Spray-Up Process


Reinforcing fibers are chopped and combined with a resin, and the mixture is sprayed onto the surface of an open mold. Manual rolling is then used to ensure even distribution of resin and to eliminate trapped air pockets.

Capabilities / Processes / Spray-Up
Spray-Up Process Volume Graph

Raw Material

A strand of reinforcing material is cut to length by a chopper gun which immediately combines with resin. This mixture is then applied to one side of the mold.


Single sided, typically composite tools are used for this process. Tool lead times are typically 8 weeks or less, shorter than many other composite applications.


Spray-up parts normally have one visible, smooth side. A gel coat can be added during molding to produce cosmetic finished or paint-ready surfaces.

  • Ideal for Lower Volume Programs
    Modest equipment and tooling requirements make the spray-up process ideal for prototypes and lower volume programs. It is often a process choice for one-off specialty products.
  • Low Cost Tooling
    Spray-up molds may be produced from almost any material, including wood, composites and even plastics. The process uses only one mold (open mold), resulting in even lower tooling costs. Molds can be “splashed” off of another part or model of almost any material, further reducing their cost.
  • Faster Speed to Market
    The nature of spray-up tooling allows very rapid product development. Molds can be produced in as little as 1-2 weeks for simple part geometries, and in less than 8 weeks for almost any part design.
  • Spraying Process Can be Automated
    The use of robotic spraying allows manual labor content to be reduced. Coupling the robot with resin scales and fiber usage sensors allows the entire spraying process to be automated. This reduces cost and improves quality, as the thickness variation that can occur with manual spraying is largely eliminated.

Inquire with us about this process