30' plywood sharpie

That line came from a framing carpenter years ago, Bill.

I was doing pickup work on a tract near the Sacramento Delta at the time, and spent two or three short evenings after work racing the sunset to build a flat-bottomed canoe. I made it out of scraps from a dumpster: 3/8" plywood shear panel cutoffs for the sides and bottom; 1x2 Douglas fir furring strips for the chines and gunwales; a 2x4 shaped with a hatchet and electric planer for the stem, and a couple of 2x8's splined together with a strip of ply for the transom. For a center mold I used a trapezoidal piece of scrap 3/4" plywood flooring. When I was done with the boat, I cut the mold out 1 1/2" from the sides and 3 1/2" from the bottom with a Skilsaw, to leave a frame. I laid the cut-out piece down for a seat, with a 2x4 block under one edge and the other tacked to the plywood frame I had cut it out of.

My total cost was less than ten dollars. The only thing I bought was a pound of drywall nails to knock it together with, a tube of adhesive caulk, and a can of paint on sale because it was a color-match mistake.

I used the canoe for years, and so did my kids and foster kids. But I still remember that carpenter coming up and incredulously asking me, "Yo're buildin' a boat outa wood? Howya gonna keep th' water out?"

Anyway, my sharpie is basically going to be an overgrown version of a flatbottomed plywood canoe, with Douglas fir framing and spars. And it'll be drysailed on a trailer, instead of living in the water. Given those circumstances, I'm not sure how relevant the research you did is going to be....but if you have anything you think would be useful, I'd be pleased to see it.

 

Egret Sharpie

Hello Angel and Troy!

When I looked for Egret building sites I learned that most builders don't care for the designed wheight and built their boats far to heavy. More important, they built to much wheight in the forward half of the boat, which is tolerated by the waterline because the boat has lots of volume there. But it's very bad for weatherhelm, because when the boat heels, it ticks it's nose into the water and the ducktail in the air. The effect is weatherhelm. Keeping the boat, and especially the interior light (Reuel Parker would agree I think) is a better way to prevent it.

Another effect is that the heavy boat is undercanvassed with the small sail area the egret have, so a jib will help in light weather.

Grrreetings from the North Sea Coast, Michel

 

Egret Sharpie

Hi Angel,

My interest for designing is pure hobby and I have (until now) no real ambition to build or own a sharpie. But the design process is what I like, solving problems and try to bring out a boat that looks and sails well. I will build a rc-modell of the boat next fall/winter to have some sailing action during the winter time!

What fascinates me about sharpies is that (in the concept of the boat) they are very close to our Jollenkreuzer-designs which ranges in concept from cruising to racing. But they are all capsiseable and not very seaworthy. I'am the helmsman and co-skipper (not the owner) of this boat ...

http://www.schrexe.de

... and it capsised twice. One time with me as skipper (which was no good experience to have and to tell the owner.)

Yes, "The Sharpie Book" from Reuel Parker was the startpoint for that. When I saw the seagoing Egret inside the Sharpie Book my thinking started to devellop the Egret to a boat that would be a more useful design and would be able to sail in our waters. The North Sea has large flat water tidal areas (Wattenmeer) as well as difficult offshore conditions (again with strong currents).

My philosophy is the Kiss principle and I want to preserve the qualities of the original Egret (Parkers Egret is the starting point) . The very simple, fast and cheap construction (flat bottom, straight flared sides, relative light displacement) the traditional look, freestanding wooden masts with just two sails, the shoal draft and the sea going abilities.

My design goals for the evolution are:

- better hydrodynamics, surfing abilities and overall performance, self righting ability
- more comfortable interior (4 bunks, sitting headroom, lower centerboard case, cooking- and navstation.
- lengh down to 26' (easier and cheaper construction, lighter wheight, no much useless overhangs), perhaps a 22' or 23' version with 2 bunks later
- possibility to integrate second-hand eqiupment into the boat (for example a finn-dinghy- or Ok-dinghy rig as mizzen mast), different sail rigs for different tastes.
- careful nesting of plywood parts for material efficiency, cheap construction.
- screw and glue contruction, possibility to avoid epoxy (allergic persons, not me!), usage of local grown wood
- auxillary power by electric motor (torqueedo or similar) for a greener world.
- towed on the trailer by a normal sized, fuel efficient car (100hp VW Passat, Audi A4 or similar).

These are my goals. We will see if this is all possible in one boat and still looking good.

Grrreetings from the North Sea Coast, Michel

 

Thanks for the input, Michel. What you're saying about the weight, and where builders put it, makes sense to me. Some of them are building their Egrets like tanks. For example, the builder of Pangur Ban says the sides are two layers of 1/2" plywood laminated together, plus multiple layers of fiberglass. That seems like overkill to me.

http://www-personal.umich.edu/~mrwizard/sail/independence/01.html

Of course, he also managed to turn building a sharpie into a five-year project....

 

Plywood

First, is it ok if I post my (slow) progress of my own design here or shall I open up a new thread?

Two layers of 1/2'' ply? Seems he wants to fight the "Bismarck" With the ply he has bought he is able to build two Egrets. This is really heavy and will ruin the performance, not to count the waste of money.

For the original 28' Egret Parker calls for 1/2'' for the sides and 3/4'' for the bottom, some sort of polyester cloth for sheating. There are 6 bulkheads. As your sharpie is a inshore boat my feeling says this could be possible plywood thicknesses for your 30 footer as well. May be one number up to avoid the cloth and epoxy that you hate (if I remenber right). But this is part of the engeneering that has to be done later.

Perhaps somebody knows what Plywood thicknesses Ian Oughtred calls for his "Haiku" to have a start point for the wheight analysis.

My 26 footer will have 10mm (?/?') okume ply in the sides and a layer of glass cloth or 12mm (~1/2') without glass. Bottom will mainly be 18 or 20mm birch multiply (cheap, relyable and available in ~5x10'). I plan to have 5 to 6 bulkheads.

Grrreetings from the North Sea Coast, Michel

 

Hi Michel,

I would love to read about your design. My preference would be a separate thread. That way the information on the individual boats will be easy to follow and find back. And the information provision and discussion of the two will not intermingle into a incomprehensible tangle.

On this thread there were two thread openers. Two what seems to be similar idea threads at that time were merged. First one was 30 footer. Troys boat will be under 29 feet LOA (post #379).


There were two articles about Iain Oughtred's HAIKU in Water Craft #61 jan./feb. 2007.


Cover shows a Grey Seal with her designer Iain Oughtred at the helm.

The second of the HAIKU articles in this Water Craft issue is the build story written by the pro builder* of the first one which is showed in the pic below.
* Adrian Noyes, Craftsman Craft, Crediton, Devon, UK.

The first article reads:
‘‘ .... She is built of 1/2" (12 mm) plywood, doubled on the flat bottom, with 3/8" (9 mm) decks and 1/4" (6 mm), again doubled, for the unobstructive, cold molded coachroof. .... ’’

Nothing explicit about the hull side thickness, but the builder says in the second article ‘‘double thickness 1/2" (12 mm) bottom’’. I guess from both stories that the hull sides are single skin of the same 1/2" (~12 mm) plywood. They used the Dutch Bruynzeel but the articles doesn't say which kind.

HAIKU - Poetry in Motion . . .


(unfortunately the sculling oar alongside the cabin distorted the image as do the booms which are not in line)

This HAIKU pic came from James Wharram's letter introducing his London Boat Show lecture in 2007. The picture is from Water Craft magazine.


In the above mentioned Water Craft issue is also a story of the restoration of Mudlark, a L. Francis Herreshoff designed / Fenwick C. Williams modied leeboard sharpie ketch.

Mudlark is a 1953 version of of L. Francis Herreshoff's 1948 Medowlark design, a 33' leeboard sharpie ketch. See Water Craft #40 jul./aug. 2003 for the start of the above restoration story and more info about Mudlark and Medowlark.

Here a Herreshoff Meadow Lark. This one is for sale.

Medowlark's design calls for a radiused bottom. Mudlark has a flat bottom, her cabin shortened and its height reduced, and a shorter mizzen mast. Mudlark looks nicer in my eyes, she is just BEAUTIFUL . .


Good Luck!
Angel

 

Those are the plywood sizes I've been tentatively planning on, Angel. Nice to know Oughtred settled on them also.

I've seriously considered building the cabin trunk out of solid redwood though, finishing it bright, and keying the paint for the rest of the boat off the colors of the heartwood and the creamy sapwood.

Unlike Angel, I think it makes sense for you to post your sharpie design here. We can contrast it more directly with mine, and the other one that was started in this thread (although that design seems to have petered out).

And I don't think it'll be that confusing.

 

I built a flat bottomed 24' Atkins "New Sister" once . It was designed to be build
in a traditional manner, but I build it of ply and epoxy. Somewhere along the way i came to the conclusion that it would have been easier to build as per plan. The cost of epoxy and glass offset the cheaper material cost and frankly the coat of good marine ply is greater than plank wood . I do think that a ply bottom is a good idea , but it must be thick to avoid additional longitudinal framing . Also any Doug fir ply will check badly , and needs to be sheathed in a cloth epoxy matrix.

I think that 3/4" pine would be good for the sides , and could be glue seam .
Explanation and contraction could be kept to a minimum if the plank width was kept to say 5" . The weight of the plank sides would also be less than for sheathed ply, if you figure 5/8 ply .

I will post a photo, if I can find one .

Frank

 

I don't think it would be practical for my sharpie to have planked sides instead of plywood, Frank. It's going to be dry sailed in the northern fringes of the Sonoran Desert, in an area where the humidity often falls below 10%.

I once built a traditional-style Caddo Lake Bateau, with a bottom made of two 1x12 fore-and aft cedar planks, and caulked the chines and bottom seams in the normal way for such a boat: by cutting a bevel on the edge of one plank, pounding it flat again with a hammer, and butting it tightly to the other plank. The first time I put it in the water it sealed up tight as a drum, and stayed that way for a couple of years--as long as I kept it in the Los Angeles area.

Then I took it to the desert. In less than a week the bottom seam opened up almost a quarter of an inch, and never closed back up again. I wound up putting a wood shim in the gap from end to end, and caulking it with unraveled kite string and acrylic household caulk (hey,it's what I had. OK?).

 

Angel and Troy

Angel and Troy,

Troy,

thanks for the invitation .. I would like to bring my brainstorm-couch into this threadroom. I agree with your opinion that we can contrast our designs more directly. Our way of thinking and working is quite similar as we both are avoiding freeship programs and are followers of the KISS principle. There will be no confusion, To be honest, in the moment your project is motivating me to spend some hours more on my drawing desk, not to count your ideas that flew into my boat.

Angel,

this is for you! A Haiku in motion

http://http://www.youtube.com/watch?v=rWEk07fGbeA&feature=related

The builder said, the boat is built after the original plans from Ian Oughtred.
There are three videos of that boat.


Frank Smith:
Beside the fact that the bottom is the only area in a sharpie where I tolerate really thick plywood, additional longitudial framing there is no big problem because you will have bunk risers anyway. Why not fasten them accurate to the bottom and you have them both with half the work. It's done this way in every sportsboat I know. You can fit them in with the hull still on the mold and before the botton goes on. That will make it easy to shape them into the correct form. My plywood nesting plan says the settee risers will be leftovers from the sideplanking.

Greetings from the North Sea Coast, Michel

 

Michel, I think I should have said 'comparing' your design with mine; that would have been a better choice of words than saying 'contrasting.' You'd think that after 61 years in an English-speaking country, I might have a better command of the language.

Just going by your verbal description, what you're working on sounds more like the last model I did years ago, that was also based on Munroe's Egret. There are a few pictures of its battered remains earlier in this thread.

 

I agree, comparing is a better word! But my english is so bad that I didn't even realised it Let us get the spirit of the words and everything will be ok. Splitting hairs helps nobody.
The translation program is my best friend!!! It's running parallel all the time and I use it often.

I saw your model with the white hull and red underwater body and yes, there are a lot of similaryties. You will see them, when you take a look on my drawings. I should be able to finish the drawings of design spiral no 2 and post them in one or two weeks. Until then I have to give my tornado cat some new paint, to sail a regatta on the weekend and to build a patio. Thanks god I'am able to post here while I'am working in my normal job.

Michel

 

Troy , I think now that it would be best to build it with fiberglassed foam panels and be done with it . Aluminum would work .

 

About the 'contrasting' vs 'comparing' thing. Like Michel I didn't notice the difference till Troy pointed it. Nuance in a language is a difficult thing like we all know from our own language. Nuance in a foreign language is even more difficult. I guess what I said about separate threads ‘‘the two will not intermingle into a incomprehensible tangle’’ sounded far more harsh then I meant it. But as far as I can see everyone looks at the spirit of what is meant and there is no nitpicking here. Thanks for that . .

Cheers!
Angel

 

Troy, can you post some pictures of your sailing area and name the lakes? I am very curious.

Cheers,
Angel