Jim Michalak's Boat Designs
118 E Randall, Lebanon, IL 62254
A page of boat designs and essays.
(15feb01) This issue presents some "how to make" stuff for rowing. Next issue will present some looks at bulkhead bevels.
A sharp looking Mixer by John Trussel in South Carolina.
I decided to rerun these rowing articles that first appeared here in the winter of 98-99. I've left out some of the details that appeared in those issues and added other details.
MAKING A SET OF OARS....
I'm going to show drawings for 7' oars which are about the most useful length for me.
WHAT KIND OF OARS....
The oars I make are really derived from the patterns of the late Pete Culler. They are characterized by having heavy square looms inboard of the locks and long narrow blades in the water. An example is shown in Figure 1.
The square looms are easy to build, help balance the oar, help locate the oar in the locks, and keep the oar from rolling around on the wales.
The long narrow blades go against modern thinking of spoons, but for long distance rowing, long and narrow is the way to go. The average mortal can only pull so much of a load, in spite of what an Olympian might do. The Culler blades can match the mortal's pull. They might slip a bit when starting a heavy boat from a standstill, but once up to speed, they have full grip on the water. They balance better. They are less fatiguing. They have less windage. By the way, the oars of traditional Irish caurrahs have no blades on their oars. Neither do the paddles of some traditional kayaks.
WHAT YOU NEED...
Oars are made from four materials - wood, glue, leathers and varnish.
For wood, I use 1x6 pine boards. The pattern shown in Figure 1 will just barely make an oar from a 1x6. I try to buy a single board long enough to get out both oars. For example, for a pair of 7 foot oars, I buy a board 14 feet long if I can. That way the oars will be a close match on weight, stiffness, and color I like to use soft wood like pine, It is easy to work and makes a light oar. It need not be clear wood although clear is easier to work Small solid knots are fine and look good too. I've never worried too much about grain because the sticks get laminated and tend to stay straight. But the straighter the grain the better.
For glue I prefer plastic resin "Weldwood" glue and doubt if there is anything better for making oars. Pour some in a cup and squirt in cold water until it has the consistency of normal woodworking glue like "Elmer's. I've found it to quite true that this glue will not set properly until it is a t 70 degrees F for twelve hours like it says on the can. But don't hesitate to use epoxy if you already have it on hand.
For leathers I don't use leather. I bind the 8 inches just below the square section of the loom with synthetic mason's twine, about 3/32" diameter. It lasts for years.
For varnish I use ordinary oil based spar varnish.
Now let's talk tools. The tool I use the most in making oars is a bandsaw and I hate to say that because it's not a cheap or small thing that everyone will have. The problem is that you've got to saw a 2-1/4" thick blank. Hand saws will work and the effort should get you in shape for rowing. After all, oars were invented long before the bandsaw. But I see Dave Carnell has built oars using his table saw and others have built oars with a sabersaw.
HOW TO BUILD...
First cut the 1x6 boards to the proper length. lay out the centerline with a straight edge. Then draw the pattern for the center piece, the one with the blade, around the centerline. Cut out the center lamination following the line closely with your saw, because the outer laminations of the blank are made from the off fall and there isn't much extra.
You can draw patterns of the outer pieces and cut them out. But it's easier to glue the pieces directly to the center piece and trim them after the glue cures. Trial fit the outer pieces. You may have to trim them for the proper shape where they blend into the blade area of the centerpiece. When you are satisfied, butter them up well with glue, and clamp them in place. You may need to tap in a a light temporary nail to keep the pieces from sliding around on each other because almost all glues are quite slippery until they start to set. Try to get glue squeezed out all around. And be sure the blank is resting straight while curing. Walk away from the blanks until the glue has cured hard.
After cure, trim the outer pieces to match the centerpiece. Use a plane and sander to work these pieces to their final lines, being careful that these faces remain square to the other two unworked faces.
Now cut the two unworked faces of the handle and loom of the oars to their final dimensions. Draw centerlines down the two worked faces and lay out the shape of the handle and loom. Cut to the lines and sand smooth. At this point the cross section of the oar from handle to loom is square.
The oar drawing shows how much of the loom is left square. The rest is to rounded. You start by drawing lines on handle and loom that allow you to make the cross sections octagonal. You can draw them using the gadget shown in Figure 2. Then cut down to the lines with a half round rasp where the lines blend to the square section of the loom. Then use a drawknife or plane to remove the rest of the material down to the lines along the shaft. Now she's eight sided. To round it you're supposed to sixteen side it and then round it out. To tell you the truth, I leave mine eight sided, including the handle and the area which fits in the rowlock.
Lastly you need to trim mass out of the blade. I plane the blade down so its edges are 1/4" thick. Then I use the front roller of my belt sander to hollow the blade slightly on either side of the center, leaving a ridge in the center.
I think the only critical part of these oars strength wise is the 1-1/4" section where the blade meets the loom.
Give the oars a good overall sanding, but leave the handles rough.
Wrap the rowlock area, from the square section down 8 inches toward the blade, with mason's twine. Wrap it tightly and use knots to secure it.
Give the oars three coats of spar varnish. That includes putting varnish on the twine binding. It will go a long way towards holding the binding in place. Don't varnish the handles.
An easy and effective "button" can be made be added to the bound area, to provide a stop which will locate the oar lengthwise in the lock, by wrapping it tightly with three wraps of 1/4" shock cord, and tying the cord with a square knot. If the tension in the cord is right, it will stay firmly in place while rowing and yet allow repositioning up and down the bound area to change rowing leverage when required.
A ROWING SEAT/DITTY BOX....
Figure 3 shows a rowing seat/ditty box that I've been using for years. You might have to tinker with it a bit to get it to fit your butt. As for the height of the box, it is nice for a bar placed across the rowlocks of your boat to cross you at belly button height. That would include any padding on the seat such as a flotation cushion which you should have on board anyway. For that matter a stack of two or three stiff flotation cushions can make a pretty good rowing seat.
Here is what the seat looks like for real, this one about 15 years old now. Here are some things you might keep inside the seat: spare oarlocks, a knife, some line, sunscreen, Vasoline, binoculars, compass, whistle, and some energy bars. Always take a lot of drinking water with you also when you go rowing.
If your hull's side have limited flare, say less than 15 degrees, you can make some cheap oarlock sockets that are as good as store bought. I got the idea for these, plus the oarlocks that follow, from Phil Bolger who used them on his Spur 2 rowing boat that appears in his book BOATS WITH AN OPEN MIND.
Here is how it's done.
What we have here is simply two metal plates bolted to the wale with the proper sized hole (usually 1/2") drilled in each. Phil had his made of stainless steel. I made mine out of aluminum and have had no problems. I used an aluminum yardstick of the type carried by lumberyards for use with drywall as the basic material. I think the metal is about 1/10" thick and about 1-1/8" wide. I cut the aluminum to 3" lengths, stacked them up and drilled the oarlock hole and the bolt holes all at the same time. Filed off any sharp edges. Clamped the plates in the proper position and drilled the wooden wale. Bolted the plates in position and that's it. These work well because the oarlock bears on the metal parts which are about 1" apart, a bit more than the usual shallow factory sockets. So far I haven't worn them out. By the way, it helps to grease any oarlock from time to time, ordinary Vasoline works well.
I haven't tried these but Phil swears by them. It is really a thole pin with a bracket to retain the oar. Phil has always said that thole pins are better than the usual factory oarlock where the oar centers directly over the rotating pin. With a traditional fixed thole pin the oar rotates around the fixed pin as it bears against it and Phil says that is a better motion than with the factory oarlocks. The pin shown here could also be fixed, the bracket rotating around the pin with the oar! I should try these.
We'll see how you can cut the bevels that fit your bulkheads to the hull.
LIGHT ROWBOAT, 11.5' X 3.5', 60 POUNDS EMPTY
After the success Frank Kahr had with Robote I designed a smaller version with most of the same features. The idea was to get a fast and seaworthy boat that would cartop so easily that you would want to leave it on the car top more or less all the time, ready to go at a moment's notice. From cartopping smaller boats like Toto I had found that they hardly slow the car down or keep a compact car from getting 30+ miles per gallon. I thought the trick was to keep the boat small enough that complicated tie downs were not required. In particular to eliminate the ties that go to the bumpers which most newer cars don't have. I knew from cartopping Piccup Pram that a short boat, around 12' long, didn't need ties to the bumpers. I also knew that Piccup, at about 90 pounds, is about the most a fellow would want to cartop. Lighter is better of course but once the weight gets below about 70 pounds the boat becomes so easy to load that getting it super light is not mandatory. Other factors that make a boat easy to cartop are some width to the stern and a limited sheer. Boats with pointy sterns and a banana sheers, such as a standard canoe, are tough to load on the roof inverted because once flipped they will try to spin upright at any chance. Usually that happens when the boat is halfway onto the cartop. (However, that can be to the good sometimes. I once saw a drunk man try to load his canoe onto his station wagon. He couldn't do it until he was sober.)
Why not stick to a canoe like Toto, that does indeed have the square stern and mild sheer and light weight? I think a good rowing boat can be as fast, dryer, and can take a passenger with more ease. The only problem I see with Vamp is that her V bottom (which is not as extreme as Robote's) can make beaching more challenging that a boat with a flat bottom plank. I have done a rowing boat with Vamp's size, but with a multichine cross section, called Smoar. Smoar proved so popular with builder of the first that he built a second. But I think Vamp, with its simpler shape and V bottom, will be easier to build, faster, and better handling. But not by a lot. By the way, the easy to build factor comes from having no twists in the planks and easy bends, both factors making also for smooth water flow and good speed.
Construction is with taped seams from three sheets of 1/4" plywood.
Vamp plans are $15 until one is built and tested.
Some of you may know that in addition to the one buck catalog which now contains 20 "done" boats, I offer another catalog of 20 unbuilt prototypes. The buck catalog has on its last page a list and brief description of the boats currently in the Catalog of Prototypes. That catalog also contains some articles that I wrote for Messing About In Boats and Boatbuilder magazines. The Catalog of Prototypes costs $3. The both together amount to 50 pages for $4, an offer you may have seen in Woodenboat ads. Payment must be in US funds. The banks here won't accept anything else. (I've got a little stash of foreign currency that I can admire but not spend.) I'm way too small for credit cards.
Here are the prototypes abuilding that I know of:
Caprice: A brave and experienced builder in Texas is making the 25' Caprice water ballasted sailboat. A big project that looks bigger with each new photo. Into the final details I'm told, for a launch in the Spring.
Jon Jr has been completed by Joe Leinweber and Dan Ellis and tested to a certain degree. Click here to read about the test and the surprize ending! ("The waters are only safe until next time!")
Skat: I'm told the prototype Skat project is underway again and very close to being done.
Normsboat: This is an 18' sharpie being built by Cullison SmallCraft in Maryland. You should be able to check on it by clicking through to his web site at Cullison SmallCraft (archived copy, actual site no longer active). He is presenting an excellent photo essay of how to assemble a flattie.
AN INDEX OF PAST ISSUES
BACK ISSUES LISTED BY DATE
Mother of All Boat Links
Messing About In Boats
The Boatbuilding Community
Kilburn's Power Skiff
Bruce Builds Roar
Rich builds AF2
Herb builds AF3 (archived copy)
JB Builds Sportdory
Hullforms Download (archived copy)
Plyboats Demo Download (archived copy)
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