Details of building at: http://groups.yahoo.com/group/LR2ACATS/
I cut foam strips 1"to 2" wide, depending on the hull shape. Determining factor was that I did not want any more than 1/16" gap between the foam and a frame. That 1/16" was for one layer of 5.8 oz. carbon, fairing bog, and paint. It also made fairing the outside of hull easy with minimal sanding on the bead-cove joint to get the hull fair.