Abstract: Methods and apparatuses are disclosed to mold complex shapes using a cast mold technique. A catalyst-initiated urethane can be used for these complex shapes as there is little thickness restriction on any part dimension. Moreover, urethane, once chemically activated, can be poured into cast molds with various shapes. Due to the exothermic nature of urethane, when the curing chemical reaction takes place, metal molds can be fabricated from aluminum. Cast molds, made from aluminum, utilize elastomeric seals to account for coefficients of thermal expansion.