Jim Michalak's Boat Designs
118 E Randall, Lebanon, IL 62254
A page of boat designs and essays.
(15Feb04) This issue will show some add-on rigs I've put on different designs. The 1March issue will rerun the issue about joining plywood sheets.
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....
ON LINE CATALOG OF MY PLANS...
...which can now be found at Duckworks Magazine. You order with a shopping cart set up and pay with credit cards or by Paypal. Then Duckworks sends me an email about the order and then I send the plans right from me to you.
Al Straub's daughter takes his Toto delux for a spin.
From time to time I am asked to draw up a new sail rig for a boat which I will do for a small fee. The new rig is always done on a separate page to the basic drawings and becomes part of the main package.
ADDING A MIZZEN...
This is one of the most common changes asked for. I think a mizzen allows for superior anchoring since you can use it to make the boat stay pointed into the wind all the time and not wander around the anchor (but they will still wander a little bit). Second a mizzen will allow you to secure the boat head to wind even if you are not anchored, thus you can reef a boat a lot more safely with a mizzen as a rule, or just take a break from sailing for a while. Mizzens also allow you to trim out your helm, especially lee helm problems. They also allow some self steering benefits.
But I don't think mizzen sails add a lot of speed or power to your sail plan with the general thought that the further aft a sail is set, the less effective it will be because it operates in the air flow already chopped up by the sails towards the bow.
Almost always you can add a mizzen straight away if it will fit without regard to "sail area math" problems. The center of sail area will move aft, of course, and by quite a bit. But since you can handle the mizzen with its own sheets you can usually trim out how much force it is producing. Not always, I'm quite sure, since when running downwind that won't be possible as a rule and then the mizzen can encourage your boat to swap ends and broach. So there are negatives involved. Also there is the added complexity and set up time. I don't like to use a mizzen sail on any boat that is mostly a day sailer. But on a boat that goes "cruising" for a few days it can make sense.
A few builders have just added a mizzen while leaving the main sail unchanged as shown above with Richard Spelling's old AF2
And remember Rob Rhode-Szudy's mizzen on his Piccup Pram:
Here is one I added to the Jukebox design a short while back for a customer who indeed expects to cruise for days at a time:
But that was not the first change I did for the Jukebox. The first looked like this:
Two small identical sails, the idea being to make sail handling easier than the one big sail called for in the original Jukebox design (about 160 sq ft I think). New mast locations are called for and the fore mast was stuck in the bow well and the aft mast stuck into the foot well in the aft deck. I don't know how well such a rig would work. I called this a "ketchooner" rig since it was neither a ketch nor a schooner but I'm pretty sure such a rig has a proper nautical name, perhaps several.
The switch to the smaller lugsails makes for easier handling. Here is one I did for the AF3:
The sail are shown here is about the same as for the original sharpie sail. But the mast required for the lug is about 2/3 that needed for a sharpie sail of equal area so now the 15 AF3 can have a 15' mast instead of the 21' mast needed with the original sharpie sprit sail. Another factor is that the balanced lug sail reefs very nicely and the sharpie sprit sail reefs very unnicely. The new rig uses the same mast step as the original with the partner shifted aft slightly. I see no reason why the boat couldn't be rigged with two partners to allow use of both the original sharpie sprit and this lug sail.
Given good sailmaking and sailing I would expect the sharpie sprit to usually outsail the lug but not by so much that the other factors mentioned can be dismissed.
I got a letter from a Petesboat customer about changing the single large (about 200 sq ft) lugsail to something more easily handled. Pete had never complained about handling the sail on his boat. It is the same I think as that of a Bolger Martha Jane. But I can see the new customer's point.
So the first proposal was for something like this which uses the same 91 sq ft lug as shown on the AF3 drawing, except two used in the ketchooner setup:
Looks a lot now like a junk rig. In order to get the area centered right I had to run the fore mast at an angle in the hopes of using the roof of the cabin as a mast partner, thus giving the mast a lot more "bury" than if it is just stuck through the fore deck. Not sure how this will balance with the thought in mind that the aft sail isn't going to be as powerful as the fore due to its operating in chopped up air, but the idea is pretty flexible in that the aft mast can be shifted further aft if needed.
The jury is still out on the updated Petesboat rig. I also proposed the use of the Jukebox yawl rig, a straight cut and paste to look like this:
I know this one would work well but now the mainsail is about 160 sq ft, more difficult to handle than the little 91 sq ft lugs of the ketchooner rig.
...we'll review ways to join plywood sheets.
JUKEBOX2, BEACHBOAT, 19' X 6', 1400 POUNDS EMPTY
Ths boat and Jewelbox are both "inspired" by the Bolger AS19, having the same size and boxy shape. They all have the same mainsail, too, although the AS19 has a mizzen and mounts the main as a gaff sail instead of as a balanced lug. The actual progression of the designs started with the original Jukebox. It was really, really functional! It's gone forever now, never sold one set of plans. Then came Jewelbox, a Birdwatcherized version of that original Jukebox. Then Phil Bolger warned me that the original Jukebox was too ugly for anyone to take. I redrew it as Jukebox2. The size and rig and cross section are the same as the original, but I sleeked it up a bit.
Thanks to Craig O'Donnell of the Cheap Pages for the colorized gif's.
I kept the basic layout of the first boat because I think it's really hard to beat for a beaching cruiser. The bow transom on Jukebox2 is just wide enough to step through. Then one finds a small draining well for wet and muddy things followed by a front porch deck. The cabin is a full 7 feet long, 4 feet deep, and 5 feet wide with storage access to the volumes under the fore and aft decks. The aft deck is a 6 foot long flat and will sleep two. That deck had a hatch which provides leg space and access to the under deck storage (in good weather). This type of deck is also far easier to build that any other. Finally, there is a draining stern well for the motor and more wet junk.
The sail rig is basically the same as Jewelbox's but here I've specified 600 pounds of inside ballast, minimum, that Jewelbox doesn't need. In spite of the invention of the Birdwatcher cabin, I don't think this older style of boat is obsolete. Many folks prefer the open sunny deck and the privacy of the separate cabim. This type hull might weigh 30% or 40% more than a equal Birdwatcher type but I don't know if that really matters too much. You can't tow something this size behind a small car anyway. The men who rate cars for towing aren't concerned with either vehicle longevity or the steepness of launch ramps.
No Jukebox2 has been built that I know of but one is under construction in frozen Canada...
Simple nail and glue "instant" construction is used in spite of her size. Plans are four blueprints with basic keyed instructions for $20 until a prototype is tested. That price includes the two added sailrig pages.
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.
The Texas Ladybug is getting details (Toto in background):
Out West the Picara project gets its bottom. Winter shifts work to sailmaking indoors:
The Deep South Skat is getting done:
Another Picara, this one with a 1' stretch in the middle, going together in Arkansas. Sailmaking right now.
AN INDEX OF PAST ISSUES
BACK ISSUES LISTED BY DATE
Mother of All Boat Links
The Boatbuilding Community
Kilburn's Power Skiff
Bruce Builds Roar
Rich builds AF2
JB Builds AF4
JB Builds Sportdory
Hullforms Download (archived copy)
Plyboats Demo Download (archived copy)
Brokeboats (archived copy)
Brian builds Roar2 (archived copy)
Herb builds AF3 (archived copy)
Herb builds RB42 (archived copy)
Barry Builds Toto
Table of Contents