Jim Michalak's Boat Designs
118 E Randall, Lebanon, IL 62254
A page of boat designs and essays.
(30Jan98) I hope we can put discussions of the President's privates aside long enough to read this essay on cartopping. It may help you now and then. It's a bit dated perhaps because I mention in it cars you might buy with real rain gutters and bumpers, important things for boat work. I doubt if the car situation has improved in that regard recently. I think on the next issue, about 15 February, I'll present a letter and some jpgs of Toto building in Central America. Then we'll get into the topic of bevels in plywood boats.
BRUCE HALLMAN'S ROAR
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 100,000 miles to a set of tires. But, HEY!, Mr. Designer, what happened to our rain gutters and bumpers.
I'm not certain if any late cars have gutters and bumpers designed for moving boats. Even some new pickups lack them. But there are still lots of suitable good cheap used cars on the market. Ford Escorts up to 1988 had good bumpers and gutters as did all the Plymouth Horizons and Dodge Omnis and I think they made a billion of them. With their short trunks and good gas mileage, these are good cartoppers. If you insist on gold plate, I've noted that some BMW's and Volvo's have excellent gutters. Bolger once suggested that a low flat car like a Lamborghini is ideal (although I noticed he was driving an Escort with roof bars). Also, the man who designed the Yugo was probably much more a boater than a driver, giving it fine bumpers and gutters and not much else.
A very short trunk or a station wagon will make loading easier, too.
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.
Someday I may get to put my full catalog on the net. For now I'll put one design in each issue.
There have been three "official" versions of Roar. Bruce Hallman built recently the original version with a plumb bow. He has written quite a web page about it at www.hallman.org/roar/. I'm goin to keep his page in the links at the end of this page as an example of how a guy with no boat building experience can go out and build a boat. Bruce's page has a photo log with blow-by-blow description of building Roar, a time log of the adventure and log of the costs. He even points out one of my mistakes! (None of the previous builders said anything about the goof. I've updated the drawing.)
I like Bruce's approach. He built the boat from materials available at his local stores. (That means polyester resin instead of epoxy. That might bring of a storm of comments but my original Roar, built in 1990, used polyester resin and still sees lots of use and shows no sign of giving up. My Piccup Pram is a year older and built the same way with the same results. No doubt epoxy is better but no doubt polyester has been successful for me.) He made his own oars per my instructions while waiting for the stores to open. Be sure to stop at Bruces wonderful page.
The original Roar is not exactly in my catalog anymore although I still sell its plans. Its photo is on the cover of the catalog and the description is found on the Roar2 page.
ROAR, LIGHT WEIGHT ROWBOAT, 14' X 45", 75 POUNDS EMPTY
Roar is an early design of mine, intended to be a fast, comfortable, light rowboat to replace a dory that was destroyed in a tornado. I think I had Whitehall on the brain at the time and gave her a plumb bow which a lot of people like. I made her size and shape ideal for cartopping. In a way, Roar was a trial for many similar boats I did like Woobo and Mixer.
Roar was everything I'd intended but needed a large skeg to behave in strong winds. I believe a multichine shape, when carried from stem to stern as in Roar, has little natural resistance to side motion as in a cross wind. I hadn't noticed the problem in Piccup because her leeboard provides a keel action if it is dragging at all in the water. Similarly the Woobo prototype had no side slip problems.
I made my own boat track well by converting to a Toto type bow and called it "Roar2" (to be covered in the next issue of this page). But Roar builder Greg McMillian in the Northwest said he solved it by adding a simple 1X2 keelson full length to the skeg. I guess I should have tried that first before going to the Roar2 conversion. I added the keelson to the Roar drawings. (Greg also "chopped" the top of his Roar by 4" and added oar outriggers, making something of a shell of the boat.)
Because they have no internal structure, these boats are great for camping. They beach upright on the flat bottom plank, they are easy to get in and out of, you can sleep on the spacious floor with no frames or bulkheads to dig you, and there is lots of room for your gear. You row sitting on a simple ditty box that you can shift for perfect trim.
Plans are two blueprints complete with instructions for taped seam construction for $15. No lofting or jigs required. Roar needs four sheets of 1/4" plywood.
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. (If you order a catalog from an internet page you might state that in your letter so I can get an idea of how effective this medium is.) Payment must be in US funds. The banks here won't accept anything else. (I've got a little stash of foreign currancy that I can admire but not spend.) I'm way too small for credit cards.
Anyway..... Anytime a design from the Catalog of Prototypes starts getting built I pull it and replace it with another prototype. So that boat goes into limbo until the builder finishes and sends a test report and a photo. There are three boats in that catagory right now.
Scram Pram, a 16' multichine Birdwatcher type, has been completed and had its first sail near Savannah. I'm hoping for a good photo one of these days. The builder said it's hard to get good photos of your own boat and he's quite right about that. The surest way is to get a good beach shot of it.
And Skat, a 12' cat boat daysailer, is being built near Phoenix. Latest word from the West Coast Spy is that the boat has been glassed on the outside and ready to flip and finish.
The Kansas Boat Psychologist keeps plugging away at his Fusebox. The bulkheads and transoms and sides are done now so it's about time for the barn raisin'. He reported problems with unset epoxy and has sworn off using pumps to deliver the proper ratio. I don't use pumps either. I'm leaving Fusebox in the Prototypes Catalog for now because it has appeared on at least three web pages.
Here on the AF4 home front, winter weather has put the brakes on construction. The wood structure is done except for the skids on the bottom. I was able to fillet the inside bottom/side joints with thickened epoxy (RAKA) which set OK on a day in the mid '50's. Looks OK. That joint is actually a nail/glue joint but I've filleted it in an effort to minimize rot. It's where my Jinni started to rot. I think the nailed and glued joint leaves small gaps that gather dirt and moisture and promote rot. I think the epoxy seal will make it easier to keep the joint clean and dry. The outside of the same joint will be similarly treated, plus with two layers of glass tape for abrasion resistance.
I've had a few second thoughts about the bimini. I know the shade is a very important feature. Biminis are not particularly easy or cheap to make. I'd like to get by with a PVC pipe frame but the bends and joint details may be difficult. Also I'm a little concerned that the bimini will be a bit in the way when entering the boat from the side. I can check that out with a mockup. But I'm wondering if something like a beach umbrella might be an all around better choice if I can figure out a good way to mount it. It's what Bolger has gone to on his own boats.
Also I'm thinking it will need a large screened vent with a water trap on bulkhead 2 and a large screen in the door area (when I figure how I'm going to treat the door opening). Boat camping is usually a summer event and a good air flow though the boat is important. With a boat like AF4 the usual situation will be to use a bug net over the slot top but that won't work in the rain.
I noticed a letter in rec.boats.building about Coast Guard power suggestions. According to the formula the AF4 would be maxed at 25 horsepower.
Right now I'm 50 hours and $300 into the project. As is it weighs 300 pounds. Usually at this stage the labor is about half done, since finishing takes about half the work. But the materials are almost all bought, paint being the main thing left to buy and I'm going to use latex house paint. Perhaps I'll get by with $400 total. As always I'm a little concerned about the weight.
So far so good.
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