Josko Catipovic
I need to plane a cup into a flat plank for carvel boatbuilding (so the plank will lie flat against bent ribs.) I have a wooden plane that sort of does the job, but has anyone encountered a metal or wooden adjustable version? It would be like a compass plane, except the curve in the sole would be 90 degrees to a compass plane's. I can sort of make it work with a flat-sole plane and a curved blade (like a scrub plane's), but it works much better with a curved plane sole. Any insight appreciated.

I suppose a cooper might use something like this to fair the insides of barrels.