How To Create a Silicone Rubber Texture Mat for GFRC Panels


The Project: Quaker Home in Bucks County, PA built in 1805 to be restored and included in the National Register of Historic Places.  Granary wall inside the barn features woodgrain textures that can be duplicated onto GFRC panels for a shower install.

Wooden Wall Model Preparation (0:52)
Excess dirt is removed and any large gaps are filled with sulfur-free clay. Sonite Wax is applied to seal the wood prior to mold making.

Building the Mold Wall (1:20)
A stud frame is measured, cut and assembled for the support structure. Melamine board is cut to size for the mold wall face. A clear acrylic window is also cut to size. This window will allow the flow of mold rubber to be observed while filling. Super Instant epoxy adhesive is applied to both sides of the acrylic window. All pieces are firmly pressed together. Super Instant cures in 10 minutes. The melamine face is nailed to the stud frame. A 3/8" (9.5 mm) thick spacer is adhered to the left and right edges. The spacers create a uniform gap between the mold wall and the barn wall where the mold rubber can be dispensed. The mold wall is lifted into position and nailed in place. A board is nailed to the top of the wall as a clamping point. "Strong back" braces are nailed to the studs. Additional bracing is fastened. Hot melt glue is used to seal all seams to prevent the liquid rubber from leaking.

Making the Mold Star 30 Silicone Rubber Mold (3:30)
A silicone meter mix and dispense machine will be used. Mold Star 30 Part A is premixed and dispensed. Mold Star 30 Part B is premixed and dispensed. Material flow rate is checked. The gun tip is positioned in the gap between the barn wall and mold wall. The trigger is pulled to start the flow of material. Material flow can be observed through the acrylic window. The mold is topped off. Mold Star 30 is allowed to cure for 6 hours at room temperature (73F/23C).

Demolding the Mold Star 30 Silicone Mold (4:35)
Rubber is checked to ensure thorough cure. The mold is partially tilted away from the barn wall. The mold is peeled away from the barn wall. The rubber mold and mold wall are slowly lowered together. Mold Star 30 reflects perfect detail captured from the barn wall. The flexible mold can be easily rolled up for transport to the shop. 

Materials Used in this Tutorial

  • Mold Star® 30 Silicone
  • Sonite® Wax
  • Dispensing Machine
  • Lumber
  • Acrylic Sheet
  • Super-Instant® Adhesive