: what would the name of this tool be?

: Sage

You can make a gauge from scraps of 1/4 inch strips.

To copy profiles which are up to 2 feet high you would need 96 strips. (4 to an inch, 48 to a foot.) You might wish to cut these to even length (say one foot long) and sand them and *wax* them so they move smoothly against each other. Varnish is not wanted here.

If you use strips which are a foot long you'll need about 100 feet of strips, which you can get by ripping an 8 foot long 1x6. You can use inexpensive pine. If there are a lot of knots you may want to get a 1x8 or two 1x4s. Since the strip pieces are so short (only a foot) you can sut between knots fairly easily to get nearly clear pieces -- and with knotty wood you'll just have a bit more waste.

Build a frame from 1x2 stock, using a piece 3/4 by 3/4 by 1 1/2 for the top and another of the same size for the bottom. Sandwich these pieces between sides which are pieces 1 1/2 inches wide by 25 3/4 inches long. You should then be able to stack your strips in the gap in this frame.

On the top, drill a hole and insert either a threaded insert, or a T nut, then screw in a thumbscrew.

Now slide your short strips into the slot, stacking them until they almost fill. Leave enough room at the tip to fit in a very short piece of hardwood, or metal right under the end of the thumbscrew. Then, when you tighten the thumbscrew that piece clamps all the strips in place.

To use this, loosen the thumbscrew, hold the gauge close to whatever you want to copy, and slide the strips until they gently rest against the surface. Tighten the thumbscrew and it holds the strips in place so you can measure or trace the outline you've duplicated.

If yo have cut all your strips to exactly the same length, then the curve on the "outside" of your gauge will be the same as the curve of your original piece, while the curved shape on the "inside" will be a shape which could be a old for your original part. If you bend a flexible woodstrip around the tips of the strips of your gauge it will give you a fair curve that should be identical to the original.

Use a level or plumb bob to position the gauge so the strips are exactly horizontal and the frame exactly vertical.

With 1/4 inch strips you can interpolate by eye down to measurements of 1/16th of an inch (1/4 the thickness of a strip) which is more precise than you need for designing a boat. Or, make a pencil mark on the side of the strip where a strip touches a critial area of the boat (sheer, chine, gunwale, etc.) and you can get slightly more precision. Later you can erase or sand off the markings so they don't onfuse you on your next project.

You might want to mount the gauge in a fixed place and slide the boat past it, taking measurements at modest intervals. I guess something like a wheeled strongback running on a straight track would be the best way to mount the original boat. Or, leave the boat fixed and run your gauge along a straight 2x4 strongback/rail which is parallel to the keel.

Hope this helps

PGJ