7' carvel planked dinghy?

[chergui]

Does anyone know of any design for a 7' carvel planked dinghy? I'm looking to build something this size, it will be my first time. Most designs this small tend to be lapstrake though. The dinghy will be stored out of the water most of the time.

I'll do a lapstrake dinghy if that's all I can come up but would prefer carvel. The two lapstrake designs I'm considering are a 7' version of the Acorn and Paul Gartsides 7' clinker pram (design #80).

[rbgarr]

You can attempt to make a 7' lapstrake design that appeals to you in carvel, but to be useful a 7' dinghy has to be, shall we say, "voluptuous" (tubby) ;) which has implications for building:

1. Carvel planking usually fastens to frames (sawn or steamed) already in place, so you'd likely need ribbands on molds, which is an additional step/expense over lapstrake.

2. Carvel planking has to have more thickness than lapstrake in order to hold caulking, if that's what you intend to do. You could spline the seams instead.

3. Steaming thicker planks, backing them out and sinking/fastening/bunging/puttying them with screws would be trickier. Rivets or clenchnails could be an option, but fairing the hull after planking is complete if rivet/nail heads are not sunk might be troublesome.

Old Town Canoe Company produced a line of 7'+ dinghies. They got around the problem of carvel construction in a boat that small and tubby by using canvas covered canoe type construction, which was their stock in trade anyway. That's another way to go.

Good luck with whatever you choose!

[ 04-29-2005, 12:13 PM: Message edited by: rbgarr ]

[chergui]

The reason I wanted something so small is so that I could store it on the deck of my boat in the winter under the cover. Maybe I should consider something a bit bigger. At what size does carvel planking become more feasible without the problems you mentioned?

Jon

[rbgarr]

WB's Catspaw dinghy is about the minimum size for carvel construction, IMO. I don't recall exactly how long they are... 11'-12+', perhaps?? I imagine that would be too big to haul up and store on your other boat.

[ 04-29-2005, 03:09 PM: Message edited by: rbgarr ]

[Venchka]

The shortest carvel planked boat Paul lists is a 12' double ender row boat. Maybe 12' is a practical limit for carvel planking.

Wayne
In the Swamp. :D

[holzbt]

http://www.boat-links.com/Atkinco/Dinks/images/Precious-2.gif

This should give you some insight into the shape a 7' boat needs to function well as a tender. Most small boats are lapstrake to keep the weight down and so they can be planked with lighter/thinner stock. Carvel planking is generally not done with less than 1/2" stock which can be a bit difficult to work into the full shapes required in short boats. Carvel is also a poor choice for a dink which will spend most of it's time out of the water. Consider a pram or cold molded round bottom design.

[ion barnes]

Strip planked or cold molded would help to keep the weight down.

[holzbt]

Here's an 8' canvas covered dink worth looking at. You might be able to shorten it to 7' by changing the station spacing. HANDY ANDY (http://www.boat-links.com/Atkinco/Dinks/HandyAndy.html)

[yorgie]

Jon,have you ever seen the 'Fancy Pram' that the Oarlock and Sail woodenboatclub built?It's down at the workshop at Heritage Harbour by the Vancouver Maritime Museum.This pram is 7' long and carvel but I've never seen it in the water so I don't know how it behaves.
http://www.woodenboatclub.ca/images/MemberBoats/IMG_0375.JPG
Here's a little more information about Mr A.C Fancy and his tenders. Oarlock and Sail Member's Boats (http://www.woodenboatclub.ca/club_boats.htm)
Chris

[ 05-01-2005, 10:13 AM: Message edited by: yorgie ]

[Thad Van Gilder]

In my experience, anything that you can clinker plank you can carvel plank. It doesn't work the other way, though.

For a 7 foot clinker dinghy, you'd have about 1/4 inch cedar (or whatever) planks. If you did her carvel, you'd want about 3/8", with a tiny bit of wicking in her seams, just rolled in.

The bent frames could be thesame size, but I would consider rivets for fasteners, as screws that size would be a pain to drive. If I recall correctly, the Herreshoff columbia dinghy was copper rivet fastened.

one could cover the hull with canvas, old town style, but I wouldn't see it as neccesary. There are a million sneakboxes around here with 3/8 cedar planking that stays fine. just let her sit on the bottom for a while before the season starts, and keep her in the water all season.

Also, to address previously posts, yes, you need ribbands for a carvel boat. They will cost at least 90 cents for a boat this size. :rolleyes:

Splining hulls this size is kind of a strange thing to do, as when the planking shrinks during the winter, you will rip the splines apart. If you only glue the spline to one plank, the splines aren't doing anything, so why put them in to begin with?

Oh, and yes, you do need to back out carvel planks. pretty much just at the turn of the bilge, though. I don't see how steaming a plank to cup it and bend it will help... that's like making a piece of paper wrap around an orange.

You do need to be carefull about fairing though. whether you fasten with screws, clench nails, or rivets, if you need to fair to much, you will hit a head. so, loft carefully.

Thad
S/V IVY

[ 05-01-2005, 09:21 PM: Message edited by: Thad Van Gilder ]

[rbgarr]

I am duly corrected. :cool:

[chergui]

Hi Yorgie. Acutally I'm a member of the OLAS smile.gif The fancy pram was built before I joined. I'll have to take a closer look at it. I think they took the lines from an existing one and I don't think there are any plans I could work from. I'd kind of like some plans to go on.

I'm not familiar with splining but it sounds like it doesn't matter. I'm reading Rossel's book and I couldn't find it mentioned.

I'll look into a carvel planked Acorn or Gartside pram. I really like both of those designs. Does lapstrake leak as much as a carvel planked boat when first put in the water? I'm in a tight city marina and there is nowhere to leave the dinghy in the water unfortunately. The reason I want carvel is partly just to learn how to do it. But I won't rule out lapstrake.

[Thad Van Gilder]

I planked up a clinker pram once with dry seems, and it did leak like a carvel boat. Now I always bed the laps with dolphinite.

-Thad
S/V IVY

[yorgie]

Hi Jon,I was wondering if you belonged to OLAS.I must have seen you at a meeting,I joined last summer.Even If they don't have plans for the Fancy pram I'm sure they still have the molds.With an existing boat to reference you'll be all set.Try the pram out and see if you like it.

Chris