Building a flat bottomed canoe

Never mind....

 

No problem....we were ignoring that comment anyway.

 

Well, !@#$. The good news just keeps rolling in.

Apparently, I also have a pulmonary embolism: there's a humongous clot hanging out in my right main pulmonary artery. My doctor kept emphasizing what a very, very lucky man I am. He says he can think of absolutely no reason for it to have stopped there--instead of traveling farther down the line into my lung, until it blocked something completely and caused havoc.

He also seems a little non-plussed that they released me from the hospital after finding the clot in a CAT scan, without even mentioning it to me. The first I heard of it was from him, when I went in to set up a schedule for checking the warfarin levels in my blood.

But now that I'm out, he settled for upping the initial dosage of warfarin--and giving me very detailed instructions about what symptoms should send me running for an emergency room or calling 911.

He also commented two or three times that I 'seem so healthy' in spite of the two blockades, kind of hinting that it's part of my problem. Apparently, I haven't been looking or acting sick enough for the health care professionals I've been dealing with to take me seriously....

 

Today my son Dwaine asked me, "what boat are we building next, dad?"

I think this might be a good one: Excelsior, a 21' Cruising Canoe by William Atkin.

http://www.boat-links.com/Atkinco/Sail/Excelsior.html

Yep, another flat-bottomed canoe. I'm in a rut.

But a decked one with two cockpits, two masts and a rudder, and the forward cockpit large enough to tent for an overnight cabin. Originally designed for lapstrake, but apparently adapts well to plywood.

Notice the narrow bottom and wide flare; I have no doubt it would spend much of its sailing time happily laying on its ear. But I believe it would be relatively dry anyway, at least in the inland waters where we'd use it. I'm not sure about those rigidly-stayed masts on something that narrow, though; I'd probably replace the setup with a sharpie rig: flexible, unstayed masts and sprit-boomed sails. I'd also go for a kick-up rudder--and a pivoting centerboard, or leeboards.

By the way, the photo's are of an Excelsior built at Northwest School of Wooden Boat Building, in 2007 & 2008

 

Troy thats a great thread and a lovely boat! Good luck on your next boat

 

Thank you.

 

Just stay alive and don't cough up a lung.

 

I plan on hanging around long enough to become an embarrassment to my grandchildren. And since I don't have any yet, it'll be a while....

 

Been taking a closer look at Billy Atkin's Excelsior (post #169). That hull isn't going to work with plywood, unless I use glued plywood lapstrake. Which I don't want; why have all those plywood edges hanging around to grind on the rough, rocky beaches the boat will getting pulled up onto?

Nor would I want to do the traditional lapstrake called for on the plans, because it'll be a trailer boat in the desert. That pretty much leaves strip planking, I think. Maybe some bead and cove redwood, sheathed on the outside and oiled inside. It could be pretty spectacular.

 

It would be much easier to build the Excelsior in ply, if it can it be done. I had the following thoughts, if anyone is interested.

From the limited resolution drawing it seems the problem would be the severe twist in the sheer planks near the stems. This allows the stems to be vertical and shortens the length on deck. If the twist is reduced to manageable proportions (for ply), it would rake the stems.

This boat will sail best on her ear, therefore the critical line is the chine which should not be changed. So the raked stems would have to be accommodated by extending the sheer at each end. One wouldn’t want to lengthen the boat too much as it is unproductive as far as capacity and performance is concerned, so a transom might be introduced to chop the stern overhang. I’m not sure at this point just how much extra length would be involved, but I think it might be managed within an extra foot.

As far as appearance is concerned, if this is an issue, it might very well be an improvement IMHO. Of course, it wouldn’t be the same boat any more. If the idea sounds workable and is not too repugnant I could knock up something in FreeShip to discuss further.

 

I have a soft spot for plumb stems, and even tumblehome bows. For some irrational reason, I just like the way they look. But you're right; we might be able to cheat the stems out a little. Even just raking each one three inches might make a lot of difference.

Why don't we hold off on fiddling with it, until I buy the plans and get a better look? The boatbuilding school's version is strip-built, according to something I read somewhere online, and they may have taken liberties with the shape of the ends to begin with.

I'm tempted to strip it anyway, even if the plywood would be easier. I think it would look good, and that flat sheer would probably give fewer problems with runoff of the strips than a lot of designs.

 

Sounds like a good idea. You will need the plans anyway for details and guidance on scantlings, and it should provide the official lines. One last point: strip planks must be glassed whereas ply doesn't have to be, maybe just the bottom if you will beach her. I don't glass my ply canoes because I can carry them over the pebbles

 

There are plenty of boats out there that were strip-planked without being glassed; just nailed together with some sealant between the strips. But for soft woods like cedar or redwood, it's a good idea. And I guess if you're using strips too thin to be nailed together, it's pretty much mandatory....

As I said, if I build this one I'll probably glass the outside, and oil the inside.

 

Especially with the 3/16 and 1/4 strips. You need the glass for the cross-grain strength so the softwood doesn't turn to mush when it's saturated. Usually it's glassed both sides.

 

Ashcroft planking (double parallel planking w overlapping seams) will reduce the thickness of the planks thus permitting the required twist and if the planks were narrow enough caulking and bedding would make it about as watertight as plywood. Repairability would suck. Just an idea.

Easy Rider