Grapeview Point Boat Works

81 E Grapeview Point Rd + Allyn, WA 98524 + 360-277-9015 + boat_works@yahoo.com

Building a Glued Lapstrake Rangeley Lake Boat

Page 2: Lofting

Lofting
Lofting

Lofting is enlarging a boat’s plans to full size. This includes drawing the hull profile, body sections, and half-breadth. Some builders avoid lofting altogether by only buying plans that include patterns for the molds, but that really limits their choices. Lofting the boat ensures that the molds (if accurately built) will be correct.

Nowadays, we loft even if patterns are provided, since it is an enjoyable process. It is unique to boatbuilding, and although the offsets can be fed into a computer to spit out the resulting mold shapes, stem patterns, transom expansions, etc, it will be a sad day when nobody takes the time to put pencil marks on the lofting grid, and fair the curved lines that represent the 3D hull in 2D.

The first step in lofting is establishing an accurate grid on which to plot the offsets that are given on the lines plan. I have stretched the hull by adding 17” between stations 4 and 5. This adds all the length in the middle of the boat, which gives more room between the rowers, and adds more stability than increasing the length between all the stations by a smaller amount.

In the first photo, the 18’ long panels will be covered with all sorts of lines showing the profile, the half-breadths (plan view), and other details. The smaller panel will contain the body sections, again drawn full size.

The three views that are lofted are all interdependent, changing the curve of one line affects at least one other view. When all the lines are smooth and flowing, they agree with each other, and conform to the offsets in the lines drawing, you have it made. At this point the hull is fair, with no ugly humps or flat spots.

Fairing lines
Tom adjusting the last long line on the Rangeley hull

In this photo, Tom is adjusting the last long line. He uses staples to hold down the various wood battens that are bent to follow the coordinates shown in the offsets table.

Seeing the hull laid out full size is always fun. This is one long rowboat. It's generally agreed that for boats of this type, 16' is the optimal length. Shorter doesn't give enough waterline length, and longer adds too much wetted surface and drag.




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