalancing Weights to Oars

    If you use the poured full copper pipe bedded in epoxy with no voids method I think it would actually add strength.

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    Default Re: Adding Counterbalancing Weights to Oars

    Just got back from trying out the newly balanced oars...and on Thursday they got a really good test because there wasn't squat for wind on my crossing, and I was required by a Coast Guard cutter bristling with machine guns to stop and wait outside the 1000 yard security zone while a freaking submarine came down the channel with its escorts--all the while drifting downstream and away from my destination at 2 1/2 knots! My ideal course and my actual route track made an equilateral triangle on the GPS screen after all was said and done. My 4 1/2 mile crossing cost me over six miles from the enforced drifting. Stupid submarine! How come they couldn't just go under me, huh? Isn't that what submarines are for, dammit?

    But anyways, I'm glad to say that the balancing was indeed a pleasant improvement and I plan on doing something similar for all my oars in the future. It was definitely and noticeably an improvement over the old way.

  28. #28
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    Default Re: Adding Counterbalancing Weights to Oars

    James, Wow what a story about the submarine!

    Sounds like counterweighting is worthwhile on the west coast, too!

    Here on the east coast, I learned of it by using some Andy Steever oars at Mystic. It was life changing, as life changing as the boat was for me. I haven't been able to get fast fixed-seat rowboats off my brain since.

    I meant to add this picture earlier...



    You can see the poured lead slugs. The walls in the handle after boring were about 3/16". No problems, have gone even less (on shoddy oars that I was trying to make better for youth rowing). It is true that it seems to add strength when glued in.

    I make some composite blade sculls...because the blades are so light -- and with a heck of a lot of laborious shaping to remove unnecessary weight (that is the art of oarmaking, smart wood removal) -- I was able to get away without any counterweight at all. Quite nice to have oars light and balanced, two different things.
    Clinton B. Chase
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    Default Re: Adding Counterbalancing Weights to Oars

    Traditional west norway oars are balanced to be just slightly 'blade-heavy' at 2/3 up the oar from the blade.
    After cutting and shaping the length, grip, blade (angle and thickness) and the shaft for correct flex, the balance is the final adjustment. The oar is left overly massive between the grip and the 2/3 point and gets planed down to acheive the proper balance. I don't have a shot of just the oars, but this will give an idea of the finished product.


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    Default Re: Adding Counterbalancing Weights to Oars

    Found this old thread about balancing oars and bring it forward again for thoughts on mine. Last weekend I finally got my CY wet after a two year build, mostly to make sure it floats. No spars or sails up as I’m still figuring out the rigging and really wanted to test out my motor bracket with the Torqueedo and the oars. Both a bit of a failure...but this is about the oars. The oars are 10.5’, two piece and Doug fir. The quick and dirty type with two piece looms dado...ed into the 2” fir.

    so in the water I could barely lift them out....and were, frankly, horrible. Thought I was close on the one third/two third wt distribution from the oarlock when I first made them...but back on land it took over 6 lbs tied to the front of the grips to make them feel right. Yes that’s 6 #! Initially was thinking I would do the drill hole with poured lead....but I’ll never be able to get 6# in there. Was the Doug fir my big mistake?
    29353EC3-652D-4B1A-AA2A-D28EBD61D7E1.jpg

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    Default Re: Adding Counterbalancing Weights to Oars

    Beautiful boat.

    If you add inboard weight to balance the oars you are adding weight that results in inertia that must be stopped, then reversed at each end of every stroke. Like pushing a box of rocks thru the air, then stopping it, then pulling it back, then stopping it, then pushing it forward, then stopping it, yada, yada.

    I am a fan of long oars. Can you move the oarlock further outboard like on a scull?

    It took me a while to realize that the blade need only come out of the water a wee bit and the blade does not have to dig in very far.

    Again, nice boat.

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    Default Re: Adding Counterbalancing Weights to Oars

    Quote Originally Posted by Clinton B Chase View Post
    Here on the east coast, I learned of it by using some Andy Steever oars at Mystic. It was life changing, as life changing as the boat was for me. I haven't been able to get fast fixed-seat rowboats off my brain since.
    Was that Sister Suzie? Andy had the only boat there that I would trade for a guideboat. He did like balanced oars.
    Management is the art of counting beans. Leadership is the art of making every being count. --Joe Finch

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    Default Re: Adding Counterbalancing Weights to Oars

    It looks like you have the oars rather far outboard. If you pull them in so far the handles overlap you have 2 advantages, the weight is less and you have more power. I think counterbalancing works, saw a french bloke have a steel profile just under the handles.

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    Default Re: Adding Counterbalancing Weights to Oars

    No I was probably referring way back then to Green Machine the Gardner-Herreshoff Rowboat or Myron's second version which was even better (skeg added).

    Now a days, I still think that GH Rowboat is one of the faster ones, but I can't wait to have a Drake Rowboat again. I will be building a 17 this winter for a client and will plank up two of them.

    GB's are definitely fast, but I prefer long and lean...St. Lawrence River Skiffs and the Drakes. Steever also preferred the SLRS. His 18-footer was his favorite.

    Balanced oars are essential. A little lead poured in a copper tube (about 7/8" D) and inserted into the handle of the oar. The only commercially made oars that don't need this are very, very short ones by S&T and Grapeview Boatworks' oars (because they ship them with lead added!)
    Clinton B. Chase
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    Default Re: Adding Counterbalancing Weights to Oars

    Before adding weight I would shave wood off of the blades and outer loom.

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