Gunwale height and rib length

tostig

Curious about Wooden Canoes
Two problems I had when I made my birch bark canoe and after trying to fix it.

1) without the ribs in place in the canoe yet, how high do you place the gunwales (ie - how high to raise the inwale frame before clamping them in place)?;

2) how do you determine where to cut the ribs for proper stretching of the bark? (I've read four methods a) in Gidmark's book to cut the ribs at the top of the gunwales; b) videos where the ribs are cut several inches above the gunwales (no details how measurements were taken); c) read instructions to pound the ribs as far as they can go then cut at the top of the guwales; d) read to take a string and measure the outside perimeter of the hull.)

In my first canoe, the inwale height ended at 19" which is pretty high and looks sort of odd as most would be at 14". Also, my ribs were too loose.
 
I usually set the height at around 11"-12" from the building bed to the top of the gunwales. Then when the canoe pops up while installing the ribs, the finished height is around 13"-14". The finished height can also be controlled by the shape of your ribs. Your canoe appears to have a rather round bottom thus making a deeper canoe.

Rib pressure is very important concerning the bark hull. To much and one takes a chance in splitting the bark. Not enough and you have loose ribs. My goal is to have even tension throughout the entire canoe. I cut the ribs off around a 1/4 " below the top of the gunwale and over the course of a coupe of days of fine tuning the hull the ribs are pounded in to the vertical.
While doing this, I pour hot water over the bark from the outside to keep the bark flexible & also to help stretch the bark. Another point is the roots also stretch in the side bark areas.

Lots of things to consider when building the most difficult wood canoe eh!:cool:
 

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