Jim Michalak's Boat Designs

118 E Randall, Lebanon, IL 62254


A page of boat designs and essays.

(15October 2014) This reports the Sail OK happenings, execpt it is really just a dumping of many photographs. I hope your internet can handle it. There was so much to see and do that it would take many issues to report. I have just now returned from the event and can't say what the 1 November issue will be about.

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.

Left:

Getting wet at SailOK...


Contents:

 

Contact info:

jim@jimsboats.com

Jim Michalak
118 E Randall,
Lebanon, IL 62254

Send $1 for info on 20 boats.

 

 


SailOK 2014

I have just returned from the 2014 Sail Oklahoma event. I have lots of photos and will do something I haven't done before in having a photos only report. Getting all the names would have been impossible for me. As you go along you will note that the weather took a turn for the worse....Anyway here we gooooo...

The last photo was taken at the Saturday night concert. That is Jackie Monies to the right. Well, with all the programs and folks around the forum building was going all the time, although the weather was never so bad that boating was not possible and, indeed, the brave did do it. We need to thank all that put on this great event and those who participated in any way.


Jonsboat

JONSBOAT, POWER SKIFF, 16' X 5', 200 POUNDS EMPTY

Jonsboat is just a jonboat. But where I live that says a lot because most of the boats around here are jonboats and for a good reason. These things will float on dew if the motor is up. This one shows 640 pounds displacement with only 3" of draft. That should float the hull and a small motor and two men. The shape of the hull encourages fast speeds in smooth water and I'd say this one will plane with 10 hp at that weight, although "planing" is often in the eye of the beholder. I'd use a 9.9 hp motor on one of these myself to allow use on the many beautiful small lakes we have here that are wisely limited to 10 hp. The prototype was built by Greg Rinaca of Coldspring, Texas and his boat is shown above when first launched with a trolling motor. But here is another one finished about the same time by Chuck Leinweber of Harper, Texas:

Jonsboat

In the photo of Chuck's boat you can see the wide open center that I prefer in my own personal boats. To keep the wide open boat structurally stiff I boxed in the bow, used a wide wale, and braced the aft corners.

I usually study the shapes of commercial welded aluminum jonboats. It's surprising to see the little touches the builders have worked into such a simple idea. I guess they make these things by the thousands and it is worth while to study the details. Anyway, Jonsboat is a plywood copy of a livery boat I saw turned upside down for the winter. What struck me about that hull was that its bottom was constant width from stem to stern even though the sides had flare and curvature. When I got home I figured out they did it and copied it. I don't know if it gives a superior shape in any way but the bottom of this boat is planked with two constant width sheets of plywood.

jonsboat

Greg Rinaca put a new 18 hp Nissan two cycle engine on his boat, Here is a photo of it:

Jonsboat

The installation presented a few interesting thoughts. First I've been telling everyone to stick with 10 hp although it's well known that I'm a big chicken about these things. Greg reported no problems and a top speed of 26 mph. I think the Coast Guard would limit a hull like this to about 25 hp, the main factors being the length, width, flat bottom, and steering location. Second, if you look closely at the transom of Greg's boat you will see that he has built up the transom in the motor mount area about 2". When I designed Jonsboat I really didn't know much about motors except that there were short and long shaft motors. I thought the short ones needed 15" of transom depth and didn't really know about the long shafts. Jonsboat has a natural depth of about 17" so I left the transom on the drawing at 17" and did some hand waving in the drawing notes about scooping out or building up the transom to match the requirements of your motor.

I think the upshot of it all is that short shaft motors need 15" from the top of the mount to the bottom of the hull and long shaft motors need 20". There was a lot of discussion about where the "cavitation" plate, which is the small flat plate right above the propellor, should fall with respect to the hull. I asked some expert mechanics at a local boat dealer and they all swore on a stack of tech manuals that a high powered boat will not steer safely if the cavitation plate is below the bottom of the hull, the correct location being about 1/2" to 1" above the bottom. But Greg had the Nissan manual and it said the correct position is about 1" BELOW the bottom. Kilburn Adams has a new Yamaha and its manual says the same thing. So I guess small motors are different from big ones in that respect.

But it seems to be not all that critical, at least for the small motors. Greg ran his Jonsboat with the 18 hp Nissan with the original 17" transom for a while and measured the top speed as 26 mph. Then he raised the transom over 2" and got the same top speed!

There is nothing to building Jonsboat. There five sheets of plywood and I'm suggesting 1/2" for the bottom and 1/4" for everything else. It's all stuck together with glue and nails using no lofting or jigs. I always suggest glassing the chines for abrasion resistance but I've never glassed more than that on my own boats and haven't regretted it. The cost, mess, and added labor of glassing the hull that is out of the water is enormous. My pocketbook and patience won't stand it. Glassing the chines and bottom is a bit different because it won't show and fussy finishing is not required.

Plans for Jonsboat are $25.

Contents


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.

I think David Hahn's Out West Picara is the winner of the Picara race. Shown here on its first sail except there was no wind. Hopefully more later. (Not sure if a polytarp sail is suitable for a boat this heavy.

Here is a Musicbox2 out West.

This is Ted Arkey's Jukebox2 down in Sydney. Shown with the "ketchooner" rig, featuring his own polytarp sails, that is shown on the plans. Should have a sailing report soon.

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:

And the first D'arcy Bryn is to the point the builder can sit and relax in it and imagine boating. You can follow the builder's progress at http://moffitt1.wordpress.com/ ....

Contents


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

1nov13, Modifying Boats 3, Piccup Pram

15nov13, Sail Area Math, Caprice

1dec13, Stretched Stability, Ladybug

15dec13, Trailering, Sportdory

1jan14, Cartopping, OliveOyl

15jan14, Width/Stability, HC Skiff

1feb14, Hiking, Shanteuse

15feb14, Dory Stability, IMB

1mar14, Scram Capsize, Scrampram

15mar14, Bulkhead Bevels, Frolic2

1apr14, Capsize Lessons, RiverRunner

15apr14, AF3 Capsize, Sneakerbox

1may14, Paper Capsize, Blobster

15may14, Prismatic Coefficient, Roar2

1Jun14, Roar2 Repair, Piragua

15jun14, Rend Lake 2014, Toto

1jul14, Mast Tabernacles, Musicbox3

15jul14, Sandell Tabernacle, Mikesboat

1aug14, Taped Seams, Cormorant

15aug14, Plywood Butt Joints, Paulsboat

1sep14, Rowing 1, Vireo

15sep14, Rowing 2, Philsboat

1oct14, Modifying Boats 1, Larsboat

SOME LINKS

Mother of All Boat Links

Cheap Pages

Duckworks Magazine

The Boatbuilding Community

Kilburn's Power Skiff

Bruce Builds Roar

Dave Carnell

Rich builds AF2

JB Builds AF4

JB Builds Sportdory

Hullform Download

Puddle Duck Website

Brian builds Roar2

Herb builds AF3

Herb builds RB42

Barry Builds Toto



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