Jim Michalak's Boat Designs
1024 Merrill St, Lebanon, IL 62254
A page of boat designs and essays.
(15December 2017) We discuss cartopping boats. The 1January issue will talk about trailering boats.
THE BOOK IS OUT!
BOATBUILDING FOR BEGINNERS (AND BEYOND)is out now, written by me and edited by Garth Battista of Breakaway Books. You might find it at your bookstore. If not check it out at the....
REND LAKE 2018...
...will take place on June 8 and 9, always on the weekend before Father's Day weekend. AS OF DEC 7 WE HAVE ALREADY NAILED SITES 25 THROUGH 29 SO THE END OF THE LOOP IS OURS. THANKS TO ALL WHO HELPED NAIL THEM DOWN.
Raoul Adamchak rolls his Rio Grande for you on youtube at https://youtu.be/PphlZHf4n8k. Note the eskimo paddle.
1024 Merrill St,
Lebanon, IL 62254
Send $1 for info on 20 boats.
If you've got a light boat, cartopping can be a great way to move it around. Your boat is up and out of the way - almost a portable car port. Compared to trailering, cartopping allows more normal maneuvering and parking and freedom from fees and maintenance. I wouldn't consider going on a car vacation without a good rowboat or canoe strapped to the car's roof. The only things carried in the car's trunk are the cushions, PFDs and row locks. The convenience of it all struck home one time when we were leaving for a non-boating weekend. "Where's the boat?" my wife asked. It turns out it's a lot easier to find the car in a shopping mall parking lot with a boat atop!
I grew up in a time when everyone drove Detroit iron. Even family sedans had chassis and drive trains roughly equal to today's half ton trucks. You could stand on the roof, hood, and trunk without buckling anything. Rain gutters and bumpers were bull stout.
Those days are gone forever and it is probably just as well. Those cars got 10 miles to the gallon of gas, wore out a set of tires in 10,000 miles and went to the junk yard before 100,000 miles. New cars weight half as much, get 40 miles to the gallon, and 50,000 miles to a set of tires. But, HEY!, Mr. Designer, what happened to our rain gutters and bumpers.
I suppose today you will have to buy or make a special rack but it can be worth the effort. Today (2017) we have two newer SUV's and both require special mods to take a boat on the roof. In my opinion it is worth it since the vehicle will be free of a trailer. Your boat can stay up there all the time ready to go in the water at your whim. And you can find your vehicle in a parking lot easier since the new cars all look exactly alike.
You should be able to load your boat easily by yourself. If you can't you should get a trailer. As for weight, a hundred pound hull is the heaviest I care to load. Lighter is better but to tell you the truth, a seventy pounder is about as easy to load as a fifty pounder. So building an ultralight hull to the point of degrading strength or increasing costs can be a marginal decision in my mind.
As far as length goes, it is nice if she doesn't overhang the car's ends very much. The long ones are actually easier to get up to the rooftop but must have their ends tied to the bumpers to be secure. That takes a little time, but, worse yet, many cars don't have suitable bumpers. I think the day has arrived when we'll drill holes in the fenders of our cars to install eyebolts to secure our boats.
But I've found that hulls under about twelve feet long will stay put without bumper lines as will some long slender canoes and kayaks. The short ones are much less affected by wind and turbulence.
As for shape, a springy sheerline is not good for cartopping. Inverted on your roof, the boat's ends will droop down in your view. It's also harder to see when you're loading the hull on the rack. Lift the stern to see what you are doing and the bow dents your roof. It's happened to me.
If you've got a springy sheer and a double ended hull, as in most canoes, you've got troubles. She will have no natural stability inverted. That's great on the water, but having her self right when you've got her halfway to the cartop is a guaranteed dent. My first homemade boat, a Teal skiff, had this problem. Eventually I bored large holes in the stern just under the wales and, after inverting the hull on the ground in preparation for the lift to the roof, passed a stick through the holes. That kept her from getting self righteous while loading. I called it my "flippin' stick" although "anti flippin' stick" would have been better.
Later I built a Bolger dory whose tiny transom was only about 10" wide on top. That's all it took to stabilize her when inverted and I didn't need my flippin' stick. I've learned my lesson and haven't designed any double enders for cartopping.
As for aerodynamics, I've cartopped big dories to little prams and I think they've all degraded the car's performance about the same. Gas mileage on my Escort dropped from the high thirties to the low thirties no matter what was up there. So I'm doubtful about some promised hull or setup having shockingly improved aerodynamics for your cartop. But it could happen.
As for boat details, it's best if there are no lumpy or bumpy things on the wales to interfere with sliding the inverted hull onto the racks. Also on an open rowboat or canoe, 6" cleats mounted inside on the stem and stern will make tying to the bumpers very quick, tight, strong and easy
The roof-to-rack brackets I prefer were purchased years ago at a canoe shop and it says on them "Quick 'n' Easy Industries, Monrovia, Ca". They are bullet proof and attach with clever and foolproof over-center lever latches with no tools. Both racks go on in about a minute.
(I think the Quick 'n' Easy brackets shown are too beefy to fit in the gutter slots of many cars. If you need to, visit a yuppie bike shop for roof racks for gutterless cars. They've got new tech gear but keep in mind they're putting a 20 pound carbon fiber bike on a Porche. Perhaps we'll see the return of suction cup racks. Perhaps we'll be drilling holes in our roof and installing permanent pads with sealant and strong blind rivets. Why not? Try it on your clunker first and tell me how it works.
My cross bars, shown in Figure 1, are from 2x4's although fancy pipe bars are available. Make your bars a foot wider than the boat so you can strap oars and sail rigs up there too. Add blocks to the top ends of your cross bars so your hull won't accidently slip over the ends while loading.
My tie downs are 1/2" lines. You want big stuff here that won't stretch and make them plenty long, too. One end is secured with a loose bowline around the interior section of the cross bar. The free end goes over the boat, under the cross bar and belays on a sturdy 6" cleat which is well fastened to the bar. You can secure the rope very tightly and quickly. My system has no redundancy. If any line or cleat comes loose, the boat comes loose. So everything needs to be solid and secure. The benefit is that there is a minimum of things to attend to.
With the major elements in place it's time to load up. Practice helps a lot. First place the inverted boat next to the hull as in Figure 2, position A. (If it worries you that all this flipping and dragging will scratch your boat, most likely you are correct and will be better off with a well padded trailer.) From position A lift the bow and swing it up to the aft cross bar and rest it in position B. Now lift the stern and push it forward to position C. After a few times you'll get a good feel for where each position is in relation to your car.
Experience will show how far forward the boat should be and you might experiment. I prefer the boat shifted slightly aft of center. Also I find shifting the boat to the right side of the rack reduces buffeting from passing trucks. Don't go to an extreme though, because it's best if the ties pull mostly straight down.
If your boat is too short (or your car too long) to bridge the span from ground to rack in position B, then try the alternate method shown in Figure 3. I use this for short dinghies. Be very careful she doesn't fall off the front crossbar as you swing the stern around.
The hard work is done. You shouldn't have lifted more than 50 pounds at one time.
Securing the boat starts with tying on a 1/4" line to keep her from shifting fore and aft on the rack. I cartopped for years without this line, relying on friction alone to the job. But when friction gives out things get exciting. Once, while exiting the interstate in Birmingham, Alabama, at night, my dory slid forward on the rack a foot or more and every line up there went slack. Luckily I was coming to a stop anyway and retied the boat. But when that happens while you are being passed by a convoy of semis in a crosswind, you'll get some new grey hairs. The fore and aft line cures that problem completely. I usually tie it through an oar socket but it could also be permanently attached about anywhere in the center of the boat. Pull tight on one end and belay on the cleat on the front crossbar. Pull the other end tight to the aft bar and cleat there. Now your boat is secure fore and aft.
Pass the large 1/2" lines over the hull, pull tight, and belay to the cleats right over the fore and aft line. Now she can't go up, down, or sideways either. For a boat about 12 feet long or less this is all you need. Skinny low canoes a bit longer than that will be OK too.
The whole process from flipping the boat to drive away takes less than five minutes.
If you have a longer boat you should really secure the ends, at least the bow, to the bumpers to keep it pulled down and centered. The best way is to have 6" cleats screwed to the bow and stern with long lines tied permanently to them. Pass each line around a bumper support on one side and pull tight, then around the other support, back to the cleat on the boat, pull tight and belay. The line forms a triangle from bow to bumper corners and back to the bow. She can't go up or sideways.
Oars and sailing spars can go up there too, secured instantly with bungee cords.
Here's a major suggestion: Once you've mastered the solo loading process, don't accept help no matter how well intentioned. You may get some new roof dents or, worse yet, be distracted from some important tiedowns. Your "help" needs to be well educated in your system first.
The beauty of cartopping is that now you can drive around as you normally would. Well, almost. I should warn you about two things.
First is high winds. Once I drove the beautiful hills of Western Kentucky on a sparkling autumn day with my 16 foot dory atop a 1.6 liter car, pushing straight into a 30 mph wind. Full throttle gave me about 55 mph on the flat, of which there ain't none in Western Kentucky. Driving straight into high winds is primarily an inconvenience but high crosswinds can be dangerous. I almost lost that dory, and maybe the car, over the side of the Pensacola Bay Bridge in a crosswind. High crosswinds can always make for spooky handling, especially when the boat on the roof is almost as big as the car.
The second warning involves turbulence near large trucks. Car transporters seem the worst. Never stay in the turbulence near a truck on the highway. Your boat will start dancing around on the rack and add jerking loads to your rack. Either pass that truck or drop back clear of his wake.
If a truck approaches you at speed in the opposite lane of a two lane road, get as far to the right as possible. His bow wave will pass quickly but can give you a good jolt. The wave seems to attenuate rapidly with distance and a few extra feet of spacing on him will make a difference. That's why I suggest loading a hull on the right hand side of the rack.
The combination of the truck wake in a crosswind is the worst case.
LIGHT ROWBOAT, 15' X 4', 70 POUNDS EMPTY
Sportdory is an attempt to improve upon the Bolger/Payson dory I built about 15 years ago. This boat is slightly smaller than my old dory. In particular the bow is lower in hopes of cutting windage. the stern is mostly similar. The center cross section is about identical. This boat has slightly more rocker than the original Bolger dory.
The hull is quite simple and light, taped seam from three sheets of 1/4" plywood, totally open with no frames. The wales are doubled 3/4" x 1-1/2" pieces to avoid the wale flexing my first boat had. I've added an aft brace to stiffen it up and give the passenger a back rest.
Mine once covered 16 statue miles in four hours. In rough water you will feel the waves are about to come on board but they won't. But if you try to stand up in one it will throw you out with no prayer of reentry.
The prototype was built by John Bell of Kennesaw, Georgia. Here is a photo of John's Sportdory under construction. You can see the sides and bottom, precut to shapes shown on the plans, wrapped around temporary forms and "stitched" together with nylon wire ties in this case. I'm quite certain that with this design one must leave the forms in place until all the structural elements like the wales and cross bracing have been permanently installed. If they are removed before then, the assembly will change shape and you won't get the same boat. In particular I think the nose will droop to no one's benefit.
One might wonder about a comparison of Sportdory, Roar2 and QT. They are all about the same size and weight, a size and weight I've found ideal for the normal guy. They are small enough to be manhandled solo yet large enough to float two adults if needed. They are all light and well shaped for solo cartopping. Roar2 is probably the most involved to build and the best all around of the three. Sportdory is simpler and lighter, at least as fast and as seaworthy, but most likely will feel a little more tippy and less secure. You shouldn't really try standing up in either of these two. QT will be the least able of the three as far as speed and seaworthiness but may be the easiest and cheapest of the three and is stable enough to stand up in. So take your pick.
Sportdory plans are $20.
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.
We have a Picara finished by Ken Giles, past Mayfly16 master, and into its trials. The hull was built by Vincent Lavender in Massachusetts. There have been other Picaras finished in the past but I never got a sailing report for them...
And the Vole in New York is Garth Battista's of www.breakawaybooks.com, printer of my book and Max's old outboard book and many other fine sports books. Beautiful job! Garth is using a small lug rig for sail, not the sharpie sprit sail shown on the plans, so I will continue to carry the design as a prototype boat. But he has used it extensively on his Bahamas trip towed behind his Cormorant. Sort of like having a compact car towed behind an RV.
And a Deansbox seen in Texas:
Another prototype Twister is well along:
A brave soul has started a Robbsboat. He has a builder's blog at http://tomsrobbsboat.blogspot.com. (OOPS! He found a mistake in the side bevels of bulkhead5, says 20 degrees but should be 10 degrees.) This boat has been sailed and is being tested. He has found the sail area a bit much for his area and is putting in serious reef points.
AN INDEX OF PAST ISSUES
THE WAY BACK ISSUES RETURN!
MANY THANKS TO CANADIAN READER GAETAN JETTE WHO NOT ONLY SAVED THEM FROM THE 1997 BEGINNING BUT ALSO PUT TOGETHER AN EXCELLENT INDEX PAGE TO SORT THEM OUT....
THE WAY BACK ISSUES
1jan17, AF3 Capsize, Normsboat
15jan17, The Weather, Robote
1feb17, Aspect Ratio, Jewelbox Jr
15feb17, Aspect Ratio 2, IMB
1mar17, Normsboat Capsize, AF4Breve
15mar17, Underwater Board Shape, Harmonica
1apr17, Capsize Lesson, RiverRunner
15apr17, Measuring Leeway, Mayfly16
1may17, Scarfing Lumber, Blobster
15may17, Rigging Lugsails, QT Skiff
1jun17, Rowing1, Mayfly14
15jun17, Rend Lake 2017, Mixer
1jul17, Rowing2, Viola14
15jul17, Rowing3, Vamp
1aug17, RowingSetup, Oracle
15aug17, Taped Seams, Cormorant
1sep17, OliveOly Capsize Test, OliveOly
15sep17, Plywood Butt Joints, Philsboat
1oct17, Sailing OliveOyl, Larsboat
15oct17, Water Ballast, Jonsboat
1nov17, Water Ballast Details, Piccup Pram
15nov17, Scram Pram Capsize, Harmonica
1dec17, Sail Area Math, Ladybug
Mother of All Boat Links
The Boatbuilding Community
Kilburn's Power Skiff
Bruce Builds Roar
Rich builds AF2
JB Builds AF4
JB Builds Sportdory
Puddle Duck Website
Brian builds Roar2
Herb builds AF3
Herb builds RB42
Barry Builds Toto
Table of Contents