Building A Pack Canoe - Part 3: Stripping The Tumblehome Area

The walnut strips were now ready to begin the actual stripping of the boat. The first one was placed so that its bottom edge would touch precisely at the marks on the station molds that define the upper edge of the boat (the gunwale). There were no marks for the attachment to the stems, so we bent the sheer strip up and down until we both agreed that it fell in a fair and sweet curve.

There is an old saying in boat building: "If it looks right, it is right." This pertains to the aesthetic qualities of the boat, particularly when it comes to the concept of "fairness" and "sweetness". Nowhere is this more obvious than in the lining out of the planking, and the sheer line is the most important and powerful line of all. Although we would get another chance at refining this line when we attach the gunwales, we took our time to make sure the the line was as sweet as we could get it. I'm sorry to say we totally forgot to take photos of this initial process.

We then carefully re-marked all of the lines on the station molds and stems and then clamped the sheer strip into place. I had already decided that we would not use staples to hold the strips down to the station molds. We just don't like looking at several thousand tiny black dots that tell all the world, "Hey, look... I stapled my boat together." We opted for small brads driven through cleats (so that the heads wouldn't be buried in the strips themselves) and what better tool to use than a pneumatic brad nailer.

Another decision we made was to use rolling bevels at the plank edges rather than a "bead and cove" fit. This was partially due to the fact that we were using 1/8" strips and couldn't get a set of router bits in that size, but also, we didn't see how any advantage would be gained in the complex curves. In fact, there would be a distinct disadvantage since bead and cove strips only nest together perfectly when they are 180º to each other. This only happens in the flatter sections of the hull, exactly where they aren't needed. Bead and cove fits in the harder and complex curves on the ends and the bilges always have gaps.

Here I am cutting the rolling bevel to fit the preceding strip. It is all a guesstimate with a lot of trial and error fitting by eye, but it doesn't have to be perfect. 90% of the strength of the hull will be in sandwiching the wood between two layers of fiberglass and epoxy resin, so all we really need it to do is not come apart before we glass it. It is the BK way, however, to overdo everything, so we spent a great deal of time trying to get the strips to match. This became infinitely easier as time went on.























The tumble home area is wider amidships than it is at the ends. Since the strips are all 3/4" wide to begin with, we either had to taper each one throughout the length of the strip (daunting, to say the least) or we could strip it out until the entire tumblehome area was covered and then cut down to the tumblehome edge. That is what we decided to do. It also allowed us to use up some shorter strips in the areas where the tumblehome was widest and full length strips were not needed.

Here is a good shot of the tumblehome area completely stripped and awaiting cutting down. You can see the small cleats that were used to nail the strips to the station molds and also the high-tack green 3M adhesive tape we used to pull the strips together between station molds. It is expensive, but it proved to be a powerful clamping tool and quickly became our best friend.

Also in the photo are a bunch of small but very powerful Pony spring clamps. They are being used along with short strips of 1/4" Plexiglass to align the strips in spots where the tape didn't cut it (lots of them as it turned out). After a while, we felt like a seasoned surgical team as one or the other of us would reach out a hand and say, "Plexi... clamp... more tape..."

Here is how we marked out the cut for the tumblehome edge:

First, a pencil mark was made on each station mold, exactly 1" above the place where the tumblehome and the hull sides meet.

Then, a spare strip was used as a lining batten. It was placed at each mark and temporarily nailed in place. Special care had to be exercised at the stems as there was no reference point from which to measure and so its placement had to be made by eye. There was no second chance with this one like at the sheer. Whatever line we chose had better be sweet as it would be locked in place by the succeeding basswood strips and would be more than a little bit obvious if it was a "doggy" line. When we were both satisfied, we nailed the batten to the stems.

We didn't have an offset-legged compass to make the next mark and the local art store was closed, so I went ahead and "invented" this sweet little scribing block Lady BK is using in the photo. It holds a press-fit pencil that I planed dead flat on one side. The top of the block was planed down until the flat edge of the pencil was exactly 1" from it, so it always marks out a 1" space. The pencil can be slid in and out in order to get the the top edge perfectly square to the lining batten and was a breeze to use.

Next, another batten was clamped in place right on the walnut tumblehome strips and touching each mark we had made. The batten was once again sighted for fairness and a line struck.

Here is Lady BK striking the line that we would cut to. We found that a 0.5mm HB mechanical pencil gave a crisp and sufficiently dark line to follow.















Lady BK wielding the 2" chisel to split away (carefully!) the excess walnut and pare it down to within about 1/16" of the line. The rest would be taken down with my Lie-Nielsen small shoulder plane, set extremely fine and honed razor sharp. Once again, my eye would be the final arbiter of fairness.











There was no photo of the final cut curve, but here it is with a few basswood side strips attached so you can see the taper of the curve and get an idea of what all the fuss might be about achieving the sweetest possible curve here.