Lofting, Part 2

Lofting in the living room.  My three
sons help fit the batten to the curve
so I can trace it on the plywood.

I spent last night laying out the station lines and marking the points of the various curves.  This morning, I drafted my sons to help hold the batten in place while I drew the curves in for the side and bottom panels.

There are four major lines to draw in - each side panel has one curved and one straight edge, and the bottom panel is curved on both edges.  There are also a number of smaller curves to trace in, along the cutout in the stern end of the bottom, and the bow and stern decks.  On the longer curves, I tacked brads in at each station.  It was then a relatively easy thing to have the boys press the batten against the brads while I drew the curve in.  Brads weren't necessary on the smaller curves.

Everything went really well; the markings came out clear and it really looks like these shapes would make a boat if you joined them.  There was one point on the bow that I had marked at the wrong spot, but that was an easy fix.  More perplexing was a station point near the bow that just didn't match the rest of the curve.  It happened on both side panels, at the same (shared) station line.  I quadruple-checked the depth of the curve at that point, and at the adjacent points, and never found an explanation, so we ignored that line and drew the curve in using all of the rest of the points.  The only explanations that make any sense are that there's an error in the plans (i.e. that they give the wrong depth for that station), or that I mis-measured the location of that entire station line (i.e., that the depth is correct and would fit the curve fine if I moved it along the line).

Before I cut those panels out, I'll recheck the station line and contact the Wharram folks for verification of measurements given in the plans.

Stern post and stem post, traced onto office
paper to avoid cutting the plans up.  The stern
is on the left and the bow is on the right - the
difference in length gives some indication of how
much deeper the boat is at the bow than the stern.

The plywood now has the shapes of both decks, both side panels, and the bottom panel drawn in.   There are many smaller pieces that fit in the gaps between; most of those are either butt straps, lashing reinforcement pads, or stem & stern posts.  The butt straps are just patches to join the long pieces together, so they and the lashing pads don't need to be precisely shaped.  But the stem and stern posts are critical, and oddly shaped, so the plans include full-sized (1:1 scale) patterns of these pieces.

I was not willing to cut my plans up to trace the stem and stern posts, so I taped several sheets of paper together and traced them onto that paper, then cut the shapes out.  They came out really nicely.  Their shape somehow evokes the hull's form better (for me) than the side panels do.

Next I'll transfer the stem and stern post shapes to the ply, and then (assuming I get an answer on that point that didn't match the curve) I'll begin cutting various hull panels out.  That's an exciting prospect!