CNC Tooling: Plug & Mold Building


The mold building process begins with an object known as the plug or buck. This is an exact representation of the object to be made, and can be made from a variety of different materials. SEG has over 20 years of tooling and mold building expertise, which inludes both conventional and advanced molds built to withstand high baking temperatures in OOA molding processes.

Depending on the project SEG can undertake any mold building exercise in our specially equipped, controlled and dedicated tooling and mold building production facilities. SEG builds molds with experienced skilled craftsmen, and in some cases with the aid of a 5 axis CAD milling machine. We have built hundreds of molds over the years in various sizes and levels of complexity.

The company is capable and fully equipped to undertake any mold building exercise.

In our conventional mold building process, after the plug has been formed, it is finished and coated with a mold release agent. The release agent will allow the mold to be separated from the plug once the mold is finished and braced.

High performance gelcoat is applied to our molds to give the mold surface a harder and more durable finish. To maintain minimal tolerances in distortion, all materials and methods used to build our molds are identical to those which are used in the manufacturing procedure of the finished product.

In the mold manufacturing laying-up process, a layer of fiberglass mat is applied, and resin is applied over it. The fiberglass spray lay-up with a chopper gun can also be used in parts of the production process which can provide good filling of corners and cavities where heavy woven glass mat may prove to be too stiff or too costly.

Steel tubing or integral stringers are constructed and laminated to the outside of the mold to prevent distortion, and increase the molds life. Once the final layers of fiberglass are applied to the mold, the resin is allowed to properly cure before the mold is released from the plug.

Our finished molds are expertly crafted ensuring years of use, and polished to an high lustrous finish before packaging and shipping to their final commercial destination.