Once the dome was shaped using cedar strips, it was then covered with Seaflex - a boat building material. Seaflex is 12" wide and consists of a layer of hardened Fiberglass rods between two layers of woven Fiberglass cloth. It is available in two thicknesses - 1/4" and 3/8". An aquaintance of Kevin Kratzberg, seen in the section on dome shaping, had a roll of 3/8" Seaflex that was left over from a project. He was offering it at a substantial saving. 1/4" Seaflex would have been a better choice, as 3/8" was very difficult to bend to conform to the 12 1/2' diameter of the dome. However, I bought the bargain roll of Seaflex and fought it into shape.
The picture below shows the dome after the Seaflex had been coated with Fiberglass resin. The shape is rough with many ridges standing out from the curved surface. This required much work with a belt sander to smooth them out.