Thread: Scribe-fitting Difficult Profiles

Ever have to scribe fit a kitchen cabinet to fit a wavy and out-of-plumb wall? How about fitting a bulkhead or partition-wall panel into the inside hull of a yacht or ship? Can you scribe fit a curve as high as 7 feet and as deep as 3 feet? And in a space where nothing is square, little is plumb and level changes constantly with payload and wind? Welcome to the world of interior ship joinery sans lasers and computers, and file away another handy but simple, old-time skill for when you may need it.

I took a half hour and got out some scaled-down panels, sticks and battens to answer a question on how to build bunkbeds into the inside curve of a yacht hull, and figured since I had the photos this may be useful to others. Now there are plenty of yachts sufficiently slab-sided for simple scribe fitting to work. But not this one. This one is a 180-ton ocean-going tug being converted to a family liveaboard. The space in question is around 7 feet high with a bulge in the outside wall around three feet deep. Time to get out some ticking sticks.

First some old-time jargon. Woodworkers “make” or “build” objects and their components. Boatbuilders and shipwrights “get out” parts as components of a boat or vessel. What y’all call a “ceiling” in a house isn’t the same thing in a boat. Boats have “overheads” instead. “Ceilings” in boats are the interior lining of the hull, in this one softwood planks. “Floors” in boats are framing members similar to the joists above your house foundation. What you walk on in a boat is it “sole”.



A vertical template is clamped temporarily next to the curve in the ceiling your new panel has to fit. Find a distance that fits both curve and template and mark it on the ticking stick. Here I'm using 16 1/2". Draw the line and distance from several points on the curve to the template. For more complicated profiles you can use multiple distances and even make your ticking sticks from wooden yardsticks.



Remove the template to your work area, align it to your bulkhead or bunk panel and simply transfer line and distance to marks.



Connect the marks fairly using a flexible batten and ice picks or nails. Draw a line, cut the profile, and fit it to the ceiling.



The hardest part often is indexing the template if the boat isn't gutted and you don't have beams and floors to clamp it to. Be prepared to screw temporary blocks to the sole and overhead to fix it in place 90 degrees to the sole. The template can be positioned at any angle to the ceiling, but is always best placed along the line the panel will lay, usually athwartships along a line equidistant from the stem, and the profile scribed is the outside of any bevel required.

Luan doorskin for templates is inexpensive. Ticking sticks and flexible battens can be got out of any straight-grained softwood like the Doug Fir you see here. Using sticks, size and depth don't matter. Get that template aligned and plumb, and with very little practice it's mark, cut, bevel if necessary and fasten regardless of size. Run the beltsander lightly over your template and run your sticks and batten thru the planer to erase the marks for the next installation. Buy a box of art gum erasers if you don't have those tools yet.