Jim Michalak's Boat Designs
1024 Merrill St, Lebanon, IL 62254
A page of boat designs and essays.
(1December 2021) We look at a real life junk rig. The 15 December issue will review taped seams.
ORDER NEWS
Armed with a fresh vaccination I ventured forth again into the world and quickly found an engineering print shop that did very good scans (alas, a 40 minute drive). Chuck at Duckworks has been updating the catalog so they are available for sale only as instant downloads, about 60 designs available.
ALSO...In addition to the Duckworks downloads I also now have access to a large format inkjet printer which is making very nice full sized prints on paper. So I can return to what I started 30 years ago, you order direct from me by snail mail using the address above only with cash or check in US funds with the prices shown on this website, and I mail you full sized 2'x 3' paper prints. The price includes first class mail to US and Canada.
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. Only downloads right now.
OliveOyl Junk Rig
Herb McLeod, up in Canada, wrote...
Hi Jim
I am writing down for you a few thoughts about the junk rig from this summer.
1) I had to replace the second from the top batten extending it so that the sheetlets would not hang up on the lower battens when tacking. It now works flawlessly both when tacking and jibing.
2) I did record a couple of tracks of mostly short tacks into the wind followed by a downwind run where I kept the pendant on the masthead pointing directly downwind. I purposely did not take advantage of any wind shifts when tacking. Unfortunately there was never a smooth gust free wind to record the tracks but my impression is this sail is about as close winded as the spritsail and more powerful in light air as it has a 25% greater sail area.
3) Also the shorter boom compared to that of the spritsail has eliminated two problems. First the sheet getting caught on the corners of the stern of the boat. Second the shorter boom length eliminates the possibility of the clue of the sail dipping into the water and tripping the boat during a partial knockdown.
4) When I initially installed the junk sail on OliveOyl I used the same vertical mast position as I had for the oversized balanced lug sail. To develop some weather helm I kept moving the mast aft until I felt I had adequate weather helm. Later to help the sail stay out when running downwind in light air the mast was tipped so that it leans forward 5 degrees. At this point I was happy with the balance of the boat and both Jamie and Kirill when they took the boat out remarked without being prompted that the "sail balance was excellent". This forward tipping of the mast really helps the heavier junk rig to stay out when running in light wind.
Before I put OliveOyl away for the winter I measured the position of the mast step and partner as well as how far the boom is forward of the mast. I then drew a � to an inch scale drawing of the junk sail and located the geometric center of effort. Then I took your sail plan drawings of the OliveOyl and drew a line that represents the center of the mast as it was finally positioned. I then traced the outline of the junk sail as it is positioned relative to the mast. Interestingly my trial and error positioning of the mast and sail, it ended up with the center of effort in the exact same fore/ aft position that you had drawn for the balanced lug rig. This is an interesting result, but not too surprising.
Next, the whole rig has to go on a diet! I agree with you that masts in the 30 pound range are about the limit for easy stepping. A hollow mast would save a few pounds at the bottom of the mast but would change the balance point toward the peak which might make stepping the mast more awkward. The +40 pound sail bundle is a lot to lug down to the boat. Kirill suggested aluminum battens as they would be lighter and I have enough 4.5 ounce material to sew another sail. The aluminum spars and lighter material in combination should cut about 10 pounds of weight. That would be a significant weight reduction.
Cheers,
Herb
Ladybug
LADYBUG, SAILBOAT, 14' X 5,5', 250 POUNDS EMPTY
Ladybug is a lot like Woobo which was one of my first designs. There was a Woobo near here for a while. I never got to sail it but was told it would really fly. (That boat was made of Lauan plywood from Home Depot which fell to pieces after rainwater filled the boat over the winter.) Ladybug is a bit shorter and wider and deeper and has bench seating, much more suited for older legs. Both boats have a small motor well. The best motor for something like this is the 2hp Johnson/Evinrude which weighs 25 pounds. Even that is overkill since 1hp will push this hull at top speed, anything more just makes bigger waves. Here Sandra Leinweber pushes into a stiff breeze with a 2hp Honda.
This shape of hull with multichines and a plumb bow seems to be a good all around thing with rough water abilities. I think if there is a problem it is that it has almost no lateral drag and unless the boat has a big skeg or keelson or something like a leeboard or daggerboard or centerboard it would just as soon go sideways as straight. I've given Ladybug a keelson and when using power you should keep the leeboard down just enough so its tip drags the water.
Ladybug's hull has the layout I like the best - a 6-1/2' cockpit between two storage/buoyancy boxes. It would be a great solo camping boat. The buoyant wooden spars prevent it from turning turtle. You bring it upright with weight on the lowered leeboard. Then you must climb back on board and a slot in the rudder seems to be the best boarding ladder around, bringing your weight back on board where it least affects the boat. You will have to bail some water.
I've kept the same sail as with Woobo, a 75 square foot balanced lugsail. It hoists on a 13' mast with 11' yand and boom. All very low tech built with common materials.
Chuck Leinweber of Duckworksmagazine.com built the prototype and brought it to our Rend Lake messabout so I had a chance to go for a long ride in it. One thing that impressed me was how large it was for a 14' boat. In the opening photo you see it sail with three men on board, all comfortably sitting to windward on the bench seat, and I'm told it has sailed with four men with no effort. I do think it would be quite suitable for a family of four say with lots of room for all and storage space for all their junk. Here Sandra Leinweber sets things up at a recent campout on the Texas coast:
Here is the same campout from a distance with the mast folded to support a tent. I'm told the tent is not done yet. Chuck has modified the bench seats so that his expand towards the center and meet in the center thus making a 6' x 5' sleeping platform. Turns out a small commercial camping tent can be set up on that platform and that is what they are using for now.
Ladybug uses taped seam construction. Six sheets of 1/4" plywood, one sheet of 3/8" plywood and two sheets of 1/2' plywood.
Plans for Ladybug are $40.
Prototype News
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
1jan21, Rowboat Setup, Normsboat
15jan21, Sail Area Math, Robote
1feb21, Bulkhead Bevels, Toto
15feb21, Trailering, IMB
1mar21, Small Boat Rudders, AF4Breve
15mar21, Sink Weights, Scram Pram
1apr21, Sail Rig Spars, RiverRunner
15apr21, Water Ballast, Mayfly16
1may21, AF3 Capsize, Blobster
15may21, Mast Tabernacles, Laguna
1jun21, Underwater Boards, QT Skiff
15jun21, Capsize Lessons, Mixer
1jul21, Scarfing Lumber, Vireo14
15jul21, Rigging Lugsails, Frolic2
1aug21, What Is Horsepower, Oracle
15aug21, Sharpie Sprit Sails, Cormorant
1sep21, Measuring Prop Thrust, OliveOyl
15sep21, Leeboard Issues, Philsboat
1oct21, Sizing Underwater Boards, Larsboat
15oct21, Choosing A Design, Jonsboat
1nov21, Lugsail Jiffyreef, Mayfly14
