Corey Schmidt wrote:maybe 2 1x4 boards attached together in a v with something to seal the joint, like tar. if you are using the water, different story, you could line it with plastic stapled to the high points.
I used to care for an old house in VT which had wooden gutters. They appeared to be 1x4s in a V-shape, sealed in pitch. They were hung on V-shaped hangers driven into the fascia board. The hangers appeared to have been hand-fabricated by a local blacksmith. Some years the gutters were taken down during the winter (except over the steps) and reinstalled in the spring; brackets were left in place. Other years the gutters were left in place, usually without damage. The length of the each gutter was 6' to 8', as I recall, and they were simply lapped over one another for longer continuous runs. At the low end, the water simply ran out. Usually a flat stone was placed on the ground, sloping away from the structure, to stop erosion and absorb the energy of the falling water.
