The company is using Ren XD 4569-1 R/H seamless epoxy modeling paste from Vantico (East Lansing, MI). This cut fixture production time by 25 percent, and retained the precision and strength needed for a long service life. Dan Crowton, fixtures and plastics foreman, says, "Fabricating fixtures from fiberglass and epoxy was a labor-intensive process that required extensive spotting during assembly of the inner and outer sections of the tool. With the seamless epoxy, we can produce both fixture sides on the same support structure to save time and hold tolerances to ±0.01 inch."

To build the paste fixtures, the company starts by machining a tooling aid for the outside of the fixture and then lays up a fiberglass and epoxy laminate for the outer dimension. A support structure is installed, and then the surface for the inner dimension is built by applying 0.8- to 1.5-inch-thick layers of the seamless epoxy paste using an automated mixing and dispensing machine. The equipment features a special nozzle designed to extrude the sag-resistant paste directly onto vertical or overhanging contours on the fixture base.