Advice For Shaping Outwales For Tumblehome, Anyone?

[T.Bird]

Hi! New guy here. I'm and handful of steps into my first wood and canvas canoe restoration project. I am approaching the point where I need to shape some new gunwales to be bent into place. (I've never steam bent anything and I'm looking forward to trying it. I think I'm going to try that "Steam in a poly tube bag" idea that everyone raves about.) My current concern, however, is this: the boat (an Old Town OTCA 16) features a bit of tumblehome that I am not sure how to address. Any advice for cutting an appropriately angled rabbet in the outwale? I seem to recall reading somewhere that, because the tumblehome angle will be most dramatic amidship and tamper to almost nothing at the bow and stern, you can estimate the average angle over the whole boat and just cut that average angle on the entire length of the outwale, but I can't remember where I heard that. Does that sound right?

Any advice on shaping, bending, and installing outwales would be greatly appreciated!

Thanks,
Tom

 

[dogbrain]

I just cut the spruce to the shape of the green box in the picture. The picture is of an original OT gunwale from a 1928 HW. I had made a form to shape the inwales already, so just used it for the outwales by cutting a piece to fit the rabbits and steam bent them together in the form. After they were dry, I screwed them to the canoe taking care that I got the screw angles correct. I shaped the inwales with a block plane, spokeshave and sandpaper. They came out close to the originals. There might be an easier way to do this, but this was what I came up with. Mark

 

[T.Bird]

Thanks dogbrain! So am I think I am hearing you say that you cut the rabbet square to the rectangular stock and then profiled the outwales to accommodate the shape of the boat, no?

 

[dogbrain]

Exactly. Having the square stock with the rabbet is the only way I could think that I could steam bend the up-swept ends. It would be a lot easier if you could shape the gunwales before the bending using the router table, but not being much of a woodworker, this was my solution.

 

[Gary Willoughby]

When I was at the Old Town factory they had a machine were they would feed in the sq stock gunnel and out the other end came out the finished gunnel. Benson might know more about this.

 

[Benson Gray]

a machine were they would feed in the sq stock gunnel and out the other end came out the finished gunnel.

Yes, it was called a shaper and had a tremendous variety of blades that could produce almost any form. There is a house in Old Town with a huge variety of fancy moldings and trim that came out of that machine.

Benson

 

[Gary Willoughby]

Benson Old Town had several machines what happened to them.

 

[Benson Gray]

Old Town had several machines what happened to them.

Everything useful was moved to the new factory or sold. Anything left was scrapped when the building was taken down. I don't know what happened to the shaper but it was too big to move easily. See http://www.wcha.org/forums/index.php?threads/11711/ for details.

Benson

 

[Just1moredave]

There's another recent discussion here on the HW model, focused more on the bending: http://www.wcha.org/forums/index.ph...-new-gunnels-on-old-town-near-the-ends.15625/

The order you do things affects the remaining steps and how easy they are.

I used ash, which bent without trouble. I used a 6 mil poly bag and the Earlex steamer, basically the same as the wallpaper steamer. I measured the bevel on the inwale and beveled the outwale to match. I rabbeted the inside face, also a matching bevel. I prebent the ends on a form, which helped in a few ways, not necessary. I had to scarf the gunwales, so I had four steaming sessions.

If I had to start over, I would not bevel the outside face of the gunwale. That means shaping it later of course. But the outside bevel made clamping annoying, because the plastic bag is slippery, and full of steam when you're clamping it. I thought prebending would make clamping to the area next to the decks easy. I still needed to hold the steaming gunwale in place. I ended up installing one screw at the end, and using the same form I prebent with to hold the upward curve. Certainly the clamping plan could be better.

Shaping later is not as easy as cutting a quick bevel on the table saw, but with straight grained wood, lots of tools work.

The poly can be sort of welded with a heat gun to match your setup.