Tuesday, May 6, 2008

Endless Lashing

With the hull folded up and the gunwales pegged in position, it was time to begin the long and tedious job of lashing the canoe. Many books mention the lashing process takes up at least half of the total building time. With 52 lashing sites along the gunwales alone and each one taking about 5-10 minutes to do, I tackled this seemingly endless job on and off over the last week before my work schedule picks up again. The photos were therefore taken over a series of many days. I just finished a major portion of the hull lashing and wanted to post right away.

The process started by taking a piece of soaked spruce root and tucking one end in between the bark and outwale. This was then folded down and slipped through a hole in the bark made carefully with the awl. The root was wrapped around tightly and slipped through the same hole and the procedure repeated twice more. Ultimately, the lashing tightly squeezed the bark between the gunwales with 6 wrappings through three holes with the final bit tucked under and trimmed on top. Each lashing spot is located on the pegging location so that the spruce root covers the peg and gives the outwale a smoother, finished look.

Steps in lashing the gunwales

At full scale, the lashing consists of 8 wrappings through 4 holes, but I couldn't get the spruce root down to the 1/32" thread size that Tappen Adney tended to use on his models. This is why I had to resort to using 6 wrappings instead, or else the bulky lashings would take up too much space on the gunwales, leaving limited room for the future rib placement. I don't think it'll make a difference in strength at the end of the build.

Slowly lashing the gunwales

The gunwales were lashed just to the end thwarts in order to fit the stem pieces first. The dried stem pieces and headboards were then positioned and the softened bark tightly folded up and clamped. The headboard was then inserted as tightly as it would go. With it supporting the gunwales, the clothes-pins could be removed and the protuding bark trimmed.

Inserted stem piece; Inserted headboard with trimmed bark

The clamp was replaced with a toothpick pegged through both layers of bark and the stem piece. The gunwales beyond the headboard were tightly lashed together using a full wrapping of spruce root securing the structure, but at this point, I ran out of thin root of sufficient length to wrap the other end - so I needed to resort to using waxed thread as a substitute for the model. Still turned out ok, but now I realize I'll need to find some Black or White Spruce somewhere and digup fresh roots if this canoe will continue to be authentic.

End gunwales lashed with root; Other side lashed with waxed thread

Next it was time to lash in the permanent thwarts. The process began by placing the permanent ones on top of the temporary thwarts and marking out the difference where tiny tenon would need to be cut. This was quite easy to do. After was marked, the thread holding the temporary thwarts was unlaced and the corresponding mortises where scratched out of the inwale (just to the bark, not through it) with an awl. With the center thwart out as well as the intermediate and end thwarts on one side, I could finally remove the plywood frame that had been resting on the hull bottom since the start of the build. It would be my first look at the inside of the hull and see its condition.

Marking the center thwart; Carving out mortise; Removing the building frame

Next, the permanent centre thwart was set into place and laced to the hull in a similar manner as the gunwales except this time, six wrappings went through 3 holes pierced into the thwart with an awl. All went perfect for one side, but on the final wrapping on the the other side, the thwart's end split right off. I was worried the whole thing would need to be done all over, but the thwart is securely being held by the lashing and is a cosmetic flaw at this point. I'm confident that in a full scale model with hardwood thwarts (ash, birch, maple,etc) the splitting would be a non-issue.

Lacing the centre thwart; One side finished; Other side split but holding

Next the fairly easy job of lashing the intermediate and end thwarts. Given their narrow width a single stitching hole was pierced into the wood to avoid any additional splitting damage.

Intermediate thwart; End Thwart; Completed thwart lashing

With the thwarts in position and tightly sewn the whole structure is relatively strong and stable. What's left at this point is trimming the bark at the bow & stern to match the stem piece and stitching these ends tightly. There are different lacing method out there and I havn't decided on one yet, so that'll be a topic of another post.

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