December 09, 2019 2 min read


If you're looking to replicate an existing part, creating a splash mold is a fast, easy, and inexpensive alternative to machining a plug from foam. Splash molding also ensures that the part will interface correctly with any surrounding components. The post below outlines the basic splash molding process. 


  • Sculpting tools
  • 2'x4' Studs
  • Drill


  • Melamine Board
  • Wood Screws
  • Molding Clay
  • TR Wax
  • Adhesive
  • Clean Rag
  • Gloves
  • Tack Cloth


First, prepare the part - the surface finish of the original part will transfer directly to the mold. Sand, buff and polish the part to the desired surface finish. Next, add flanges so that you have room for vacuum tape and resin ports. Use a smooth, rigid material that will release easily and does not flex. We recommend a melamine board or something similar. 

Ideally you want 4 inches of flange around your entire part. Depending on the shape of your part, there may be seams but these can be filled with wax or a silicone caulking. Cut the board to shape and mount it to the back side(s) of the part. If the underside doesn't sit flat on the board, use 2×4 blocks to level it as best as possible. Screw the blocks to the board and glue the part to the blocks with a high strength adhesive, then fill gaps between the board and part with a molding clay. Fill any features on the part that you want to modify or 'delete', and any undercut features. These will need to be molded separately and post bonded on to the final part.  

The plug itself is temporary and intended to be cheap.  Don’t spend too much time here as you will expect this to come apart when you pull the mold.Finally, apply five to six layers of TR wax, according to the directions on the can. For the next steps in the mold making process, read in our posts on spraying gelcoat, the mold lamination process, and how to finish your mold.

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