Tuesday, February 16, 2010

Tech Tip Tuesday

One thing that is often glossed over in books on canoe building is the actual stripping process. There are many things that will change how easily a strip-built boat goes together. These include the following:
  • Hull Length
  • Hull Shape
  • Strip Thickness
  • Strip Width
  • Strip's Grain Direction
  • Wood Type
All things being equal, a longer canoe is typically easier to strip. This is because the bending and twisting of the strip is much gentler as it takes place over a longer length.

Each different boat design has a different shape and these different boat shapes can be drastically different in terms of the contours of the hull. For example, Mac McCarthy's Wee Lassie and Wee Lassie 2 designs are 11' and 13' respectively, but I find the Wee Lassie a bit easier to strip than the Wee Lassie 2, even thought it is longer because of the shape of the hulls.

Strip Thickness - the thicker the strip, the more difficult it is to bend.

Strip Width - the wider the strip, the more difficult to twist and certainly more difficult to flex in this long axis- and the more likely it is to break.

Grain direction is key - you're looking for your strips to have vertical grain on the face. If you have flat grain on the face, it can peel as you flex it. Inconsistent grain direction along the length of the strip can cause "hard spots" which can lead to difficult stripping.

Wood type can be an issue as well. We typically strip our hulls with Western Red Cedar and it is fairly rigid and brittle stuff. If I could get enough good, long lengths of Atlantic White or Northern White Cedar, it would bend a bit more easily than the Western Red. Port Orford Cedar, on top of being more heavy than any of the above, would be stiffer as well. I did have a student strip a canoe in Sassafrass which we found to be fairly stiff stuff and difficult to get it to take the hull contours that the Western Read mated to relatively easily.

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